WPR11FA093

The pilot stated that, during the landing roll, the airplane veered right concurrent with him placing the propeller into reverse. The pilot attempted to realign the airplane with the runway, but it 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. Postaccident examination of the nose landing gear steering assembly revealed no anomalies; the nose landing gear steering travel and rake angle were within manufacturer’s prescribed limits. Examination of the 8-ply nose landing gear tire revealed that the tire was underinflated at 43 psi, whereas the manufacturer’s recommended pressure is 70 psi. According to a Customer Information Letter that addressed nose landing gear steering concerns, the manufacturer stated that a nosewheel tire inflated to 70 psi allowed better steering control forces and warned that an underinflated tire could increase forces associated with steering. The pilot reported that he did not check the tire inflation pressure during the preflight.

HISTORY OF FLIGHT On January 9, 2011, about 1400 mountain standard time, a Piper PA46-500 single-engine turboprop airplane, N5365D, sustained substantial damage following a runway excursion during the landing roll at Phoenix Sky Harbor International Airport (KPHX), Phoenix, Arizona. The private pilot and four passengers were not injured. The airplane was registered to Fiesta Foods of Hermiston, Oregon, and operated by the pilot. Visual meteorological conditions prevailed, and an instrument flight rules flight plan was filed for the Title 14 Code of Federal Regulations (CFR) Part 91 personal flight. The flight originated from Boeing Field, Seattle, Washington, with an intermediate fuel stop in Reno, Nevada. The pilot's planned destination was Phoenix Sky Harbor International Airport. During a telephone conversation with the National Transportation Safety Board (NTSB) investigator-in-charge, the pilot reported that during the landing roll on runway 7R, he moved the propeller lever into reverse and the airplane veered “hard” right of 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, which resulted in substantial damage. AIRCRAFT INFORMATION The Piper Meridian PA46-500TP is a low-wing, single-engine airplane powered by a Pratt & Whitney PT6A-42A turbine engine. The airplane was configured with two pilot seats and four passenger seats. The most recent annual inspection of the airplane, engine, and propeller was completed on January 30, 2010. At that time, the airplane and engine had accumulated about 1,306 total flight hours. The airplane was in compliance with all applicable airworthiness directives. The airplane is equipped with a retractable tricycle air-oil strut type landing gear which is hydraulically operated by an electric hydraulic pump. A selector handle/switch on the instrument panel to the left of the control quadrant is used to select gear UP or DOWN positions. The nose gear is steerable through a 60 degree arc by use of the rudder pedals. As the gear retracts, the steering linkage separates from the gear so that rudder pedal action, with the gear retracted, is not impeded by the nose gear operation. The nose gear rotates 90 degrees to stow in the horizontal position. A steering bungee is also incorporated in the nose wheel steering mechanism. METEOROLOGICAL INFORMATION Weather at Phoenix Sky Harbor International Airport during the timeframe 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 degrees Celsius, and altimeter 29.88 inches of mercury (Hg). TESTS AND RESEARCH Following the accident, the landing gear and nose wheel steering systems were examined; the full examination report is contained in the public document for this case file. The noselanding gear (NLG) was intact and remained attached to the airframe. The NLG wheel assembly appeared to be in line with the longitudinal axis of the airplane when the rudder pedals were centered, and the steering travel was within limits, as denoted by the steering limit markings. The airplane was equipped with the upgraded “white mount” engine mount assembly (Service Bulletin 1154C) and no anomalies were noted. The NLG tire was a Michelin AR 500-5 P/N 070-310-0 (8-ply with an installed tube) and the measured pressure was 43 psi. The Airplane Flight Manual (AFM), section 8, states that the nose landing gear tire should be inflated to 70 psi. There were no flat spots or areas of abnormal wear. There were several rocks wedged between the left tire sidewall and the bead, however, the tire rolled free and no leaks were noted. The NLG strut rake angle was measured and yielded a 0.4 degree angle (forward); Piper Aircraft recommends a rake angle of 0.0 degrees to 0.5 degrees forward (which equates to an approximate angle of 90 to 90.5 degrees between the longitudinal axis and the NLG strut). ADDITIONAL INFORMATION On March 27, 2008, Piper issued a Customer Information Letter - PA46 Operational and Maintenance Information, Nose Gear Steering. The letter addressed customer concerns regarding nose gear steering anomalies associated with PA46 series airplanes, and provided specific actions that operators could take to ensure continued operations and conformity to factory specifications. In addition to design changes, stiffer steering bungee and an 8-ply nose tire inflated to 70 psi (the accident airplane had both design changes incorporated), the letter addressed tire pressure. The letter stated, in part, that low tire pressure could increase the forces associated with steering and, conversely, a tire inflated to 70 psi allowed better steering control forces. The letter reiterated that an underinflated tire could increase forces associate with steering and advised pilots to check tires for proper inflation during the preflight. The pilot reported that he did not check the tire inflation pressure during the preflight.