Are the Jumbo Jet days numbered?

KSCessnaDriver said:
Look at the numbers of MD11's crashed at FedEx vs UPS. I'm surprised they managed to keep the same type between the DC-10 and MD-11.
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Yeah. It's a problem. The MD-11 is not like other airplanes in its landing characteristics. Cross flying the MD-11 and MD-10 is problematic, because in the approach and landing they are not very similar in their handling characteristics. If you are used to flying the MD-10 night after night, and then get an -11, you have consciously think that it is not going to perform like what you've been used to.

After FedEx 80 crashed in Narita, there was again a good hard look at MD-11 landings characteristics, focusing on energy management through the approach and landing, and especially bounce recoveries.

Then, after Lufthansa had their hard landing in Riyadh, the NTSB released a second safety recommendation white paper outlining the intricacies of MD-11 landings and the reasons why it had the most hard landings out of any commercial aircraft, and what could be done to help mitigate those problems.

http://www.ntsb.gov/_layouts/ntsb.recsearch/Recommendation.aspx?Rec=A-14-008

Bottoms line is, if you're flying an MD-11... don't flare late, and don't touch down in a crab.
 
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Sluggo63 said:
Bottoms line is, if you're flying an MD-11... don't flare late, and don't touch down in a crab.
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Please expand on this for my entertainment/education:

What makes it different? Is the MD-11 hyper sensitive to something? Under engineered landing gear? Odd sink characteristics? Isn't "Don't flare late and don't touch down in a crab." good advice for any any aircraft?

Disclosure - My father and both of my Grandfathers retired from Lockheed GA, so I have a bit of pro-Lockheed bias.
 
kyleb said:
Please expand on this for my entertainment/education:

What makes it different? Is the MD-11 hyper sensitive to something? Under engineered landing gear? Odd sink characteristics? Isn't "Don't flare late and don't touch down in a crab." good advice for any any aircraft?

Disclosure - My father and both of my Grandfathers retired from Lockheed GA, so I have a bit of pro-Lockheed bias.
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If you read the NTSB link, it describes it better than I can, but basically, when MD made the -11, they stretched the DC-10, and made the horizontal stab much smaller. They forced an aft CG on purpose to compensate for the smaller stab, and for fuel savings. But this has the negative effect of creating a airplane which has a "relaxed pitch stability."

The other issues are that the MD-11 also has an extremely long cockpit to CG length and also very high approach speeds.

These high approach speeds necessitate a higher sink rate on approach, and make the window for the flare/roundout very small. The NTSB paper says the flare should happen 1.4 seconds after passing 50'. In the Narita and Riyadh hard landings/crashes the flare was initiated at 1.8 & 2.0 seconds respectively. Those crews were about a half a second late in flaring, and had hull losses.

With the longer cockpit to CG length, if you realize you are flaring late, pulling back on the yoke doesn't have the effect of arresting your descent like you would think. All you're doing there is driving the landing gear into the runway at an extremely high G. The only thing you can do to mitigate a late flare is hold pitch and add power.

Also, with the long distance between the cockpit and CG, during a bounced landing, there's the possibility that as the aircraft rotates around the CG, the pilots' eye height won't change, and they won't even know they bounced, leading to a derotation and coming down hard on the nose.

That's just a brief pilot perspective. If you are really interested read the NTSB paper. It's pretty eye-opening.
 
Having flown the MD-11 for only about 12 of my 18 years at World Airways, I'm still trying to find out why pilots have a hard time landing the plane.

Both McDonald Douglas and Boeing have you fly every landing with the autothrottle system engaged. Every other jet I've flown, you always shut the autothrottle system off by 50 ft unless you're doing an autoland. I have seen pilots get screwed by the system when their flare profile doesn't match the flare sequence that the autopilot system flies in an autoland. What most pilots forget is that your hand can move the throttles even with the autothrottle system engaged.

The aft CG is only in cruise. It's not a factor for landing.

The stab is smaller, but the arm is longer. Still, the MD-11 has LSAS which is like a yaw damper, but only in pitch and only when the autopilot system is off.

Land most planes with the nose gear touching first and bad things happen. It seems that certain operators had bigger problems than others. Was it training, culture, pilot background and experience, I don't know.
 
jonnyjetprop said:
Having flown the MD-11 for only about 12 of my 18 years at World Airways, I'm still trying to find out why pilots have a hard time landing the plane.

