Latrobe-Arnold Palmer-Westmoreland County

Aircraft entered an area of forecast moderate icing. Ice detection system had been intermittently inoperative. The aircraft entered holding in icing conditions while checking flight inspection equipment. Evidence indicated crew noted ice accretion, activated surface de-ice system, ice broke loose and entered engine intakes. Both engines flamed out. During emergency descent crew initially re-starts, but neither engine would sustain power. Crew requested vectors to more distant airport. Both pilots were seen drinking previous night. Copilot had recently lost drivers license for dui. Captain had decided to retire that day. Copilot had worked in flight ops 3 days in 8 weeks and had limited training in flight inspection. Both pilots had personal stresses which may have influenced performance. Captain's contaminated thoracic blood revealed 0.057% alcohol. Putrefaction would accentuated for part of alcohol level. Copilot had trace alcohol in urine only. Both engines showed compressor fod consistent with ice ingestion. No other aircraft system or engine malfunction found.

During arrival, the pilot was advised the destination weather was: estimated 500 feet overcast, visibility one mile with fog, airport below minimums. The pilot elected to make an NDB runway 23 approach, but said he would divert if a missed approach was made. He was provided radar vectors and was cleared for the approach. At the IAF (initial apch fix/tiney intersection), radar service was terminated and the pilot was told to contact tower. On tower frequency, the pilot was again reminded the airport was below minimums. Approximately two minutes later, he reported over the outer marker (OM) which was 4.2 miles past (southwest of) the NSB/final approach fix (FAF) and 3.9 miles northeast of the airport. Seconds later, the tower transmitted info (just recorded from ARTCC) that the aircraft was 2-1/2 mi east of course. Tower tried to notify the pilot, but radio and radar contact were lost. Investigations revealed the aircraft impacted a ridge nearly 4 miles past the NDB and two miles left of course at an elevation of approximately 1,900 feet, but before passing the OM. Minimum descent altitude (MDA) between the NDB and OM was 2,220 feet msl. MDA after passing the OM was 1,940 feet; airport elevation was 1,161 feet. No preimpact aircraft problems were found. The NDB facility operated satisfactorily during flight and ground checks. All five occupants were killed.

During an IFR arrival, the aircraft was vectored for an NDB runway 23 approach to the Westmoreland County Airport. At the NDB final approach fix (8.1 miles from the runway), the crew turned inbound and continued to the airport. They contacted the tower and reported over the ILS outer marker (an intermediate point on the NDB final approach, 3.9 miles from the runway). The tower issued the local landing advisories and cleared the aircraft to land. Moments after the copilot advised the captain that they were 15 seconds from the missed approach point, the aircraft collided with trees. Impact occurred 3.8 miles se of the airport at the minimum descent altitude (MDA) of 1,900 feet amsl. An examination of the aircraft records indicated a recurring and current squawk concerning the hsi slaving system. Just before beginning the approach, the Latrobe wind had changed from 230° at 4 knots (a headwind) to a strong quartering tailwind. During arrival the crew were advised the wind was from 340° at 18 knots. They had figured their timing to the missed approach point by using a ground speed of 120 knots. Earlier that day, the same crew and aircraft had terminated the same NDB approach, 1 mile east of the airport. All seven occupants were injured, five seriously.

Aircraft was on its runway 29 approach when it collided with ground one mile from the airport. A witness saw he aircraft fly over the airport to the west between 500 to 1,500 feet. Witnesses near the accident site saw the aircraft making abrupt maneuvers at low altitude prior to the accident. Engine sounds was described as 'racing', 'uneven', and 'loud'. Weather condition was described as fog, low ceiling, and light rain. Another pilot in same type aircraft was unable to land due to weather. Examination of the aircraft did not disclosed evidence of malfunction. Flight approach navaid facilities flight checked to be operational. There was no evidence of pilot physical impairment or incapacitation. The aircraft collided with the ground in a near vertical attitude. All four occupants were killed.