High-speed rejected takeoffs (after V1) tend to result in aircraft damage, loss of control, and put the airplane in exactly the wrong place for coming to a stop: at the end of the takeoff roll.
Never a truer word. A couple of short stories that might interest readers. During type rating training on the 737-200 simulator with brand new 200 hour graduates, we were practicing rejected take off procedure on a performance limiting runway. In other words if everything went as planned from an flame-out about 10 knots below V1, the student would stop within 100 metres or so before the end. We must have conducted ten of these within 15 minutes just to get the right sequence of actions. Both students were lightning quick on the actions - after all there was no stress because it was a training session; not testing.
In the majority of the rejected take off's, one student would consistently go off the end of the runway by 100 metres or so. Yet his actions were fast and accurate same as the other chap who pulled up OK.
From my position on the jump seat, by chance I turned around to look at the instructor panel screen as the student who was over-running, accelerated down the runway through 70 knots or so. I suddenly noticed that the indicated brake hydraulic pressure at the rudder pedals was not zero as it should have been, but oscillating rapidly between zero and around 500 psi during the length of the take of roll. This indicated the pilot must have been inadvertently riding the brake pedals on the roll. In the darkness of the simulator it was not possible to see exactly where his toes were on the rudder pedals.
The slower acceleration to V1 nullified the planned decision speed to the extent that, even the 10 knots below V1 chosen for the flameout, didn't make up for the slow acceleration.
This explained why he constantly over-ran after aborting - despite correct actions. When this was pointed out to him, he vehemently denied he had his feet up on the brakes during the take off. I think there was a culture aspect with loss of face which is why he refused to accept the obvious.
There had to be a way to convince him; since if he did this in real life, one day he was going to be in real trouble. Hot brakes for one.
So I asked his PNF (same country of birth) to sit at the instructor panel and observe for himself the brake pressure readings for each wheels. Sure enough, as the simulator went down the runway the little red indicators showing pressure at the brake pedals, bobbed up and down signifying partial brake being applied by the student. I then asked them to discuss this between themselves in their own language. Eventually there was an understanding nod of the head of the culprit when his mate explained what he had personally seen. After that he had no problems with the rejected take off's.
On a separate occasion in a real 737-200, the crew noticed the occasional flashing of the wing body overheat light while taxiing for take off. The runway was short (5400 ft) and the over-run area deadly with a cliff 20 yards from the end of the actual runway. The captain lined up and by now the wing body overheat light had extinguished. He briefed his F/O (who had just 500 hours total time) that below 80 knots he would abort for any Master Caution indication and after 80 knots he would keep on going except of course for anything serious like engine failure.
The 737 was runway limited that day and V1 was around 128 knots. At 10 knots below V1, the Master Caution light came on caused by illumination of the wing body overheat light. The captain instantly aborted, but in his haste initially forgot to select manual speed brake for a few seconds. With full braking and full reverse he was able to stop the 737 with the nose wheel right on the very end of the runway. It was a very close thing.
During the taxi back to the terminal, the F/O asked why had the captain aborted contrary to his briefing. The captain was honest and said he could not explain his change of decision but that it was an instantaneous reaction to the sudden appearance of a large amber Master caution light in front of him. One could easily criticise the captain's potentially disastrous action -especially his initial failure to extend the spoilers. But that is not the point of the story.
Both events of the dragging brakes student and the high speed abort just mentioned, are typical where incorrect pilot actions at a critical time on the take off roll and leading to a high speed abort, can increase the dangers of high speed aborts on a limiting length runway.
In the case of the brake dragging mistake, the V1 was compromised. Because of the inevitable momentary indecision that a crew will experience if something out of the ordinary happens when fast approaching V1, this writer is convinced that it is a much safer bet to keep on going than risk a stuffed-up late abort.