Both McDonald Douglas and Boeing have you fly every landing with the autothrottle system engaged. Every other jet I've flown, you always shut the autothrottle system off by 50 ft unless you're doing an autoland. I have seen pilots get screwed by the system when their flare profile doesn't match the flare sequence that the autopilot system flies in an autoland. What most pilots forget is that your hand can move the throttles even with the autothrottle system engaged.

The aft CG is only in cruise. It's not a factor for landing.

The stab is smaller, but the arm is longer. Still, the MD-11 has LSAS which is like a yaw damper, but only in pitch and only when the autopilot system is off.

Land most planes with the nose gear touching first and bad things happen. It seems that certain operators had bigger problems than others. Was it training, culture, pilot background and experience, I don't know.
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I don't think they have near as bad of a problem flying it when they fly just the MD-11. It's when you go back and forth between then MD-10 and MD-11 that the problems seem to manifest themselves.
 
Art VanDelay said:
They make sense for State Subsidized Airlines that don't TRULY and I do mean TRULY have to make a profit. You'll almost certainly never see them in any US passenger livery. Both Delta and United's 747s are scheduled to go away. The 777x and 787-10 as well as the Airbus 350-1000 are the future of long haul for those carriers that have to actually make money.
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British Airways and Lufthansa are exceptions to this rule. They make profit and operate the A380.
 
mtuomi said:
British Airways and Lufthansa are exceptions to this rule. They make profit and operate the A380.
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Really ? Let's just start with something simple - how much do each of those carriers pay for their employee health insurance ? It is not a level playing field between US carriers and those two. With the two you named it is somewhat closer than the Asian and Middle Eastern carriers but still not the same rule book or playing conditions.
 
Art VanDelay said:
Really ? Let's just start with something simple - how much do each of those carriers pay for their employee health insurance ? It is not a level playing field between US carriers and those two. With the two you named it is somewhat closer than the Asian and Middle Eastern carriers but still not the same rule book or playing conditions.
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Well, considering our model of doing things has left us with the developed world's worst airline service and airline career path, perhaps we should think about 'leveling the playing field' by looking at changing our model.:dunno:
 
jonnyjetprop said:
Even the 747 days are numbered. Large 777 are rapidly replacing them. Even as a cargo plane, it burns too much fuel. It's time for Boeing and Airbus to pull the plug. Tim Clarke of Emirates is ****ed because his airline is operating something like half the A-380 fleet.
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Emirates does have a fair number of A380's (I think Quantas is the other major player), but the B777 is the backbone of the Emirates fleet, and if their website is to be believed, will be for quite some time.

My office (and apartment) is under the final approach to DXB and I watch an endless stream of 777's. One would think it's the only type they have. Emirates did, however, just build a new terminal specifically for the A380 so I guess Tim Clark is justified in being upset.

I have a buddy who flys the 777 for Emirates and he tells me there is a movement to acquire more Airbuses because of the guaranteed income. Boeing has a tendency to undersell their aircraft. If it's in the manual, the aircraft will do it (and more). Airbus, on the other hand, has a tendency to oversell their aircraft. The airline buys based on the specs and when it doesn't deliver the promised performance, Airbus has to compensate the airline.
 
Henning said:
Well, considering our model of doing things has left us with the developed world's worst airline service and airline career path, perhaps we should think about 'leveling the playing field' by looking at changing our model.:dunno:
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Simple, bring back regulation.
 
jonnyjetprop said:
Having flown the MD-11 for only about 12 of my 18 years at World Airways, I'm still trying to find out why pilots have a hard time landing the plane.
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I don't know either. I really enjoy the airplane, but landing in high, gusting crosswinds is an event which is higher threat than in other planes, IMO. Agree?

jonnyjetprop said:
Both McDonald Douglas and Boeing have you fly every landing with the autothrottle system engaged.
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It's recommended, but definitely not mandated. I try to fly at least one approach every trip with AP/AT turned off.

jonnyjetprop said:
What most pilots forget is that your hand can move the throttles even with the autothrottle system engaged.
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Correct, I "guard" the throttles on every approach, especially at lighter weights. I'm ready to add power if I get that "sinking feeling" in the flare.

jonnyjetprop said:
The aft CG is only in cruise. It's not a factor for landing.
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With TFM (Tail Fuel Management) it is, but the CG in the MD-11F, depending on how it's loaded, has a wider variance than in the passenger version.

