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convair880mfan
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When pilots speak of a specific type of aircraft as "unforgiving" does that indicate a design flaw?

Wed Oct 20, 2021 5:20 pm

I am not a pilot or engineer or anything like that. I've read some debates here on the Forums on various aircraft types described with the adjective "unforgiving." This is a term taken from morality, ethics and psychology and then used analogically of aircraft. When an aircraft is described as "unforgiving" does that imply a deficiency in the actual design of the aircraft?

I'm also interested to know whether this video of an MD-11 crash is authentic or fake.

https://youtu.be/4Ey_3f_pyck

Not trying to denigrate the MD-11. It is one of my favorite aircraft!
Last edited by convair880mfan on Wed Oct 20, 2021 5:45 pm, edited 1 time in total.
 
GalaxyFlyer
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Joined: Fri Jan 01, 2016 4:44 am

Re: When pilots speak of a specific type of aircraft as "unforgiving" does that indicate a design flaw?

Wed Oct 20, 2021 5:43 pm

Real video of a real crash.
 
mxaxai
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Re: When pilots speak of a specific type of aircraft as "unforgiving" does that indicate a design flaw?

Wed Oct 20, 2021 8:03 pm

Not a 'deficiency' per se, but narrow margins for error and/or rapid changes in behavior despite overall similar situations. You won't usually notice it in regular operations but the design 'does not forgive' large deviations.

For example, some aircraft will give clear and early clues of an imminent stall, like buffeting, and feature a slow onset of stall, while others will stall abruptly with little to no warning. Not an issue if you take care to maintain sufficient airspeed, but 'unforgiving' if you do make a mistake. Trainers will usually aim for more 'forgiving' behavior at the cost of performance.
 
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Pythagoras
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Re: When pilots speak of a specific type of aircraft as "unforgiving" does that indicate a design flaw?

Wed Nov 10, 2021 7:10 pm

convair880mfan wrote:
I am not a pilot or engineer or anything like that. I've read some debates here on the Forums on various aircraft types described with the adjective "unforgiving." This is a term taken from morality, ethics and psychology and then used analogically of aircraft. When an aircraft is described as "unforgiving" does that imply a deficiency in the actual design of the aircraft?

I'm also interested to know whether this video of an MD-11 crash is authentic or fake.

https://youtu.be/4Ey_3f_pyck

Not trying to denigrate the MD-11. It is one of my favorite aircraft!


My partner spent a significant part of her career in aviation safety and would be considered having expertise in the field. Based upon statistical analysis and similarity of accidents, she believes the MD-11 to be an inherently dangerous airplane which is inappropriate for passenger operations.
 
DN4CAAD
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Re: When pilots speak of a specific type of aircraft as "unforgiving" does that indicate a design flaw?

Wed Nov 10, 2021 9:43 pm

Pythagoras wrote:
convair880mfan wrote:
I am not a pilot or engineer or anything like that. I've read some debates here on the Forums on various aircraft types described with the adjective "unforgiving." This is a term taken from morality, ethics and psychology and then used analogically of aircraft. When an aircraft is described as "unforgiving" does that imply a deficiency in the actual design of the aircraft?

I'm also interested to know whether this video of an MD-11 crash is authentic or fake.

https://youtu.be/4Ey_3f_pyck

Not trying to denigrate the MD-11. It is one of my favorite aircraft!


My partner spent a significant part of her career in aviation safety and would be considered having expertise in the field. Based upon statistical analysis and similarity of accidents, she believes the MD-11 to be an inherently dangerous airplane which is inappropriate for passenger operations.


Could you expand on this?
 
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Aaron747
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Re: When pilots speak of a specific type of aircraft as "unforgiving" does that indicate a design flaw?

Wed Nov 10, 2021 11:45 pm

convair880mfan wrote:
I am not a pilot or engineer or anything like that. I've read some debates here on the Forums on various aircraft types described with the adjective "unforgiving." This is a term taken from morality, ethics and psychology and then used analogically of aircraft. When an aircraft is described as "unforgiving" does that imply a deficiency in the actual design of the aircraft?

I'm also interested to know whether this video of an MD-11 crash is authentic or fake.

https://youtu.be/4Ey_3f_pyck

Not trying to denigrate the MD-11. It is one of my favorite aircraft!


I have no idea why one would even ask if that video is fake...
 
113312
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Re: When pilots speak of a specific type of aircraft as "unforgiving" does that indicate a design flaw?

Thu Nov 11, 2021 1:29 am

It's all too real. However, this version of the clip has had frames removed so I can see why you might think it's not real. This was an airport surveillance camera which also is not the best resolution. Colleagues of mine perished in that and very close associates participated in the field investigation. I was ready to go too but we were restricted as to how many safety reps we could send.
 
113312
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Re: When pilots speak of a specific type of aircraft as "unforgiving" does that indicate a design flaw?

