Pump Ops Book Flashcards
1
Q
What is required before operating a manual regeneration switch for a DPF system?
A
The vehicle must be in park.
2
Q
What does the HEST indicator signify on post-2007 diesel apparatus?
A
High Exhaust System Temperature during active regeneration.
3
Q
What can happen if DEF fluid is not topped off regularly?
A
The engine can be derated or enter a 5 MPH limp mode.
4
Q
How long should a hot engine idle to cool before shutdown?
A
3 to 5 minutes.
5
Q
Why should a diesel engine never be shut off while in motion?
A
It cuts off fuel flow that lubricates injectors and may cause pressure build-up.
6
Q
What is ‘due regard’ in emergency vehicle operations?
A
Operating with the safety of others in mind.
7
Q
What type of apparatus has the most frequent mechanical issues?
A
Homebuilt apparatus.
8
Q
What is ‘situational awareness’ while driving?
A
Knowing surroundings and anticipating events.
9
Q
Where do most emergency vehicle crashes occur?
A
At intersections.
10
Q
What causes brake fade?
A
Overuse of brakes leading to loss of function.
11
Q
What are the three angles used to assess truck movement over terrain?
A
Angle of Approach, Angle of Departure, and Breakover Angle.
12
Q
What happens when the steering axle is too heavy?
A
Hard steering and increased tire wear.
13
Q
What is engine lugging?
A
Using too high of a gear for the engine’s demand.
14
Q
What is overthrottling?
A
Injecting more fuel than can be burned, causing carbon buildup and oil dilution.
15
Q
How much following distance should emergency vehicles maintain?
A
300 to 500 feet.
16
Q
Why should apparatus turn headlights on during daytime responses?
A
To increase visibility to civilians.
17
Q
What is the function of strobe light preemption devices?
A
To change traffic lights in favor of approaching emergency vehicles.
18
Q
What is visual head time?
A
The time a driver has to see and react to conditions ahead.
19
Q
What is the purpose of an exhaust brake?
A
To help slow the vehicle by restricting exhaust flow.
20
Q
What should always be done when backing apparatus?
A
Use one or more spotters positioned 8–10 feet behind the truck.
21
Q
What is the NFPA standard that prohibits dashboard riding?
A
NFPA 1500.
22
Q
What safety feature is required during hose loading operations?
A
One dedicated spotter and forward movement at no more than 5 MPH.
23
Q
What does DPF stand for and what does it do?
A
Diesel Particulate Filter; collects soot from exhaust gases.
24
Q
What causes diesel particulate filters to enter ‘regen’ mode?
A
Accumulated soot requiring high heat to burn off during regeneration.
25
What component allows operators to inhibit regen for safety?
Regen Inhibit Switch.
26
What is the danger of running an engine without DEF fluid?
It may enter limp mode at 5 MPH and require dealership servicing.
27
What are the three zones established at hazmat incidents?
Hot Zone, Warm Zone, and Cold Zone.
28
What does a 2 short horn blast signal mean during backing operations?
The spotter is signaling the operator to stop or pause backing.
29
How much should apparatus cabinets be able to restrain?
10 times the weight of the contents.
30
What is the recommended method for positioning apparatus for fire attack?
Pre-incident planning and pulling past the building for visibility.
31
When should pumpers lay their own supply lines?
When access is limited or narrow, to avoid delays.
32
Why should pumpers park uphill during a fuel spill incident?
To prevent fuel from running toward the apparatus.
33
What is a collapse zone and how is it calculated?
1.5 times the height of the building.
34
What is the preferred side of the building for aerial apparatus during collapse risk?
Corner of the building.
35
When positioning pumpers for high-rise support, where should they park?
As close to the aerial as possible.
36
What is a dry hydrant?
A non-pressurized pipe with a strainer submerged in water for drafting.
37
How deep must the strainer be for a dry hydrant?
At least 2 feet under water.
38
What is dual pumping?
Using one hydrant to supply two pumpers.
39
What is tandem pumping?
Using two pumpers in series to increase pressure or distance of supply.
40
When should relay pumping be used?
To increase volume over long distances between source and fire.
41
Where should wildland engines be parked during a fire attack?
Leeward side of structures with AC set to recirculate.
42
How far should units stage in Level 1 staging?
1 to 2 blocks away.
43
What distinguishes Level 2 staging?
It’s used for multiple alarms and managed by a Staging Area Manager.
44
Where should the side-mounted pump panel face?
Toward the fire scene for visibility and access.
45
How far must fire apparatus park from railroad tracks?
Maintain a 30-foot clear zone.
46
What is the function of a breakover angle?
It determines the point where the midpoint of the chassis could contact the ground.
47
How does excessive rear overhang affect the angle of departure?
Increases the risk of bottoming out when exiting slopes.
48
Why should firefighters avoid parking on vaulted surfaces?
Due to structural collapse risks from underground voids like basements or culverts.
49
What is the appropriate response if the operator loses visual contact with a spotter?
Stop immediately, set the parking brake, and exit the cab.
50
What is the difference between forward lay and reverse lay?
Forward lay runs hose from source to scene; reverse lay goes from scene to source.
51
What is the main risk when using the exhaust brake system in bad weather?
Loss of traction and control due to reduced braking balance.
52
What is the total stopping distance composed of?
Braking distance plus reaction distance.
53
What is the skid recovery technique for a locked wheel skid?
Ease off the brake and straighten the steering wheel.
54
What type of skid results from excessive throttle?
Acceleration skid.
55
What are the three basic types of auxiliary braking systems?
Engine compression brake, transmission output retarder, exhaust brake.
56
What is the required auxiliary braking system for vehicles over 36,000 lbs per NFPA 1901?
At least one auxiliary braking system.
57
Why should automatic traction control (ATC) be used carefully?
Improper use can reduce traction on slick surfaces by limiting power.
58
What is the Driver Controlled Differential Lock (DCDL)?
Locks wheels to turn at the same speed for improved traction.
59
How should the DCDL be used on slopes?
Disengage while turning or descending downhill.
60
What does the Interaxle Differential Lock do?
Locks tandem axles to improve traction.
61
What is Roll Stability Control (RSC)?
Reduces engine power or applies brakes to avoid rollover.
62
What does Electronic Stability Control (ESC) do?
Applies brakes to specific wheels to maintain direction of travel.
63
What is the visual and audio signal for backing a truck?
Two short horn blasts and visual contact with a spotter.
64
How fast can hose deploy from a moving truck?
7 feet per second at 5 MPH.
65
What is the weight of one cubic foot of water?
62.4 pounds.
66
What is the boiling point of water?
212°F.
67
How much does a gallon of water weigh?
8.3 pounds.
68
How much does water expand when converted to steam?
1700 times its original volume.
69
What extinguishment methods does water provide?
Cooling and smothering (for fuels with specific gravity >1).
70
What is surface tension and how does it affect firefighting?
It resists water penetration; wetting agents help reduce it.
71
Why are water curtains ineffective against radiant heat?
Radiant heat passes through water vapor.
72
What is atmospheric pressure at sea level?
14.7 psi.
73
How much head pressure does 1 psi create?
2.304 feet.
74
What is residual pressure?
Pressure remaining in the system after water flows.
75
What does friction loss vary directly with?
Length of hose and velocity of water flow.
76
What effect does hose diameter have on friction loss?
Larger diameter decreases friction loss.
77
How many 1.5" lines are needed to equal the flow of one 3" line?
Four 1.5" lines.
