History of Flight
On November 19, 2012, about 0618 local time, a Piper PA-32-300, registration N4267R, was destroyed when it impacted airport terrain during an attempted turnback immediately after takeoff from Francisco C. Ada/Saipan International Airport (PGSN), Obyan, Saipan, Northern Mariana Islands. One passenger sustained fatal injuries, the pilot and four passengers sustained serious injuries, and one passenger sustained minor injuries. The on-demand charter flight was operated by Star Marianas Air, Inc. under Part 135. Dawn visual meteorological conditions prevailed, and no flight plan was filed.
The airline typically shuttled tourists between Saipan and Tinian. The passengers included five Chinese nationals and one Filipino national, destined for Tinian.
The pilot first contacted the air traffic control tower (ATCT) at 0604, requesting taxi clearance. The flight was instructed to taxi to the end of runway 7 and was cleared for takeoff about 4 minutes later. About 4 minutes after takeoff, the pilot requested an immediate landing, and the airplane landed uneventfully on runway 7, exiting at taxiway B. After a brief engine runup, the pilot informed the ATCT of readiness for an intersection departure from runway 7. About 45 seconds later, the airplane was observed turning left, with garbled radio transmissions. Shortly after, it impacted airport property near the northeast end of runway 6.
The main wreckage came to rest at the treeline northwest of runway 6, and a post-accident fire began. The pilot and most passengers exited, but the front-right-seat passenger remained and was fatally injured.
Personnel Information
The pilot held a commercial pilot certificate with an instrument rating. He began flying for the airline in January 2012 and was qualified as pilot-in-command and check airman in the PA-32-300. His most recent flight review was in January 2012, and his last first-class medical was in August 2012. He had about 1,238 total flight hours, including 674 hours in the accident airplane make and model. He flew about 54 hours in October 2012 and 31 hours in November. Duty records showed he was on duty for almost 12 hours at the time of the accident.
Toxicology tests on the pilot detected no carbon monoxide, ethanol, or screened drugs.
In a telephone interview two weeks after the accident, the pilot recalled most of the flight except the takeoff and return just prior to the accident. He reported a normal initial takeoff and climbout, but at about 400-500 feet above ground level, he noticed a significant change in engine sound and power. Manifold pressure and rpm gauges did not indicate full takeoff power, though he noted that the airline's engine gauges were "never accurate." He pushed throttle, propeller, and mixture full forward, turned on the electric fuel boost pump, and switched the fuel selector from left to right tank. Believing insufficient runway remained to land, he chose to attempt a turnback. He intended to land on runway 24 but overshot, then aimed for the ramp. He maintained a bank angle of about 35-45 degrees, but when the airplane was about 15-20 feet above the ground, it suddenly dropped.
The pilot had no recollection of a previous air turnback, landing, and runup that occurred just prior to the accident, though ATCT records showed it happened. He recalled a similar event but could not place it in time.
Aircraft Information
The Piper PA-32-300 was manufactured in 1969, equipped with a Lycoming IO-540 series engine. It had fixed tricycle landing gear and seated seven in a 2-3-2 arrangement. Flaps had positions of 0, 10, 25, and 40 degrees, spring-loaded to retracted. Fuel system had four individually-selectable tanks: left tip, left main, right main, right tip, total capacity 84 gallons. The Owner's Handbook specified using the fullest main tank for takeoff and alternating tip tanks in cruise.
Maintenance records showed total time in service of about 6,805 hours at the accident. An overhauled engine was installed in July 2012 at 6,290 hours. The most recent inspection, AAIP-1, was completed on November 17, 2012, at 6,799 hours airframe time and 516 hours since engine overhaul.
Meteorological Information
The 0554 automated weather observation at PGSN reported winds from 060 degrees at 10 knots, visibility 10 miles, scattered clouds at 2,000 feet, broken at 5,000 feet, overcast at 11,000 feet, temperature 27°C, dew point 23°C, altimeter 29.91 inHg.
Communications
The ATCT, operated by Serco under FAA contract, provided a transcript. The pilot first contacted at 0604:32. After taxi and delay for wake turbulence, takeoff was cleared at 0608:27 with an early right turnout. At 0612:35, the pilot requested immediate landing, was cleared, and landed uneventfully. After exiting, the controller remarked it was the second such occurrence in less than two weeks. The pilot performed a runup on taxiway B, then at 0616:17 requested intersection departure. At 0617:17, the pilot made an incomplete transmission. At 0617:27, observing the airplane turning and descending, the controller cleared it to land, but only a garbled response was received.
Airport Information
PGSN had two parallel runways: 7/25 (8,700 x 200 ft) and 6/24 (7,000 x 100 ft). Runway 7 was used for both departures. Taxiway B, perpendicular to the runways, was about 3,150 feet from the runway 7 threshold. An intersection departure from taxiway B left about 5,550 feet of available runway. Runway 6/24 was offset 750 feet northwest of runway 7/25. The shoreline was about 2,600 feet northeast of runway 7 and about 4,300 feet southwest. Airport elevation was 211 feet.
Wreckage and Impact Information
The main wreckage came to rest at the junction of the grassy area adjoining runway 6 and the treeline about 290 feet northwest of runway 6/24 centerline, about 1,050 feet from runway 7/25 centerline, and about 700 feet before the departure ends. Evidence indicated the left wing struck first while the airplane was in a left turn. Ground scars and debris path oriented northwest, curving 15 degrees left. The first ground scar was 35 feet from the northwest side of runway 6. The left wing was found fracture-separated at the root, about 108 feet from first impact. The left main landing gear was separated. The main wreckage came to rest upright against the treeline, oriented about 240 degrees. Cockpit and cabin contents were fire damaged. The right wing outboard half was consumed by fire. The aft fuselage and empennage were intact. Pitch and rudder control continuity was established. The pitch trim tab was set about 1/2 inch below the stabilator trailing edge. The right wing flap was retracted; the left flap was fracture-separated. The cockpit flap handle appeared in the retracted position in later photographs. The fuel selector handle appeared set to a right-side tank, but specific position could not be determined. The engine control levers were near full forward.
Medical and Pathological Information
Toxicology on the front-right passenger detected a carbon monoxide level of 25 percent in femoral blood but no cyanide, ethanol, or drugs.
Test and Research
The engine was examined and tested at Lycoming Engines. After initial start difficulties due to a blocked fuel pump and high oil pressure from dormancy, the engine ran and completed the production test sequence, developing full rpm and manifold pressure, with no deficiencies that would preclude continued operation. Two cylinders had partially occluded fuel injector nozzles (75% and 100%), but the age and reason for occlusion were not determined.
The magnetos were examined. The left magneto functioned normally. The right magneto had internal timing trailing by three distributor gear teeth, but bench tests showed it would not have adversely affected engine performance. Disassembly revealed the distributor block bushing was loose, allowing the distributor gear to tilt and potentially disengage. The investigation did not determine the forcing mechanism for the mis-timing.