Lufthansa cargo plane crash
Trash du Blanc
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Huck, as I recall we did not add wind additives to the MD11 if the autothrottles were left on til touchdown. Has something changed?
As far as overriding the autothrottles - that works great until a stiff crosswind, an MD 10 and a small (i.e. female) pilot. Takes two hands on the yoke at that point, and throttles come back on their own.
I guess my main point would be, after 2000 hours in the MD11 at two carriers and in both seats, that it is a plane. It's just a plane. It flies like a plane. I started clicking the A/T's off when I clicked off the A/P and my landings got better. Just like a Cessna - practice makes perfect.
As for the 777, we'll see....
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By short final, Spooky, I mean anywhere below 2000' AGL. You are correct, a disconnect at 50' doesn't give the handling pilot enough time to put butt properly in seat, so to speak.
In answer to your question, F35 is SOP around here.
In answer to your question, F35 is SOP around here.
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Manual flight - manual thrust. That's the way it is tought throughout Lufthansa.
Just day before yesterday I landet a heavy A340-600 at a fairly small US airport that I happen to know quite well. The approach end of the runway is set in a dip with a ridge and the edge of a forest just before it. In other words, winds can be tricky there. Plus the temperature at our arrival time in the afternoon was 34°C, so the sun had heated the touchdown zone quite a bit. Taking all this into account I added 5 Knots to the Vref in order not to come low on energy.
Overhead the concrete the sinkrate still increased remarkably and I had to yank the side stick back to its mechanical stop to break it. Appearently I did it just in the right splitsecond, because it turned out to be a greaser. It could have turned out very differently, too. Especially if I had used autothrust all the way to touchdown, it might have pulled back the power just that very moment when I needed it most. While I don't think I would have broken off the tail, it would have made a loud bang at least...
What I'm saying is: even when you know what's coming, hot and high in a heavy jet is demanding, and that's without A/T playing nasty tricks on you. I'm really glad that these colleagues were able to walk away from their mishap and I wish them all the best. Although everything points to a hard landing right now I do not believe the main contributing factor was lack of skill on their part. They are well trained and do have more short sectors and fewer three man legs than we do on the mainline longhaul.
Regards,
DL
Just day before yesterday I landet a heavy A340-600 at a fairly small US airport that I happen to know quite well. The approach end of the runway is set in a dip with a ridge and the edge of a forest just before it. In other words, winds can be tricky there. Plus the temperature at our arrival time in the afternoon was 34°C, so the sun had heated the touchdown zone quite a bit. Taking all this into account I added 5 Knots to the Vref in order not to come low on energy.
Overhead the concrete the sinkrate still increased remarkably and I had to yank the side stick back to its mechanical stop to break it. Appearently I did it just in the right splitsecond, because it turned out to be a greaser. It could have turned out very differently, too. Especially if I had used autothrust all the way to touchdown, it might have pulled back the power just that very moment when I needed it most. While I don't think I would have broken off the tail, it would have made a loud bang at least...
What I'm saying is: even when you know what's coming, hot and high in a heavy jet is demanding, and that's without A/T playing nasty tricks on you. I'm really glad that these colleagues were able to walk away from their mishap and I wish them all the best. Although everything points to a hard landing right now I do not believe the main contributing factor was lack of skill on their part. They are well trained and do have more short sectors and fewer three man legs than we do on the mainline longhaul.
Regards,
DL
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Bug Smasher I see your point. Pilots were always reluctant to use flaps 50 if the 35 would work and of course that helps account for the higher approach speeds your commenting on. I prefered the flaps 50 landings and we encouraged pilots use it when they could but sometimes it's hard to convince a pilot what is good for him in the long run.
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That's intersting as we did not include wind additives unless the component was in excess of 20Kts. That was the first airplane I had seen that in having previously flown the DC10 and L10LL. It was sort of un-nerving at first but it seemed to work out without incident at the time. Those additives to Vapp and flaps thirty five would certainly account some of those high approach speeds. Also for the first year or more, we did not use ABS for landings due to some CLG issues that needed to be resolved.