78
What are the components of a municipal water system?
Primary feeders, secondary feeders, and distributors.
79
What is an OS&Y valve used for?
Indicating valve for sprinkler systems.
80
What is a PIV valve?
Post Indicator Valve that shows open/closed position for water supply.
81
What happens to friction loss in older hose?
It can be up to 50% greater than in new hose.
82
What does NPDP stand for?
Net Pump Discharge Pressure.
83
How is NPDP calculated?
Pump discharge minus intake pressure.
84
What is the formula for Total Pressure Loss (TPL)?
TPL = Friction Loss + Elevation + Appliance loss.
85
What is the coefficient for friction loss in 1 3/4" hose?
15.5
86
What is the coefficient for friction loss in 2.5" hose?
2
87
What is the coefficient for friction loss in 3" hose?
0.677
88
What is the coefficient for friction loss in 4" hose?
0.2
89
What is the coefficient for friction loss in 5" hose?
0.08
90
What nozzle type produces a solid stream?
Smoothbore nozzle.
91
How is GPM calculated for smoothbore nozzles?
GPM = 29.7 x d² x √NP
92
What is the typical nozzle pressure for fog nozzles?
100 psi or 50–75 psi for low-pressure fog nozzles.
93
What angle range defines a narrow fog stream?
15° to 45°.
94
What is a cellar nozzle used for?
Distributing water in concealed spaces without shut-off capability.
95
What is a piercing nozzle designed for?
Penetrating walls or floors to deliver water to concealed fires.
96
What pressure and flow rate is common for a piercing nozzle?
125 GPM at 100 psi.
97
What is nozzle reaction?
The backward force generated by water leaving a nozzle.
98
What is the nozzle reaction formula for a solid stream?
NR = 1.57 x d² x NP
99
What is the nozzle reaction formula for a fog nozzle?
NR = 0.0505 x Q x √NP
100
What is a constant flow nozzle?
A nozzle that discharges the same volume of water regardless of stream pattern.
101
What is an automatic fog nozzle?
A nozzle that adjusts flow rate to maintain constant pressure.
102
What is considered a handline in terms of GPM?
Less than 350 GPM.
103
What is the purpose of a master stream?
To deliver large volumes of water in defensive operations or where handlines are ineffective.
104
When should a master stream be used?
Defensive fire, limited personnel, or when greater reach is needed.
105
What is the typical psi loss for appliances flowing more than 350 GPM?
10 psi for handline appliances, 25 psi for master stream or elevated waterway.
106
How is elevation pressure calculated in buildings?
5 psi per floor above the first.
107
What is the formula for Friction Loss (FL)?
FL = C x Q² x L.
108
What does each variable in FL = C x Q² x L represent?
C = Coefficient, Q = Flow rate in hundreds of GPM, L = Length of hose in hundreds of feet.
109
What is the standard nozzle pressure for smoothbore handlines?
50 psi.
110
What is the standard nozzle pressure for fog handlines?
100 psi.
111
What is the standard nozzle pressure for smoothbore master streams?
80 psi.
112
What is a residual pressure reading used for?
Determining how many additional lines can be added to a system.
113
What is considered a safe residual pressure threshold?
No less than 20 psi.
114
What are the four categories of residual percentage drop?
0-10% = 3 lines; 11-15% = 2 lines; 16-25% = 1 line; >25% = 0 lines.
115
What is cavitation?
Formation of air bubbles due to water being discharged faster than intake.
116
What are signs of cavitation?
Popping noise, pressure fluctuation, gravel sound, no pressure gauge response.
117
What is the ideal lift height for drafting?
10 feet.
118
What is the maximum recommended lift height for effective fire streams?
20 feet.
119
What happens to pump capacity at 20 feet of lift?
Drops to 60% of rated capacity.
120
What is the purpose of a primer?
To create a vacuum for drafting by evacuating air from the pump.
121
What is the most common drafting issue?
Air leak on the intake side.
122
What is a low-level strainer ideal for?
Drafting from portable tanks or pools with low water levels.
123
How much water should cover a barrel strainer during drafting?
At least 24 inches.
124
What is the most common blockage point in a drafting operation?
Distal end of the intake strainer.
125
What is the formula for pump discharge pressure (PDP)?
PDP = Nozzle Pressure + Total Pressure Loss (TPL).
126
Why must you shut the tank-to-pump valve when switching to external water supply?
To prevent tank over-pressurization.
127
How much psi is added for elevation when calculating PDP for standpipe operations?
5 psi per floor above the 1st.
128
What is the maximum standpipe pressure per NFPA?
Do not exceed 185 psi.
129
Why should you confirm a fire before charging an FDC?
To avoid wasting water on false activations or malfunctions.
130
What is the preferred position of a pumper when supplying an FDC?
Close to water source with a straight lay to the FDC.
131
What are the components of a dry standpipe?
A pipe system requiring external water supply before use.
132
What nozzle pressure is used for standpipe fog lines?
100 psi.
133
What is a hydraulic water tower?
An aerial with a large capacity elevated stream (up to 300 GPM).
134
What is the primary difference between aerial ladders and telescoping booms?
Aerial ladders are for climbing, telescoping booms are not.
135
What is a platform rated to hold without water?
At least 750 lbs.
136
How much weight can a platform hold when water is flowing?
At least 500 lbs.
137
What is the flow requirement for aerial apparatus in any position?
At least 1000 GPM.
138
How long should an aerial <110 ft take to fully deploy and rotate 90°?
150 seconds.
139
What are the two types of waterway systems on aerial ladders?
Bed-mounted and telescoping.
140
What is a pinnable waterway?
Allows switching between rescue and elevated stream positions.
141
What type of bolts are used in aerial ladders and cannot be reused?
Huck bolts.
142
What angle provides maximum load capacity for aerial ladders?
70° to 80°.
143
What is torsional stress?
Twisting force on the ladder, often from uneven loading or angle.
144
What is a gravity circle?
The rotating footprint traced by the aerial during operation.
145
What is the preferred stabilization method?
Use of jack plates and stabilizers on a level surface.
146
What is short-jacking?
When one side of the truck cannot fully extend stabilizers due to obstructions.
147
What are the three common types of stabilizers?
Post, box, and A-frame (scissor).
148
What is the safe lateral unevenness limit for aerials?
5% (5 feet for every 100 feet).
149
What should be used when placing stabilizers on ice or soft surfaces?
Jack pads or cribbing.
150
How can uneven apparatus leveling affect aerial operations?
Shifts the center of gravity and reduces safe working load.
151
What is a common stabilization failure in cold weather?
Melting snow leaves voids under jack plates, reducing support.
152
What does NFPA 1901 require for aerial tip radios?
Hands-free radio at the tip/platform.
153
What type of aerial platform can perform below-grade rescues?
Bronto Skylift or similar articulating platforms.
154
What causes 'deadheading' in hydraulic systems?
Running the hydraulic pump with no fluid flow, causing heat buildup.
155
What is the effect of high hydraulic oil temperature?
Pump failure or reduced aerial operation efficiency.
156
What happens if a water curtain nozzle is used improperly?
Can create false sense of safety in high-heat conditions.
157
What is the maximum allowable ice buildup on aerial ladders per NFPA 1901?
0.14 inches.
158
What technique helps remove ice from an aerial ladder?
Slowly extend and retract the ladder to 'shrug' off ice.
159
Why should an aerial never be extended or retracted while someone is on it?
Creates pinch points and unsafe conditions.
