CNN Reports FEDEX crash in Tokyo

[MGifos]

While I am more interested in the cause of the accident than the consequent effects, I have noticed that there are some comments suggesting that the failure of the LHS Main Gear directly caused the LHS Wing to fail. While this may be correct, it is also likely that the failure of the LHS Main Gear caused the LHS Wing and Engine to contact the ground with forces likely to separate the Wing from the Body. So discussions of design issues related to failure modes of the Main Gear may not be relevant, because it is likely that the failure of one, rather than two Main Gear that is likely to be the main determining factor causing a roll to inverted.

[MD11Engineer]

From Muduckace, reply #242:

I have been with 3 MD-11 air carriers, I have held several positions, not a pilot but spent more than four years as a Maintenance Rep. or Flight Mechanic. Plenty of time to discuss with pilots and observe the aircraft charartistics.

To answer your question, the MD-11 was a reliability nightmare as it was cutting edge technology when first delivered. It had tons of "nuisance" pireps that did not have the support from MDC and especially Boeing to iron out all the issues in time. Boeing baught MDC to shut the MD-11 down to sell B-777's. Especially after the lack of tech support the guys on the line lost alot of support to resolve these issues.

EG: The fly by wire aircraft required constant monitoring of systems for given feedback (voltage and discrete) thresholds to log a failure. This was uncharted territory and as minimal faults generated by fault monotoring systems logged failures that were not actually significant but still out of design spec. It became a hard aircraft to maintain. Especially for PAX airlines who were operating many more aircraft that were not like it at all.

Fedex has been operating the aircraft for years and were able to apply the "nuts and bolts" approach to understand the aircraft better as they had been operating DC-10's for years as their "meat and potatoes" of heavy long haul aircraft.

I started out with an ACMI outfit that allowed me to work with DC-10's and MD-11's exclusively. This was great because the maintenance and flight crews could gain a better understanding of the aircraft. Flight crews became knowledgable of nuisance faults and maintenance could work better with them to resolve the issues for better reliability.

As my username implies, I also used to work on MD-11 freighters in maintenance for several years (not anymore since 4 years, because I changed jobs). In fact I'm holding an EASA Part 66 B1 licence on this type (among other types).
The MD-11 was the first aircraft for me where I really knew my stuff and even memorized the LAMS schematics.
A lot of colleagues hated the MD-11, but I have to say that they approached the work with a Boeing or Airbus mindset. The MD-11 IS different,it has different design philosophies (in fact, IMO the MD-11 rather resembles a big Cessna than an Airbus or a Boeing, and so far I have worked on products of all three big Western aircraft manufacturers). If you treat the aircraft as a Douglas and not as a Boeing or Airbus, and do the mainenace it requires, it isn't a maintenance hog at all. Our airline had some trouble because they bought a bunch of second hand aircraft from at the time bankrupt Varig and VASP and you could see that for the last years these airlines had been scrounging on maintenance and performed sloppy work. On the other hand the MD-11s we received from JAL were all in very good condition and rarely gave trouble.
For me the MD-11 seemed to be very straight forward and simple in design.
Talking to MD-11 pilots, sure, the plane seemed to have some quirks, but most of them loved to fly this plane.
I just hope that my current employer signs a maintenance contract with one of the many MD-11 operators which frequent our airport, do that I can get my hands back on one.

[brit bus driver]

Whilst your scathing denigration of the modern-day first officer is undoubtedly a debate worth having, this is not the forum. I also think it is trite of you to say that this accident was caused - and could have been prevented - by the pilots; I was not aware that you were privy to more of the facts than the rest of us.

And I'll see your 3-jet wide-body command time, and raise you.

[What-ho Squiffy!]

MU, that is very interesting reading.

I'd take a tail scrape and arse kicking over a porpoise-and-rollover any day.

Maybe the books might be changed after this latest accident?

[bubbers44]

Bouncing and nose diving into the runway usually happens in the first 20 hrs of learning to fly not after thousands of hours of flying time. I hear the MD11 has a very small elevator so requires agressive movement to not let the nose rise with spoiler deployment but the crew knew that. Why did the nose get high enough to lift off again on the first bounce?

