An MD11 flight crew rejected two consecutive takeoffs followed by a return to the blocks for maintenance in each instance.
Synopsis
An MD11 flight crew rejected two consecutive takeoffs followed by a return to the blocks for maintenance in each instance.
Narrative
With the First Officer the pilot flying and in the takeoff high speed regime; received a MASTER CAUTION warning and the SPEED BRAKE handle moved. I elected to abort the takeoff and return to the gate. I had no clear warning indications for the abort. We did have the Master Caution light and the sound of the Speed Brake handle movement. It also felt out of position when I put my hand on it. No other anomalies were recorded. I thought we aborted at 100 KTS. Things happened fast and the data showed we were closer to 130 KTS but still below V1. Maintenance deferred the AUTO SPEED BRAKE and we re-dispatched. Second takeoff at around 60 KTS received another MASTER CAUTION. This time PFD (Primary Flight Display) FLAP 24 indication; momentarily went to yellow boxed 30 and a second reading of 23. I have never seen a dual reading like that. We did a low speed abort and returned to the gate. Once we slowed down the indications were again all normal. On each abort runway remaining was not an issue so I did a less than maximum effort abort. Both times the onboard computers showed no faults. The flight data showed that the flap position indicator was sending multiple erroneous indications. It was indication from flaps up to near Flaps 44 degrees. We are awaiting replacement position indicators and will dispatch tonight after they are installed.
Second reporter narrative
Returned to the ramp. Again there were no faults displayed in the system. We later learned that one of the flap position indicators was broken and was sending erroneous data. Maintenance said that the aircraft did not know if it was in the air or on the ground; hence all the erroneous warnings.
Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.