PERFORMANCE EXAM REVISION Flashcards
Define Balanced Critical Field Length (BCFL)
- What does it primarily depend on?
Is the total runway distance required to accelerate all engines to Vcef, experience an engine failure then either continue the takeoff or stop.
- Aircraft weight
Define VMCG
The minimum speed at which the aircraft my lose an outboard engine during the takeoff roll and maintain directional control
What factors is VMCG based on? (7)
- # 1 engine inop/windmilling on NTS
- Max TQ on all remaining engines
- Zero (or normal) bleed
- Flaps 50, 3000psi ruddber boost
- Max rudder deflection or 180lbs rudder pedal force (whichever occurs 1st)
- Max deviation from CL of 30ft
- Wings level
Define VMCA1
The minimum speed at which directional or lateral control can be maintained for a given configuration
What factors is VMCA1 based on? (7)
- # 1 engine inop/windmilling on NTS
- Max TQ on all remaining engines
- Zero (or normal) bleed
- Flaps 50
- Max rudder deflection or 180lbs rudder pedal force (whichever occurs 1st)
- 5 to the live
- Gear down
Define VMCA2
The minimum speed at which directional or lateral control can be maintained for a given configuration
What factors is VMCA2 based on? (9)
- # 1 engine inop/windmilling on NTS
- # 2 engine inop & feathered
- Max TQ on all remaining engines
- Bleeds off
- Flaps 50, 3000psi ruddber boost
- Max rudder deflection or 180lbs rudder pedal force (whichever occurs 1st)
- 5 to the live
- Gear down
- Utility hyds inop
How does nose-wheel steering effect VMCG;
- Steering available
- Steering available: additional directional control provided by nosewheel steering results in approx 20kt decrease in VMCG
How does nose-wheel steering effect VMCG;
- When to use NWS Not available graphs?
Graphs to be used when there is likely to be reduced control on the ground due to wet/icy/sandy runway conditions
Define Driftdown
If failure of one or more engines occurs during 4 engine cruise ops, due to loss of power the aircraft will need to descend.
What is driftdown based on? (4 & NOTE)
- Prop feathered
- Set 1010deg C
- Decelerate to driftdown airspeed (Best Lift:Drag - sep flashcard)
- Automation: IAS until 100fpm, then VS
NOTE: 3eng cruise ceiling increases as fuel is burnt
Driftdown airspeeds/RODs
- Descend until ROD decreases to 100fpm
- Maintain 100fpm until service ceiling is reached.
> provides max possible terrain clearance with some loss in range - If terrain clearance is not a consideration, continue 100fpm descent to cruise ceiling where flight = max range.
Define cruise ceiling
What is it based on?
The altitude at which the max rate of climb capability at MCP and best climb speed is 300fpm
- MCP
- Max rate climb
- 300ft ROC
Define service ceiling
What is it based on?
The altitude at which the max rate of climb capability at MCP and best climb speed is 100fpm
- MCP
- Max rate climb
- 100ft ROC
Define Vrot?
- Speed at which the aircraft will have sufficient acceleration capability to achieve Vto over time interval during which it is rotated to pitch attitude required for T/O
What Weight/Speed is Vrot based on?
- Either Vto or VMCA1 IGE - 5kts (whichever is higher)
- At approx 120,000lbs it changes from being based off of VMCA1 IGE to Vto
What are the GECs you can used for climb speeds (when calculating for 5,10,15,20,25k)
- 4 engine climb: -4kts per 5000ft
- !0,000ft climb speed is more or less equal to 3 engine climb speed
Landing performance numbers;
THRS speed
1.35 x power off stall speed
Landing performance numbers;
Max effort THRS speed
1.28 x power off stall speed
Landing performance numbers;
Touchdown speed
1.2 x power off stall speed
Landing performance numbers;
Min THRS speed
106.5kts
Landing performance numbers;
Appch speed
THRS speed + 10kts
How to calculate PA. Provide an example
- Calculate the difference between 1013 and ACTUAL QNH
- Times difference by 30 & TAKE from A/D elevation
E.g. elev 2700AMSL, QNH 1023 1023 - 1013 = 10 10 x 30 = 300 2700 - 300 PA = 2400ft
How to calculate DA. Provide an example
DA = PA + 120(TEMP - ISA TEMP)
E.g. elev 2700AMSL, QNH 1023, PA 3000ft, Temp 20
ISA temp at 3000ft: 15deg - (2x3) = 9deg
DA = 3000ft + 120(20-9)
= 3000 + 1320 (hotter so less dense)
= 4320ft
