Critical engine (jet)

[Chris Scott]

Old hats

Hello Buenos Aires,

Do I detect a certain frustration in your post last night?
[ Fifty-odd threads, and still trying to define/understand what is a "critical engine"...? ]

Your post Of Feb21 was not in vain: many of us got a timely reminder of the dangers of using tiller-steering during the take-off (and landing) run. Also, you pointed out the crosswind effect that D. P. Davies, presumably, had incorporated into the UK ARB (CAA) figures for VMCG (and VMCA ?). Why not the FAA? Sounds like politics.

So your post was not lost on all of us. For the benefit of those who missed it, and may not be inclined to turn back the pages, I hope you will not mind me reposting some extracts from what you wrote...

Quote from BelArgUSA [Feb21/22:12]:

We have concluded that the procedure to "guard the tiller" during the takeoff roll to 80 knots increased the likelihood for overcontrol of the nosewheel, and that we should eliminate the procedure. From then on, our procedure changed to instruct the captain not to guard the tiller, and place his hand on the wheel, after alignment for takeoff on the runway. I was instructed by the chief pilot to effect the new procedure to all types (747, 737, MD-80 and A-310s), effective immediately. There were no further problems since the procedure changed.

Further, "elevator down" to "increase nosewheel effectiveness" is worthless. It is obviously worthless at low speeds, worse, it does increase aerodynamic drag at higher speeds. Directional control should rely only on aerodynamic forces, once the aircraft starts rolling for takeoff. Elevators are kept in a "neutral/faired" position.

...the British CAA accounts for crosswind effect on VMCG. In the case of 747-200/300s as an example, in the minimum V1 speeds (restricted by VmcG), speeds in the FOM/QRH are different in airplanes certificated as per FAA and CAA.
VmcG/V1 speeds are higher for CAA certification.

[Unquote]

I know what you mean about back-seat syndrome...
Chris