160
What is the 75-80-80 rule for aerial ladders?
75° elevation, 80% extension, 80 psi nozzle pressure.
161
What are dynamic loads in aerial operations?
Loads that involve motion, such as climbing or equipment movement.
162
What is the preferred direction for ladder operation on grades?
Over the uphill side.
163
What is the most stable aerial operating position?
Directly over the front or rear of the truck.
164
What is jackknifing and what is its effect on stability?
Turning the trailer at an angle; 60° is most stable.
165
How much clearance is required from power lines?
10 feet for standard, 50 feet for high-voltage lines.
166
How should rescue ladders be placed for aircraft access?
Treat doors like windows and wings like roofs.
167
What is the best ladder placement for mid-rise rescue?
Outside of the engine for ≤5 floors, inside for >5 floors.
168
What is the primary use of aerial ladders in aircraft incidents?
Scene lighting and crew access—not typically rescue.
169
What is the minimum load a platform must support while flowing water?
500 lbs.
170
Why are floodlights mounted near aerial tips?
To illuminate the work area during nighttime or interior ops.
171
How should electrical cords be managed on aerials?
Should not exceed 200 feet in length to prevent overheating.
172
What are four types of hydraulic rescue tools?
Shears, Spreaders, Combination tools, Rams.
173
What is the maximum practical length for hydraulic tool hose?
100 feet.
174
What kind of aerial uses a knuckle boom design?
Articulating platform.
175
What aerial platform design allows for 'up and over' movement?
Articulating platform.
176
How is torque managed during aerial operations?
Avoid lateral loads and operate at high elevation angles.
177
What are signs of structural collapse?
Bulging walls, falling bricks, sagging roofs, interior collapse.
178
What is the collapse zone distance?
1.5 times the height of the structure.
179
Why are building corners preferred for aerial operations?
They are the safest areas in case of collapse.
180
What is the base rail of an aerial ladder?
The lower support structure running the length of the ladder.
181
What is 'K' bracing in aerial ladders?
Diagonal supports for rigidity between rungs and rails.
182
What is a turntable?
The rotating platform that supports the aerial device.
183
What is an interlock system on aerials?
Prevents aerial operation unless stabilizers are deployed.
184
What safety device is used to prevent hydraulic backflow?
Interlock valves.
185
What is a tiller apparatus?
A tractor-drawn aerial with a separate rear steering control.
186
What is the primary function of a water curtain nozzle?
Protect personnel from radiant heat during emergency operations.
187
What is the function of a selector valve?
Diverts hydraulic fluid to either the ladder or stabilizers.
188
What aerial component operates at over 3,500 psi?
The hydraulic system including actuators and pump.
189
Why is huck bolt removal critical?
They are single-use and must be drilled out for replacement.
190
What is the aerial ladder's platform height measured to?
The highest handrail at full extension.
191
What differentiates a telescopic platform from an articulating platform?
Telescopic extends straight; articulating folds like an elbow.
192
What is the minimum water flow from any platform position?
1000 GPM.
193
What aerial design offers the greatest reach at low angles?
Telescoping platforms.
194
Why is grease applied to aerial sections in winter?
Helps shed ice buildup when extending or retracting.
195
What does NFPA 1901 require for salvage equipment?
Salvage covers and two scoop shovels per truck.
196
What is the purpose of ventilation with smoke ejectors?
To remove heat and smoke using negative pressure.
197
What is service testing for trucks?
Annual inspection and testing while the vehicle is in service.
198
What is a nondestructive test?
Testing aerial metal strength without stressing or damaging components.
199
What is the first priority when positioning aerial apparatus?
Stabilization, even if the aerial is only raised a few feet.
200
What is a 'hot shift' system in modern aerials?
Allows PTO engagement with the transmission in neutral.
201
How large are stabilizer pads typically?
24 inches by 24 inches with built-in handles.
202
What tool can be used to estimate stabilizer clearance?
A short pike pole or arm span.
203
How should stabilizers be deployed in a 4-jack system?
Parallel side to side or front to back, not one at a time.
204
What causes repetitive stabilizer damage?
Operating one side repeatedly without alternating load distribution.
205
What grade level is considered safe for aerial operations?
Up to 5% lateral unevenness.
206
What should be avoided when placing stabilizers?
Curbs, sidewalks, unpaved, icy, or sandy surfaces.
207
Why should trucks not be parked over storm drains or manholes?
Potential for explosion or collapse.
208
How should trucks be parked on bridges during incidents?
Staggered and not clustered to avoid weight concentration.
209
What emergency vehicle gets parking priority at medical scenes?
EMS/ambulance.
210
How should aerial apparatus be parked near a structure fire?
To protect operator side and apparatus from heat or collapse.
211
What are the three types of aircraft incidents involving aerials?
Extrication only, extrication with fire, and non-accident roadway fires.
212
What are signs of structural instability or collapse?
Cracks, falling bricks, bulging walls, sagging roof.
213
What are common aerial access challenges?
Narrow driveways, overhead obstructions, dead ends.
214
How should apparatus be positioned near railroads?
Same side as incident, 25 feet away from tracks.
215
What is a vault surface and why is it a hazard?
Underground voids like basements that may collapse under apparatus weight.
216
What should be used when visual contact with the aerial tip is lost?
A spotter to assist with operations.
217
What happens to stress on the aerial if rungs are not parallel to the ground?
Stress increases and stability decreases.
218
What is feathering?
Slow and controlled movement of aerial controls.
219
What is the preferred parking direction for rear-mount aerials?
Backing in, for best operational positioning.
220
What is the danger of operating a ladder near power lines?
Electrocution risk and equipment damage.
221
What distance should be maintained near high-voltage lines?
At least 50 feet.
222
What type of lighting improves civilian response to emergency vehicles?
Sound and light combinations with changing pitch or tone.
223
Why are headlights used during daytime response?
Improves visibility to civilian drivers.
224
What is the danger of overthrottling a diesel engine?
Wasted fuel, excessive carbon buildup, and oil dilution.
225
What should be done before climbing or descending an aerial?
Personnel must be anchored or tethered.
226
What can affect acceleration and braking on hills?
Differential lock and load distribution.
227
What should be done before manually operating a regen system?
Ensure the vehicle is parked and not in pump gear.
228
What is the recommended post-fire overhaul method?
Use of thermal imaging and careful inspection for hidden fire.
229
What is the function of a PASS device?
To alert rescuers when a firefighter is motionless.
230
What does positive pressure ventilation accomplish?
Clears smoke and heat by creating airflow out of the structure.
231
What is the function of a smoke ejector?
Negative pressure fan used to draw smoke out.
232
What does the term 'nozzle reaction' refer to?
The force pushing back on the firefighter from water flow.
233
How is engine compression braking accomplished?
By converting mechanical energy into heat through compression.
234
Why is DEF fluid important in diesel engines?
Reduces emissions and prevents engine derating.
235
What happens if DEF is empty?
Vehicle may enter 5 MPH limp mode and need dealer service.
236
What do strobe light preemption systems do?
Change traffic signals in favor of emergency vehicles.
237
What are the two common nozzle types for interior fire attack?
Fog and smoothbore.
238
What type of nozzle should be used with protein-based foam?
Aspirating nozzle.
239
What is the primary concern with wheel fires?
Risk of explosion due to heat and pressure buildup.
240
What is the preferred suppression method for magnesium fires?
Class D extinguisher from a safe distance.
241
What is the most dangerous gear failure during landing?
