History of Flight
On January 9, 2011, at about 1400 mountain standard time, a Piper PA46-500 single-engine turboprop airplane, registration N5365D, departed from Boeing Field, Seattle, Washington, with an intermediate fuel stop in Reno, Nevada. The flight was operated under Title 14 Code of Federal Regulations Part 91 as a personal flight. The pilot filed an instrument flight rules flight plan and visual meteorological conditions prevailed at the destination. The intended destination was Phoenix Sky Harbor International Airport (KPHX), Phoenix, Arizona. During the landing roll on runway 7R, the pilot moved the propeller lever into reverse and the airplane veered “hard” to the right of the runway centerline. The pilot attempted to realign with the runway, but the airplane exited the right side of the paved surface. During the runway excursion, the left main landing gear collapsed and the left wing contacted the ground, resulting in substantial damage. The private pilot and four passengers were not injured.
Aircraft Information
The Piper Meridian PA46-500TP is a low-wing, single-engine airplane powered by a Pratt & Whitney PT6A-42A turbine engine. It is configured with two pilot seats and four passenger seats. The airplane has a retractable tricycle air-oil strut type landing gear, operated hydraulically by an electric hydraulic pump. A selector handle on the instrument panel to the left of the control quadrant is used for gear selection. The nose gear is steerable through a 60-degree arc via rudder pedals. As the gear retracts, the steering linkage separates. A steering bungee is incorporated in the nose wheel steering mechanism. The most recent annual inspection of the airplane, engine, and propeller was completed on January 30, 2010, at which time the airplane and engine had accumulated about 1,306 total flight hours. The airplane was in compliance with all applicable airworthiness directives.
Meteorological Information
Weather at Phoenix Sky Harbor International Airport at the time of the accident was reported as: variable wind at 3 knots, visibility 10 miles, few clouds at 10,000 feet, overcast ceiling at 25,000 feet, temperature 16°C, and altimeter 29.88 inches of mercury.
Tests and Research
After the accident, the landing gear and nose wheel steering systems were examined. The nose landing gear (NLG) remained attached to the airframe, and the NLG wheel assembly aligned with the longitudinal axis when rudder pedals were centered. Steering travel was within limits per steering limit markings. The airplane was equipped with the upgraded “white mount” engine mount assembly (Service Bulletin 1154C) with no anomalies. The NLG tire was a Michelin AR 500-5 P/N 070-310-0 (8-ply) with a measured pressure of 43 psi. The Airplane Flight Manual (AFM) section 8 specifies 70 psi for the nose landing gear tire. No flat spots or abnormal wear were noted, but several rocks were found wedged between the left tire sidewall and bead; the tire rolled free with no leaks. The NLG strut rake angle measured 0.4 degrees forward; Piper Aircraft recommends 0.0 to 0.5 degrees forward.
Additional Information
On March 27, 2008, Piper issued a Customer Information Letter addressing nose gear steering anomalies on PA46 series airplanes. It provided actions to ensure continued operations and conformity to factory specifications, including design changes such as a stiffer steering bungee and an 8-ply nose tire inflated to 70 psi (both incorporated on the accident airplane). The letter stated that low tire pressure could increase steering forces, while a tire inflated to 70 psi allowed better steering control. It reiterated that an underinflated tire could increase forces and advised pilots to check tire inflation during preflight. The pilot reported that he did not check the tire inflation pressure during the preflight.