'Overhead the concrete the sinkrate still increased remarkably and I had to yank the side stick back to its mechanical stop to break it.'
I am not, for a moment questioning your technique but I do find it amazing you would have to ever go 'to the stops' with your flight controls.
Is this not that unusual on the Airbus and is it a case of having to put in more input than is really needed to ensure the Aircraft reacts in time after your inputs are 'filtered' through the flight control system ?
I am not, for a moment questioning your technique but I do find it amazing you would have to ever go 'to the stops' with your flight controls.
Is this not that unusual on the Airbus and is it a case of having to put in more input than is really needed to ensure the Aircraft reacts in time after your inputs are 'filtered' through the flight control system ?
When using auto throttle during manual flight, especially during approach and landing, there may be several pitfalls depending on the aircraft type and auto system.
For example if the aircraft enters the flare (A/T retard phase) slightly steeper or with a higher rate of descent then the reduction in thrust is perhaps not what is required. Without thrust intervention, only pitch control is available and if used excessively may result in a high nose attitude with risk of tailstrike or reducing speed more quickly than in a normal flare which incurs other risks.
Alternatively if the approach is shallow then the retard mode may operate early (lower Rad Alt), again requiring pitch control to regain the approach angle and control speed, which may be reducing rapidly. See the accident here:- Transportation Safety Board of Canada - AVIATION REPORTS - 2007 - A07A0134
In addition some autothrottle installations are mildly destabilising in pitch; although not obvious to the crew this may increase the likelihood of arriving at the flare steeper or shallower than planned.
For example if the aircraft enters the flare (A/T retard phase) slightly steeper or with a higher rate of descent then the reduction in thrust is perhaps not what is required. Without thrust intervention, only pitch control is available and if used excessively may result in a high nose attitude with risk of tailstrike or reducing speed more quickly than in a normal flare which incurs other risks.
Alternatively if the approach is shallow then the retard mode may operate early (lower Rad Alt), again requiring pitch control to regain the approach angle and control speed, which may be reducing rapidly. See the accident here:- Transportation Safety Board of Canada - AVIATION REPORTS - 2007 - A07A0134
In addition some autothrottle installations are mildly destabilising in pitch; although not obvious to the crew this may increase the likelihood of arriving at the flare steeper or shallower than planned.
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I guess my main point would be, after 2000 hours in the MD11 at two carriers and in both seats, that it is a plane. It's just a plane. It flies like a plane. I started clicking the A/T's off when I clicked off the A/P and my landings got better. Just like a Cessna - practice makes perfect.
As for the 777, we'll see....
As for the 777, we'll see....
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Front-runner
I'm not a pilot and I don't profess knowledge but as far as I understand you have to click the A/T off such that you can reduce the power to idle manually, dump lift and flare, Unless you're doing a cat 3 landing that is then only you'll keep it on.
If someone has another view on this matter please share.
Also any info as to how the incident occured will be most appreciated.
Thanks in advance
I'm not a pilot and I don't profess knowledge but as far as I understand you have to click the A/T off such that you can reduce the power to idle manually, dump lift and flare, Unless you're doing a cat 3 landing that is then only you'll keep it on.
If someone has another view on this matter please share.
Also any info as to how the incident occured will be most appreciated.
Thanks in advance
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Without thrust intervention, only pitch control is available and if used excessively may result in a high nose attitude with risk of tailstrike or reducing speed more quickly than in a normal flare which incurs other risks.
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"attempting to stop an excessive rate of descent close to the ground by aggressive use of elevator, w/engines at idle after A/T retard".
That technique will get you the same results in just about any large airplane. Nothing unique to the MD11 here.
That technique will get you the same results in just about any large airplane. Nothing unique to the MD11 here.
Spooky, will get you the same results in just about any large airplane, but this depends on the characteristics of each aircraft – the pitch control sensitivity, lift slope, and interaction with direct lift control or compensating devices. The pitching moment due to thrust may be adverse, e.g. reducing thrust on under slung engines may cause the aircraft to pitch down.
