Bell Helicopter Textron Canada 407 N451PH

Summary

On 23 May 2023 at about 15:15 local time, a Bell Helicopter Textron Canada 407 registered N451PH, operated by PHI Aviation LLC, was involved in an accident near Abbeville, Louisiana, 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

23 May 2023 at 15:15

Classification

Accident

Location

Abbeville, Louisiana, United States

Nearest airport

Abbeville Chris Crusta Meml (IYA)

Coordinates

29.9752, -92.0847

Aircraft

Bell Helicopter Textron Canada 407

Registration

N451PH

Category

Helicopter

Year built

2012

Engines

1

Operator

PHI Aviation LLC

Operating rule

Part 91: General Aviation

Purpose of flight

Instructional

Phase of flight

Not recorded

Route

Lafayette → Unknown

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

CEN23LA199

Nobody was injured.

The pilot’s failure to maintain proper helicopter control during autorotation that resulted in an abnormal ground contact which caused the subsequent main rotor strike on the tail boom that severed the tail rotor driveshaft. Contributing to the accident was the main rotor blowback condition, due to the aft tilting of the main rotor disk.

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

Read the full NTSB narrative

The check pilot and the pilot receiving instruction were performing initial new hire training for the commercial operator. The pilot previously performed three practice 180° autorotations, terminating with a power recovery. The pilot then performed a practice, straight-in, full down autorotation to touchdown on the sod area parallel to the runway. During the touchdown, the two pilots heard a “loud bang.” The helicopter came to rest upright on the sod area and both pilots were able to egress from the helicopter without further incident. A postflight inspection revealed that the main rotor blades struck the tail boom, severing the tail rotor driveshaft. The main rotor blades, the tail boom, and the tail rotor system sustained substantial damage. The operator reported there were no preimpact mechanical malfunctions or failures with the airframe or the engine that would have precluded normal operation. According to another helicopter manufacturer, main rotor blowback occurs when the forward portion of the helicopter’s main rotor disk is displaced upward, while the rear portion of the main rotor disk is displaced downward. If the resulting blowback is excessive, the main rotor blades may impact the tail boom. A review of the accident helicopter rotorcraft flight manual (RFM) found no information listed to provide awareness to pilots about the main rotor blowback condition.

Quoted verbatim from the NTSB record.