Gulfstream Aerospace G IV N701DB incident near Eagle, Colorado

Probable cause

The pilot's rejected takeoff due to perceived flight control system anomalies, which led to excessive brake temperatures and resulted in a right main landing gear brake fire.

NTSB analysis

The pilot reported that the pretakeoff flight control check was "normal" with "no binding or resistance issues." During the initial takeoff, the pilot used the autothrottles. Shortly after, a triple chime and master warning indication activated, so he rejected the takeoff. However, the pilot observed no messages on the crew alert system nor any tripped electrical circuit breakers, so he chose to attempt another takeoff. During this takeoff, he did not use the autothrottles. As the airplane accelerated through 75 knots, the triple chime and master warning indication activated again. The engine low-pressure turbine speed was within the yellow arc, so the pilot reduced the engine thrust slightly to return to the normal operating range and continued the takeoff. At rotation speed, he pulled back on the control yoke, but the flight controls did not seem to respond normally. The pilot added that the controls had no "noticeable pressure resistance and felt unloaded with hydraulic pressure." He noted that the yoke was moved "forward and then back further aft" with the same result. The pilot subsequently rejected the takeoff and applied maximum braking and full reverse thrust. He taxied the airplane off the runway and stopped it on the parallel taxiway.

A postincident examination of the airplane, including the flight control system, did not reveal any anomalies that would have compromised the effectiveness of the flight control system. Although minor variations in the inboard elevator control cable tension and elevator control surface deflections were noted, these variations also likely existed during the initial flight of the day; the pilots of that flight reported no discrepancies. After repairing the fire damage to the right main landing gear, the airplane manufacturer had two test pilots conduct an evaluation test flight. The pilots reported that the elevator response during takeoff was "positive, obvious, and 100% normal." The pilots continued the takeoff and subsequently returned for a full-stop landing. They reported that no anomalies occurred during the evaluation test flight.

Text from the NTSB. Open the NTSB docket for CEN15IA139 for the full record.