[CorpJetJock]

DC10/MD11 vs. the rest of the aviation fleet

In aviation, like any other aspect in life, things go wrong, people make mistakes. Aviation, being such a critical venue, safeguards are built in to mitigate these errors from causing catastrophies. Problem is, when McD designed the DC10, they were racing against the clock, the original scheduled intro of the L1011, and doing so on a minimal budget. There were inherent mistakes made and shortcuts taken, some were patched over the years due to accidents and incidents. But I believe the history has shown this design to be not as tolerant or forgiving of those everyday mistakes and failures, and prone to pranging badly over seemingly recoverable circumstances. Many of those accidents reports discuss design shortcuts and flaws vs. the Boeing and Lockheed competitors. Going cheap and in a hurry seems to always catch up with this airframe.

[captjns]

Many of those accidents reports discuss design shortcuts and flaws vs. the Boeing and Lockheed competitors. Going cheap and in a hurry seems to always catch up with this airframe.

Tuition comes at a very heavy price... not just money either.

[rottenray]

Not a pilot - and infrequent SLF...

There was a MD10/MD11 landing at McCaren in Vegas in 2005 which could have been similar - the aircraft touched, and a wing lifted because of serious ground level turbulence (what we commonly call "dust devils" here in the southwest) causing more lift on one side and nearly resulted in a wingtip touching the runway.

It made FOX and CNN, but I can't find anything at the NTSC site, probably because it wasn't a "real" incident. I don't recall hearing about any injuries or aircraft damage after.

(If anyone can recall this and comment, I'd appreciate it - I've tried finding the footage and can't. To me, it looked like that aircraft ran into a lot less headwind and some substantial crosswind at the same time.)

Seems like this one was a case of wind shear catching an MD11 at the most vulnerable point, and after watching this video a few times I start to doubt if any other frame would have fared much better.

My sympathies are with the families of the crew - I can't begin to imagine how it must be for them. Over-the-road truckers can now make nearly the same money and nobody umpteenth-guesses what they did when they're unfortunate enough to get killed on the job.

I've flown on MD11 several times and don't really recall anything bad about "the ride," although I have had to wait and transfer twice because of failures - an APU went south once, and "a problem with the navigation equipment" caused another.

As far as the comments regarding McDonnell, and Douglas, and Boeing - I don't know the full history of any of the companies, but it seems to me that at one point or another they have all built stellar aircraft.

It's sad that there is only room for 2 airframe makers now.

As a passenger, I've flown on DC8s, DC9s, B727s, B737s, A300s, A310s, A320s, B747s and B777s. And a slew of regionals.

What it really comes down to is the skill of the folks at the pointy end. And sometimes even skill can't overcome events.

Frankly, I miss the days when flying was part of the adventure of going somewhere, business or vacation.

...

[armchairpilot94116]

http://www.cad.gov.hk/reports/main1.pdf

The final report on the Ci MD11 crash in HK lends some insight into some of the MD11's characteristics while landing in difficult weather.

In that accident it was decided that a possible loss of headwind component along with the ATS powering engines down to idle by 35feet RA (per design) resulted in the RMLG contacting ground at 18 feet per second. This was beyond its design limit of 12 feet per second and caused the gear to shear off outwards resulting in right wing failure due to number 3 ground contact and subsequent aircraft inversion and resultant fire. It is noted that the left wing still had sufficient lift and contributed to the inversion of the aircraft. It was recommended that the MD11 not be flown on A/T while descending on final in possible windshear situations. And that perhaps the timely addition of power seconds before the main gear contacted could perhaps have kept the rate of descent within design limit and thus avoided this incident. However this passage is interesting to note:

"The simulator FCC was initially loaded
with the standard – 907 model FCC software used in the accident
aircraft, and a series of approaches were flown by a number of
Boeing and China Airline pilots, and by a HKCAD accident
investigator type-qualified on the MD11. During these approaches,
ability to flare the simulator below 50 ft using the technique
recommended in the China Airlines Operations Manual and achieve
a normal touchdown at a low rate of descent proved unsuccessful on
the majority of approaches flown; if power was manually applied late
in the flare, the rate of descent could be reduced but was still high at
touchdown. By comparison, and although the crosswind exceeded
the published limits for autolanding, successful autolandings could
be completed but involved an exaggerated pitch up to nearly 10°,
well beyond that which would normally be expected.
The China Airline’s co-pilot involved in the accident observed the
latter simulations. He subjectively assessed the simulated
conditions as realistic, except that he recalled the turbulence level
below about 150 ft as being greater on the accident approach than
even the highest level which could be set in the simulator.."

Leaving me to believe that the MD11 really is a handful in gusty crosswind landings. Could we call it "unsafe" even in such a situation given this latest Fedex crash and the Ci crash. The 1997 Fedex crash was in good weather but it was bounced during landing and improperly restrained? It takes way better then average ability to land this big bird safely in high winds or a bounce it would appear.

It was also interesting to note that the Captain left HK within days of the incident without reference to the local authorities or China Airlines and refused to be interviewed regarding this incident outside of later sending a prepared statement and answering some questions via fax. I understand he gave up flying after that. But in fact he seems to have done most things right that fateful night. Other then in hindsight he would've done better to have diverted in view of the knowledge of the crosswind gusting to 35 knots plus. The only mistake he seemed to have made in the actual landing is that he should have been on manual throttle control in the landing phase in order to be able to apply thrust during the fateful last few seconds. Maybe he really should've been flying another plane altogether that night? Perhaps a 777? I am just saying that the MD11 seems not the ideal aircraft in that kind of weather to land in, being so exacting in its requirements.

The latest Fedex accident really brought home how lucky the crew and passengers of the Ci HK incident were in surviving with only 3 deaths out of over 300 onboard.

The report gives these insights regarding the LSAS :

"
1.6.5. Longitudinal Stability Augmentation System
The aircraft is equipped with a Longitudinal Stability Augmentation
System (LSAS) which provides pitch attitude hold and limiting pitch
rate damping, automatic pitch trim, speed protection and stall
protection. LSAS is not provided when the autopilot is engaged.
Below 100 ft RA, and transparent to the pilot, LSAS is progressively
removed from the pitch control system.
LSAS holds the aircraft’s current pitch attitude if there is no force on
the control column and the bank angle is less than 30º. If the pilot
manually changes pitch attitude and then removes the control
column force, the aircraft will hold the new pitch attitude.
LSAS holds pitch attitude by deflecting the elevators up to 5º, and
the stabiliser is then automatically adjusted to relieve sustained
elevator deflection and maintain a full 5º of elevator authority.
LSAS also limits pitch attitude to less than 10º of aircraft nose down
(AND) or 30º of aircraft nose up (ANU). Below 15,000 ft, if there
is more than approximately two pounds (lb) (0.9 kilogram) of force "


This report had these comments in regards to the Fedex crash in Newark in 1997:



"1.18.8. MD11 landing accident – Newark International Airport, USA
On 31 July 1997, a MD11 freighter aircraft was involved in an
accident with similar consequences when landing at Newark
International Airport, New Jersey, USA. In that accident, which
occurred in good weather conditions, the aircraft also suffered
structural failure of the RMLG and right wing rear spar, and came to
rest inverted.
The US National Transportation Safety Board (NTSB) investigation
concluded that the probable cause of the accident was overcontrol of
the aircraft during landing. This involved elevator deflections
varying from 26º ANU to 18º AND, and resulted in an initial
touchdown that become airborne again followed by a heavy second
touchdown during which the structural failure occurred. The
second touchdown was in a 9.5º right wing down attitude with a rate
of descent at the RMLG calculated as 13.5 feet per second. "


This may help us understand this latest MD11 incident.

[denkraai]

LSAS

Below 100' RA the MD11 LSAS control law implements a pitch attitude limiting function.Also the PNL (positive nose lowering) function of LSAS pushes the nose down at wheel spinup.
My experience is that every landing on the MD11 varies greatly with flapsetting, CG value, and wind (especially X-wind), and overspeed makes it very difficult to land.

