What's the truth about the MD11?

[Wickerbill]

I have heard from numerous sources that the MD11 is a difficult plane to fly and some have theorised that the relatively high accident rate of the type (8 or 9 write-offs?) may be the result of this. Most of this comes from people who have never flown the type, so I was wondering if any current or former MD11 pilots could share their opinion? Are they totally different to a DC10?

[service monkey]

Search, my son.

YouTube - Classic Movie Line #15 (http://www.youtube.com/watch?v=UXoNE14U_zM)

[muduckace]

From over the captains shoulder for 4 years and more than a decade around the aircraft. The key factor is that the aircraft performs differently, it is more demanding of a pilot under certain conditions.

Are they totally different to a DC10

The aircraft is very different, but this is not important. What is important is it has it's own set of parameters it operates within, when those are not respected hull losses are a result. You will find that the majority of losses (swiss air is still a mystery) are a result of human error. Is the aircraft more demanding?...Yes... Is the aircraft safe?... Yes when operated within it's means, just like any other machine.

[zerozero]

I don't think it's fair to include the Swiss Air accident in this discussion.

That accident was not the result of the typical MD11 hard landing then flip over syndrome we've seen so much of.

I don't want the thread to take a tangent on that accident either. I just thought it was important to point out because I'm also very interested in the question posed by the original poster.

[bugg smasher]

This subject has been explored extensively here on Pprune, do a keyword search on the MD-11, you'll find an entire book's worth of opinion provided by experienced MD=11 pilots.

[muduckace]

(swiss air is still a mystery)

Trying to be gentle as all other incidents I know of were pilot error. Probably the reason why (other than this topic being a dead horse) has not received a pilot answer yet. I am Sure the topic poster counted swiss air into his statement of hulls lost, so it is applicable.

My curiosity is centered on the lack of a complete investigation into FDX flt80 @ Narita. Seems odd a year has gone by plus some and a crash that had recorders found, video to watch and all pieces of aircraft accounted for had not been finalized.

That accident was not the result of the typical MD11 hard landing then flip


The bounce and flip should be a fedex trademark, Having only happened twice (EWR & narita), (corrected, oops I see air china has one as well)

The only TYPICAL problem that still remains despite FCC program changes is a pitch up upon ground spoiler deployment that is more harsh than in the DC-10 and most other airframes. As long as the pilot is aware of this tendency it becomes an operational characteristic that the pilot should be proficient in compensating for

[Wickerbill]

Thanks Muduckace for a succinct reply and also to service monkey for his jocular interlude!

[atpcliff]

Hi!

ALL large commercial aircraft have about the same accident rate, except for two aircraft.

The 737, 747, 757, DC-9 MD-whatever, Airbus 310, 320, 330, 340, DC-10, L-1011, etc., etc. have all about the same accident rate.

The Concorde is by far the worst, but that is not indicative of the Concorde's design: It is because they had the one crash when they ran over the CAL aircraft part that fell off the CAL plane onto the runway. Because there were so few Concourde's, the one crash skewed the accident statistics tremendously.

Then, we come to the 2nd plane that has the higher accident rate.

The MD-11's accident rate is SEVEN TIMES higher than the rest.

Question answered.

cliff
LFW

[SNS3Guppy]

Is that mishap rate based on per hours flown, or as a percentage of the fleet?

One can't realistically base an "accident rate" on the numbers of aircraft alone, but must take into consideration usage. Accordingly, I believe you'll find other aircraft which have in times past far exceeded either the Concorde or the MD-11, for loss rates.

[atpcliff]

Hi.

It is the accident rate per 100,000 flying hours. The comparison is apples-to-apples. The MD-11 is 7x more likely to crash than any recent Boeing/Airbus, and even MD/Douglas product, other than the -11.

I'm sure the accident rate for airplanes like the Comet and DC-4 and Ford Trimotor were higher.

cliff
LFW

[q100]

I've been avoiding weighing in, but here goes. Read the accident reports.

Yes there have been seven hull losses.

