N421NSCessna 421C · 1980

On February 15, 2019, about 1000 central standard time, a Cessna 421C airplane, N421NS, was destroyed when it was involved in an accident near Canadian, Texas. The pilot and passenger were fatally injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight.

Recorded flight track data showed that, at 0900, the airplane climbed out from Tradewind Airport (TDW), Amarillo, Texas, and proceeded to the north-northeast toward Hemphill County Airport (HHF). The airplane passed through 5,500 ft mean sea level (msl), then turned northeast and continued to climb to a cruise altitude of about 7,500 ft msl. From 0918 to 0921 the airplane gradually descended until the track data was temporarily lost at 4,900 ft msl and 13 nm southwest of HHF.

The pilot was receiving visual flight rules (VFR) flight following services from Amarillo terminal radar approach control (AMA TRACON), who transferred him to Albuquerque Center (ZAB) Sector 15, which were terminated at 0920 when the airplane was 18.7 miles southwest of HHF. The pilot did not request an instrument approach or solicit any other assistance from air traffic control.

At 0925, about 6 nm west of HHF, the flight track resumed, and the airplane was recorded at 4,100 ft msl and climbing to the north. The airplane continued to the north and climbed through 6,000 ft msl, then began a shallow left turn and continued to climb to 6,600 ft msl. The shallow left turn continued, but the airplane began a descent; the final recorded data ended at 0935; the airplane was about 20 nm northwest of HHF, at an altitude of 5,100 ft msl on a southwest heading. The final recorded data was about 13 nm northwest of the accident site.

A witness located about 5 miles northeast of HHF was monitoring the common traffic advisory frequency at HHF about 0915 to 0930. He reported that he heard the pilot over the radio and responded since he recognized his voice. The witness reported that the pilot asked about the cloud height; the witness responded that the clouds were 800 to 1,000 ft above ground level (agl). The witness reported that he had checked all of the local automated weather reports about 0900, which indicated the cloud were 700 to 1,000 ft agl and visibility 6 to 10 miles. In his final radio call, the pilot responded to the witness, "Ok, see you in a little bit." The witness did not see the airplane in the air. The witness reported that at 1006 he was notified of a fire west of Canadian, so he flew his helicopter to the fire and discovered that the airplane had crashed.

A review of the pilot's available logbook entries from 2014 to 2016 revealed that the pilot had completed several GPS instrument approaches and accumulated 23.8 hours of simulated instrument flight time and 18 hours of actual instrument flight time during that period. A logbook entry indicated that the pilot completed a flight review in the accident airplane in January 2018. The only logbook entries after 2016, was the 2018 flight review.

The airplane was not equipped with anti-icing or de-icing equipment.

An acquaintance who spoke with the pilot and was familiar with the airplane reported that the airplane's horizontal situation indicator and pressurization system were not working, and he did not know if the pilot had them repaired. He did not give an exact timeframe for the non-working components.

A review of the maintenance logbooks revealed that on January 21, 2019, an overhauled horizontal situation indicator was installed in the airplane, which replaced an old unit that had malfunctioned. There was no record of any unresolved maintenance issues for the accident airplane.

Archived FAA documentation for the airplane revealed that a Garmin GNS-530W GPS system and related components were installed in the airplane in June 2008.

Instrument meteorological conditions prevailed across the region surrounding the accident site. Cloud bases were solid overcast; at HHF the ceiling was 800 ft agl, about 30 miles west of HHF at Mesa Vista Ranch Airport (TX13), Pampa, Texas, the ceiling was about 900 ft agl, and about 33 miles southwest of HHF at Perry Lefors Field Airport (PPA), Pampa, Texas, the ceiling was at 400 ft agl. At each of these stations the ceiling rapidly deteriorated over the previous 1 to 2 hours. The conditions at HHF had been clear about 2 hours before accident, and visual flight rules conditions about 1 hour before accident.

