Being perfectly honest, how could anyone, be they pilot or passenger, be comfortable flying in that thing, after its horrible history of crashes and problems, that it has been plagued with since its introduction decades ago?
UPS MD-11 Crashes on Takeoff
- Thread starter MolaKule
- Start date
Because most of the problems with this plane were early on and had been addressed. American 191 was really the fault of American's maintenance practices, the crash in the Antarctic was a navigation/pilot error, another one was a bombing....
United 232 was an engine that performed an unscheduled partial disassembly of itself... one could argue the layout of the airframe hydraulics played a huge role, and I wouldnt argue. But that tail engine.....
Its hard to make a case without being a bit pedantic, but really, most of the well-known incidents really werent an issue with the plane itself.
I'll hold my opinion on this most recent UPS accident until the final report is made public, although I've pretty much already made up my mind about it.
Truth is, I'd feel a whole lot safer climbing into an DC-10/MD11/KC-10 right now, as is, compared to a privately owned C172 or Cirrus or similar being flown by a weekend warrior with a little too much money in his pockets who flies 3-4 hours a month and thinks his name should be Maverick.
United 232 was an engine that performed an unscheduled partial disassembly of itself... one could argue the layout of the airframe hydraulics played a huge role, and I wouldnt argue. But that tail engine.....
Its hard to make a case without being a bit pedantic, but really, most of the well-known incidents really werent an issue with the plane itself.
I'll hold my opinion on this most recent UPS accident until the final report is made public, although I've pretty much already made up my mind about it.
Truth is, I'd feel a whole lot safer climbing into an DC-10/MD11/KC-10 right now, as is, compared to a privately owned C172 or Cirrus or similar being flown by a weekend warrior with a little too much money in his pockets who flies 3-4 hours a month and thinks his name should be Maverick.
- Joined
- May 9, 2023
- Messages
- 490
As much as it pains me to say so since I am a A&P mechanic, the American boys screwed up with 191. They didn’t disclose or uncover a design flaw. They took a shortcut and it had disastrous results.
MolaKule
Staff member
The AA191 crash WAS the result of improper maintenance, as per the NTSB report, since AA was trying to shorten the labor time needed to reinstall an engine. Proper maintenance procedures are there for a good reason.
However, as I conjectured in previous post #247, it is possible that the original stress analysis by Douglas for this fitting at this location may have shown the calculated stresses were lower than they should have been.
Take a look at post #35 here:
Look at the aft pylon mount, the spherical bearing, the forward and aft lugs, and the wing clevis. On takeoff, this area has various concentrated stress vectors that it has to carry and react to.
Last edited:
Take this one FWIW, but I spent the second half of my working career at an aerospace component supplier. We made, primarily, but not exclusively, water and waste system components/systems. Even though our stuff wasn't heavily stressed, our lead stress analysis engineer had a PHD, and his backup, was our lead Chief Engineer. Stress analysis is no BS.
It seems like how to properly attach an under-wing engine should have been worked out by then.
Was the MD11 the last tri-jet? The optimum number of engines on an airliner is two, unless they could be made perfectly reliable, then it would be one.
Was the MD11 the last tri-jet? The optimum number of engines on an airliner is two, unless they could be made perfectly reliable, then it would be one.
MolaKule
Staff member
In and of itself this would be true.
There are two lugs that contain or house the spherical bearing. It is believed that one or more of these lugs broke allowing the engine and pylon to rotate downward, breaking the front mount, and flipping over and above the wing.
However, continued operation would only further damage that bearing and stress those lugs. I think this was a progressive wear problem. The spherical bearing started to wear excessively, due to insufficient inspection and lubrication, placing further stress on those lugs.
My theory today is the two containment lugs were too narrow, and the spherical baring too small, for the type of material in which they were composed.
There are two lugs that contain or house the spherical bearing. It is believed that one or more of these lugs broke allowing the engine and pylon to rotate downward, breaking the front mount, and flipping over and above the wing.