One main gear up failure.
242
What causes the greatest risk in fuel vapor fires?
Unconfined vapor and ignition source proximity.
243
What are the two primary extinguishing agents for ARFF?
Water/foam and dry chemical agents.
244
What is used to measure foam concentrate accuracy?
Refractometer or conductivity meter.
245
What happens when a pump is cavitating?
Water intake is insufficient, creating vapor bubbles and damage.
246
What is the function of a bypass valve during pump operation?
Allows water to circulate and prevent overheating.
247
What is the difference between maintenance and repair in apparatus serviceability?
Maintenance is keeping equipment in a state of readiness; repair is restoring something that has become inoperable.
248
What does NFPA 1002 require driver/operators to be skilled in?
Routine maintenance checks and functions.
249
What standard outlines qualifications for fire apparatus mechanics?
NFPA 1071.
250
Who determines maintenance and repair assignments within each department?
The Authority Having Jurisdiction (AHJ).
251
Why must tire types not be mixed on fire apparatus?
Mixing radial and bias-ply tires can cause unsafe handling and instability.
252
How often must all fire apparatus tires be replaced according to NFPA 1911?
Every seven years, regardless of condition.
253
What can cause poor road handling and excessive fuel use in fire apparatus tires?
Incorrect tire pressure.
254
Why should road salt be rinsed off fire apparatus?
Salt causes corrosion on steel parts and electrical components.
255
What is load shedding in electrical load management systems?
The automatic shutdown of less important equipment to prevent electrical overload.
256
What should be done before lifting a tilt cab?
Ensure adequate vertical clearance and secure all loose items.
257
What is the primary function of slack adjusters?
Connect the brake actuator to the brake drum and maintain proper brake adjustment.
258
What is the maximum air pressure drop allowed in 1 minute during an air brake leak test on a straight chassis?
3 psi.
259
What is the air pressure cutout range for fire apparatus compressors?
120 to 130 psi.
260
What temperature warning must be heeded when checking radiator coolant?
Check coolant levels only when the engine is cool.
261
What type of fluid check requires the engine to be running and warm?
Transmission fluid.
262
What is a sign that apparatus batteries may need service?
Regular need for charging or jump-starting.
263
How often should a driver/operator lift a tilt cab for inspection?
Weekly, even if inspection doors are used.
264
What is the acceptable pressure loss in a hard intake hose service test over 5 minutes?
No more than 10 inches of mercury.
265
According to USFA 2010, how many firefighters were killed while responding or returning from incidents?
17 firefighters.
266
What does NFPA 1002 establish?
Minimum qualifications for apparatus driver/operators.
267
What training must be completed to meet NFPA 1002?
Firefighter I course or equivalent.
268
Why is a full water tank safer than a partially filled one?
Provides better braking and stability due to consistent weight distribution.
269
What is the definition of 'Due Regard' in emergency vehicle driving?
A legal obligation to drive with care and caution for public safety.
270
What is brake fade?
Loss of braking function due to excessive use and heat buildup.
271
What must be confirmed verbally before apparatus is in motion?
That all personnel are onboard and belted.
272
How should hose loading be performed while the vehicle is in motion?
With at least one safety observer, driving slowly (max 5 mph), and no riders on the apparatus.
273
How often should mirrors be adjusted?
At the start of each shift and whenever driving responsibility changes.
274
What is the definition of angle of approach?
The angle from level ground to the lowest front projection from tire contact point.
275
What does Roll Stability Control (RSC) do?
Reduces engine power or applies brakes when rollover risk is detected.
276
What is the purpose of the regeneration inhibit switch?
To prevent DPF regeneration during unsafe conditions like parked on dry grass.
277
What happens if the DEF tank is empty?
Engine speed is limited to 5 mph and may require dealer service.
278
What are the four types of auxiliary braking systems?
Exhaust brake, Engine Compression Brake, Transmission Output Retarder, Electromagnetic Retarder.
279
What are signs of a locked-wheel skid?
Vehicle skids despite steering; wheels are locked from hard braking.
280
What type of retarder offers the highest braking torque?
Transmission output and electromagnetic retarders.
281
What must you do before removing an inlet or discharge cap?
Open the drain or bleeder valve to relieve trapped pressure.
282
What are the responsibilities of tiller operators?
Trailer placement, cornering, public and crew safety, and local regulation familiarity.
283
What must be done when climbing on top of apparatus without railings?
Maintain three points of contact, use slip-resistant surfaces, and have a second person present.
284
What should a driver/operator consider when positioning apparatus on a narrow street?
Ensure access for aerial apparatus and allow space for supply hose lays.
285
What is the primary tactical priority in a rescue situation?
Life safety.
286
Why should the pumper be pulled past the building during investigation mode?
To allow viewing of three sides of the structure.
287
What action must a driver take if standard placement isn't possible?
Notify incoming units of situation and any necessary changes.
288
What zone must be maintained around a potentially collapsing structure?
1.5 times the height of the building.
289
Why are corners considered safe for aerial positioning during structural collapse risks?
They are generally more stable and safer if collapse occurs.
290
What distance should be maintained for potential falling glass from high-rises?
At least 200 feet.
291
Why should drivers avoid positioning apparatus directly under utility lines?
Fire or weather conditions could bring lines down onto the apparatus.
292
What is the 'Inside/Outside' method of positioning aerial and attack pumpers?
Buildings <5 floors: aerial outside pumper; buildings >5 floors: aerial inside closer to structure.
293
What is the best position for a pumper supporting an FDC?
As close to both the FDC and a water source as possible.
294
What should be avoided during drafting operations from natural sources?
Soft or unstable surfaces that may collapse or trap apparatus.
295
What must personnel working near water edges wear?
Personal flotation devices (PFDs).
296
What intake hose type should not be connected directly to a hydrant?
Hard intake hose not rated for positive pressure.
297
What is the recommended pumper placement for large diameter intake hose connections?
A few feet short of being in line with the hydrant, allowing a slight curve.
298
What is the wildland/urban interface?
Where structures meet undeveloped land, often requiring unique apparatus positioning.
299
Why should wildland apparatus back into position facing an exit route?
To allow for quick escape if fire conditions change.
300
What positioning precautions should be taken during wildland firefighting?
Avoid unburned fuels, position off road, close windows, use anchor points.
301
What is Level I Staging?
Initial staging for multi-company responses; units stop 1–2 blocks away and await orders.
302
What is Level II Staging?
Used in large incidents with multiple resources, assigned a specific staging area.
303
What is a 'Base' in incident management?
Central location for logistics, personnel coordination, and initial orders.
304
How should apparatus be used to protect firefighters on highways?
Position to shield from traffic; may block one additional lane for safety.
305
Why should firefighters avoid stepping beyond the tailboard in highway operations?
To reduce the risk of being struck by vehicles.
306
What is the best approach direction for hazmat incidents?
From uphill and upwind.
307
What is the purpose of control zones at hazmat scenes?
To regulate access and protect personnel based on hazard level.
308
How should hoses be laid across active railroad tracks?
Only if confirmed that rail traffic is stopped; otherwise use overhead or under-rail methods.
309
Where should apparatus be parked near railroads?
Same side as incident, no closer than 30 feet from tracks.
310
What positioning considerations exist for EMS incidents?
Ensure ambulance loading access, protect from traffic, avoid exhaust near patients.
311
What is the recommended intake connection distance for dry hydrants?
15 inches (375 mm).
312
What is the specific weight of water per cubic foot and per gallon?