Swissair - improperly installed aftermarket IFE system with no way to shut it off...

Korean - Captain decided to put aircraft into a low-level, steep dive when he got confused over feet vs. meters (at a time when KAL was writing off 1 widebody per year)

FedEx over-run Subic Bay - surely you can't be serious about blaming the design.

Avient Shanghai - No official report yet but those in the know would tell you the design was probably not a factor (ask yourself why an aircraft would fail to get airborne on takeoff roll on 13,000' runway...).

That leaves the 3 roll-overs. Again, read the reports. I'll give you this though - The MD-11 is demanding and not terribly forgiving. She has a high wing loading and high approach speed and must be flown by the book. She does not like rough handling, and a bad or unstable approach is probably best salvaged by going around. The fact that the wing broke when design loads were exceed is not good - witness the BA 777 that glided into LHR for a better failure mode. However, if you want to be truly informed, read the reports find out why the design loads were exceeded. That said, of the three rollovers, including one aircraft full of passengers, there have been 5 fatalities. Douglas always did build robust machines...

[Wickerbill]

ah, now there 's a reply I was hoping for!

[atpcliff]

Hi!

q100: I hear you saying that many of the hull losses on the MD-11 were totaly crew error, and nothing was wrong with the plane?

My info is based on accidents per 100,000 flight hours. The info counted EVERY crash by EVERY airframe, per 100,000 hours. Do you not think that MANY 737/747/-320/MD accidents were also caused by 100% crew error, and had nothing to do with the plane?

It was an apples-to-apples comparison, and the MD-11 is 7x more likely to crash than any other large, commercial airframe out there flying today.

cliff
LFW

[q100]

Cliff,

Perhaps you read something in my post where I questioned your numbers and you therefore feel compelled to repeat your assertions with the use of CAPS LOCKS for good measure?

I did not question your numbers (although a statistic without a source probably should be questioned) - what I did was to look behind the numbers, and attempt to answer the original poster's original question, which that poster appeared to appreciate.

If you want to play with numbers, you could easily say that from 2000 to 2008 the MD-11 was the safest large airliner, with zero hull losses during that time frame. Or you could say that based on the last 12 months, the A330 is a deathtrap. Or say, as the media did when they leapt to the (false) conclusion that the Colgan 3407 crash was due to icing "that's the 3rd regional turboprop to crash in the US due to icing in the past 14 years" where it would also have been the 1st since the late 1990s if ice was indeed the culprit. Look how many 737s have been wrecked in the last few years for various reasons, but there sure are a lot of them flying. Safely. Or see how ugly the record of the A320 was in its first year before crews learned how to operate it properly, but there sure are a lot of them flying. Safely.

I hope you get my point, which is that statistics have context which should be considered. Same goes for the MD-11. Yes there have been hull losses, but that does not mean that the MD-11 is NOW (oops, caps lock) 7 times more likely to crash than any other airliner. Context again - the first 5 losses were in the span of about 26 months 1997-1999, and many things were modified, changed or learned from since then. Past is not necessarily prologue, and indeed the whole point to air crash investigation is to make sure of this.

Okay, I'll concede your point that the hull loss rate is 7x higher (which I never disputed, although I'm curious as to your source). What I do not concede that this is the whole story, "question answered," and that based on the past the MD-11 is in the future "7x more likely to crash.' Statements like that don't reflect well on you, and may not help you much if you are serious about getting hired by, say, EVA....:)

Fly safe and best of luck,

Q

[atpcliff]

Hi!

I would/will fly the MD-11 if that is the best job I can get. If EVA's T&Cs were better, I would apply (was applying, and stopped after I found out T&Cs). Would fly the MD for World (but would hope for the 747).

BUT, I feel that flying the MD-11 is riskier than it should be, and that the FAA improperly certified that aircraft. Relative to real life, the MD-11 is VERY safe, but I don't believe it's as safe as the other airframes, which is a shame.

On the other hand maybe it will turn out to be true that since the MD-11 is relatively new with not very many airframes flying, that the current accident rate is negatively skewed "abnormally".

