Quote:
Originally Posted by N121PP
W0X0F, I wanted to let you know, your thread came in pretty handy last Thursday, 4/21/2011. I was on AA1962 MD80 PHX-DFW. We had an engine failure right at V2. I have to say, it was the most nervous I have ever been on a flight. I noticed right when the forward wheel lifted off, the left engine sounded like it powered down. We struggled to get in the air, stayed at about 2000' AGL, circled back and landed in the opposite direction that we took off from, all in about 10 minutes. Can you take me through what the pilots did as this occurred at what I suspect was the most critical part of the take off roll? The pilots did a great job and while we stayed unusually low, I didn't feel any unusual movements like I thought I would when losing an engine. After I realized the pilots where in control of the aircraft, my main concern turned to our landing weight, but I assumed you can't circle on one engine and it's better to get on the ground regardless of the weight of the aircraft? Thx!
http://www.azcentral.com/community/p...-0421abrk.html
You're ahead of me on this one, N121PP — I've never experienced a real engine failure at liftoff. (BTW, this is at, or just after, V1, not V2. V1 is the speed at which we are committed to flying; V2 is the initial climb speed we use right after takeoff. We normally hold this speed, or close to it, until 1000' agl.)
When we have an engine failure before liftoff (but at or after V1), we slow the rotation rate on purpose to gain some speed and also to establish proper rudder input to counteract the asymmetric thrust. If it was hot and the airplane was heavy, the initial climb would be lethargic and might be only 200-400 hundred feet per minute rather than the usual initial climb rate of >2000 fpm. Once they start climbing, the non-flying pilot will call "Positive rate" and the flying pilot will call "Gear up."
After establishing directional control and rotating for takeoff, little is done before 400' agl. The flying pilot has all of his attention on maintaining a positive rate of climb and not straying from runway heading (or whatever heading is dictated by the particular departure procedure). He will accelerate to V2 and hold that until 1000'. The non-flying pilot will announce the problem, e.g. "Looks like we've lost the left engine." During this initial climb, the flying pilot might ask the other guy to give him some rudder trim in order to relieve the amount of force he has to maintain during the climb. About 15 units of trim into the good engine is needed to trim out the rudder pressure during the climb (we rarely use more than one unit of rudder trim during normal two-engine operations).
At around 400' agl, the flying pilot will call for the engine fire or failure checklist and ask the non-flying pilot to declare an emergency. The non-flying pilot will perform certain actions from memory and then consult the QRH (Quick Reference Handbook) for additional steps. Any action that requires a movement of a control for the failed engine will first be confirmed by the flying pilot before the action is completed. For example, one step would be "Thrust Lever for affected engine - ****** to idle." It would be really be bad to pull back the wrong thrust lever, so as the non-flying pilot reads this step and puts his hand on the thrust lever, the flying pilot will glance down and say "Confirmed" before the non-flying guy actually moves it.
At 1000' agl, the pilot will lower the nose slightly in order to accelerate so they can get some flaps up. He might also ask the non-flying guy to take out some of the rudder trim (as the airspeed increases, the rudder becomes more effective and less is needed to maintain directional control).
At this point, the decision would be made about whether they can return to land at the airport they took off from. If the weather was too low for landing, they might have to proceed to another airport. In that case, they would bring the flaps all the way up and accelerate to 250 kts and, of course, continue the climb. For an immediate return, they would probably only accelerate to 180-200 kts and leave some flaps hanging (5° in the 767; I think it was 8° in the MD-88).
Now they've got some things to do before landing: talk to the flight attendants, the passengers, the company and ATC.
For the flight attendants: for any emergency, we give them the type of emergency, how much time is remaining before landing (i.e. how much time they have to prep the cabin), whether or not an evacuation will be required and any special considerations (e.g. if the left engine is on fire, we probably want to avoid using emergency exits on the left side of the plane).
For passengers, we of course want to tell them to "Sit back, relax, and enjoy the flight." Ha ha...kidding. Everyone here knows I
hate that phrase, right? No, we'll tell them what we can about the situation, being mindful that we don't want to cause panic. We'll stress that it's under control and to pay close attention to the directions of the flight attendants.
For the company, we will call and tell them we're returning to land and give them the nature of the emergency. In a pinch, we can just ask ATC to "notify company" and they'll do it for us.
For ATC, we just have to tell them what our intentions are. We will get very good service once an emergency is declared.
[BTW, in sim world we gloss over all this during emergency training by just saying "Two in, two out" meaning we've talked to FAs and Pax (two in) and company and ATC (two out).]
We also have to accomplish the "After takeoff checklist" and the "Descent/Arrival checklist". A single-engine landing will have some special considerations, notably reduced flap setting and higher approach and landing speed, and this will be specified in the QRH checklist we ran for the situation.
The last consideration is landing weight, but we'll land overweight in an emergency. The MD-88 has no fuel dump capability, so the only way to reduce landing weight is to tool around the sky at high power settings. For some types of emergencies, this might be acceptable but I don't think any of us want to spend any more time than we have to on one engine.
Quote:
Originally Posted by chiglet
I'm sure W0X0F will answer this but one thing I'd like to point out is that since the MD-80 has fuselage mounted engines, the asymetric thrust would be less than if you were flying in a type with wing mounted engines.
Oh, and typical of aviation (mis)reporting, doesn't an engine deliver power rather than receive it?
True about the fuselage mounted engines, but the asymmetric thrust is still an issue. It's not like they're centerline thrust.
And I agree with you on the reporting. The problem was with the power being produced or delivered by the engine. I'm kind of surprised this got by an editor.
Last edited by W0X0F; 04-27-2011 at 02:11 PM.