62.4 lb/ft³ and 8.3 lb/gal.
313
What is the expansion ratio of steam at 212°F and at 500°F?
1700:1 at 212°F and approximately 2400:1 at 500°F.
314
What is water’s primary extinguishment method on Class A fires?
Cooling by heat absorption.
315
Why is water not suitable for fires involving sodium or combustible metals?
It reacts violently and can cause explosions or spread fire.
316
What does high surface tension in water affect?
Penetration into dense materials; wetting agents help reduce it.
317
What is the force exerted by a 1 ft high water column?
0.434 psi.
318
How much elevation is needed to generate 1 psi of water pressure?
2.304 feet.
319
What principle explains why pressure is the same in all directions in a confined fluid?
Pascal’s Law (3rd Principle of Fluid Pressure).
320
What principle states that fluid pressure is independent of vessel shape?
6th Principle of Fluid Pressure.
321
What is atmospheric pressure at sea level in psi and mmHg?
14.7 psi and 759 mmHg.
322
What is head pressure and how is it calculated?
The pressure due to elevation; ft ÷ 2.304 = psi.
323
What is the primary cause of friction loss in fire hose?
Contact of water molecules with hose surfaces and internal friction.
324
What effect does older hose have on friction loss?
Up to 50% more friction loss than new hose.
325
How does friction loss relate to hose length?
Directly proportional — doubling the length doubles the loss.
326
What is the relationship between hose diameter and friction loss?
Inversely proportional to the fifth power of the diameter.
327
What causes water hammer?
Sudden stop of water flow, creating a pressure surge.
328
How can water hammer be prevented?
Close valves and nozzles slowly in stages.
329
What are the three basic rates of water consumption used in system design?
Average Daily, Maximum Daily, and Peak Hourly Consumption.
330
What type of valve visually shows its open or closed position?
Indicating valve (e.g., PIV, OS&Y).
331
What is the purpose of backflow prevention in private water systems?
To prevent contamination of municipal water supplies.
332
What are the three methods of moving water in municipal systems?
Direct pumping, gravity, and combination systems.
333
What is the advantage of a combination water system?
Redundant pumping and elevated tanks maintain pressure and supply.
334
What are the three types of water mains in a grid system?
Primary feeders, secondary feeders, and distributors.
335
What hazard can sedimentation and encrustation cause in water mains?
Reduced effective diameter and increased friction loss.
336
What is critical velocity?
The point at which water flow becomes turbulent and reduces flow efficiency.
337
What are the four principles of friction loss?
1. Varies with length, 2. Increases with square of velocity, 3. Inversely with diameter⁵, 4. Unaffected by pressure.
338
What is the purpose of elevated storage tanks in water systems?
Provide emergency storage and maintain pressure during peak demand or failure.
339
What is a dead-end hydrant?
A hydrant fed from only one direction, prone to low pressure.
340
Why should hydrants be flushed periodically?
To remove sediment and maintain water quality and flow.
341
What are the three basic fire streams?
Solid, fog, and broken streams.
342
How is a solid fire stream created?
Using a smooth bore nozzle with a fixed orifice.
343
What nozzle pressure is typical for solid stream handlines?
50 psi (350 kPa).
344
What nozzle pressure is typical for solid stream master stream appliances?
80 psi (560 kPa).
345
What is the formula for calculating GPM from a solid stream nozzle (customary)?
GPM = 29.7 × d² × √NP
346
What is the metric formula for solid stream nozzle discharge?
L/min = 0.067 × d² × √NP
347
How are fog streams formed?
By deflecting water against an obstruction to create finely divided particles.
348
What nozzle type maintains constant GPM at all stream patterns?
Constant flow fog nozzle.
349
What is a selectable gallonage nozzle?
A nozzle with adjustable flow settings predetermined before use.
350
What is a high pressure fog nozzle used for?
Wildland fires, flowing 8–15 GPM at up to 800 psi.
351
What is the maximum flow rate for handline nozzles?
350 GPM (1,400 L/min).
352
What is the minimum flow rate for master stream nozzles?
Greater than 350 GPM (1,400 L/min).
353
What are the three types of master stream appliances?
Fixed, combination, and portable monitors.
354
What types of master stream appliances are found on aerial devices?
Elevated master streams.
355
What is the flow rate and pressure of a piercing nozzle?
125 GPM at 100 psi.
356
What is a chimney nozzle?
A solid brass or steel device producing a fine mist for chimney flues, flowing 1.5–3 GPM.
357
What is the nozzle reaction formula for a solid stream (customary)?
NR = 1.57 × d² × NP
358
What is the nozzle reaction formula for a fog stream (customary)?
NR = 0.0505 × Q × √NP
359
What is the 'rule of thumb' for estimating nozzle reaction (solid stream)?
NR ≈ Q / 3
360
What is the 'rule of thumb' for fog stream nozzle reaction?
NR ≈ Q / 2
361
Why is excessive nozzle reaction dangerous?
It can injure firefighters or hinder hoseline control.
362
What is the main function of a master stream device?
To apply large volumes of water from a fixed position.
363
What happens if driver/operator supplies incorrect pressure to a selectable gallonage nozzle?
It will not flow the selected gallonage correctly.
364
What allows automatic fog nozzles to adapt to variable flow?
A spring-activated device adjusts the baffle opening.
365
Why are cellar nozzles often used with inline shut-off valves?
For safety and ease of operation.
366
What types of monitors are considered combination monitors?
Monitors that can be apparatus-mounted or detached for remote use.
367
What are piercing nozzles used for?
Aircraft fires, car fires, or fires in inaccessible voids.
368
What are the components of Total Pressure Loss (TPL)?
Friction Loss, Elevation Pressure Loss, and Appliance Loss.
369
What is the formula for friction loss (customary)?
FL = C × Q² × L
370
What does each variable in the friction loss formula represent?
C = coefficient, Q = flow rate ÷ 100, L = hose length ÷ 100.
371
When is appliance pressure loss considered insignificant?
When flow is less than 350 GPM (1,400 L/min).
372
How much pressure loss is added for each appliance at ≥ 350 GPM?
10 psi (70 kPa).
373
How much pressure loss is added for master stream appliances?
25 psi (175 kPa).
374
What is the formula for elevation pressure loss (customary)?
EP = 0.5 × Height (ft).
375
What is the formula for elevation pressure loss in multistory buildings?
EP = 5 psi × (Stories – 1).
376
What is the pressure loss in 200 ft of 2½” hose at 200 GPM?
16 psi.
377
What is the pressure loss in 150 ft of 1¾” hose at 150 GPM?
52.3 psi.
378
What is the total pressure loss for 200 ft of 1¾” hose at 180 GPM with 10 ft elevation?
105.4 psi.
379
How is pump discharge pressure (PDP) calculated?
PDP = Nozzle Pressure + Total Pressure Loss (TPL).
380
What is the formula for Net Pump Discharge Pressure from a pressurized source?
NPDP = PDP – Intake Pressure.
381
How is PDP set when supplying multiple hoselines?
Based on the line with the highest pressure requirement.
382
What pressure is added for elevated waterways with master stream appliances?
25 psi.
383
What nozzle pressures are typical for fog nozzles?
100 psi (standard), 50 or 75 psi (low pressure).
384
What is the pump pressure loss for aerial piping bends in elevated waterways?
Approximately 25 psi, though varies by manufacturer.
385
What should a driver/operator do to determine pressure loss specific to apparatus?