jonnyjetprop said:
The stab is smaller, but the arm is longer. Still, the MD-11 has LSAS which is like a yaw damper, but only in pitch and only when the autopilot system is off.
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LSAS is good, but I don't know if it's all its cracked up to be. There is good and no-so-good about it.

jonnyjetprop said:
Land most planes with the nose gear touching first and bad things happen. It seems that certain operators had bigger problems than others. Was it training, culture, pilot background and experience, I don't know.
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I assume you're talking about us (FedEx). Yes, we haven't had the most stellar accident history with the MD-11. The curious thing is that the same crew force flies the MD-11 and MD-10 interchangeably. We haven't had these issues in the MD-10. The same pilots fly both airplanes, but it seems all our problems happen in the MD-11. I don't think you can point to any one issue as to why... If I had to guess, I'd say a lot of it had to do with the law of averages. We have over 60 MD-11s. I don't know how many World, or Swissair or Lufthansa had (UPS has about 30, I think). But the number of cycles, segments, legs is bound to catch up. That's in my opinion.

KSCessnaDriver said:
I don't think they have near as bad of a problem flying it when they fly just the MD-11. It's when you go back and forth between then MD-10 and MD-11 that the problems seem to manifest themselves.
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Maybe, but I think it's more than that. I think the MD-11 is a great airplane and flies really well, when it's good. And it's good the majority of the time. It doesn't do it very often, but when it goes bad... it goes bad in a hurry and it becomes really bad...

jonnyjetprop said:
At FedEx, there is the issue of the common type rating for the MD-11 and the modified DC-10, now known as the MD-10. The MD-10 is aerodynamically the same as a DC-10, I believe.
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Yes, the MD-10 is a DC-10 airframe that they gutted the cockpit out of, and replaced it with (for all intents and purposes) an MD-11 cockpit. There are some minor (and some not-so-minor) differences between the two in switch/lever locations, systems operations, and most importantly, flying characteristics, but the FAA deemed it "close enough" to a MD-11 to give it a common type rating. Who am I to argue...
 
No slam against FedEx. There have been several incidents/accidents with derotation and hitting nose gear first on several different types of planes. I remember a 767 that drove the nose gear straight into the EE compartment.

World mandated autothrottle use, per the manufacturer. Line ops saw some not using it or the guarding the throttles.

It maybe the differing types of cargo carried, but World's freighters often were nose heavy when loaded. We had to factor in not getting the cruise CG back to the limit and burning extra gas.

I have more time in the MD-11 than any other plane, so I'm biased. I enjoyed the plane. It broke my heart to see them getting cut up.


Sluggo63 said:
I don't know either. I really enjoy the airplane, but landing in high, gusting crosswinds is an event which is higher threat than in other planes, IMO. Agree?

It's recommended, but definitely not mandated. I try to fly at least one approach every trip with AP/AT turned off.

Correct, I "guard" the throttles on every approach, especially at lighter weights. I'm ready to add power if I get that "sinking feeling" in the flare.

With TFM (Tail Fuel Management) it is, but the CG in the MD-11F, depending on how it's loaded, has a wider variance than in the passenger version.

LSAS is good, but I don't know if it's all its cracked up to be. There is good and no-so-good about it.

I assume you're talking about us (FedEx). Yes, we haven't had the most stellar accident history with the MD-11. The curious thing is that the same crew force flies the MD-11 and MD-10 interchangeably. We haven't had these issues in the MD-10. The same pilots fly both airplanes, but it seems all our problems happen in the MD-11. I don't think you can point to any one issue as to why... If I had to guess, I'd say a lot of it had to do with the law of averages. We have over 60 MD-11s. I don't know how many World, or Swissair or Lufthansa had (UPS has about 30, I think). But the number of cycles, segments, legs is bound to catch up. That's in my opinion.

Maybe, but I think it's more than that. I think the MD-11 is a great airplane and flies really well, when it's good. And it's good the majority of the time. It doesn't do it very often, but when it goes bad... it goes bad in a hurry and it becomes really bad...

Yes, the MD-10 is a DC-10 airframe that they gutted the cockpit out of, and replaced it with (for all intents and purposes) an MD-11 cockpit. There are some minor (and some not-so-minor) differences between the two in switch/lever locations, systems operations, and most importantly, flying characteristics, but the FAA deemed it "close enough" to a MD-11 to give it a common type rating. Who am I to argue...
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