Thank you for illustrating my point, Nubian. There was even one aeroplane that was statistically far, far worse than Concorde. It was A320 on the evening of June 26th 1988. And then there was passenger jet that never crashed during its entire career; Dassault Mercure. A320s are commonplace today, while no Mercure is active. Go figure.
Dear PPRuNers, some of you are putting forward the arguments similar to the following:
Premise A: MD-11 has worse accident statistics than B737
Premise B: Aeroplane that has worse accident statistics than B737 is dangerous.
Conclusion: MD-11 is dangerous.
The logic of the argument is impeccable. However, the conlusion is false, as the premise B is false and represents
the misuse of statistics. Last year is not as "good a period as any" as there were no MD-11 incidents or accidents. This year? Very significant for anyone unaware of the meaning of the word "streak" in statistics. Statistics can point to areas requiring further examination but most of the time cannot be relied on to provide definite answers by itself.
Recommended reading: Carl Sagan: "Significance Junkies", Darell Huff: "How to lie with statistics"
Originally Posted by Lederhosen
There are around 6000 Boeing 737s. Yes they do crash, but apparently not at the same rate as MD11s. If we knew why there is such a difference, it might allow a few more colleagues to spend Xmas with their loved ones to use the emotive language of our cabin crew correspondent a few posts earlier.
If we knew.... well if you did bother to read reports, you would know the causes of every MD-11 accident bar the last two, as the investigation teams are still working on them! Do you really have no incentive to look them up?!? Would you like to be spoon-fed? OK, let's go:
First there was FedEx at Newark
Originally Posted by Aviation Safety Network
The aircraft touched down 1175 feet down runway 22R at 149 knots with a 500f/min descent rate and 1,67g acceleration. The flight bounced, yawed and rolled right, and touched down again 2275 feet from the threshold, at 1,7g (lateral acceleration 0,4g to the right) and dragging the no. 3 engine 238 feet further on. The right roll, pinning the no. 3 engine to the ground, possibly continued until the right wing's spars broke. The MD-11 skidded off the right side of the runway and ended up on its back 4800 feet from the threshold and just short of Terminal B.
It appeared that the aircraft (N611FE) had suffered a similar incident (bounced on landing) in Anchorage, November 4, 1994.
PROBABLE CAUSE: "The captain’s overcontrol of the airplane during the landing and his failure to execute a go-around from a destabilized flare. Contributing to the accident was the captain’s concern with touching down early to ensure adequate stopping distance."
Then there was SR111; using MPETs was design error which had no bearing on aeroplane's handling and would probably go undetected if it wasn't for slopilly concieved and executed instalation of IFE.
Korean at Shanghai:
Originally Posted by Aviation Safety Network
When the aircraft climbed to 4500 feet in the corridor, the captain, after receiving two wrong affirmative answers from the first officer that the required altitude should be 1500 feet, thought that the aircraft was 3000 feet too high. The captain then pushed the control column abrubtly and roughly forward causing the MD-11 to enter a rapid descent. Both crew members tried to recover from the dive, but were unable. The airplane crashed into an industrial development zone 10 kilometers (6 miles) southwest of Hongqiao airport.
After that it was China Airlines at Chek Lap Kok
Originally Posted by Aviation Safety Network
CAUSAL FACTORS:
"The cause of the accident was the commander’s inability to arrest the high rate of descent existing at 50 ft RA.
Probable contributory causes to the high rate of descent were:
(i) The commander’s failure to appreciate the combination of a reducing airspeed, increasing rate of descent, and with the thrust decreasing to flight idle.
(ii) The commander’s failure to apply power to counteract the high rate of descent prior to touchdown.
(iii) Probable variations in wind direction and speed below 50 ft RA may have resulted in a momentary loss of headwind component and, in combination with the early retardation of the thrust levers, and at a weight only just below the maximum landing weight, led to a 20 kt loss in indicated airspeed just prior to touchdown.
Fast forward to Subic Bay:
Originally Posted by Aviation Safety Network
PROBABLE CAUSE: The failure of the flight crew to properly address an erroneous airspeed indication during descent and landing, their failure to verity and select the correct airspeed by checking the standby airspeed indicator, and their failure to execute a missed approach. These failures led to an excessive approach and landing speed that resulted in a runway overshoot.
4 out of 5 losses mainly attributable to pilot error. Take note: errors committed were largely not type specific, they were more indication of wanting airmanship. Read the reports and learn; lessons might be pertinent to you even if you are not MD-11 pilot.
Dear Lederhosen, if your Bobby has
Kranich on her tail, then I can understand your
Angst beim Elfer. However, I'm really not amused by you and your colleagues 1) making dubious statements based on less than firm grip on statistics 2) accusing posters that don't agree with you for:
Rubbishing the data is most people's first reaction to something they do not believe in.
(...)
misplaced loyalty to an inanimate, unforgiving poorly designed machine
Such a statements are (to my despair) acceptable in modern politics. What we're discussing is aviation. Mix of the two never produced satisfactory results.
So is the MD-11 dangerous? Hell, yes! She's 250t+ and goes down the glide at 150kt, there are not many people in the world that can handle this. Those who can are called "MD-11 pilots" and every day they prove that the beast can be tamed. All of you believing that being a pilot is easy money are dead wrong. When this notion permeates the flightdecks, we'll be truly and deeply
ed.