redflyer From United States of America, joined Feb 2005, 4177 posts, RR: 30 Posted (1 year 6 months 2 weeks 6 days 18 hours ago) and read 2438 times:
Was watching this video of an LH 744 cockpit during a take-off. Noticed that when the call was made for gear up, the pilot not-flying, which was the captain, reached over the throttles, pushed the LG lever up, then pulled his arm back over the throttles when he was done. The PF, which was the co-pilot, kept both hands on the yoke.
I have two questions for the experts:
1. Isn't there a chance that the PNF's arm could have hit the throttles and accidentally pulled them back, however slightly, when he was retracting his arm? I realize if it happened it would have been momentary and easily rectified, but it would have been a distraction nonetheless and at a critical point in flight.
2. Why not have the PF in this instance, and who was sitting closest to the LG lever, just reach over and throw the lever? I mean, is there a reason he was flying with two hands? Company policy?
The sequence I'm referring to occurs at about the 4:50 mark in the video.
RoseFlyer From United States of America, joined Feb 2004, 8740 posts, RR: 52 Reply 1, posted (1 year 6 months 2 weeks 6 days 17 hours ago) and read 2390 times:
It is pretty common for the Captain to raise the gear when the first officer is flying. He has to reach over, but the landing gear lever is required to be in a position that is accessible to both pilots, so it is only slightly off center. There are other areas where the captain will have to reach beyond center to make inputs such as controls on the glareshield. In the case of the lever, the FO is occupied by flying the airplane at that time and is not preocuppied with the distraction of moving the gear and also monitoring the position of the gear.
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KELPkid From United States of America, joined Nov 2005, 5932 posts, RR: 4 Reply 2, posted (1 year 6 months 2 weeks 6 days 17 hours ago) and read 2388 times:
Quoting redflyer (Thread starter): 2. Why not have the PF in this instance, and who was sitting closest to the LG lever, just reach over and throw the lever? I mean, is there a reason he was flying with two hands? Company policy?
Probably company procedure...
I always love how older aircraft have the gear handle squarely on the copilot's side. A throwback to the days where the copilot was along for the ride and only did what the captain told hm to Glad CRM has advanced a lot since that time...
Quoting redflyer (Thread starter): 1. Isn't there a chance that the PNF's arm could have hit the throttles and accidentally pulled them back, however slightly, when he was retracting his arm? I realize if it happened it would have been momentary and easily rectified, but it would have been a distraction nonetheless and at a critical point in flight.
Yeah, but maybe LH, through their own CRM research, found it was more of a distraction for the PF to be manipulating the gear and watching the indication lights during a critical phase of flight? There are valid points to be made both ways...wonder if there was a critical accident somewhere along the way caused by distraction due to gear manipulation (other than the Eastern L-1011 lost over the everglades in 1973...).
Celebrating the birth of KELPkidJR on August 5, 2009 :-)
redflyer From United States of America, joined Feb 2005, 4177 posts, RR: 30 Reply 3, posted (1 year 6 months 2 weeks 6 days 16 hours ago) and read 2369 times:
Quoting RoseFlyer (Reply 1): In the case of the lever, the FO is occupied by flying the airplane at that time and is not preocuppied with the distraction of moving the gear and also monitoring the position of the gear.
Quoting KELPkid (Reply 2): maybe LH, through their own CRM research, found it was more of a distraction for the PF to be manipulating the gear and watching the indication lights during a critical phase of flight?
Good point you both raised, but the PF wouldn't have to monitor the indicator lights. He would only have to throw the lever. The PNF would monitor the retraction sequence and confirm gear up and locked.
But this brings up another thought I had, which was how would this sequence work on an Airbus, say an LH A340? Since the PF (assuming it's the co-pilot again) would have a free hand, would he throw the LG lever or would the PNF (Captain) still throw the lever?
BoeingGuy From United States of America, joined Dec 2010, 2307 posts, RR: 7 Reply 4, posted (1 year 6 months 2 weeks 6 days 14 hours ago) and read 2313 times:
Keep in mind too that the autothrottle was engaged. Pilots don't make a habit of just accidentally bumping the throttles, but if he did, the autothrottles would have immediately moved them back to the commanded position with minimal loss of thrust.