Thu Nov 11, 2021 1:32 am

The MD-11 could turn a good landing into something else in a heartbeat. Too many factors to discuss in a forum. Other than KLM and World, they didn't stay with passenger operations very long.
 
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Pythagoras
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,

Thu Nov 11, 2021 7:58 am

DN4CAAD wrote:
Pythagoras wrote:
convair880mfan wrote:
I am not a pilot or engineer or anything like that. I've read some debates here on the Forums on various aircraft types described with the adjective "unforgiving." This is a term taken from morality, ethics and psychology and then used analogically of aircraft. When an aircraft is described as "unforgiving" does that imply a deficiency in the actual design of the aircraft?

I'm also interested to know whether this video of an MD-11 crash is authentic or fake.

https://youtu.be/4Ey_3f_pyck

Not trying to denigrate the MD-11. It is one of my favorite aircraft!


My partner spent a significant part of her career in aviation safety and would be considered having expertise in the field. Based upon statistical analysis and similarity of accidents, she believes the MD-11 to be an inherently dangerous airplane which is inappropriate for passenger operations.


Could you expand on this?


See the following hull loss accidents which occurred in a relatively small fleet.

FedEx N611FE, 31 July 1997
https://aviation-safety.net/database/record.php?id=19970731-0

China Airlines B-150 Flight 642, 22 August 1999
https://aviation-safety.net/database/record.php?id=19990822-0

FedEx N526FE, 23 March 2009
https://aviation-safety.net/database/record.php?id=20090323-0

Lufthansa Cargo D-ALCQ, 27 July 2010
https://aviation-safety.net/database/record.php?id=20100727-0
 
LCDFlight
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Re: When pilots speak of a specific type of aircraft as "unforgiving" does that indicate a design flaw?

Thu Nov 11, 2021 3:36 pm

DN4CAAD wrote:
Pythagoras wrote:
convair880mfan wrote:
I am not a pilot or engineer or anything like that. I've read some debates here on the Forums on various aircraft types described with the adjective "unforgiving." This is a term taken from morality, ethics and psychology and then used analogically of aircraft. When an aircraft is described as "unforgiving" does that imply a deficiency in the actual design of the aircraft?

I'm also interested to know whether this video of an MD-11 crash is authentic or fake.

https://youtu.be/4Ey_3f_pyck

Not trying to denigrate the MD-11. It is one of my favorite aircraft!


My partner spent a significant part of her career in aviation safety and would be considered having expertise in the field. Based upon statistical analysis and similarity of accidents, she believes the MD-11 to be an inherently dangerous airplane which is inappropriate for passenger operations.


Could you expand on this?


The statistical analysis would be frames lost per 100,000 departures. The MD-11 simply had more crashes per departure. Over time, there was enough data to establish this as a fact that future MD-11 flights have a greater probability of loss of control crash than a 777 or A330. Around ten times more dangerous AFAIK. The MD-11 was still probably safe enough for passengers -- almost -- if pilots are well trained. But the airplane has bad statistics compared to peers.

This is without getting into exactly why the MD-11 is more likely to crash, which (as another poster said) is so complicated, and relies on so much expertise that it is beyond our capability here.

In 2011, the US NTSB highlighted seven major landing incidents with MD-11, and advocated additional training. Knock on wood, the results in the recent decade have been better.

https://www.wsj.com/articles/SB10001424 ... 1608343706
 
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Pythagoras
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Re: When pilots speak of a specific type of aircraft as "unforgiving" does that indicate a design flaw?

Thu Nov 11, 2021 5:52 pm

LCDFlight wrote:

The statistical analysis would be frames lost per 100,000 departures. The MD-11 simply had more crashes per departure. Over time, there was enough data to establish this as a fact that future MD-11 flights have a greater probability of loss of control crash than a 777 or A330. Around ten times more dangerous AFAIK. The MD-11 was still probably safe enough for passengers -- almost -- if pilots are well trained. But the airplane has bad statistics compared to peers.

This is without getting into exactly why the MD-11 is more likely to crash, which (as another poster said) is so complicated, and relies on so much expertise that it is beyond our capability here.

In 2011, the US NTSB highlighted seven major landing incidents with MD-11, and advocated additional training. Knock on wood, the results in the recent decade have been better.

https://www.wsj.com/articles/SB10001424 ... 1608343706


If your solution to a safety problem is more training, you inherently have a safety problem. Reliance upon the human to always do the right thing is not a robust means of ensuring safety.
 
Zeke2517
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Re: When pilots speak of a specific type of aircraft as "unforgiving" does that indicate a design flaw?

Thu Nov 11, 2021 8:15 pm

Pythagoras wrote:
LCDFlight wrote:

The statistical analysis would be frames lost per 100,000 departures. The MD-11 simply had more crashes per departure. Over time, there was enough data to establish this as a fact that future MD-11 flights have a greater probability of loss of control crash than a 777 or A330. Around ten times more dangerous AFAIK. The MD-11 was still probably safe enough for passengers -- almost -- if pilots are well trained. But the airplane has bad statistics compared to peers.

