Beech B36TC N6860W accident near Laporte, Texas

Probable cause

The loss of engine power due to a torn intercooler hose that resulted in an overly rich fuel mixture, which, when combined with the pilot's activation of the auxiliary fuel pump, flooded the engine.

NTSB analysis

The student pilot was conducting a local flight. He said that during the initial climb, the engine began to make a "weird very loud sound" and that the engine started to lose power. He stated that the "engine noise started to get louder and power was almost gone." When he activated the auxiliary fuel pump, the engine noise became "real loud" and sounded "very deep." The airplane was descending, and the student pilot performed a forced landing near a housing development. During the landing, the right wing separated and the airplane's cabin collapsed inward. Although a Federal Aviation Administration inspector expressed concerns about the exhaust pipe v-band clamp, the nature of those concerns were not conveyed to the NTSB. The airplane's engine was removed and later examined and test run at the manufacturer. During a postaccident examination, the v-band clamp was found to be loose and could have allowed manual rotation of the turbo outlet collar. However, it could not be determined what effect this may have had on the accident. The examination also revealed that the induction hoses to and from the intercooler were both torn. If the induction hose to the intercooler failed in flight, manifold pressure would have dropped immediately, and the noise the pilot heard could have been turbo discharge pressure escaping through the tear in the hose. When the engine lost turbo pressure, the fuel pump would have continued to operate with a much richer mixture because it would not have sensed a loss of induction pressure. When the pilot turned on the auxiliary fuel pump, the engine would have been flooded with excess fuel. Thus, it is likely that the torn induction hose combined with the excess fuel from activation of the fuel pump led to the engine being flooded resulting in the loss of engine power.

Text from the NTSB. Open the NTSB docket for CEN18LA340 for the full record.