Consult manufacturer or conduct field testing.
386
How is friction loss calculated in wyed hoselines of equal length?
Add FL from one attack line + FL from supply + appliance and elevation losses.
387
What must be done if wyed or manifold lines have unequal lengths?
Calculate each line’s FL separately; gate down lower-pressure lines.
388
What are the four types of hose layouts?
Single, Multiple Equal, Wyed, and Siamesed.
389
What is the advantage of siamesed hoselines?
Reduced friction loss—approximately 25% less than a single line.
390
How much pressure is added for a Siamese appliance at flows > 350 GPM?
10 psi.
391
What’s the friction loss for 300 ft of 4-inch hose at 400 GPM?
9.6 psi.
392
How can drivers avoid overpressuring lower-pressure lines in multi-line setups?
Use gated discharges or valves to reduce pressure.
393
What PPE should driver/operators wear when operating pump panels?
Full PPE to reduce injury risk during mechanical failures.
394
Why is wheel chocking recommended even when the parking brake is set?
For added safety in case of brake failure or unintentional movement.
395
What is the first step after exiting the cab to operate the pump from tank water?
Chock the wheels.
396
What should be used to cool the pump if no water is flowing?
Tank fill line or circulator valve to prevent overheating.
397
What is the minimum residual pressure to maintain from a pressurized source?
20 psi (140 kPa).
398
Why must the bleeder valve on the intake be opened when transitioning to an external source?
To release air and prevent disruption of attack lines.
399
What is a four-way hydrant valve used for?
Allows uninterrupted supply transition from hydrant pressure to pump pressure.
400
Why might forward lay be insufficient in long hose stretches?
Available hydrant pressure may be inadequate; second pumper needed.
401
When is reverse lay typically used?
When the first pumper arrives at the fire and must stay at scene while a second pumper lays hose to a water source.
402
What is the key function of a transfer valve in a two-stage pump?
To switch between pressure (series) and volume (parallel) modes.
403
Why should throttle not be increased below 20 psi intake pressure?
Risk of pump cavitation.
404
How do you estimate additional water available from a hydrant?
Using the Percentage, First-Digit, or Squaring-the-Lines Method.
405
What causes pump cavitation?
Water discharges faster than it enters the pump, forming air bubbles.
406
What is the ideal lift height for drafting to retain full pump capacity?
10 feet (3 meters).
407
What is the minimum water depth required over and around a strainer during drafting?
24 inches (600 mm).
408
What is a floating strainer used for?
Shallow water drafting; reduces whirlpool and debris risk.
409
What does high vacuum reading near 22 inches Hg indicate?
Pump is near maximum capacity; risk of cavitation increases.
410
What are symptoms of cavitation?
Popping sounds, pressure fluctuation, gravel noise, no gauge change with throttle.
411
What type of water requires flushing the pump system afterward?
Nonpotable water with salt, sediment, or chemicals.
412
What pressure does atmospheric pressure drop to at 5,000 ft elevation?
Approximately 12.2 psi (85 kPa).
413
How can you compensate for increased lift during drafting?
Use larger diameter or additional intake hose.
414
What is the purpose of a jet siphon?
Uses Venturi effect to create water movement for water transfer.
415
What is the maximum rated lift for NFPA/UL fire pumps?
25 feet, though only 60% capacity remains at 20 feet.
416
Why is it better to lay 100 ft of supply hose to a better drafting site?
To improve water quality and reduce friction loss.
417
What causes loss of prime during operation?
Air leaks, suction hose defects, sudden discharge opening, or whirlpools.
418
What action is recommended when booster tank is empty and tank-to-pump valve does not seal?
Prime cannot be achieved; refill tank or repair valve.
419
How does salt water affect pump operation?
Causes corrosion; requires fresh water flushing afterward.
420
How should strainers be supported in sloped terrain?
Use rope, ladders, or metal objects to elevate and stabilize strainer.
421
What causes suction hose inner liner to collapse?
Vacuum stress during high lift or defective hose.
422
What is the general pump discharge pressure for sprinkler/standpipe FDCs if unknown?
150 psi (1,050 kPa).
423
What are the three elements needed to create foam?
Foam concentrate, water, and air.
424
What is eduction in foam systems?
Using the Venturi effect to mix foam concentrate with water in a nozzle or proportioner.
425
Why is mixing different foam concentrates during incidents problematic?
It can clog eductors and reduce foam quality due to incompatibility.
426
What are the two main categories of Class B fuels?
Hydrocarbon fuels and polar solvents.
427
What foam type is needed for polar solvents?
Alcohol-resistant foam.
428
What does 'miscible' mean in reference to polar solvents?
They mix with water in all proportions.
429
What are the four methods of foam proportioning?
Induction, injection, batch mixing, and premixing.
430
What is the primary method of foam discharge in CAFS?
Compressed air injected into foam solution before discharge.
431
What does the Jet Ratio Controller (JRC) do?
Supplies foam concentrate to a self-educting master stream from distances up to 3,000 feet.
432
What is the proportioning range for Class A foam?
0.1% to 1.0%.
433
What are the recommended Class A foam percentages for fire attack with standard fog nozzles?
0.2% to 0.5%.
434
What is the expansion ratio for medium-expansion foam?
20:1 to 200:1.
435
What is the formula to calculate application rate for Class B foam?
Application Rate = Nozzle Flow Rate ÷ Fire Area.
436
What is the foam type that forms an air/vapor excluding film?
Aqueous Film Forming Foam (AFFF).
437
What is burnback resistance?
The foam's ability to resist flame re-ignition after initial extinguishment.
438
What is the main hazard of discharging foam into natural water bodies?
It reduces oxygen levels and can be harmful to aquatic life.
439
What are durable agents made of?
Water-absorbent polymers used for fire blocking and structure pretreatment.
440
What is the correct nozzle/eductor back pressure limit for in-line foam eductors?
70% of the inlet pressure.
441
Why should foam tanks be airtight?
To prevent the formation of surface film on the foam concentrate.
442
What is batch mixing primarily used for?
Class A and regular AFFF foams when no other system is available.
443
What are the three main foam application methods for Class B fuels?
Roll-on, bank-down, and rain-down.
444
How should AR-AFFF be applied to polar solvents?
Gently, to allow membrane formation; use aspirating nozzles for best results.
445
What is the typical shelf life of properly stored synthetic Class B foam?
20–25 years.
446
What are compressed air foam systems (CAFS) best known for?
Creating high-quality, clingy foam with long drainage time.
447
What is the advantage of foam nozzle eductors?
Nozzle and eductor are matched for proper flow and pressure.
448
What is the biggest drawback of batch mixing?
The entire tank must be emptied before changing foam percentage or type.
449
What can happen if you exceed the rated GPM of an in-line eductor?
Foam quality may decrease or stop entirely.
450
What device allows foam and water to be delivered from different outlets at the same time?
Bypass-type balanced pressure proportioners.
451
What type of foam has the highest expansion ratio?
High-expansion foam (200:1 to 1000:1).
452
What method uses foam solution sprayed into the air to fall gently onto a fuel surface?
Rain-down method.
453
What is the primary purpose of aerial fire apparatus?
To place personnel and/or water streams in elevated positions.
454
What are the three NFPA® 1901 categories of aerial devices?
Aerial ladders, elevating platforms, and water towers.
455
What structural advantage do truss ladders provide?
They are lighter than solid beams with equal strength due to triangular stress distribution.