Hopefully, it will turn out, in the long run, that the MD-11 is NOT 7x more dangerous than the other airframes!

cliff
LFW

[A.B.I.]

I was wondering, we do have a route request for one of our clients. At first it was a A300B4 they wanted but due to the tech. stops it would have to do, it would not make much of a profit to them. I was wondering if the MD-11 can be more economic on a 7 hour trip with msx. 60t loading.

[q100]

What are length and elevation of departure runway. Feel free to approximate if you are trying to keep secret....

Point is, that unless you are departing from a very performance-restricting field, the MD-11 will carry 60t for 7+ hours easily.

Q.

[muduckace]

The fact that the wing broke when design loads were exceed is not good

Why do you blame the machine when pilot decisions or environment that pilots decided to land in resulted in an exceedence of it's operating spec's.

Great aircraft, safe aircraft. Just needs responsible drivers...

[MD11F]

@muduckace
Well sayed,that is the truth:ok:,best regards MD11f

[HKAforever]

The MD-11's sales were limited not so much by safety questions per se, but mainly by the aircraft's inability to meet the original performance expected by the airlines. MD was also facing a cash crunch at the time and simply did'nt have the financial resources to build a better plane, even if they technically have the know-how to do so. It was unable to compete with the A330/A340s and the 777. Another reason for it's short production history is the fact that MD was taken over by Boeing in 1997, this meant it would be competing against Boeing's own products, so Boeing ended production in around 2001 I think.

Legitimate questions can be asked of MD-11's design such as the horizontal stablizer, etc. But the short production ofthe MD-11 was not driven by safety questions.

[q100]

Muduckace - you kinda quoted me out of context. As much a I love flying the 11 and am quite loyal to Douglas, I'd prefer after an excessively hard landing to see the gear come through the top of the wing ala BA @ LHR to seeing the gear stay attached but the wing break...

It's rare, and does seem to be the result of incorrect technique, but it's still happened 3x too often.

That said, to "achieve" that result, you REALLY have to slam it on.

So, no, I don't blame the machine. I do suggest that having the gear attach fail before the wing attach would be better! But if you my posts in their entirety, I think you'll find that on balance I'm an MD-11 defender.

[Embraer_Flyer]

I have heard from numerous sources that the MD11 is a difficult plane to fly and some have theorised that the relatively high accident rate of the type (8 or 9 write-offs?) may be the result of this. Most of this comes from people who have never flown the type, so I was wondering if any current or former MD11 pilots could share their opinion? Are they totally different to a DC10?

From talking to MD11 pilots, the plane also has less rudder authority when compared to other aircraft. My ERJ145, for example, lacks in aileron authority. This means that when landing in high crosswind we actually touchdown with full aileron deflection. Without it, you won’t land. In the MD11, I think this lack of rudder authority has caused issues because, as you know, when you kick the rudder and add a horizontal component of lift, you lose vertical component of lift as the plane only generates so much lift. I think this might play into what causes the plane to land very hard on one side, crushing one main gear and causing a roll over.

[C152gal]

And now, the MD11 even gets robbed (LH robbery yesterday).
DEFINITELY the unsafest airplane ever designed ;)

[ZFT]

From talking to MD11 pilots, the plane also has less rudder authority when compared to other aircraft. My ERJ145, for example, lacks in aileron authority. This means that when landing in high crosswind we actually touchdown with full aileron deflection. Without it, you won’t land. In the MD11, I think this lack of rudder authority has caused issues because, as you know, when you kick the rudder and add a horizontal component of lift, you lose vertical component of lift as the plane only generates so much lift. I think this might play into what causes the plane to land very hard on one side, crushing one main gear and causing a roll over.

Is this correct? I understood the MD11 had an abundance of rudder and this was even emphasised during upset recovery training.

