It is not as much the failing of the MLG (although in a few cases at a fairly low limit, some at only 1100'/min), it is the way it fails: MLG fails -> wing(root) gets structurally damaged in the process (design) -> wing fails -> aircraft flips over -> ... a number of crashes show a similar pattern.
As far as the cause of these crashes: trained professionals establish the cause of a crash, I consider myself very lucky not having to establish cause. I just observe a pattern in the way the MLG failed on several of these crashes.
MLG failures due to hard landings on large civilian aircraft are rare AFAIK, but compare this pattern to f.i. the way the B777 wing gear failure at LHR (1700'/min if I remember correctly): right and left MLG collapsed, but the damage to aircraft -although substantial- was survivable to the passengers and crew (thankfully the worst injury was a broken leg). At the very least the wings were still attached to the hull (and the wing tanks remained largely intact).
But perhaps I am being a bit too outspoken on this issue (in which case I apologize); good people have died in this crash...
the MD-11 may not be a "dangerous" airplane as it has managed thousands of perfectly good landings. but, just the fact that you need specific training and honned skills does imply that the plane is less forgiving than your average 737 or... 747 (to stay in the "heavy" category). Since the error margin is narrower, it just becomes more difficult in tight situations.
Every transport category airplane requires specific training and skills to fly. The MD11 is no different in that respect. The MD requires no special skills. It does require strict attention to being very stabilized during the final approach and landing phase of flight. That is also true of all large airplanes. Any competent and experienced airline pilot should have no trouble with the MD11.
Most, if not all, of the landing incidents or accidents relating to MD11s can be traced back to an non stabilized approach or a destabilized landing.
Do you leave the auto-throttle on for cross-wind landings in the MD11 ?
In the Hong Kong accident , the approach was flown at 170kts (Vapp152) with the A/P off and the auto-throttle on. At 50ft, the system retarded the thrust to idle causing a rapid speed decay . One of the casual factors causing the accident, was the Captains inability to stop the rapid ROD at 50ft.
Could this be one of the factors in the Tokyo accident ?
What is the best cross-wind technique in this situation ?
Unless something has changed since I few the MD, the autothrottles start their power reduction at 47' AGL. The voice callouts are a subtle but an effective cue as to the rate of descent at that time. A rapid 50,40,30,20,10, would be indicative of a impending harder that desired landing. The AT retardation is easlily overridden IMO, and in and of it's self should not be a factor assuming your hand is on the throttles to begin with.
I do not reacll any specific AT guidelines for not using the AT's during crosswind landings. Maybe someone here with more recent time in the aircraft can correct me on this.
At Faro the decent rate was lower, but landed only on the RMLG which (with a high G-force) broke, wingtip hit the surface and the rest is history.
I recently spoke to a MD11 cpt who is also curios about this accident (due to the very high bounce), but also the ZSPD one.
One of the big causes of the Faro accident was the reducing of thrust to idle at 150 feet leading to a descent rate of 1000'/min which could not be arrested during a last second intervention of power by the captain(they were in a thunderstorm at the time).
Apparently the landing technique on the DC-10 with and without CWS is significantly different and the fact that the CWS was turned off quite low may have led to the abrupt flare.
The AT retardation is easlily overridden IMO, and in and of it's self should not be a factor assuming your hand is on the throttles to begin with.
Here's the problem - you're teaching your hand to override an automatic system.
And an MD-10 in a crosswind is a totally different beast. Much higher control forces. Throw in a female pilot and I think it's easy to predict - both hands on the yoke. Then the A/T's do their thing at 50 feet and you're sitting there at idle power with lots of yaw-induced drag.
MD was fixated on the A/T's with this airplane. I had an MD ground instructor tell me - the initial concept was no throttles at all - just a push-button engine system.
So, to answer the question, I'd say 90 % of the pilots I fly with never click off the A/T's on the MD11, ever. They override them when they feel the need.
I do not see any problem in overriding the AT's in this case and I would agree that most pilots tend to use the AT's through the touchdown and this is very comon in some Boeing aircraft.
As I recall you moving on up to the 777 soon. The AT system in the this airplane is very similar to the MD11 although it may react just a little quicker. Point here is that just becasue you have the automation working does not mean that you are not part of the solution in getting the airplane on the ground.
Where I flew the MD11 we encouraged the pilots that if they were inclined to turn off the AT's prior to touchdown, go ahaed and do it around 1000' AGL and get into the stck and rudder mode early in the game, thus not clicking them off at 100' and finding yourself not part of the game.
The recommendation from MDC (now Boeing) is that if the ATS is available, it SHOULD be used. This is different from the BAC philosophy - if AP is disconnected, ATS should also be disconnected.
Our company follows the MDC recommendation, so ATS generally always engaged.
Way back when... my IOE instructor was a MDC test pilot with the MD11 program and he also stated that if MDC had their way, the MD11 would have be installed with only start switches and no throttle levers per sic.
All FDX ramps throughout the network use the same W&B procedures same ppwk for DG etc,you also have two ramp agents doing the W&B(P.S.T) as for finding out the weight of each ULD&pos the origin station would have a printout of the maindeck&lower deck config and closeout slips for each ULD(including weight, dest etc)
Hi, just wanted to mention that in my company almost nobody is flying the approaches on the MD11 with autothrust. That means: very, very close to a 100%. That is the philosophy here in my company.
Also I would like to mention that there are speeds that need to be added during the approach at gusty or strong winds that might add up pretty significantly to the Vref. Just because this was stated further up (170 to 154kts Vapp ).
For me the MD11 is a very sporty aircraft and operating it, you all the time seem to be on the edge of the performance envelope.
Unless I'm doing an auto-land [CAT-II, CAT-IIIb] . . . I click off the automatics and handfly the approach with my left hand on the wheel, and I move my 4 thrust levers with my right hand. Why? Because it feels good to be doing something after 12 hours of doing nothing. Get it?
Glueball
Your problems are obvious:
The MD11 has THROTTLES (not thrust levers) and only THREE (not four).
(All said with tongue firmly in cheek)
Spooky 2
to answer your question (ATS and X-winds):
There are no restrictions, either in FCOM Limitations or Normal Operating Procedures requiring ATS to be disconnected with ANY cross-wind.
Having said that, here is an autopilot auto-land cross-wind limitation of 15 knots (max) (nothing to do with ATS).
Huck
I agree with you about overriding the ATS when necessary. What I have experienced is that the younger ones have their eyeballs glued to the speed trend and over-react to the trend (not the actual airspeed variances) by use of a fist-full of throttle and then massive and fast throttle retardation, instead of letting the ATS sort it out, which, for 99.9% of the time, does so without me getting an off-the-scale pukka factor.
In a strong crosswind, it is highly recommended to carry power all the way to touchdown. The autothrottles will reduce power at the programmed RA, regardless of cross-control induced drag and/or remaining elevator authority. With control wheel and rudder input approaching maximum throw at crosswind landing limits, said premature power reduction results in a landing very similar to that experienced by a set of car keys tossed out a fifth-story window.
Disconnect, or prevent them from retarding (a counter-intuitive push in my opinion).
Either that,or carry extra speed. The beast is already a very fast lander, even the longest runways sometimes become short, not my first choice.
to the 777 soon. The AT system in the this airplane is very similar to the MD11 although it may react just a little quicker. Point here is that just becasue you have the automation working does not mean that you are not part of the solution in getting the airplane on the ground.
Linear Mode