However, continued operation would only further damage that bearing and stress those lugs. I think this was a progressive wear problem. The spherical bearing started to wear excessively, due to insufficient inspection and lubrication, placing further stress on those lugs.
My theory today is the two containment lugs were too narrow, and the spherical baring too small, for the type of material in which they were composed.
Based on a 2011 Boeing Service Letter to all MD-11, Boeing stated "failure of the spherical bearing would not result in a safety of flight issue."
GON
$175 Site Donor 2026
Would replacing these parts with the same parts on a scheduled basis provide you confidence for the air worthiness of this aircraft, or are you saying new/ bigger/ better parts should replace the parts causing this failure?
MolaKule
Staff member
So you're basically lowering your standards to what pretty much is the aviation basement, in order to establish a false comfort level, for flying on one of the most problem plagued commercial airliners in existence.
- Joined
- May 9, 2023
- Messages
- 490
All the tragic garbage was created for international travel. It’s always a good thing in the airlines to have redundancy. Nothing man-made will ever be perfectly reliable.
- Joined
- May 9, 2023
- Messages
- 490
Actually, if you go back and look at the data, the Boeing 737 series has the worst safety record. It’s more than double that of the MD11
What data specifically? I'm sure it is skewed in some way. If based on fatalities, then of course it is as the MD has been primarily freighter for quite some time while the 737 is passenger. The 737 is also flown in far more sketchy areas with sketch operators. And probably has far older units still flying vs the MD. I would hope at a minimum that we aren't talking raw incidents, but adjusting for quantity of aircraft and flight hours. A passenger 737 is in the air far more than a cargo MD-11 and sees more flight cycles.
The 737 had a couple of high profile MCAS issues and the media just couldn't stop ragging on Boeing. It became a way of getting clicks. It seemed as though the media were trying to implicate Boeing in non Boeing things for views. So of course, the perception from the public is that the 737 is a death trap. But look at Flight Aware and just see how many are buzzing overhead at any given time. Comparing safety records is like Warren Buffet counting couch change.
Sure, but look at the production numbers. They couldn't be anymore lopsided. Around 446 DC-10s, and 200 MD-11's were produced. That comes to 646 aircraft total... Compare that to 12,372, 737's delivered in total. You're talking over 19 TIMES the amount of airplanes. So yeah, more are going to crash.
Not sure what data you're referring to.
Here's a link to an authoritative presentation from Boeing covering hull loss and fatality rates from 1959 to 2024.
See page 13.
https://www.boeing.com/content/dam/boeing/boeingdotcom/company/about_bca/pdf/statsum.pdf
The MD-11 has a worse hull loss and fatality rate than do even the original 737-100/200 models and the 737-200 remains in service in limited numbers to this day. The DC-10 isn't much better than the MD-11 either. Indeed the only commercial airliner with a worse hull loss rate is the F-28. This is a little surprising in that in its later developments as the F-100 and F-70 the aircraft has a very low hull loss rate.
I said I'd feel a whole lot safer, I didnt mean to imply I'd necessarily be completely comfortable. And in the scenario I gave, the comfort level wouldnt be false either.
But I stand by my statement. You asked why people would get on one of these, and I gave my reason. A lot of the highly publicized issues with them werent a fault of the aircraft itself. Not to say its a perfect plane.....its got one of the worst records and we both know that. But thats a big relative. Do you still drive a car? Have you seen those numbers? Way, way worse than a DC-10 or MD11. Why would you still do that?
One could look at the number of venomous snakes in Arizona and ask why the hell anyone with a brain would live there, yet people do. Why? When you come up with an answer, cross out "bitten by a venomous snake" and scribble in "flying on a DC-10/MD11" and you'll kind of see where I'm coming from.
I agree 100%. This and your comment about the inspection schedule being too long.
None of the incidents listed on the F28 wikipedia page are mechanical failures. It's all pilot error, weather/icing, one blown tire, and one contaminated fuel. Seems a remarkably safe plane from the criteria of "is anything vital going to break down / blow up / fall apart?" Regional jet pilots may not be very good though.
Last edited:
Similar threads