A cold front had advanced from the northeast, and produced some wind shear in the lowest 3,000 ft agl. The wind between the surface and about 3,800 ft msl was from the northeast at 6 to 8 knots. However, at 4,300 ft msl, the wind was from west-southwest at 8 knots, and increased in magnitude above this level to a west wind of about 40 knots at 5,700 ft msl. There was potential for severe or greater turbulence between about 3,700 ft and 5,700 ft msl. Clouds were estimated between about 3,100 ft and about 4,500 ft msl. There was likely some icing in the clouds between the bases and tops, and there was also potential for light icing below 4,300 ft msl. The atmosphere was below freezing below about 4,350 ft msl and a steep temperature inversion was noted between about 3,750 ft and about 5,700 ft msl.

AIRMET advisories for instrument flight rules conditions, for moderate turbulence below flight level (FL) 180, and for moderate icing between the freezing level and FL230 were active for the accident site at the accident time.

The investigation did not find any record that pilot received a weather briefing on the day of the accident. The pilot was receiving VFR flight following services from air traffic control during a time when instrument meteorological conditions were known and reported.

The witness who responded in his helicopter reported that when he arrived at the accident site the clouds were overcast at 500 ft agl, 10 miles visibility, temperature 27°F, and light wind from the north.

The airplane was not equipped with anti-icing or de-icing equipment.

An acquaintance who spoke with the pilot and was familiar with the airplane reported that the airplane's horizontal situation indicator and pressurization system were not working, and he did not know if the pilot had them repaired. He did not give an exact timeframe for the non-working components.

A review of the maintenance logbooks revealed that on January 21, 2019, an overhauled horizontal situation indicator was installed in the airplane, which replaced an old unit that had malfunctioned. There was no record of any unresolved maintenance issues for the accident airplane.

Archived FAA documentation for the airplane revealed that a Garmin GNS-530W GPS system and related components were installed in the airplane in June 2008.

The airplane impacted remote terrain and a post impact fire consumed a majority of the wreckage (see figure 1).

Figure 1 – Aerial image of the accident site. A majority of the airplane was consumed by fire.

A postaccident examination indicated the airplane impacted the ground in a slight nose-low and wings-level attitude and there was no evidence of forward momentum. All major airplane components were observed at the accident site. The empennage was displaced to the right. The flap setting was 15° extended. The cockpit and instrumentation were destroyed by fire and none of the components could be examined. The engines were found embedded in the mud and all propeller blades were accounted for. The engines and propellers exhibited signatures consistent with rotation at the time of impact. The examination did not reveal any preimpact mechanical malfunctions or anomalies that would have precluded normal operation.

South Plains Forensic Pathology, Lubbock, Texas, performed an autopsy on the pilot. The cause of death was blunt force injuries.

Toxicology testing performed at the FAA Forensic Sciences Laboratory identified tadalafil, which is a prescription medication used to treat erectile dysfunction and the symptoms of benign prostatic hyperplasia. The FAA recommends not flying for 36 hours after use of this medication. FAA toxicology also identified a small amount of ethanol in muscle but not in brain. After absorption, ethanol is uniformly distributed throughout all tissues and body fluids; therefore, the finding in one tissue but not another is consistent with post-mortem production in these samples. Another alcohol, n-propanol, was also identified in the testing and it is also produced postmortem. The tested samples sustained putrefaction.

AIR TRAFFIC CONTROLThe airplane departed TDW in visual meteorological conditions and was provided VFR flight following services to HHF by an AMA controller. The flight appeared routine and normal to the Albuquerque center (ZAB) air traffic manager (ATM) and he described the traffic was light in volume and complexity. The ZAB controller was not aware of any adverse weather conditions in the area or along the accident airplane's route of flight. HHF does not have weather reporting capability; however, the controller did have access to the weather in the vicinity of HHF via a weather request function. The ZAB ATM stated that there is no facility expectation for controllers to obtain the weather or ensure a pilot has the weather for their destination airport when receiving VFR flight following services. The ZAB ATM stated that radar services for the accident airplane were terminated when it descended through 5,900 ft and about 18 miles from HHF Airport. The ATM stated that this is a normal practice in the area due to insufficient radio and radar coverage below 7,000 ft.