This is without getting into exactly why the MD-11 is more likely to crash, which (as another poster said) is so complicated, and relies on so much expertise that it is beyond our capability here.

In 2011, the US NTSB highlighted seven major landing incidents with MD-11, and advocated additional training. Knock on wood, the results in the recent decade have been better.

https://www.wsj.com/articles/SB10001424 ... 1608343706


If your solution to a safety problem is more training, you inherently have a safety problem. Reliance upon the human to always do the right thing is not a robust means of ensuring safety.


True. Take the example of the 737MAX. You can blame the pilots or their training, but if you have an airplane that unilaterally decides to dive towards the ground without warning, there is something very wrong with the airplane.

Sometimes designs are just bad.

(Can of worms -> opened)
 
convair880mfan
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Re: When pilots speak of a specific type of aircraft as "unforgiving" does that indicate a design flaw?

Thu Nov 11, 2021 8:32 pm

I wonder if McDonnell Douglas should have just stretched the DC-10 or perhaps made a twin engine aircraft right off the bat.

The design of an aircraft is a job for many engineers. I would think the engineers at MD had plenty of expertise and experience with those with the most expertise and experience at the top tier of designers. So what went wrong?

The MD-11 seemed to have performance shortfalls from the very beginning. It didn't meet its range goals which put off a lot of MD believers like American Airlines and Singapore Airlines. Wonder why the top folks at MD didn't see the writing on the wall that the future was in twin turbine powered airliners. Problems seemed to go beyond the normal teething problems of new airliners. PIPs didn't seem to completely remedy the difficulties with the design.

Can there be problems that designers and wind tunnel testers cannot foresee? Approach and Landing characteristics. Takeoff characteristics?

I would like to think that it was just a matter of making a jet transport for a niche market that never materialized, like the Convair 880 did, but I think it goes beyond this.

I've flown on the Finnair MD-11 and thoroughly enjoyed the flights and have heard that the two-person flight deck automation was sweet, but I just wonder what went wrong? Was it flaws at the design stage, the wind tunnel stage. Wish I knew.
 
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Aaron747
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Re: When pilots speak of a specific type of aircraft as "unforgiving" does that indicate a design flaw?

Thu Nov 11, 2021 9:34 pm

Past threads are your friend:

viewtopic.php?t=762453
 
FlapOperator
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Re: When pilots speak of a specific type of aircraft as "unforgiving" does that indicate a design flaw?

Fri Nov 12, 2021 4:15 pm

convair880mfan wrote:
I've flown on the Finnair MD-11 and thoroughly enjoyed the flights and have heard that the two-person flight deck automation was sweet, but I just wonder what went wrong? Was it flaws at the design stage, the wind tunnel stage. Wish I knew.


Build an aircraft with high approach speeds, a fairly basic autothrottle system, aft CG and aircraft geometry that puts the cockpit well ahead of the CG.

All of the decisions came from the requirements to build, certify and sell an airplane. They are all functions of ultimate the sales requirements to make the aircraft successful in the market.
 
LH707330
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Re: When pilots speak of a specific type of aircraft as "unforgiving" does that indicate a design flaw?

Fri Nov 12, 2021 11:24 pm

convair880mfan wrote:
I wonder if McDonnell Douglas should have just stretched the DC-10 or perhaps made a twin engine aircraft right off the bat.

The design of an aircraft is a job for many engineers. I would think the engineers at MD had plenty of expertise and experience with those with the most expertise and experience at the top tier of designers. So what went wrong?

The MD-11 seemed to have performance shortfalls from the very beginning. It didn't meet its range goals which put off a lot of MD believers like American Airlines and Singapore Airlines. Wonder why the top folks at MD didn't see the writing on the wall that the future was in twin turbine powered airliners. Problems seemed to go beyond the normal teething problems of new airliners. PIPs didn't seem to completely remedy the difficulties with the design.

Can there be problems that designers and wind tunnel testers cannot foresee? Approach and Landing characteristics. Takeoff characteristics?

I would like to think that it was just a matter of making a jet transport for a niche market that never materialized, like the Convair 880 did, but I think it goes beyond this.

I've flown on the Finnair MD-11 and thoroughly enjoyed the flights and have heard that the two-person flight deck automation was sweet, but I just wonder what went wrong? Was it flaws at the design stage, the wind tunnel stage. Wish I knew.

Back then, there was no way to get the payload/range they had planned on 2 engines. The MD-11 EISed in 1990, while the 777-200ER did in 1997. If you wanted to move 300 pax 6700 nm in 1992, your options were as follows:
1. Buy an MD-11
2. Wait a year or 2 for an A340
3. Wait 5ish years for a 777-200ER
4. Upgrade to a 747

As to why the MD-11 behaved how it did, essentially MD cheaped out on the design and the handling suffered as a consequence. Once the A340 came on line, MD-11 sales dried up.

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