Originally Posted by robsawatsky
So, exactly how often has an A34X failed to take-off before the end of the runway? Must be a lot given the concern expressed here.
At least this
once. Note that the flight crew was using the reduced flex thrust power level selection I mentioned earlier. This is supposed to make use of JNB's long runway (albeit at high altitude) to minimuse stress and wear on the engines. I didn't see a cause for this accident. It didn't involve an U.S. mfg'd a/c, a U.S. airline or on a flight involving the U.S. so no NTSB report which generally indicate a cause.
Here's an excerpt from some site (and a warning to automating flight controls too much):
An A340-313X of Emirates ran off the runway when taking off from Johannesburg International Airport on April 9 2004. Both pilots were unfamiliar with this lighter variant of the Airbus. At the call to rotate, the pilot flying pulled back on the stick. However, according to a report by the airline, "for approximately six or seven seconds the aircraft nose did not move upward" [5]. The nose finally came up, but the aircraft still did not become airborne. The crew felt a rumbling, selected full power, and about two seconds later the aircraft lifted off the ground [6]. The airport says 25 runway threshold and approach lights, and part of the runway surface, were damaged as the aircraft went over the end of 21R. Apparently the calculated rotation speed (Vr) was too low, so the Airbus fly-by-wire system kept it on the ground, rather than risking an overrotation. The pilot had received incorrect rotation instructions during a simulator session. Emirates Training establishment was censured by Airbus after an investigation.