456
What is the typical pressure in hydraulic aerial systems?
May exceed 3,500 psi (24,500 kPa).
457
What is the function of the selector valve in hydraulic systems?
Directs fluid to stabilizers or aerial device; must be preset during inspection.
458
What are the types of hydraulic pumps used in aerial systems?
Load sensing piston, rotary vane, and rotary gear positive-displacement pumps.
459
What function do counterbalance valves serve?
Prevent aerial motion if hydraulic lines fail.
460
What is a trunnion?
The pivoting end of a piston rod in a hydraulic hoisting cylinder.
461
How much can modern elevating platforms typically flow?
Up to 2,000 GPM (8,000 L/min).
462
What are the three types of elevating platforms?
Aerial ladder platforms, telescoping platforms, and articulating platforms.
463
What is the minimum floor space of an elevating platform per NFPA®?
14 square feet (1.3 m²).
464
What is the maximum uncharged load capacity of a platform?
750 lbs (375 kg); 500 lbs (250 kg) when charged.
465
What does the fog curtain nozzle under platforms do?
Creates a protective fog shield and must flow at least 75 GPM (300 L/min).
466
What are the primary uses of articulating aerial platforms?
Rescue, ventilation, elevated master streams, and access to upper floors.
467
What is the purpose of a pinnable waterway?
Allows monitor positioning at base or tip depending on operation (rescue or fire suppression).
468
What does NFPA® 1901 require for communication on aerials?
A two-way system with hands-free capability at the tip/platform.
469
What does a tiller operator interlock do?
Prevents the vehicle from starting unless the tiller operator is seated or engages override.
470
What is the purpose of a deadman foot switch?
Ensures intentional activation of aerial movement.
471
What happens if a waterway monitor isn’t anchored properly before charging?
It can launch from pressure and cause damage or injury.
472
What is the maximum nozzle movement range for detachable ladder pipes?
15° to either side of center.
473
What is the flow range of water towers?
1,000 to 5,000 GPM (4,000 to 20,000 L/min).
474
What are key safety features of hoisting cylinders?
Safety valves that lock oil in place during leaks to prevent collapse.
475
What kind of lighting is recommended near the tip of the aerial device?
Floodlighting, though not required by NFPA® 1901.
476
What are the four standard aerial apparatus control levers (right to left)?
Elevation, rotation, extension, and platform controls.
477
What are the key power generation options on aerials?
Inverters, portable generators, and vehicle-mounted generators.
478
What NFPA® standard governs breathing air systems if installed?
NFPA® 1989.
479
What is the danger of exceeding air system pressure in aerial breathing systems?
It can damage moisture filters and cause pressure loss.
480
What is the most common hydraulic tool power source on aerials?
Hydraulic pump powered by PTO, electric motor, gas engine, or compressed air.
481
What size ladder is required for fourth or fifth story access?
Pole ladders (≥ 40 ft or 12 m).
482
What is required testing frequency for aerial apparatus according to NFPA® 1911?
Annually for service tests, every 5 years for nondestructive testing.
483
What is the most important factor when initially placing an aerial apparatus?
Getting it right the first time due to fixed reach and limited repositioning options.
484
What building height affects SOP placement of engines and aerials?
5 stories (≈60 ft); aerials outside engines for <5 stories, inside for >5.
485
What is the 'collapse zone'?
Area beneath a wall that would be impacted if it collapsed.
486
Why is a low angle with long extension discouraged?
It increases stress and reduces load capacity of the aerial device.
487
What term describes loads involving motion, such as wind or vibration?
Dynamic load.
488
How should aerials be positioned in windy conditions?
Parallel to wind, minimize extension, operate over front or rear.
489
What clearance should be maintained from power lines energized from 600–50,000 volts?
10 feet (3 m).
490
What should you do if a vehicle becomes energized by a power line?
Stay in or on the vehicle until it's de-energized and grounded by professionals.
491
What is the best practice for jackknifing a tillered aerial?
60° from in-line with aerial extended away for maximum stability.
492
When should aerial devices avoid supported positioning?
When a structure is weakened or shows collapse signs.
493
What direction should you approach incidents from when possible?
Uphill and upwind.
494
What should be done in dead-end access situations?
Back apparatus in to allow a quick escape.
495
What surface warning sign appears during hot weather?
Shiny/glassy 'bleeding' asphalt.
496
What should never be done with warning lights on highways at night?
Never shut off all warning lights.
497
What is the minimum clearance from railroad tracks?
25 feet (7.5 m).
498
What must be confirmed before raising an aerial over railroad tracks?
Train traffic is halted and device is 25 ft above rails.
499
Where should apparatus be positioned on bridges?
On separate spans or lanes; not all units on same area.
500
What is the recommended angle of aerial operation for best stability?
Inline with the vehicle’s longitudinal axis (front or rear).
501
What are key hazards to avoid during structural incidents?
Collapse zones, falling debris, roof signs, parapet walls.
502
What is the priority for aerial placement during medical incidents?
Shielding personnel and providing ambulance access.
503
What causes excessive stress on aerial devices?
Low angles, long extensions, sudden movements, heat, wind, torsion.
504
What should driver/operators avoid at hazmat incidents?
Parking over manholes/storm drains or approaching from downwind/downhill.
505
Why must aerials avoid blocking aircraft slides?
Slides are primary evacuation paths and deploy automatically from doors or wings.
506
Where should aerials park at petroleum storage sites?
Outside the dike walls unless a roadway is built atop the dike.
507
What does OSHA recommend for power line clearance during construction operations?
20 ft for <350 kV lines, 50 ft for >350 kV.
508
What should you do if someone is trapped in an energized vehicle?
Do NOT touch them—wait for power company; instruct them to stay inside unless fire threatens.
509
What must be considered when operating aerials near bridges?
Load capacity, wind, movement, superstructures, and safe staggered parking.
510
Why avoid placing apparatus on vaulted surfaces?
They may collapse due to being above underground voids like basements or culverts.
511
What does 'Look Up and Live' refer to?
Checking for power lines before and during aerial operation.
512
What is the function of stabilizer pads?
Distribute aerial weight more evenly on ground surfaces to prevent sinking or tilting.
513
What causes most aerial tip-overs during stabilization?
Operator error and improper jack placement on unfamiliar apparatus.
514
What does short-jacking mean?
Deploying stabilizers to unequal lengths, often due to space restrictions.
515
What risk does short-jacking introduce?
Gravity circle may extend beyond base of stability, risking overturning.
516
What are the three types of stabilizers?
Post-type, box (H-style), and fulcrum-type (A-frame, X-style).
517
What is the gravity circle?
The lateral shift of the center of gravity when the aerial rotates or extends.
518
When does the gravity circle become dangerous?
When it extends beyond the base of stability.
519
What action can broaden the base of stability?
Full extension and deployment of stabilizers.
520
Why should PTO only be engaged when properly positioned?
To prevent drivetrain or pump system damage.
521
What must be done before stabilizer deployment?
Activate PTO, chock wheels, and check terrain for stability.
522
What tool is commonly used to estimate stabilizer travel?
Short pike pole or firefighter’s arm span.
523
What is a stabilizer shoe?
Flat metal pad at the bottom of the stabilizer to distribute load.
524
Why avoid placing stabilizers over manholes, curbs, or water covers?
These may collapse or provide unstable footing.
525
What is cribbing used for?
To supplement stabilizer support on unstable or uneven surfaces.
526
What slope is acceptable for lateral grade correction?