[Machaca]

Douglas’ landing gear design philosophy for the DC-10 and MD-11

Excerpts from NTSB Report on N611FE accident in 1997, which includes a Submission of Proposed Findings by Boeing’s Long Beach Douglas Products Division:

Because a fuse [pin] in the vertical plane may not prevent substantial loads from
entering the wing structure once the fuse has released, and because the review of
historical data indicated that failure due to overload was most likely to occur as a
result of high drag loads, a different approach was taken to assure fuel tank
integrity for the high vertical load (above 2.0 g’s) condition. For vertical loads
above 2.0 g’s, the [MLG] is not designed to separate from the wing. Instead, the
landing gear and its back-up structure are designed to be very robust, i.e., they are
designed to withstand significantly greater descent rates than the 12 fps (ultimate)
required per Part 25.723 (b). Analysis has indicated that for a maximum landing
weight, typical-landing-configuration landing, the MD-11 [MLG] can withstand
up to a 16.9 fps descent rate without bottoming the shock struts or failing its
backup structure including the wing rear spar. Similarly, for a rolled landing (8
degrees one-wing-low attitude, with lift equal to aircraft weight), the landing gear
can withstand up to 15 fps descent rate without bottoming the shock strut or
failing its back-up structure including the wing rear spar. 57

For ‘fused’ aircraft the (remaining) energy of vertical descent would then be
absorbed by flexing the low-side wing, or by some combination of exercising the
high-side landing gear, and flexing the low-side wing. For some combinations of
sink and roll rates the low-side gear may fuse (followed by the wing
engine/nacelle) and the aircraft may ‘settle in’ on the remaining gear and the lowside
wing without compromising fuel tank integrity. For higher sink and roll rates
(or lower amounts of wing lift) the low-side wing may fail nonetheless, as a result
of exceeding its flexure (bending) limits.

57 Boeing further stated in its submission that it had “begun an evaluation into the net safety benefit of installing a fuse for vertical overload in the DC-10 and the MD-11 [MLG]…that could take a year or more to complete.” Boeing also stated that it would include the Newark accident scenario in its study of the potential safety benefits of vertical fusing.

...it is most probable that, as a result of loads applied to the right [MLG] that were
substantially beyond design limits, the right wing structure failed. The failure
most probably initiated at the rear spar/bulkhead (trunnion) rib interface and
progressed through the primary wing box structure. As a result of this failure, the
right main gear trunnion moved substantially upward and aft with respect to the
trap [trapezoidal] panel fitting. This motion was sufficient to cause the fixed side
brace to bind against the pillow block footing, tearing the pillow block loose from
the trap panel. 63

63 The Boeing submission also noted that, according to simulations, “subsequent to the failure [of the spar web structure], the right wing twists substantially nose-down under the imposed loads. This twisting causes the right wing to ‘dump’ most of its lift and results in a sudden and substantial outboard motion of the right main gear bogie, caused by the fixed and folding landing gear side braces pivoting about their (common) attachment at the trap panel fitting attachment point.”

[SMOC]

There's is a video where you can see one fire truck's foam spray just being blown away in the wind before it's able to make contact with the A/C. This particular fire truck might as well not been there. I hope fire services learned something from the experience regarding the effect of strong winds and in future not just position themselves according to their SOPs. I also hope they practice during appalling weather which is more conducive to accidents.

[bugg smasher]

Re MD-11 handling in strong and gusty crosswinds, it is essential to carry power all the way to touchdown; some disconnect the autothrottles on short final, others hold the throttles forward (a technique I find counter-intuitive). More than a few pilots new to the type have been rewarded with bone crunching landings when, at 35’ RA the throttles go to idle as they are simultaneously kicking the crab out. (The ‘yard sale’ maneuver)

Spooled up engines also provide for a hasty escape should a nasty bounce occur.

That being said, she’s a fine aircraft, crisp at the controls, a pilot's airplane in every sense. Getting to know her just takes a little more patience than most.

