Vcef
Critical Engine Failure
- Speed at which one engine can fail and the same distance is required to either continue to accelerate to lift-off speed or abort to stop.
CFL
Critical Field Length
- Length of runway required to accelerate on all engines to (Vcef), experience an engine failure, then either continue to lift-off or stop.
Vmcg
Minimum Control Speed Ground
- 88 KTS
- Min control speed during takeoff run, at which, when an engine has failed and the other at TRT, it is possible to maintain directional control +/- 25 ft with three wheels on the runway and not exceeding 180 lbs of rudder force.
- PRIOR TO Vmcg PRIMARY FLIGHT CONTROLS ARE NOT EFFECTIVE
- Crosswinds and RCR may increase Vmcg
Vmca
Minimum Control Speed Air
- 89 KTS
- Min control speed in the T/O config out of ground effect, with one engine at TRT and the other out
- aircraft trimmed for T/O
- 5 deg AOB into operating engine
- 180 lbs rudder force
Vr
Refusal Speed
- Max speed that can be attained with normal acceleration, from which a normal stop may be completed within the available runway length
Vb
Maximum Braking Speed
- 14.8 MILLION FOOT-POUNDS
- Max speed the acft can be brought to a stop without exceeding the maximum designed brake energy
- acceleration check should be chosen with the speed resulting below Vb
Take-off acceleration check
- Should be adjusted to be at least 10 KIAS less than S1
- Always compute with split markers (S1 < Vrot)
S1
Go/No-Go Speed
- Committed to T/O at or above S1
- Equal to or greater than the higher of (Vcef) or (Vmcg)
Vrot
Rotation Speed
- from taxi attitude to a lift off attitude
- Vmcg < Vrot
Reference Zero
Distance to 50 ft
If S1 = Vrot:
T/O ground run + T/O flare = Reference Zero
If S1 < Vrot:
Critical Field Length + T/O Flare = Reference Zero
–> Compute acceleration check speed
Take-off speed
“The speed which permits attaining the obstacle climb-out speed at or before reaching the 50 ft obstacle height above the runway”
TRT
Take-off Rated Thrust
- Max allowable thrust (determined by % N1)
- Limited to 5 min
MCT
Maximum Continuous Thrust
- Max allowable thrust (determined by % N1) with no time limit
- adjusted every 5k ft
Vco
Climbout Speed
- scheduled single engine climbout speed
- based on 1.2 times the stall speed at the T/O weight
- should be obtained prior to 50 ft
- WITH BOTH ENGINES OPERATING, CLIMBOUT AT (Vco) + 10
Vt
Final Segment Climb Speed
- Flaps 10: (Vco) + 15
- Flaps 0: (Vco) + 5
- Climbout speed from 400 ft (1500 optional) above airfield elevation to the end of the take-off flight path
–> 125% of stall speed at T/O weight
S1 Equation
Vmcg, Vcef ≤ S1 ≤ Vr, Vrot, Vb
What do you need to be legal to takeoff per the 11-2T-1 V3?
6,000 ft min for takeoff (may NEVER be lower than CFL)
What do you need to be legal to land per the 11-2T-1 V3?
6,000 ft min for takeoff (may NEVER be lower than computed landing distance)
Assumptions for T/O data (IFG)
- No tailwind
- No slope
- Anti-skid on
- 1500 climbout profile
What distance from the AF/D are you particularly concerned with during a touch and go?
LDA