Up to 5% or approximately 3°.
527
How should stabilizers be deployed on lateral grade?
Lower uphill side first, then downhill side to level apparatus.
528
What direction is safest for aerial operation on slopes?
Over the uphill side of the apparatus.
529
What happens when operating on longitudinal grade?
Ladder rungs no longer remain level, introducing lateral stresses.
530
Why are icy or snowy conditions dangerous for stabilization?
Melting causes voids under pads; surfaces become slippery.
531
How can stability be enhanced on icy ground?
Use sand or friction material—never salt, which reduces traction.
532
How do stabilizer interlocks work?
Prevent aerial operation unless stabilizers are deployed and locked.
533
What provides mechanical locking of jacks?
Steel pins inserted through post holes below the jack housing.
534
What must be checked before retracting stabilizers?
Ensure personnel and equipment are clear; remove safety pins.
535
What is the correct order to retract stabilizers?
Reverse the order they were deployed to avoid chassis stress.
536
What must be done after raising stabilizers?
Disengage PTO and return stabilizer pads to storage.
537
How do manual stabilizers differ from hydraulic ones?
They require manual arm extension and screw jack adjustment.
538
What angle provides maximum stability in tillered aerials?
60° between tractor and trailer with ladder operated outward.
539
What should be avoided when jackknifing tiller apparatus?
Angles >90° due to poor stability and possible damage.
540
What should be done after setting tiller angle?
Set all brakes, including trailer axle brake, and deploy stabilizers.
541
What does Skill Sheet 18-1 cover?
Steps to deploy, lock, and stow hydraulic stabilizers.
542
What does Skill Sheet 18-2 cover?
Steps to stabilize a tractor-trailer aerial apparatus.
543
What must a pedestal operator be ready to do during tower ladder operation?
Override unsafe basket movements and warn of danger.
544
What is the first priority before climbing or descending an aerial ladder?
Ensure the device is in position and stable.
545
When must personnel be tethered while on aerial devices?
Any time not actively climbing, descending, entering, or exiting.
546
Where should safety tethers be anchored?
To structural features only, never to cables, wires, or non-structural elements.
547
Why must ladder belts and tethers meet NFPA® 1983?
To ensure fall protection equipment meets life safety standards.
548
What is a fall hazard during aerial operation?
Operating with unsecured personnel on a moving device.
549
What is the danger of extending/retracting aerials with people on them?
Pinch and crush hazards from moving rungs and sections.
550
What is required before rotating or elevating aerials with personnel aboard?
All personnel must be tethered and communication maintained.
551
Why is using wire rope near pulleys a hazard?
It creates pinch points and tension-related injury risks.
552
What should be avoided when giving rotation commands?
Ambiguous terms like 'left/right' without clarifying viewpoint.
553
What is the primary control position on an aerial apparatus?
Lower control station, typically on the turntable.
554
When can secondary controls be used?
Only with a trained operator present at the primary controls.
555
What must secondary control operators be aware of?
Tip movement, ladder personnel, water flow, and electrical hazards.
556
What is the purpose of the load chart?
To determine safe operating limits based on extension, elevation, and conditions.
557
What are electronic load systems used for?
Monitoring aerial stability, but not replacing operator judgment.
558
What sequence should be followed when raising a telescoping aerial device?
Elevate, rotate, extend, and then lower to objective.
559
What is feathering in aerial control?
Slow, smooth movements to avoid dynamic stress or hydraulic spikes.
560
What does Skill Sheet 19-1 cover?
Raising and lowering a telescoping aerial without a platform.
561
How does the operation of articulating aerials differ?
Includes concern for knuckle movement and requires additional spatial awareness.
562
What are pinnable waterways?
Fixed nozzles that can be mounted at the tip or one section lower.
563
Why is video monitoring helpful on aerial platforms?
It enhances safety by allowing operators to see tip hazards remotely.
564
What is the 75-80-80 guideline?
75° elevation, 80% extension, 80 psi nozzle pressure for safe ops.
565
What are key dangers of detachable waterways?
No tip control, exposure risk, and hose/nozzle failure risk.
566
How does cold weather affect aerial operation?
Increases oil viscosity, forms ice, and adds weight to aerial device.
567
What is ice shrugging?
Slowly extending/retracting aerial device to remove ice buildup.
568
What are signs of heat damage to an aerial?
Discoloration, deformed welds, warped metal, improper function.
569
When must a damaged aerial be removed from service?
Immediately, until EVT repairs and NFPA® 1911 retesting is complete.
570
What signs indicate aerial mechanical/power failure?
Unusual noise, fluid leaks, gauge abnormalities, or aerial drift.
571
What action is taken if aerial failure occurs?
Stop operation, remove personnel, bed device, and take unit out of service.
572
When can below-grade operations be performed?
Only if the manufacturer approves and within rated limits.
573
What are the four fireground strategies for aerial devices?
Rescue, Ventilation, Elevated Fire Attack, Exposure Protection.
574
What should be announced before aerial master stream operations?
Interior attack crews must be notified and clear.
575
What is the safest rescue approach with an aerial device?
Upwind, level grade, no obstructions, with the turntable upwind of the target.
576
Why should you avoid contacting a building with an aerial ladder during victim boarding?
It can cause twisting and potential failure if the opposite beam bends.
577
What is the 'knee-sit method'?
Rescue method where victim sits on firefighter's knee while descending the aerial ladder.
578
What angle should the blitz attack stream enter a window?
Approximately 30 degrees upward toward the ceiling.
579
What is the first priority during rescue operations?
Victims most severely threatened.
580
What does 'platform placement' depend on?
Rescue method: either lifting over rail or entering through access gate.
581
What is required for rope rescue using aerials?
NFPA® 1983 compliant equipment and personnel trained to NFPA® 1670.
582
When should a Stokes basket be used with an aerial?
When victims are unconscious or unable to climb down.
583
Why are aerial devices not ideal for water rescues?
They are not designed for lateral forces and may become unstable or damaged.
584
How should aerials be used for ventilation?
From the unburned side, with 6 ft of ladder extending past roof edge.
585
Why should you avoid breaking windows during exposure protection?
May worsen fire spread and increase water damage.
586
How should fog streams be positioned for cross ventilation?
Slightly above window and to the upwind side.
587
What is the role of elevated standpipes?
Provide hoselines to upper levels when interior standpipe systems are inoperable.
588
What stream should be used to avoid pushing fire into unburned areas?
Solid or straight stream aimed from the unburned side.
589
What is a significant risk of foam use in elevated master streams?
Wind can break up the foam due to its high air content.
590
How should apparatus be placed for exposure protection?
With a clear escape route and ability to swing stream between fire and exposure.
591
What happens if rope is anchored to the ground while using an aerial device?
Device bears double the load, increasing collapse risk.
592
What does Skill Sheet 20-1 cover?
Steps for deploying elevated master stream operations.
593
What is the main advantage of articulating aerial devices for parapets?
Ability to reach over parapet and set platform directly on roof level.
594
Why must extension locks be engaged before aerial rescues?
To reduce twisting and increase structural rigidity of the aerial device.
595
What are indicators for switching to a defensive attack?
Unsafe conditions for handlines, IC decision, or high water needs (e.g., attic fires).
596
What hazard may result from elevated stream use on structure fires?
Structural collapse due to water weight (2,000 lb per 250 gpm).
597
How can aerial devices aid in aircraft rescue?
Providing elevated access to aircraft or assisting with ventilation and thermal imaging.
