Aviation Accident Summaries

Aviation Accident Summary CEN20LA058

Bandera, TX, USA

Aircraft #1

N350XL

Piper PA46

Analysis

During flight, the pilot observed a warning message on the primary flight display indicating “AVIFAN FAIL.” As he was trouble-shooting the electrical system, smoke began to enter the cabin from the front of the cockpit. The pilot suspected an electrical fire. He disconnected the autopilot, lowered the landing gear, and turned off the battery master switch. After he declared a “Mayday,” the pilot searched for the nearest airport, which was about 13-miles from his position. Smoke was still coming into the cabin, and the pilot's "eyes were burning." The pilot decided that he had to land the airplane without delay because of the potential fire. He decided to land the airplane in what appeared to be a flat field directly ahead. As the airplane approached the landing point, the pilot extended the first notch of flaps, the airplane crossed over a fence, and landed. The pilot immediately realized that the airplane was fast and on a collision course with another fence and trees, so he rotated the airplane and cleared the obstacles. He immediately turned the airplane to the right and landed the airplane on an adjacent roadway. Upon landing, the airplane hit a roadway signpost with the right wing and the airplane spun 90 degrees to the right, and came to rest with the nose against a roadway guardrail. The outboard section of the right wing sustained substantial damage. Detailed examination of the airplane’s electrical system revealed thermal damage and discoloration on a circuit board of one of the avionics cooling fans. The thermal damage to the fan circuit board would have likely produced smoke that would be irritating to the eyes, which was consistent with what the pilot reported. No other damage or electrical anomalies were found during the examination.

Factual Information

On January 11, 2020, about 1720 central standard time, a Piper PA-46-350P, N350XL, was substantially damaged when it was involved in an accident near Bandera, Texas. The pilot and one passenger were not injured. The airplane was operated as a Title 14 Code of Federal Regulations (CFR) Part 91 personal flight. The pilot reported that he was on a local flight and filed an Instrument Flight Rules (IFR) flight plan. He took off from the San Antonio International Airport (SAT) and his intention was to return to SAT after the flight. The takeoff was normal and the airplane performed as expected. After being cleared to climb to 24,000 ft, he heard what seemed to be some sort of sound as if metal was rubbing against metal," and the sound subsided. The pilot continued the flight, and all engine performance indications were as expected. The pilot asked Air Traffic Control (ATC) to start his return to SAT and descend. During the descent, a CAS message, "AVI FAN Fail," message appeared on the primary flight display (PFD). The message was white in color. He consulted his Garmin 1000 (G1000) reference guide to decode the CAS message and to see the recommended procedure for troubleshooting the code. The pilot stated that since the CAS message was white in color, he thought that it was "advisory" in nature, because the manual stated that a "white" CAS message was Advisory, "yellow," was Caution, and "red" was Warning. As the pilot was consulting the G1000 manual, smoke started to come into the cabin from the front of the cockpit. The pilot immediately suspected an electrical fire. He disconnected the autopilot, lowered the landing gear, turned the battery master switch off, dumped cabin pressure, and turned the EMER switch on. As a precaution, he also pulled the hydraulic pump circuit breaker just in case it was the cause of the electrical fire. The pilot had his passenger read out the emergency checklist for an electrical fire. After completing the checklist, the pilot radioed a "Mayday." Meanwhile, the pilot searched for the nearest airport to land, which was about 13 miles from his position. The airplane was in a 600-ft per minute descent. Smoke was still coming into the cabin, and the pilot's "eyes were burning," The pilot decided that he had to land the airplane without delay because of the potential fire. A red "X" indication appeared on the manifold pressure gauge as the airplane descended. The airplane seemed descend at a higher rate of descent than the pilot expected. The airplane was about 3,000-4,000 ft MSL and the terrain in the area was between 1,000 to 2,000 ft AGL. The pilot thought that he did not have much time to land given the higher-than-expected rate of descent. He decided to land the airplane in what appeared to be a flat field directly ahead. The pilot chose his landing point in the field, and as the airplane got closer, the pilot saw that the field appeared to be a large field made up of three rectangular fields separated by fences, and the last fence was followed by thick trees. The pilot decided to land in the third field and planned on braking heavy to stop. As the airplane approached the landing point, the pilot added one notch of flaps in, the airplane crossed over a fence, and landed. The pilot immediately realized that the airplane was fast, and a collision with another fence and trees would be unavoidable. The pilot thought that he had enough airspeed and momentum to try to clear the fence and trees, maybe even land on top of them rather than into them, so he rotated the airplane and cleared the obstacles. He immediately turned the airplane to the right and landed the airplane on an adjacent roadway. Upon landing, the airplane contacted a roadway signpost with the right wing, the airplane spun 90 degrees to the right, and came to rest with the nose against a roadway guardrail. The pilot and passenger exited the airplane and called for assistance. The outboard section of the right wing sustained substantial damage. After recovery, the airplane's avionics were powered up and a methodical examination was performed on each electrical system, including the avionics cooling fans. After confirming that the pilot's side avionics cooling fan would not operate when connected to an electrical power source, the fan was disassembled. After removing the fan blades from the motor assembly, an area of thermal damage and discoloration was observed on the circuit board. Photographs of the fan assembly were sent to a National Transportation Safety Board fire specialist for consultation. The specialist stated that the thermal damage to the fan circuit board would have likely produced smoke that would be irritating to the eyes, which was consistent with the pilot reported. No other damage or electrical anomalies were found during the examination.

Probable Cause and Findings

The in-flight electrical fire, which resulted in smoke in the cabin and an emergency landing. Contributing to the accident was the unsuitable terrain for the emergency landing.

 

Source: NTSB Aviation Accident Database

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