CNN Reports FEDEX crash in Tokyo
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What of the MD-11? What makes a "pilot's airplane"? Is it a plane for men with above average skills who love to demonstrate same? No slight intended to those who like that sort of thing, and no slight intended to those who've identified it as a pilot's plane
Like the smaller stabilizer : If you compare a 747SP with a -300, you will notice a bigger tail ... because there is less leverage, so you need more surface, simple physics. Same applies to the DC10 and the longer MD11 with the stabilizer, no mystery there. As for the aft CG, .. well with a trim tank you can vary the CG, so it might be aft, but for TO and LDG it will be forward as in other aircraft. Some astronauts blocked the auto-re-transfer as to keep it back longer, forgot it and nearly crashed. Maybe the myth comes from this.
Now to the landing characteristics. They are not good, agreed. When someone says it needs a REAL pilot, it's partially true, but only because too many newer pilots never had the chance to learn to fly this kind of aircraft. They were bread on Airbus et al. The reasons for this difficult behaviour was mainly: High surface load and a steep increase of the power-drag curve below Va. The only plane that was worse, was the DC-9-50, with a surface load higher than a fighter jet! Pilots coming from the DC-9 series and well trained in pitch/power flying never had big problems with the MD11, those coming from the A320, ... lots. Even old DC9-50s had the hard landing tendency, allthough with the main gear behind the centre of rotation, it did not result in bouncing, rather slamming the nose wheel into the ground.
The most important thing on approach with a MD11, was to keep it as stable as possible in pitch and speed, above Va. Funnily enough, this proved to be a challenge for many pilots. They often had huge pitch variations, therefore thrust variations, constant mistrim and finally speed excursions. As the beast has very high approach speeds, no one liked this too much on shorter runways. If you found yourself in a slight overspeed correction close to flare, with low thrust and increasing pitch and the trim anywhere but where it should, the hard one was assured. Pulling hard might help, but as this resulted in ugly pitch up landings, the LSAS got programmed to dampen the hard up-input. I suppose that this might be a co-contributor to some hard landings that resulted in bounces.
If you manged to keep the pitch nice and stable, to keep the speed above Va by helping the AT a little (especially keeping it up a notch below the 50' retard command), if you defended the GS nicely right down to minimum and applied the aiming point landing technique, even in strong crosswinds and windshears, the MD11 was really ok.
BUT: These should be basic flying skills for Ailine pilots, shouldn't they?????? (no comment)
Again, aerodynamically the MD11 was not the jewel in the crown, but it was absolutely managable in the same enveloppe as the other brands.
(The cockpit layout however, I can't resist to add that, is still light-years ahead of any Bus or Boeing)
Warning Toxic!
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Disgusted of Tunbridge
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I am still very intrigued by a feature of the MD11 that concerns me. I have witnessed it many times, but in all the photos of the plane on final approach (example), the extraordinary download on the tailplane is demonstrated. The nose-up trim must be enormous. It has been shrugged off as 'doesn't matter', but it does. Icing issues on tailplanes have been of concern for years, but I'm interested in how it fares in a bounced landing with a sudden loss of 20kts airspeed with the tailplane and elevators having to provide even more download. Something made the nose fall frighteningly after the first touchdown- if that was a natural response of the aeroplane, then it is unsatisfactory to have behaviour like that. Reference has been made to pilots 'running out of elevator'. Other types have no such characteristic of the tailplane being at such an extraordinary angle. It's always looked to me like an out of balance aeroplane with an insufficiently sized tailplane to take up the load- the pictures of tailplane position on final approach show something is not right- I suspect there is the reason for the peculiar landing characteristics- once the aeroplane enters ground effect, even more download is required on a too-small tailplane. Hence the admonishments to remove drift before flare.
Things seem to point to an unsatisfactory behaviour in the flaps down/low speed regime- the whole area has received a lot of attention and criticism, and the builders have applied a variety of software automatic solutions to what is an unadmitted problem. Pilots say 'it's alright if you know what you're doing and understand the aeroplane'! It just means when the weather catches you and maybe you're not at your best, the result is more likely to be unsatisfactory than if you were flying a 747 with its far blander characteristics. The unwritten words seem to be 'nice plane, but a bastard to land!'
Things seem to point to an unsatisfactory behaviour in the flaps down/low speed regime- the whole area has received a lot of attention and criticism, and the builders have applied a variety of software automatic solutions to what is an unadmitted problem. Pilots say 'it's alright if you know what you're doing and understand the aeroplane'! It just means when the weather catches you and maybe you're not at your best, the result is more likely to be unsatisfactory than if you were flying a 747 with its far blander characteristics. The unwritten words seem to be 'nice plane, but a bastard to land!'
Last edited by Rainboe; 28th Mar 2009 at 10:05.
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Tailplane..
The pic of the KLM aircraft on approach shows what appears to be a high angle of attack, but in reality is inline with the relative wind - remember the aircraft is in a nose high attitude in descent - because it is inline with the relative wind, that means the tailplane is lightly loaded, as opposed to another aircraft type on approach; the light tail loading (instead of tail downforce) causes increased pitch sensitivity, which is why the MD-11 requires an LSAS system...
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What is the typical approach speed of the MD11? Can't be much faster than a 737-800 above 60 tons.
For 200t take 160kt, for 180t it's around 152kt.
For a flaps 50 landing substract 5kt from the flaps 35 speeds.
All speeds given are without any correction for wind, gust or windshear. Depending on the wind, the corrections applied on the approach speeds given above can be as high as 20kt.
