Multi Flashcards
(84 cards)
1
Q
What is VMC
A
Minimum controllable airspeed with critical engine INOP
- slowest airspeed at which directional control can be maintained with critical engine INOP
- marked by a red line
2
Q
How to determine VMC speed
A
CUSTOMFAM
3
Q
What is CUSTOMFAM
A
How to determine VMC
- critical engine INOP and windmilling
- up t 5 degrees bank and 0 side slip
- standard day at SLP
- trimmed on takeoff
- out of ground effect
- max power in operation engine
- flaps set for takeoff & gear up
- AFT CG
- most unfavorable weight (lighter)
4
Q
How would Critical engine INOP effect performance and VMC
A
- Aircraft performance would decrease because of less power
- VMC would increase because PAST factor and prop drag
5
Q
How does up to 5 degrees bank and zero slide slip effect performance and VMC
A
- aircraft performance would increase because of less drag
- VMC would decrease because it decreases PAST
( raise the dead engine) ( we are gaining more horizontal component of lift )( we are aligning the longitudinal axis of there aircraft with the relative wind)
6
Q
How does standard day at SLP effect performance and VMC
A
- aircraft performance increases because of more dense air
- VMC would increase because asymmetrical engine performance
( More power = More PAST )
7
Q
How does trimmed for takeoff effect performance and VMC
A
- aircraft performance stays the same
- VMC stays the same
8
Q
How does out of ground effect, effect performance and VMC
A
- aircraft performance decreases because of greater induced drag
- VMC increases because less control effectiveness
( your now battle in both induced drag and directional control )
9
Q
How does max power on the operating engine effect performance and VMC
A
- aircraft performance would increase because of more power
- VMC would increase because of greater asymmetric engine performance
( more power = more PAST )
10
Q
How does Flaps set for takeoff and gear up effect performance and VMC
A
Flaps down
- aircraft performance would increase because of less drag
- VMC would increase because its less stable
( adding flaps adds stability because its taking some of the PAST out )
Gear up
- aircraft performance would increase because of decreased drag
- VMC would decrease because of keel effect
( gear coming forward shifts the CG forward creating a greater moment arm from the rudder making it more stable)
11
Q
How does Aft center of gravity effect performance and VMC
A
Aft CG
- aircraft performance would increase because of less elevator/ stabilator drag
- VMC would increase because less rudder authority so less stable
( opposite for forward CG) ( moment arm from rudder to CG either creates a shorter arm (less stable) or a greater arm (more stable))
12
Q
How does most unfavorble weight effect performance and VMC
A
Lighter
- aircraft performance would increase because of less work the plane has to do
- VMC would increase because less contribution from horizontal component of lift
(being lighter is easier to make unstable)
(Being heaver you have to have more momentum to make unstable so it’s harder to make unstable)
13
Q
What is critical density altitude
A
Where VMC and VS are equal, so the airplane will reach VMC and VS at the same time which can be dangerous
14
Q
Accelerated STOP distance
A
Start— engine failed at Vr — abort takeoff — full stop
- calculated from POH performance charts
15
Q
Why do we need to know single engine performance
A
We need to know for making the right decisions in an emergency, must know your airplanes single engine performance available for each phase of flight
16
Q
Why do we zero slide slip
A
- During flight with one engine INOP we do a very slight bank up to 5 degrees to create HCL on the dead engine (raise the dead)
- splitting the rudder into their operating engine creates alignment with the longitudinal axis with the relative wind
- zero side slip conditions align wind to minimize drag for best performance
17
Q
What is a service ceiling
A
Both engines working and is able to climb at a 100 FPM
18
Q
Absolute ceiling
A
Climb is no longer possible
19
Q
Single engine service ceiling
A
No longer able to maintain a climb of 50 FPM
20
Q
What is the unavoidable decent called when you are above the single engine service ceiling and you lose an engine
A
Drift down
21
Q
Climb to cruise flow
A
- when advancing power, check all engine instruments and RPM has been reached
- tap breaks to stop from spinning to retract gear up
- climb out at blue line + 10kts ( Vyse + 10kts )( this creates a safe margin of airspeed in the instance that you lose an engine)
- when 500’ above airport elevation reduce throttles to 25 and prop to 2500 RPM
22
Q
Before landing checklist
A
GUMPS
( do in each leg of the pattern)
- Gas on, for both tanks, fuel pumps on
- Undercarriage (gear) down below Vle
- mixture rich
- Propeller full on final