[tubby linton]

What is the crosswind limit for the MD-11?

[MoodyBlue]

More than a few pilots new to the type have been rewarded with bone crunching landings when, at 35’ RA the throttles go to idle as they are simultaneously kicking the crab out. (The ‘yard sale’ maneuver)

I guess that's why the book (our book anyway) states that decrabbing should be done before the flare. Kicking out crab during the flare is a dicey proposition on this aircraft. Learning to consistently make safe xwind-landings is something that takes most pilots converting to the MD11 quite a bit of practice, some a lot of practice.

If, in an MD11 simulator, you do not flare and do not decrab, you will certainly make a bone crushing landing but it will not bounce (but remember it's just a simulator). However, if you make a last-ditch flare input at say 10 or 5ft (e.g., if the guy/gal next to you forgets to flare), you will pull the mains onto the runway hard and after that become airborne again. If you pulled hard enough, you will easily zoom up to 30, 40, 50ft. If you then do nothing for just a few seconds, the aircraft will nose over and start to roll, just like it appears to happen in the horrible video from Narita. Once this is in motion there's not much you can do. It is a sickening thing to do in the sim, and it unfolds quickly.
The only way out (again, in the sim) appears to be, as has been stated here, a go-around. After a bounce like this, full thrust ASAP and wiggle your way out with some delicate pitch-control until it starts flying again.

[Broomstick Flier]

Moody

Here is what I understand is a text-book x-wind landing with the MD11
YouTube - KLM MD-11 Crosswind Landing at Montreal

The nose down tendency often mentioned is not very clear to me on in, though.

Cheers
BF

[MoodyBlue]

BF

Here is what I understand is a text-book x-wind landing with the MD11
YouTube - KLM MD-11 Crosswind Landing at Montreal

The nose down tendency often mentioned is not very clear to me on in, though.

Yep, that's a classic. Decrab before the flare into a "one wing low", crosscontrolled position and flare from there. Takes a bit of practice but very satisfying if it works out well.

Re. the tendency of the nose going places - it used to be a pronounced nose up tendency, but this has been (mostly) suppressed by the Positive Nose Lowering feature of the LSAS. But still, depending on flap setting, CG, wind ánd what you did to the elevator just before touchdown, the nose may go up, down, or nowhere. The trick is to be prepared for any of the above and then land the nosewheel ASAP, and that is what appears to be demonstrated nicely in the video.

MoodyBlue

[bugg smasher]

Skinning Cats

I guess that's why the book (our book anyway) states that decrabbing should be done before the flare.

Yes indeed, a very sensible way to fly this machine, the autothrottles compensate for cross-control drag induced airspeed decay by increasing thrust. Another technique is to enter additional knotage into the FMC, above that determined by the tower wind formula, giving added energy protection.

Some of our IP’s teaching crosswind landings in the Mad Dog have had students straighten out at 500 feet, a very visceral, butt-in-trousers demonstration of required control input for a given wind condition.

Book or no, though, legislating technique into SOP is an industry practice often fraught with misinformed opinion.

[leewan]

Code:

I hear the MD11 has a very small elevator so requires  agressive movement to not let the nose rise with spoiler deployment

Er... can anyone explain why would the nose rise when the spoiler is deployed. When spoilers are deployed, lift is destroyed, weight is dumped onto the wheels, brakes applied, a/c sticks to the ground. Unless, of course if the pilot raises the pitch. Or is it something to with the wing of MD11 too far aft compared to other a/cs or the third engine.

[BreezyDC]

The Yomiuri Shimbun carries an article discussing the accident at Winds, handling seen causing jet crash / Analysts, pilots say MD-11 notoriously difficult to land, has history of problems : National : DAILY YOMIURI ONLINE (The Daily Yomiuri) that includes the usual array of aviation "experts" (which probably includes most of the supposition in this thread). It notes: "The Japan Transport Safety Board is to investigate the accident, and intends to pay particular attention to the model's handling."

Can anyone offer any insight into the JTSB procedures? Are they as public as NTSB, with processes including factual and probable cause reports?