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(Video) NTSB Chairman's Thursday Briefing on Asiana 214
On Thursday afternoon, the NTSB Chairman discussed the status of the investigation and provided in-depth information on the accident flight. (www.youtube.com) Daha Fazlası...
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" One has to wonder if the gear would have cleared the seawall if PF had kept the nose down in those last few seconds instead of pulling up."
Actually been wondering this all week.
It would be good to know what the optimal attitude should be for a large jet (777) with minimal attitude and ridiculously low near-stall speed to get the highest altitude possible.
Nose up - hail mary attempt in hope that trust will spool up in time.
Level - to increase lift quickly and minimize altitude loss
Pointing slightly down - to increase lift as quickly as possible, with some continued loss of altitude but in a more controlled way.
Would it have have aerodynamically possible to actually land the aircraft at the last minute when they first spotted the decreased airspeed? If so, which of the above options in attitude would have been most likely to get them the best chance of 1) entirely clearing the sea wall and then 2) having the closest to a non-disruptive landing, no matter how rough.
Completely clearing the seawall at near stall speed with engines that are just beginning to be spooled up could lead to a quite unremarkable landing (apart from the underwear change) with the entirety of a quite long runway to cone to a stop.
Actually been wondering this all week.
It would be good to know what the optimal attitude should be for a large jet (777) with minimal attitude and ridiculously low near-stall speed to get the highest altitude possible.
Nose up - hail mary attempt in hope that trust will spool up in time.
Level - to increase lift quickly and minimize altitude loss
Pointing slightly down - to increase lift as quickly as possible, with some continued loss of altitude but in a more controlled way.
Would it have have aerodynamically possible to actually land the aircraft at the last minute when they first spotted the decreased airspeed? If so, which of the above options in attitude would have been most likely to get them the best chance of 1) entirely clearing the sea wall and then 2) having the closest to a non-disruptive landing, no matter how rough.
Completely clearing the seawall at near stall speed with engines that are just beginning to be spooled up could lead to a quite unremarkable landing (apart from the underwear change) with the entirety of a quite long runway to cone to a stop.
PhotoFinish, if you read the few posts below your above questions are answered.
Thanks, Steve.
I did read the posts below. I may have even read yours twice. It was quite dense with information.
The issues you raised in your post reawakened my curiosity in the issue.
I have since read a post elsewhere by a glider pilot that suggests that:
1. When slow and trying to avoid an obstacle, aim for a point just above your obstacle and give it all you've got (75%+ power). You want to use build up as much speed and lift as possible. Let gravity help you. Certainly don't fight gravity. Turning your nose up before attaining speed would actually cause you to lose altitude faster, as doing so would put you into a stall.
2. Then lift your nose at the last second for an extra bump up after you've built up as much speed as possible.
Notes:
Of course, a 777 has a large mass and momentum.
Your point about An attitude with a pitch up not necessarily resulting in decreased rate if descent is noted. However, my concerns are: the stick shook meaning they had 10 knots before stalling before pitching up, but probably entering a stall immediately upon pitching up.
They increased airspeed 4 knots with a putch up, buy may have gotten a more significant increase with a more optimal attitude.
And the concern about deck angle is a real concern. If only the rear gear and tail struck the seawall, then it seems that the plane may have entirely cleared the seawall with a less sever deck angle. The nose would've certainly been lower but the tail and gear would've been higher.
The landing would've still been a mess and would almost certainly still be considered a crash landing into the stop zone.
However, the forces applied to the aircraft and the passengers would've been significantly less, resulting in less damage to the aircraft and less severe injuries.
So sad to realize that 5 seconds was probably the only difference between crashing into the seawall and getting up to full thrust and just missing the seawall to then climb up into a go around procedure, hopefully to be followed by a successful landing.
It is not clear that the increase in altitude from the increased pitch up was greater than the increased loss of altitude from the more aggressive pitch.
Also, the engines only powered up to 50% so they were late to that party as well.
It is possible that they executed the only option they had (being they were in the last seconds before impact when the initiated corrective action).
And we are entirely in speculative territory.
And it would've been best had they monitored airspeed and altitude, and started corrective action sooner, which is the real moral of the story.
But it is fun to hypothesize about what might've been. Monday morning quarterbacking (or in this case piloting).
I did read the posts below. I may have even read yours twice. It was quite dense with information.
The issues you raised in your post reawakened my curiosity in the issue.
I have since read a post elsewhere by a glider pilot that suggests that:
1. When slow and trying to avoid an obstacle, aim for a point just above your obstacle and give it all you've got (75%+ power). You want to use build up as much speed and lift as possible. Let gravity help you. Certainly don't fight gravity. Turning your nose up before attaining speed would actually cause you to lose altitude faster, as doing so would put you into a stall.
2. Then lift your nose at the last second for an extra bump up after you've built up as much speed as possible.
Notes:
Of course, a 777 has a large mass and momentum.
Your point about An attitude with a pitch up not necessarily resulting in decreased rate if descent is noted. However, my concerns are: the stick shook meaning they had 10 knots before stalling before pitching up, but probably entering a stall immediately upon pitching up.
They increased airspeed 4 knots with a putch up, buy may have gotten a more significant increase with a more optimal attitude.
And the concern about deck angle is a real concern. If only the rear gear and tail struck the seawall, then it seems that the plane may have entirely cleared the seawall with a less sever deck angle. The nose would've certainly been lower but the tail and gear would've been higher.
The landing would've still been a mess and would almost certainly still be considered a crash landing into the stop zone.
However, the forces applied to the aircraft and the passengers would've been significantly less, resulting in less damage to the aircraft and less severe injuries.
So sad to realize that 5 seconds was probably the only difference between crashing into the seawall and getting up to full thrust and just missing the seawall to then climb up into a go around procedure, hopefully to be followed by a successful landing.
It is not clear that the increase in altitude from the increased pitch up was greater than the increased loss of altitude from the more aggressive pitch.
Also, the engines only powered up to 50% so they were late to that party as well.
It is possible that they executed the only option they had (being they were in the last seconds before impact when the initiated corrective action).
And we are entirely in speculative territory.
And it would've been best had they monitored airspeed and altitude, and started corrective action sooner, which is the real moral of the story.
But it is fun to hypothesize about what might've been. Monday morning quarterbacking (or in this case piloting).
The 4 knot increase in airspeed(update from 103 knots) right before impact and pitch up, was a result of engine thrust increasing......but as the saying goes. Too little, too late.
LOL. Yes, from the CVR, passenger testimony and video the go-around was actually initiated...just too late. Engine power was increasing and at aproximately 50% at time of impact. No information on power lever angle (PLA) after impact. The engines clearly shut down by impact. It was a crash and I seriously doubt the crew was concerned with the engine shutdown checklist. Initial engine inspection showed signs of high rotational force damage....meaning the engines were generating thrust at time of impact and stoppage.
Good point bravowren. Not just reverse command but because the gear are behind the center of lift, pitching up actually moved the gear lower. If he had held what he had or even pitched down they may have cleared the seawall and had a very very hard landing probably still bending if not breaking the airplane.
From passenger accounts we do know that there was rapid advancement of the throttles right before impact, and video shows a very high nose-up attitude on short final. One has to wonder if the gear would have cleared the seawall if PF had kept the nose down in those last few seconds instead of pulling up. When that slow, he must have been in the "area of reverse command", where pulling up actually increases your angle of descent. It takes some stick and rudder skills learned in emergency training to fight that human instinct to pull.