Starlionblue From Hong Kong, joined Feb 2004, 15870 posts, RR: 66 Reply 5, posted (1 year 6 months 2 weeks 6 days 14 hours ago) and read 2296 times:
Quoting redflyer (Thread starter): 1. Isn't there a chance that the PNF's arm could have hit the throttles and accidentally pulled them back, however slightly, when he was retracting his arm? I realize if it happened it would have been momentary and easily rectified, but it would have been a distraction nonetheless and at a critical point in flight.?
1. The throttles are pretty stiff so if he bumped them lightly they would probably not have moved at all. Even if they had moved, it wouldn't be by much. You can't just nudge them lightly. They require quite deliberate force and they will not keep going once pushed since there is friction all the way.
But ok. Say they had moved, say, an inch. We're talking a pretty big airliner with lots of mass, meaning lots of inertia. I'm guessing not much will have time to happen between the nudge and the time the autothrottles or the PF push the throttles back to their original position.
Also:
Quoting BoeingGuy (Reply 4): Keep in mind too that the autothrottle was engaged. Pilots don't make a habit of just accidentally bumping the throttles, but if he did, the autothrottles would have immediately moved them back to the commanded position with minimal loss of thrust.
Quoting redflyer (Thread starter):
2. Why not have the PF in this instance, and who was sitting closest to the LG lever, just reach over and throw the lever? I mean, is there a reason he was flying with two hands? Company policy?
2. Company policy indeed. It is procedure. the PF should not be distracted by raising the gear. He has his job and the PNF has his job. That way the PF avoids distractions.
Quoting redflyer (Reply 3): But this brings up another thought I had, which was how would this sequence work on an Airbus, say an LH A340? Since the PF (assuming it's the co-pilot again) would have a free hand, would he throw the LG lever or would the PNF (Captain) still throw the lever?
Same procedure. It's not about free hands. It's about not being distracted.
"There are no stupid questions, but there are a lot of inquisitive idiots." - from Citadel by John Ringo
BoeingGuy From United States of America, joined Dec 2010, 2307 posts, RR: 7 Reply 6, posted (1 year 6 months 2 weeks 6 days 13 hours ago) and read 2286 times:
Quoting Starlionblue (Reply 5): The throttles are pretty stiff so if he bumped them lightly they would probably not have moved at all.
That's only partially true for the 744. On Boeing Airplanes, the autothrottle servo motor has a clutch and it only takes about 5 lbs of force to move them with the autothrottle is engaged. Thus, it's easy to override the autothrottle if necessary in an emergency. One you take your hand off, or finish bumping it, the servo motors would drive them back to the commanded position.
Starlionblue From Hong Kong, joined Feb 2004, 15870 posts, RR: 66 Reply 7, posted (1 year 6 months 2 weeks 6 days 11 hours ago) and read 2233 times:
Quoting BoeingGuy (Reply 6): Quoting Starlionblue (Reply 5):
The throttles are pretty stiff so if he bumped them lightly they would probably not have moved at all.
That's only partially true for the 744. On Boeing Airplanes, the autothrottle servo motor has a clutch and it only takes about 5 lbs of force to move them with the autothrottle is engaged. Thus, it's easy to override the autothrottle if necessary in an emergency. One you take your hand off, or finish bumping it, the servo motors would drive them back to the commanded position.
Easy to move if you want to, sure. But if you just bump the throttles lightly they probably won't move. What I meant is that it takes force to move them AND they stop moving the instant you take your hand off. You can't just flick the throttles lightly with your fingers and have them fly off along the tracks. It takes deliberate and constant pressure.
Of course the autothrottles will also move the throttle levers as you say.
"There are no stupid questions, but there are a lot of inquisitive idiots." - from Citadel by John Ringo
CCA From Hong Kong, joined Oct 2002, 708 posts, RR: 14 Reply 8, posted (1 year 6 months 2 weeks 6 days 9 hours ago) and read 2199 times:
What if there is a failure of some sort and the PF is working hard flying, do you expect him to raise the gear?
If not, you better rewrite the FCOM and explain when he does and when he doesn't raise the gear for every possible failure and also procedures for which nothing is written.
This is why he doesn't raise the gear the PF has 3 jobs.