- Seatbelts secure and lights on
23
Q
Why might your gear horn be going off while doing normal maneuvers and proper configuration
A
Check your POH
- below 14” of manifold pressure and gears is still up
- flaps extended past 25 and gear is still up
- gear selector is in the up position when aircraft is on the ground
- stall warning does not sound on the ground
24
Q
Why do we fly Multiengine aircraft
A
Redundancy
25
What happened to our performance when we lose one engine
With one engine INOP we lose 50% of our power and 80% loss of climb performance
26
What is the critical engine
The engine failed it would have the most negative effect on performance and directional control
27
What are the two types of rotating twin engines
Conventional, and non conventional
28
What is a conventional engines
2 clockwise spinning props
- left engine is the critical engine
29
What is non-conventional engines
Counter rotating props
- no critical engine because the yawing, amid rolling caused from losing either engine is identical
30
What does P-factor cause
YAW
- with one engine INOP
- The greater the moment arm is, the tendency to turn left is greater
31
What does accelerated slipstream cause
Roll
-
32
What is our single engine best angle if climb
Vxse - 82
33
What os single engine best rate of climb (blue line)
Vyse - 88
34
What is the safe intentional OEI (one engine inop) speed
Vsse - 82
35
What is our minimum control airspeed (red line)
VMC - 56
36
What is our landing gear extension/ operation speed
Vle/lo - 140
37
What is our maximum landing gear retraction speed
Vlr - 109
38
What is our rotation speed
Vr - 75
39
What is our best angle of climb speed
Vx - 82
40
What is our minimum stall speed in landing configuration ( dirty )
Vs0 - 55
41
What is our minimum stall speed in clean configuration
Vs1 - 57
42
What is our maneuvering speed
Va - 112-135
43
What is our maximum structural cruising speed (smooth air)
Vno - 169
44
What is our never extend speed
Vne - 202
45
Departure brief with 4 outcomes if engine fails
1. Has rotation occurred? No, then pull both throttles back and come to a stop
2. We rotated with gear still down, pull both throttle and land straight ahead
3. Rotation occurred gears up and below 2000agl,
- engine our flow
- feather inop engine
- declare
- return to land
4. Rotation occurred, gear is up, and above 2000agl
- engine out flow
- trouble shoot try and restart
- come back to land
46
Accelerate — go distance
Start — engine fails at Vr — continue takeoff — climb 50ft
( part 23.2120 — why we don’t have accelerate go distance )
47
What is a scimitar blade
Scimitar blade has swept tips, behaves similar to seat wings to minimize sonic shock wave formation at blade tip at high RPM
- performs better at cruise
- slows down the air flowing over it
48
What’s a good lean to
1325 degrees F — EGT
49
Tell my about our landing gear
It’s hydraulically operated, fully retractable, tricycle landing gear
- two way selector switch that activates am electric pump, which the pump then manages the hydraulic pressure to move the gear
- 6-10 seconds transit time
- gear selector switch should not be moved while gear is I transit
- gear retraction speed is VLR - 109
- gear extended/operating speed is VLE/LO - 140
50
What keeps the gear up and down
- hydraulic pressure keeps it up
- gravity keeps it down and the lack of hydraulic pressure
- also we have down lock hooks that keep it down
51
What type of engines do we have
Left - Lycoming IO-360-B1G6
Right- Lycoming LIO-360-B1G6
Rated at 180 horse power
Rated RPM 2700
52
What does Lycoming IO-360-B1G6 and LIO mean
I- fuel injected, O- horizontally opposed, 360- 361 cubic inches of displacement ( the amount of volume inside the cylinders)
The L before the LIO - means counter rotating
53
What is rate of climb
Is the altitude gain per unit of time
54
What is the time gradient
Is their actually measure of altitude gained per 100ft of horizontal travel, expressed as a percentage
55
What s induced flow
The propellers on the wing mounted engine creates an accelerated flow or accelerated slipstream of air over the wings
- happens in single engine as well but not as much because of the location of the prop in relation to the wings
56
What happens to p-factor and torque in a counter rotating props
They cancel each other out, so less rudder4 is needed to oppose these factors
57
What are the two motions that happen when an engine fails
YAW and ROLL
58
What causes YAW
Asymmetrical thrust will causer a yawing moment around the C.G. Towards the inop engine
59
What causes ROLL
The yawing moment from asymmetrical thrust will cause the wing with the operating engine to move faster through the air as the airplane yaws. This causes a faster velocity of air over the wing with the operative engine meaning more lift on that wing and results in a roll towards the inoperative engine.
