Cessna 421 N123SM

Summary

On 24 June 2023 at about 16:15 local time, a Cessna 421 registered N123SM, operated by Fernair LLC, was involved in an accident near Rockport, Texas, United States. 4 people were on board and nobody was injured. The aircraft was substantially damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

24 June 2023 at 16:15

Classification

Accident

Location

Rockport, Texas, United States

Coordinates

28.0206, -97.0544

Aircraft

Cessna 421

Registration

N123SM

Category

Airplane

Year built

1968

Engines

2

Operator

Fernair LLC

Operating rule

Part 91: General Aviation

Purpose of flight

Personal

Phase of flight

Not recorded

Route

Corpus Christi → West Houston

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

CEN23LA267

Nobody was injured.

The failure of the left engine starter adapter gear, which resulted in catastrophic damage to other engine components, and the subsequent loss of engine power.

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

Read the full NTSB narrative

The pilot reported that, while climbing through 6,000 ft above mean sea level (msl), the left engine tachometer generator went offline but the engine was still operating normally. He stated that about 2 minutes later, the left engine lost power and the airplane banked left. He attempted to stabilize the airplane with aileron and rudder control, but the airplane entered a spin. The pilot was able to regain control, but after the spin the right engine’s propeller was stopped and the left engine’s propeller was windmilling. The pilot executed a forced landing to a field and the airplane sustained substantial damage to the horizontal stabilizer. During a postaccident engine test run, the right engine operated normally. Examination of the left engine revealed the starter adapter gear had failed, which resulted in damage to other engine components that rendered the engine inoperable. The starter adapter was subject to an FAA Airworthiness Directive (AD), and an associated manufacturer mandatory service bulletin (SB). Maintenance records indicated that the AD and SB had been complied with less than 1 month and 10 operating hours before the accident. The mechanic that performed the SB inspection reported that he had performed this test numerous times in the past and did not find the procedures difficult but required patience. He recalled that the backlash on both starter adapter assemblies were well within the limits specified in the SB.

Quoted verbatim from the NTSB record.