1. Fly the plane.
2. Fly the plane.
3. Fly the plane.
And when they don't, accidents happen as stated above.
tdscanuck From Canada, joined Jan 2006, 12709 posts, RR: 80 Reply 9, posted (1 year 6 months 2 weeks 6 days 7 hours ago) and read 2161 times:
Quoting redflyer (Thread starter): 1. Isn't there a chance that the PNF's arm could have hit the throttles and accidentally pulled them back, however slightly, when he was retracting his arm?
Yes. But there's also a chance that any pilot, at any time, could hit the throttles and pull them back (or push the forward). Pilots familiar with a type are very used to how to move in the flight deck to avoid whacking the numerous controls...try barking your head on the P5 panel on a 737 and, eventually, you'll learn to duck.
wilco737 From Greenland, joined Jun 2004, 8473 posts, RR: 78 Reply 10, posted (1 year 6 months 2 weeks 5 days 6 hours ago) and read 1975 times:
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I am FO on 744 of LH. I will write my reply as well
Our SOP's say: If you are handflying, you are handflying and nothing else. You touch the yoke and the throttles only. All others are job by the PNF... So reaching forward to the gear lever is a big nono when handflying!
The throttles doesn't move too easily, but it is not too hard as well to move them. And when the Captain bump on them and pull them back about an inch, that makes about 10% of thrust. But I am sure the Captain recognizes that at once, the FO as well and the Autothrust as well and readjust the 744 throttles. So nothing to worry about.
And bumping on the throttles can happen as well if the Captain sets the flaps. When I am handlying, I have one hand on the throttles, one on the yoke. And now imagine the hand of the Captain has to read over to set the flaps from up to 1.... Not so easy for him to reach. But I am not allowed to set them myself when PF.
dogbreath From United Kingdom, joined Mar 2008, 237 posts, RR: 0 Reply 11, posted (1 year 6 months 2 weeks 5 days 4 hours ago) and read 1950 times:
Having flown Boeing's (B747 Classic's and B738) for 15 years and 10,000+hrs, the issue you're writing about has never happened to me once. So the risk of the Thrust Levers being inadvertently knocked is extremely low, and as been mentioned plenty of times above, not of great concern due Auto-Throttle and monitoring of systems by the PNF/PM.
ThrottleHold From South Africa, joined Jul 2006, 622 posts, RR: 1 Reply 12, posted (1 year 6 months 2 weeks 4 days 2 hours ago) and read 1807 times:
Quoting BoeingGuy (Reply 4):
Keep in mind too that the autothrottle was engaged...... the autothrottles would have immediately moved them back to the commanded position with minimal loss of thrust.
From 80kts until 400' aal, the autothrottle is in HOLD mode and the autothrottle drive motors are de-powered. Manual movement of a thrust lever will cause the thrust on that engine to change. At 400' it reverts to THR REF.
mandala499 From Indonesia, joined Aug 2001, 6180 posts, RR: 74 Reply 13, posted (1 year 6 months 2 weeks 3 days 21 hours ago) and read 1745 times:
Quoting redflyer (Thread starter): 1. Isn't there a chance that the PNF's arm could have hit the throttles and accidentally pulled them back, however slightly, when he was retracting his arm? I realize if it happened it would have been momentary and easily rectified, but it would have been a distraction nonetheless and at a critical point in flight.
Yes, there's always a chance. But... the other replies is clear enough...
Quoting redflyer (Thread starter): 2. Why not have the PF in this instance, and who was sitting closest to the LG lever, just reach over and throw the lever? I mean, is there a reason he was flying with two hands? Company policy?
It's not about 2 hands on the yoke or not... the PF flies the aircraft, the PM assists... This is on a 777... http://www.youtube.com/watch?v=-8a6qbF9ECg
Notice, same thing. 2 hands is for rotation. It gives better control for both pitch and roll.
Quoting redflyer (Reply 3): But this brings up another thought I had, which was how would this sequence work on an Airbus, say an LH A340? Since the PF (assuming it's the co-pilot again) would have a free hand, would he throw the LG lever or would the PNF (Captain) still throw the lever?
Still PF flies, PNF does the other stuff, including raising the landing gear.
Mandala499
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Glad CRM has advanced a lot since that time...
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