Induced flow (accelerated slipstream) over the wing from the operating engine and lack of induced flow (accelerated slipstream) over the inoperative engine causes asymmetrical lift on the wings, resulting in a rolling moment around
the C.G. towards the inoperative engine.
60
What is the critical engine
The critical engine is the engine that, if it were to fail, would most adversely affect the performance or handling characteristics of the airplane
61
What is the critical engine on a conventional twin
The left engine
62
What is the critical engine in a counter rotating prop twin
there is not a critical engine since the yawing and rolling effects of losing one engine will be identical no matter
which engine fails.
63
What are the factors to determine them critical engine
PAST
P-factor (yaw)
Accelerated slipstream (roll)
Spiraling slipstream (yaw)
Torgue (roll)
64
What is P-factor
YAW
Pfactor is where the descending propeller blade creates more thrust than the
ascending blade. This causes asymmetrical thrust on each side of the propeller. To figure
out the effect on the airplane, the formula THRUST x Arm = Moment can be used. This
means that the longer the arm from the C.G. to the thrust, the larger the yawing moment
will be
65
What is accelerated slipstream
ROLL
Basically with one engine INOP the is no extra air from the prop flowing over that wing so there is less lift on one wing and vise Versa on the other wings so most air and more lift top it creates that asymmetrical thrust
P-factor - so because of pfactor there is greater airflow on the right side of the engines so changes the center of lift rightward. Just like P‐factor, the arm to the right engine is longer than the arm to the left engine. This means that if the left engine fails, the roll moment will be greater to the left than if the right engine fails. Therefore the left engine is the critical engine.
66
How does spiraling slipstream work
YAW
- Left engine prop-wash interacts with the vertical stabilizer and rudder which helps counter the asymmetrical thrust
- right prop-wash trails off
67
How does torque work
ROLL
- Rolls into dead engine
- In the counter rotating twin, the torque will oppose the yawing and rolling moment caused
by an inoperative engine. The resulting yaw will be the same no matter which engine fails.
Therefore, there is no critical engine.
As the engine and propeller rotate in one direction, they, in turn, try to rotate
the airplane in the other direction. This is due to Newton’s third law which states, “For
every action there is an equal and opposite reaction.” This force also acts when an engine
fails because there is still a second operating engine.
68
What must VMC not exceed
1.2 X Vs1 at maximum takeoff weight
69
VMC must be determined with
1. Most unfavorable weight (not necessarily maximum gross weight)
2. Most unfavorable center of gravity position
3.The airplane airborne and the ground effect negligible
4.Maximum available takeoff power initially on each engine
5.The airplane trimmed for takeoff
6. Flaps in the takeoff position
7. Landing gear retracted
8.All propeller controls in the recommended takeoff position.
70
When recovering from VMC
1.The rudder pedal force required to maintain control must not exceed 150 pounds.
2.It must not be necessary to reduce power of the operative engine(s).
3.The airplane must not assume any dangerous attitude.
4.It must be possible to prevent a heading change of more than 20 degrees.