Also, consider the retard characteristics of the A/T; some modern systems have wind (ground speed) correction.
The MD-11 is reported as having a ‘difficult’ pitch control system.
Also, consider the retard characteristics of the A/T; some modern systems have wind (ground speed) correction.
The MD-11 is reported as having a ‘difficult’ pitch control system.
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Safetypee, tell me what airplanes use groundspeed as a component of AT operations? I'm not aware of anything in the MD11 that does this and neither the B777 or 787 use groundspeed in their algorithm architecture. Maybe it's an Airbus feature? The 777/787 use a different solutions for airspeed with the 787 using static anolog pressure put through the ADRS and coming out as "voted airspeed" which is used by the AT's. In either case there is no groundspeed vector applied to the AT solutions.
Spooky 2;
The Airbus A319/A320/A330/A340-300/500 series uses what is called "GroundSpeedMini". The intent is to maintain the energy level of the aircraft in strong headwinds and/or shear conditions. It will add more than 20kts but take it off quickly, as/when required. In my experience with all 3 types, the system is very responsive; it works extremely well. I can't recall a landing when it caused us to eat up more runway due to a higher than required speed over the fence.
The computation works in concert with the FMC-entered winds given by ATC. The added speed to Vapp was limited to 15kts, (Vapp is Vref + 5kts, so we're really adding 20kts to Vref), but the GSMini will, (and has, in my experience) added quite a bit more. Below 400ft, the software will maintain sufficent energy to land at Vapp.
What I have seen both from the flight deck and in flight data is the autothrust, still engaged, (thrust levers not closed to idle), increasing thrust to maintain the approach speed as the aircraft is in the flare and speed is bled off. This almost always results in a long flare and a long, (beyond the TDZ) landing.
DonLeslie;
Agree with your thoughts on adding 5 to the Vapp - BTDT and it works. Sometimes letting the airplane just hang on Vapp is a bit too small an energy reserve. That said, I much preferred manual thrust levers in manual flight and control my own energy level.
As an aside, on the A330/340 I always tried to derotate with enough rate to beat the forward bogies to the ground before they slammed down and was successful only part of the time. There wasn't the same problem with the 345.
PJ2
The Airbus A319/A320/A330/A340-300/500 series uses what is called "GroundSpeedMini". The intent is to maintain the energy level of the aircraft in strong headwinds and/or shear conditions. It will add more than 20kts but take it off quickly, as/when required. In my experience with all 3 types, the system is very responsive; it works extremely well. I can't recall a landing when it caused us to eat up more runway due to a higher than required speed over the fence.
The computation works in concert with the FMC-entered winds given by ATC. The added speed to Vapp was limited to 15kts, (Vapp is Vref + 5kts, so we're really adding 20kts to Vref), but the GSMini will, (and has, in my experience) added quite a bit more. Below 400ft, the software will maintain sufficent energy to land at Vapp.
What I have seen both from the flight deck and in flight data is the autothrust, still engaged, (thrust levers not closed to idle), increasing thrust to maintain the approach speed as the aircraft is in the flare and speed is bled off. This almost always results in a long flare and a long, (beyond the TDZ) landing.
DonLeslie;
Agree with your thoughts on adding 5 to the Vapp - BTDT and it works. Sometimes letting the airplane just hang on Vapp is a bit too small an energy reserve. That said, I much preferred manual thrust levers in manual flight and control my own energy level.
As an aside, on the A330/340 I always tried to derotate with enough rate to beat the forward bogies to the ground before they slammed down and was successful only part of the time. There wasn't the same problem with the 345.
PJ2
Last edited by PJ2; 12th Aug 2010 at 00:19. Reason: drop extraneous comments, add more info re GSMini
Trash du Blanc
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always ck the VHF 3 antenna tip during walk around) associated with speed deficiencies in takeoff and landing phases
Spooky, Re “ … what airplanes use groundspeed as a component of AT operations?” #259
IIRC, in addition to the Airbus described above, the Avro RJ uses something similar. During autoland operations the overall autopilot/throttle system adjusts the intended point of touchdown according wind speed; this minimises the longitudinal dispersion of the landings.
