Hi Silverhawk, Regarding your B737 reverse thrust useage after landing with one engine inoperative - Not So!
Boeing does not recommend any particular use of one engine out reverse thrust after landing. They just say that each individual airline should develop their own procedure, and practice that procedure in training sessions.
I don't think any operator would suggest such an extreme procedure, it's simply way to dangerous, most, I believe, would use only idle reverse on the operating engine, and auto brakes to suit the conditions.
When I flew the 767 our Flight Ops recommended a higher autobrake setting and a reduction in use of reverse thrust (idle). After all don't they combine to produce a set retardation rate ?
Now I'm on the 737 our operation wants full use of reverse thrust. Hence I agree it appears Mr Boeing has left the final decision to the individual operators think tanks.
Silverhawk- I qoute from the Boeing FCTM for the 737, Revision 2 dated 31 Oct 2002, Page 4.88:
" Asymmetrical reverse thrust MAY be used with one engine inoperative. Use normal reverse thrust procedures and techniques with the operative engine. If directional control becomes a problem during deceleration, return thrust lever to reverse idle detent."
Also reverse thrust is not taken into account for you landing distance certification.
Well, I'm for using as much reverse as I can control after touchdown when the brakes are in a high-energy zone. Use of lots after touchdown, when there is normally plenty of rudder control and it is most effective, will save the brakes a bit for later in the roll. There are no directional control problems at high speed, and if the crosswind is howling or the ice is thick, a) perhaps you should not be there and b) use less.
'Until a safe stop is assured' are good words. Surely no-one is suggesting that you keep max reverse on as you slide off the runway
Can't recall the last time a 737 sim of any description tried to head for the ditch whilst in max asymmetric reverse thrust. Only time in the aircraft was completely controllable, but that is what you would expect. N'est-ce-pas?
Dont forget that with a single engine approach you will be using flaps 15 rather than 30/40 for a normal landing which gives an increase in approach speed and landing distance so briefing for full reverse on the operating engine is not a bad thing.
In practical terms if you use autobrake and don't float too far then you may call for reverse idle before full reverse actually bites.
Yup, Having actually landed a 737 on one engine, I CHOSE to use full reverse knowing it was my choice, and could be reduced at any time. (20-25 knots crosswind) Absolutely no directional control problems, not even a little bit, zilch, zero! Of course an icy runway might be a tad different, but that's precisely why we have a choice. ( If you are landing on an "icy" runway on one engine then you are having a bad day) It's called common sense, professionalism, airmanship, etc.
From what I recall, the Auto Brake system, set at anything less than 'MAX', gives a certain rate of deceleration NOT a fixed amount of braking pressure (got them written down somewhere). Thus when using Auto Brake PLUS Thrust Reverse the Auto Brake system bleeds of the brake pressure to maintain that given rate of deceleration.
Perhaps this is why it is still controllable with N-1 reverse thrust. I dont know if the auto brake system is sensative to assymetry or not (ie deceleration per wheel bogie or just total deceleration).
MAX Auto brake plus Reverse Thrust might be a different story!
hi all, The boeing B737 Flight Crew training manual simply states that you use single engine reverse thrust as you normally would, pointing out that a reduction to reverse idle may be necessary if directional control problems are encountered (not their words!) There are no words in there at all that require any particular course of action. Hope this helps, Cheers
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