Piper PA-46-500TP N747BL

Summary

On 16 January 2007 at about 18:55 local time, a Piper PA-46-500TP registered N747BL, operated by Battista A. Locatelli, was involved in an incident near Parowan, Utah, United States. One person was on board and nobody was injured. The aircraft was slightly damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

16 January 2007 at 18:55

Classification

Incident

Location

Parowan, Utah, United States

Nearest airport

Parowan Airport (1L9)

Coordinates

37.8594, -112.8161

Aircraft

Piper PA-46-500TP

Registration

N747BL

Category

Airplane

Engines

1

Operator

Battista A. Locatelli

Operating rule

Part 91: General Aviation

Purpose of flight

Personal

Phase of flight

Not recorded

Route

Las Vegas → Parowan

Aircraft damage

Minor

Weather

VMC

Light

Day

NTSB number

SEA07IA058

Nobody was injured.

The inadequate design of the engine mount, which caused an uncommanded left turn during the landing roll, loss of directional control, and impact with snow-covered terrain.

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

Read the full NTSB narrative

At the end of the landing rollout the pilot experienced a loss of control, which resulted in the airplane veering off the left side of the runway and impacting a snow bank before the nose landing gear collapsed. An examination of the nose gear revealed that the rear actuator bolt had failed due to overload during the event sequence and that the engine mount was bent near the nose gear actuator attach feet. Following the identification of a number of cracked engine mounts, several Piper service bulletins were issued and the original engine mount was redesigned. The redesign process included finite element model analysis and other testing programs. These design tools were not incorporated in the original mount design. During a postaccident examination of a similar accident in Steamboat Springs, Colorado, in 2006, investigators found that there was compliance (flexibility) in the original engine mount actuator attach feet structure, which sometimes resulted in cracks in the engine mount at the actuator feet. The NTSB’s investigation of the Steamboat Springs accident determined that compliance was sometimes exacerbated at some speeds, resulting in a high shimmying effect and a subsequent uncommanded left or right turn of the nosewheel during takeoff or landing. Subsequent to the Steamboat Springs investigation, evidence was received of bulkhead damage immediately behind the engine mount found on a PA-46-310P in Greeley, Colorado. The Steamboat Springs accident airplane was reexamined in 2008, and similar firewall damage was found. The mechanical damage and marks were consistent with the engine mount contacting the bulkhead periodically before the accident. The new engine mount, which the manufacturer subsequently replaced under warranty on all PA 46-500TP airplanes, incorporates a heavy-duty, reinforced one-piece design at the actuator attach point, eliminating the two-piece design, which was previously produced in two-weld and subsequent single-weld versions. The reinforced, one-piece design provides a less compliant structure, which prevents relative motion between the two feet in the original engine mount design.

Quoted verbatim from the NTSB record.