71
What does VMC deal with
Directional control not performance
72
Warning signs to recognize that VMC is occurring
1. Loss of directional control -the rudder pedal is depressed to its fullest travel and the airplane is still turning towards the inoperative engine.
2. Stall warning horn – a single‐engine stall could be just as dangerous as running out of rudder authority and could even result in a spin.
3. Buffeting before the stall – same reason as the stall warning horn.
4. A rapid decay of control effectiveness – any loss of control effectiveness could
result in loss if control of the airplane.
73
How to recover from VMC
Reduce power on the operating engine – this will reduce the asymmetrical thrust
causing the VMC in the first place. Reducing the power all the way to idle may help stop the VMC, but the loss of power and resulting loss of airspeed could lead to a stall.
2. Pitch down – Lowering the nose of the airplane will increase the forward airspeed making the rudder more effective in regaining and maintaining directional control.
74
As density altitude increases what happens to VMC
VMC speed decreases due to the fact that as density altitude increases engine power will decrease. The decrease in engine power results in less asymmetrical thrust, meaning the yawing from a failed engine will be less at a high density altitude than a lower density altitude
75
More power equals what
Most PAST
So more power or thrust in the operating engine, the more rudder is needed to stop the resulting yaw
76
What happens to your stall speed as your altitude increases and decreases
You stall speed is an indicated airspeed that will remain constant
77
As your density altitude increases what happens to VMC and why
Your VMC decreases because your engine output decreases, so less power = less PAST so easier to control the airplane and not as much rudder needed
78
How does forward CG effect VMC
the longer the arm, the more
effective the rudder; the more effective the rudder, the lower VMC. As the C.G. moves
forward, VMC decreases; as the C.G. moves aft, VMC increases.
79
What does your landing gear extended do to VMC and why
In the extended (down) position,
the landing gear can also act like the keel of a boat (increasing in longitudinal stability) , giving the airplane a stabilizing effect.
This stabilizing effect helps prevent a turn, thereby lowering VMC (very small effect on VMC)
The landing gear extended (down) always decreases performance due to parasite drag.
80
What does a windmilling prop vs feathered prop do to your VMC
A windmilling propeller creates more drag than a feathered propeller. This extra drag adds
to the yawing from a failed engine to make the total effect worse. This situation will require more rudder deflection to maintain directional control, which means that less rudder is available to the pilot, thereby increasing VMC.
Once the propeller is feathered the drag is reduced, thereby reducing VMC.
A windmilling propeller decreases performance due to the parasite drag created by the
propeller blades.
81
How does your flaps down effect your VMC
When the flaps are down the wings create more lift than if the flaps were up. However,
when lift is created, drag is also created (as lift increase, drag increases)
The side with the operating engine is creating even more lift because of the accelerated air
flowing over the wing. When the flaps are extended, the drag caused by the accelerated
flow opposes the yaw caused by the inoperative engine allowing the pilot to use less rudder to maintain heading. Having more rudder available to the pilot lowers VMC.
It should be noted more lift on the right wing will cause a roll to the left. If ailerons are
used to counteract the rolling of the airplane , the drag from the adverse aileron yaw will
actually increase the yaw towards the inoperative engine.
82
How does weight effect VMC
- The horizontal component of lift (the force that causes the airplane to turn) will help
oppose the yaw due to an inoperative engine. The more weight, the more horizontal lift is
available to oppose the turn from the inoperative engine.
- This means that horizontal lift can be used along with rudder to stop the turn. When more
horizontal lift is available, less rudder is needed, which means more rudder is available to the pilot and VMC decreases. So, as weight increases, VMC speed decreases. As weight
decreases, VMC increases.
83
How does the direction of the relative wind affect drag
Anytime the relative wind is not parallel to the longitudinal axis of the airplane more drag is created
84
What happens if the critical engine fails
If the critical engine fails the resulting yaw and roll would be worse that if the non-critical engine had failed. The greater yaw and roll will require more rudder and control surface input to maintain directional control.
The result is less rudder is available to the pilot which increases VMC.
Performance will be worse because the greater control inputs the control surface deflection will cause a greater amount of drag to be created
