Beechcraft 35B33 N9745Y

Summary

On 29 June 2018 at about 13:15 local time, a Beechcraft 35B33 registered N9745Y was involved in an accident near Berlin, Maryland, United States. 2 people were on board and one was seriously injured, one had minor injuries. The aircraft was substantially damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

29 June 2018 at 13:15

Classification

Accident

Location

Berlin, Maryland, United States

Nearest airport

Ocean City Muni (OXB)

Coordinates

38.3114, -75.1300

Aircraft

Beechcraft 35B33

Registration

N9745Y

Category

Airplane

Year built

1963

Engines

1

Operator

Not recorded

Operating rule

Part 91: General Aviation

Purpose of flight

Personal

Phase of flight

Not recorded

Route

Berlin → Dublin

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

ERA18LA181

1 person was seriously injured.

The failure of the No. 3 cylinder exhaust valve, which resulted in the total loss of engine power during takeoff.

Quoted verbatim from the NTSB record. This site does not paraphrase or interpret it.

Read the full NTSB narrative

The pilot stated that, shortly after he retracted the landing gear during the initial climb after takeoff, the airplane began to vibrate and the engine lost power. The pilot initiated a 180° return to the runway, but unable to reach it, performed a forced landing to a golf course. Postaccident examination of the airplane’s engine revealed that the No. 3 cylinder sustained catastrophic damage, including heavy mechanical damage to the piston and separation of the exhaust valve, a portion of which was lodged under the intake valve. Numerous pieces of metal consistent with material from the No. 3 piston head were found in the oil sump. Given this information, it is likely that the loss of engine power was due to the failure of the No. 3 exhaust valve. The engine manufacturer's maintenance manual recommended that this engine be overhauled at 1,500 hours of operation or every 12 years, whichever occurred first. The maintenance manual also recommended that a borescope be used to inspect the engine’s cylinders during every 100-hour/annual inspection in conjunction with a compression test. The engine maintenance records listed the compression test results during previous annual inspections but did not indicate whether the cylinders had been inspected with a borescope. At the previous annual inspection, about 1 month before the accident, the engine total time was 1,769.1 hours. Additionally, the engine was manufactured about 37 years prior to the accident and had not been overhauled. The investigation did not determine if the impending failure of the exhaust valve could have been detected and corrected had the borescope inspections been performed and/or the engine had been overhauled.

Quoted verbatim from the NTSB record.