dutchroll Posted June 27, 2013 Posted June 27, 2013 A plane spotter captured this rejected takeoff a couple of days ago at Manchester airport. The incident occurs at 0:17. It looks to me like a big compressor stall (yes you do get the big sheet of flame with a compressor stall), though they haven't confirmed exactly what it was. Talking through what the pilots would hear, see and do for the benefit of those not familiar with a big jet rejected takeoff: 1. Loud bang and simultaneous violent yaw would be experienced (if the engine totally loses power). 2. Instantly apply FULL opposite rudder to counteract the yaw, close thrust levers and select reversers as available. Rudder then as required. 3. Closing the thrust levers above about 70 knots initiates maximum autobrakes (quite violent!) and automatic spoiler deployment. You can see this on the video. The plane stops very quickly! Looks well handled from an outside observer perspective. 1 1
Teckair Posted June 27, 2013 Posted June 27, 2013 If that happened after rotation would that be the end of the deal ie. not recoverable?
dutchroll Posted June 27, 2013 Author Posted June 27, 2013 If that happened after rotation would that be the end of the deal ie. not recoverable? No, a single engine failure is always recoverable at any point. This is designed into RPT jets. In fact I should've more correctly said "up to full rudder". The large, abrupt rudder input is needed on the larger twin jets to stop and reverse the sudden yaw, which depending on the point at which it happens can be quite violent and needs quick recovery action or else you can get close to the runway edge. This of course is because you're at fairly slow speed and thus lower rudder effectiveness, but still at very high thrust on one side when the other side fails. The V1 speed (at which takeoff must be continued) is always greater than minimum single engine control speed (Vmcg or Vmca), so there is always enough rudder authority to keep the plane going in a straight line at any point after V1. You just need to be on it quickly to avoid diverging too far across the runway. 2
dutchroll Posted June 27, 2013 Author Posted June 27, 2013 And another view (gee the poms are keen plane-spotters!). You can see how quickly the thing stops in max autobrakes.
Teckair Posted June 28, 2013 Posted June 28, 2013 No, a single engine failure is always recoverable at any point. This is designed into RPT jets.In fact I should've more correctly said "up to full rudder". The large, abrupt rudder input is needed on the larger twin jets to stop and reverse the sudden yaw, which depending on the point at which it happens can be quite violent and needs quick recovery action or else you can get close to the runway edge. This of course is because you're at fairly slow speed and thus lower rudder effectiveness, but still at very high thrust on one side when the other side fails. The V1 speed (at which takeoff must be continued) is always greater than minimum single engine control speed (Vmcg or Vmca), so there is always enough rudder authority to keep the plane going in a straight line at any point after V1. You just need to be on it quickly to avoid diverging too far across the runway. That is nice to know, just have to hope the pilot is right on it.
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