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DBate
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Somewhere I believe that I read that the estimated crosswind component at the time of this landing was 7kts? Please correct me if this is an error.
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All tailstrikes/hard landings in the MD11 have two things in common:
1. High sink rate
2. Pitch-up rotation at touchdown.
Those AT's come back at 50', regardless of where you are or what your energy is.
If I were king I'd make it mandatory that you click them off at 100', every approach. That's how I fly it. Learned it from my days in max-weight DC-10-30's. The fear is that you'll go around with them disengaged, but it is not a problem at all. I do practice approaches/missed approaches in my current position and standing them up and putting the needles in the carrots is child's play.
I DO NOT like flying with autopilot off, autothrottles on. I am 75% more in-the-loop if I click both off. And I can't find any reason not to, except laziness.....
1. High sink rate
2. Pitch-up rotation at touchdown.
Those AT's come back at 50', regardless of where you are or what your energy is.
If I were king I'd make it mandatory that you click them off at 100', every approach. That's how I fly it. Learned it from my days in max-weight DC-10-30's. The fear is that you'll go around with them disengaged, but it is not a problem at all. I do practice approaches/missed approaches in my current position and standing them up and putting the needles in the carrots is child's play.
I DO NOT like flying with autopilot off, autothrottles on. I am 75% more in-the-loop if I click both off. And I can't find any reason not to, except laziness.....
Last edited by Huck; 29th Mar 2009 at 00:11.
What's To Fear
The fear is that you'll go around with them disengaged, but it is not a problem at all.
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Well just to counter your technique and at the same time not saying your wrong but in my previous MD11 experience we "suggested" that if the pilot was going to turn the AT off during the landing phase he would be better off to do so at 1'000 AFE and simply fly the airplane down to the runway as one would do with any old iron bird, but not disconnet them at the low altitude close to the ground in which they may or may not be in the exact position or power setting that you believed they were. It was a novel concept....fly the airplane from the OM or at least 1,000" AFE.
Most often the landing was better in the latter mode of operation.
Most often the landing was better in the latter mode of operation.
Last edited by Spooky 2; 28th Mar 2009 at 23:15. Reason: spelling
quidquid excusatio prandium pro
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I swear I'll never get in one now. Not as a passenger, nor as a pilot.
All the rest belong to the freight community, FedEx and UPS mostly, with a scattering of various cargo haulers elsewhere in the world.
(Certain times of the day in Anchorage, you could swear every last one of them was present and accounted for on the tarmac at the same time, really impressive to see.)
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"Greetings Thomas
flying little Bugsmackers
but also renembering that a specific aircraft has specific handling characteristics."
flying little Bugsmackers
but also renembering that a specific aircraft has specific handling characteristics."
The only similarity between the two besides the cockpit layout are the FCC's and LSAS in reference to operation. Otherwise they are a DC-10 and a MD-11 in their performance specs and general handeling.
Granted pilots bid routes and are likely to generally operate one type of airframe for the duration of their bid. None the less, going from an MD-10 to an MD-11 and possibly back has to be very demanding of their skillset and a negative factor in maintaining proficiency.
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As has been stated several times previously in this long thread, the MD10 is a back variant of the MD11, and shares a type rating.
The DC10 is a different type rating and truly a different animal.
The DC10 is a different type rating and truly a different animal.
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"As has been stated several times previously in this long thread, the MD10 is a back variant of the MD11, and shares a type rating.
The DC10 is a different type rating and truly a different animal. "
It shares the type rating, this is the problem. Stick and rudder the MD-10 is no different than the DC-10. "Back Variant"??? Man they take a DC-10, cut a hole in the bell and drop the E-rack. Rewire most of the aircraft and slap a bunch of shiny knobs and screens in the cockpit then call it a MD-10. Are you under the impression that the MD-10 was produced new?
The DC10 is a different type rating and truly a different animal. "
It shares the type rating, this is the problem. Stick and rudder the MD-10 is no different than the DC-10. "Back Variant"??? Man they take a DC-10, cut a hole in the bell and drop the E-rack. Rewire most of the aircraft and slap a bunch of shiny knobs and screens in the cockpit then call it a MD-10. Are you under the impression that the MD-10 was produced new?
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No more handling differences in the MD11 vs MD10 than you would find with the 727-200 vs 727-100 or the DC8-55 vs DC8-63.
The MD-11 is dramaticaly different. Don't get me wrong I love the MD-11 but it is a completely different machine. The MD-10 has the same engines as the DC-10's (not FADEC), The same flight control surfaces and empty weight more or less.
The MD-11 was designed for efficiency at altitude, more efficient thrust less drag (small tail being the largest change for efficiency).
This is the MAJOR question posed to it's safety values. I still maintain that it is just as safe as the DC-10 given the driver respects and understands it's limitations.
I have been intimate with both airframes for more than 11 years.
You can not compare the DC-8-50 and -60 series as a relevant comparason, the technology and aggresive improvements do not compare at all. All DC-8's land like pancakes, heavy structure, airframe weight and aerodymic cleanliness was not a significant factor only size to increase revenue.... It is the only thing that the MD-11 shares with the DC-8/super-8 and the MD-11. Same goes for the 727.
Bottom line, the MD-11 has different flight chararistics than the MD/DC-10. Less Drag, more thrust and a smaller margine for error especially at slow speeds. When she is lite she is also much more difficult to slow down in decent but she climbs with much respect.
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I DO NOT like flying with autopilot off, autothrottles on. I am 75% more in-the-loop if I click both off. And I can't find any reason not to, except laziness.....