Bell OH 58A N916PD

Summary

On 4 December 2016 at about 05:00 local time, a Bell OH 58A registered N916PD, operated by City of Sacramento, was involved in an accident near Sacramento, California, United States. 2 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

4 December 2016 at 05:00

Classification

Accident

Location

Sacramento, California, United States

Nearest airport

Mc Clellan Airfield (MCC)

Coordinates

38.6678, -121.4006

Aircraft

Bell OH 58A

Registration

N916PD

Category

Helicopter

Year built

1971

Engines

1

Operator

City of Sacramento

Operating rule

Public Use

Phase of flight

Not recorded

Route

Sacramento → Sacramento

Aircraft damage

Substantial

Weather

VMC

Light

Night

NTSB number

WPR17LA034

Nobody was injured.

The failure of the vertical stabilizer due to fatigue. 

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

Read the full NTSB narrative

The pilot reported that during the takeoff, flight, and landing for a local routine helicopter patrol flight, he did not experience any turbulence nor did any of the flight controls reveal an indication that something was wrong. The pilot reported that during the postflight inspection, the vertical stabilizer was found bent downward away from the tail rotor. A postaccident examination of the vertical stabilizer revealed a fatigue crack that initiated at the aft end of the inboard skin at about the middle of the span. A stop-drill hole was present above the upper aft attachment hole, indicating that the vertical stabilizer was allowed to continue in service after a crack had been detected that extended about 1 1/4 inches from the aft edge of the inboard edge. The crack intersected the lower side of the stop-drill hole, and a fatigue crack reinitiated from the forward side of the stop-drill and continued to propagate towards the leading edge. The operator acquired the helicopter as US Army surplus. Since 2003, the US Army’s daily inspection checklist included inspection for cracks originating from the four attachment inserts on the inboard of the vertical stabilizer. The operator’s maintenance vendor was not aware of the US Army aviation safety action message for the daily inspection for cracks inboard of the vertical stabilizer. Had those daily inspections of the vertical fin attachment area been accomplished, these cracks would likely have been identified.

Quoted verbatim from the NTSB record.