Piper PA-28-140 N261FC

Summary

On 27 March 2025 at about 22:00 local time, a Piper PA-28-140 registered N261FC was involved in an accident near Royal Kunia, Hawaii, United States. 2 people were on board and 2 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

27 March 2025 at 22:00

Classification

Accident

Location

Royal Kunia, Hawaii, United States

Coordinates

21.4121, -158.0339

Aircraft

Piper PA-28-140

Registration

N261FC

Category

Airplane

Year built

1968

Engines

1

Operator

Not recorded

Operating rule

Part 91: General Aviation

Purpose of flight

Instructional

Phase of flight

Not recorded

Route

Honolulu → Unknown

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

ANC25LA028

2 people had minor injuries.

Improper alteration of the crankshaft propeller flange at an unknown time, which resulted in an in-flight separation of the propeller assembly.

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

Read the full NTSB narrative

During an instructional flight, the flight instructor detected a vibration; shortly thereafter he heard a loud bang, the engine lost total power, and the nose dropped. He performed a forced landing to a heavily vegetated field. After landing, the flight instructor noticed that the propeller was missing. It was later found in a nearby residence; no one was injured. The airplane sustained substantial damage to both wings, the fuselage, and the empennage. Examination of the separated propeller revealed that the engine crankshaft had fractured and separated just aft of the crankshaft propeller flange (CPF). This flange is an integral part of the crankshaft and is where the propeller attaches to the engine; however, the CPF was found attached to the separated propeller and not the crankshaft where it belonged. The CPF was removed from the propeller and examined by an NTSB metallurgist to determine why the crankshaft had fractured and separated. The examination revealed that the CPF had been improperly modified by the drilling and installation of additional bolts. Investigators were unable to determine the purpose for the modification, when it was made, or by whom.    Available maintenance records did not include any entries noting that the propeller assembly had been removed or altered since initial installation. Additionally, there are no Lycoming maintenance instructions, repair instructions, or service bulletins that permit hole drilling and filling of the CPF.

Quoted verbatim from the NTSB record.