Perhaps it is of some significance that the Avro RJ auto flight system consists of half of the MD 11 system hardware; however, the algorithms are based on the MD 80, tuned for the higher lift / slower speed RJ.
IIRC, in addition to the Airbus described above, the Avro RJ uses something similar. During autoland operations the overall autopilot/throttle system adjusts the intended point of touchdown according wind speed; this minimises the longitudinal dispersion of the landings.
Perhaps it is of some significance that the Avro RJ auto flight system consists of half of the MD 11 system hardware; however, the algorithms are based on the MD 80, tuned for the higher lift / slower speed RJ.
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LH Intranet
Der Spiegel claims to have had access to an LH Cargo internal description of the accident:
- 2 bounces & then fuselage broke somewhere aft
- aircraft left runway after 2400 m and came to stop after additional 375 m, started burning
In the middle part of the cargo section were 2 pallets with inflammable chemicals, also machine guns for Saudi Arabia and unspecified cargo for US military on board.
Verunglückte Lufthansa-Cargo-Maschine hatte Gefahrengut an Bord - SPIEGEL ONLINE - Nachrichten - DER SPIEGEL
- 2 bounces & then fuselage broke somewhere aft
- aircraft left runway after 2400 m and came to stop after additional 375 m, started burning
In the middle part of the cargo section were 2 pallets with inflammable chemicals, also machine guns for Saudi Arabia and unspecified cargo for US military on board.
Verunglückte Lufthansa-Cargo-Maschine hatte Gefahrengut an Bord - SPIEGEL ONLINE - Nachrichten - DER SPIEGEL
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LH latest
from the Aviation Herald.
A statement by Lufthansa provided to Lufthansa employees on Lufthansa's internal website said, that the black boxes have been analysed by the German Bureau for Aviation Accident Investigation (BFU). The results indicate, that the airplane touched down normally in the touch down zone, however two more ground contacts followed which caused the rear of the aircraft to fracture just aft of the main gear. After 2400 meters (7880 feet) the airplane departed the runway 33L to the left, at this stage the nose gear collapsed. The airplane came to rest after another 375 meters (1230 feet). The crew left the airplane via slide 1L. Further information can not be provided due to the ongoing investigation, every (internal or external) statement must be authorised by Saudi Arabia's investigator in charge. The investigator hopes to release a preliminary report in fall 2010, which requires interviews with the crew however. The interview has been scheduled for next week (Aug 16th-20th). A final report is expected in about a year. The wreckage has been removed from the accident site and is currently being dismantled. Lufthansa Technics checks whether some of the undamaged parts can be re-used, all the rest is going to be scraped in Saudi Arabia.
The German BFU stated, that the airplane bounced after first touch down and broke on next touch down.
A statement by Lufthansa provided to Lufthansa employees on Lufthansa's internal website said, that the black boxes have been analysed by the German Bureau for Aviation Accident Investigation (BFU). The results indicate, that the airplane touched down normally in the touch down zone, however two more ground contacts followed which caused the rear of the aircraft to fracture just aft of the main gear. After 2400 meters (7880 feet) the airplane departed the runway 33L to the left, at this stage the nose gear collapsed. The airplane came to rest after another 375 meters (1230 feet). The crew left the airplane via slide 1L. Further information can not be provided due to the ongoing investigation, every (internal or external) statement must be authorised by Saudi Arabia's investigator in charge. The investigator hopes to release a preliminary report in fall 2010, which requires interviews with the crew however. The interview has been scheduled for next week (Aug 16th-20th). A final report is expected in about a year. The wreckage has been removed from the accident site and is currently being dismantled. Lufthansa Technics checks whether some of the undamaged parts can be re-used, all the rest is going to be scraped in Saudi Arabia.
The German BFU stated, that the airplane bounced after first touch down and broke on next touch down.