[casablanca]

I flew the MD11 for 11 years...it was a tank! Yes the gear came through the wings but normally on the 3rd bounce with over 9g’s, which would probably happen to anything
Every crash was very similar in the fact that all started with a bounce, followed by pushing the nose down, unloading the wing and the plane would bounce very hard of nose wheel, followed by a 5g then a 10g touchdown....got ugly very quickly
The vertical stab was 40% smaller than the DC10 and any type of crosswind technique or cross control would often result in high sink rate, coupled with fact that autothrottles would retard at 50 feet, regardless of what speed was, so often needed to add thrust or block the thrust levers from coming back for few seconds
Despite all this , 99% of pilots who flew her still will say it was their favorite airplane

[N1EPR]

I flew the MD11 for5 years, mostly cargo. Its hand flying qualities left a lot to be desired. After clicking the a/p off there was still a lot of input to the flight controls by the computer system. Landings were fine, but an unstableized approach could cause more problems than in other types.


The systems were the best I have ever flown.

[stilton]

I flew the MD11 for 11 years...it was a tank! Yes the gear came through the wings but normally on the 3rd bounce with over 9g’s, which would probably happen to anything
Every crash was very similar in the fact that all started with a bounce, followed by pushing the nose down, unloading the wing and the plane would bounce very hard of nose wheel, followed by a 5g then a 10g touchdown....got ugly very quickly
The vertical stab was 40% smaller than the DC10 and any type of crosswind technique or cross control would often result in high sink rate, coupled with fact that autothrottles would retard at 50 feet, regardless of what speed was, so often needed to add thrust or block the thrust levers from coming back for few seconds
Despite all this , 99% of pilots who flew her still will say it was their favorite airplane



It’s very obvious the horizontal stabilizer is significantly
smaller on the MD11 than the DC10


But I don’t see what you’re saying about the vertical
stabilizer as being accurate, there’s no difference in
size between the two variants

[Anilv]

Nothing mentioned about what a pig it is to load? Well here goes..

Tail-tipping. Because of the engine at the back, the MD-11 is naturally tail-heavy. In my previous company, the empty CG was at 97.xx and the tail-tip limit was at 100. You had to be real careful when loading and offloading.

Load-planning. When all pallets were loaded up, the CG was way up in front. If you were loading general cargo you could plan your load so that you loaded your heavy stuff on the pallets which went in the aft hold (lower-deck) and rear contour zones (main deck). I did the load-sheet for one flight from Asia to Europe with a stop in SHJ. For the SHJ-Europe leg there it was not possible to add pax (crew family) as the aircraft would've been out of trim. A bit of bitching but in actual fact nothing was wrong!

But if this was a charter with all cargo having the same load density then you may have problems which had to be solved by leaving a few pallet positions empty.

While it is possible for the 747 freighter to tail-tip, the guys at Boeing saw fit to develop a tail-stand. On the MD11 you depended on the loading sequence. Some airlines mandated the use of a weight-cart as a fail-safe.

A loadmaster on an MD11 is constantly going going out on the main-deck loader to look at the nosewheel extension as this is a good gauge of how high the nose is. Oh, and a 6 inch step from the top of the passenger steps to the aircraft entryway can develop into 2 feet.

Anilv

[Flightmech]

I flew the MD11 for 11 years...it was a tank! Yes the gear came through the wings but normally on the 3rd bounce with over 9g’s, which would probably happen to anything
Every crash was very similar in the fact that all started with a bounce, followed by pushing the nose down, unloading the wing and the plane would bounce very hard of nose wheel, followed by a 5g then a 10g touchdown....got ugly very quickly
The vertical stab was 40% smaller than the DC10 and any type of crosswind technique or cross control would often result in high sink rate, coupled with fact that autothrottles would retard at 50 feet, regardless of what speed was, so often needed to add thrust or block the thrust levers from coming back for few seconds
Despite all this , 99% of pilots who flew her still will say it was their favorite airplane

I think you need to re-check your facts about the vertical stabiliser/fin being 40% smaller than the DC10????

[Setpoint99]

As I understand it, the MD11 has a super-critical wing, which reduces drag, but it therefore lands hot. How much faster is the 11's landing speed compared to the DC-10?