Accident
On July 4, 2017, at 1721 Atlantic daylight time, a Piper PA28-180, registration N9427J, operated by Horizon Aviation, sustained substantial damage when it impacted the San Antonio Canal shortly after takeoff from Fernando Luis Ribas Dominicci Airport (SIG) in San Juan, Puerto Rico. The private pilot and three passengers were not injured. Visual meteorological conditions prevailed, and no flight plan was filed for the local personal flight conducted under 14 CFR Part 91.
Flight History
The pilot reported that the purpose of the flight was to fly to a designated practice area and return. Before departure, the airplane was fueled, and the pilot calculated weight and balance, performed a preflight inspection, and conducted an engine run-up with no issues noted. During the takeoff roll on runway 9, engine instruments were in the green and full power was developed. During the initial climb at about 250 ft above ground level, the engine began to run rough and lose power, and did not respond to throttle inputs. The pilot informed the control tower of the intention to return and land on runway 27. While flying toward a marina, the pilot recalled seeing people on the ground and wanted to avoid them; he did not recall the remainder of the accident sequence.
A passenger who was also a certificated pilot stated that the takeoff roll was normal, with liftoff at 60 knots. The pilot flying reported engine roughness and radioed for a return to runway 27. The passenger estimated altitude at 200–300 ft and noted engine roughness, loss of power, and vibrations. As the pilot turned left, the passenger observed decreasing airspeed and a stall warning light flashing, called out "airspeed" several times, then recalled the airplane in a stall/spin attitude.
A witness at the marina recorded part of the flight on video. Review showed that about 20 seconds before impact, the airplane flew level eastward for about 5 seconds, then was obscured by a water drop. About 7 seconds later, it reappeared on a southerly heading in a left descending turn. The bank angle increased to about 90° left wing down before impact.
Aircraft and Pilot Information
The pilot held a private pilot certificate with ratings for airplane single-engine land and instrument airplane. His most recent first-class medical certificate was issued on October 9, 2012. According to his logbook, he had about 142 total flight hours, with his previous flight on April 10, 2017, a rental check in the accident airplane.
Maintenance records showed the most recent 100-hour inspection was on March 25, 2017, about 90 hours prior to the accident. The most recent annual inspection was completed on July 19, 2016, about 193 hours prior. The engine had 4,233 total hours since new and 937 hours since overhaul.
Investigation
An FAA inspector examined the airplane post-accident. The left wing was separated at the root, the right wing partially separated, and the empennage crushed in several locations. The left stabilator was partially separated and bent upward about 90°. The throttle and mixture controls were full forward, carburetor heat off, fuel selector on the right tank, and electric fuel pump on. Both fuel caps were secure with intact seals.
The engine was drained of seawater, oil, and sediment. Spark plugs showed no wear or damage, and the carburetor was undamaged. The propeller could be rotated and compression was obtained on all cylinders; no preimpact anomalies were found.
An onboard video and witness video were analyzed. The onboard video showed liftoff at 35.2 seconds elapsed time. At 1:16.3, the airplane rolled slightly right. Engine noise decreased between 1:18.7–1:19.7 and further decreased between 1:27.2–1:30.1. At 1:30.8, a left bank began; at 1:34.9, the airplane was in a descending left turn. Momentary increases in background noise occurred between 1:34.0–1:36.6, then decreased slightly, remaining stable until impact at 1:44.6.
Sound spectrum analysis showed engine rpm at 2,265 for about 7 seconds during the right bank, then decreasing to 1,980 rpm as the left bank began. The rpm momentarily increased to 2,292 about 5 seconds later, then decreased to 1,950, and stabilized between 2,373–2,451 rpm for about 6 seconds before impact.
The recorded weather at SIG at 1729 was: wind 070° at 14 knots, visibility 8 miles, thin scattered clouds at 3,500 ft, scattered clouds at 8,000 ft, temperature 29°C, dew point 25°C, altimeter 30.01 inHg. A carburetor icing chart for those conditions indicated "Icing (glide and cruise power)."