Crash of a Piper PA-31T-620 Cheyenne II in Cascais: 5 killed

Date & Time: Apr 17, 2017 at 1204 LT
Type of aircraft:
Operator:
Registration:
HB-LTI
Flight Phase:
Flight Type:
Survivors:
No
Site:
Schedule:
Cascais – Marseille
MSN:
31T-8020091
YOM:
1980
Country:
Region:
Crew on board:
1
Crew fatalities:
Pax on board:
3
Pax fatalities:
Other fatalities:
Total fatalities:
5
Captain / Total flying hours:
4900
Aircraft flight hours:
8323
Circumstances:
Shortly after takeoff from runway 17 at Cascais-Tires Airport, while climbing, the twin engine aircraft went out of control and crashed in flames on a Lidl parking lot located southeast of the airfield. The aircraft was destroyed by impact forces and a post crash fire and all four occupants were killed. The driver of a truck hit by the plane was also killed. Three other people were slightly injured. An adjacent house was destroyed by fire.
Probable cause:
The Safety Investigation Authority GPIAAF, determines the probable causes of this accident to be:
- The pilot’s failure to maintain the airplane control following the power loss in the left critical engine. The root cause for the left engine failure could not be determined due to the extensive impact damages and intensive fire.
Contributing factors:
- Lack of proper pilot training especially concerning the emergency scenario of critical engine failure immediately after takeoff.
Final Report:

Crash of a Piper PA-31T Cheyenne in Elko: 4 killed

Date & Time: Nov 18, 2016 at 1920 LT
Type of aircraft:
Operator:
Registration:
N779MF
Flight Phase:
Flight Type:
Survivors:
No
Schedule:
Elko - Salt Lake City
MSN:
31-7920093
YOM:
1979
Location:
Crew on board:
1
Crew fatalities:
Pax on board:
3
Pax fatalities:
Other fatalities:
Total fatalities:
4
Captain / Total flying hours:
7050
Aircraft flight hours:
6600
Circumstances:
The airline transport pilot departed in the twin-engine, turbine-powered airplane on an air ambulance flight with two medical crew members and a patient on board in night visual meteorological conditions. According to a witness, during the initial climb, the airplane made a left turn of about 30° from the runway heading, then stopped climbing, made an abrupt left bank, and began to descend. The airplane impacted a parking lot and erupted into flames. In the 2 months before the accident, pilots had notified maintenance personnel three times that the left engine was not producing the same power as the right engine. In response, mechanics had replaced the left engine's bleed valve three times with the final replacement taking place three days before the accident. In addition, about 1 month before the accident, the left engine's fuel control unit was replaced during trouble shooting of an oil leak. Post accident examination revealed that the right engine and propeller displayed more pronounced rotational signatures than the left engine and propeller. This is consistent with the left engine not producing power or being at a low power setting at impact. Further, the abrupt left bank and descent observed by the witness are consistent with a loss of left engine power during initial climb. The extensive fire and impact damage to the airplane precluded determination of the reason for the loss of left engine power.
Probable cause:
A loss of engine power to the left engine for reasons that could not be determined due to the extensive fire and impact damage to the airplane.
Final Report:

Crash of a Piper PA-31T Cheyenne II near McKinleyville: 4 killed

Date & Time: Jul 29, 2016 at 0105 LT
Type of aircraft:
Operator:
Registration:
N661TC
Flight Phase:
Flight Type:
Survivors:
No
Schedule:
Crescent City – Oakland
MSN:
31-8120022
YOM:
1981
Crew on board:
1
Crew fatalities:
Pax on board:
3
Pax fatalities:
Other fatalities:
Total fatalities:
4
Captain / Total flying hours:
7300
Captain / Total hours on type:
125.00
Aircraft flight hours:
7309
Circumstances:
About 13 minutes after takeoff for a medical transport flight, while climbing through about 14,900 ft mean sea level (msl), the pilot reported to air traffic control (ATC) that he was smelling smoke in the cockpit and would be returning to the originating airport. The flight was cleared to return with a descent at pilot's discretion to 9,000 ft msl. The pilot replied, "okay," and said that it looked like he was going to lose some power shortly. The pilot then stated that he had smoke in the cockpit, declared an emergency, and requested that ATC contact the fire department. About 1 minute 15 seconds after the initial report of smelling smoke, the pilot made the last radio transmission of the flight stating that he had three people on board. The wreckage was located about 9 hours later in an area of brush and heavily forested terrain. Portions of the burned and fragmented wreckage were scattered along a debris path that measured about 2,400 ft in length, which is consistent with an inflight breakup. The center fuselage and cockpit areas were largely intact and displayed no evidence of fire; however, there was an area of thermal damage to the forward fuselage consistent with an inflight fire. The thermal damage was primarily limited to the floor area between the two forward seats near the main bus tie circuit breaker panel and extended to the forward edge of the wing spar. All exposed surfaces were heavily sooted. Some localized melting and thermal-related tearing of the aluminum structure was present. The primer paint on the floor panels under the right aft corner of the pilot seat and the left aft corner of the co-pilot seat was discolored dark brown. An aluminum stringer in this location exhibited broomstrawing indicating that the stringer material was heated to near its melting point prior to impact. A single wire located in the area exhibited notching consistent with mechanical rubbing. The main bus tie circuit breakers were partially missing. The remaining breakers were heavily sooted on their aft ends, and one breaker was thermally discolored. Areas of charring were on the backside of the panel. Examination of the wiring in this area showed evidence of electrical arcing damage. Four hydraulic lines servicing the landing gear system were located in this area, and all the lines exhibited signs of thermal exposure with melting and missing sections of material. Six exemplar airplanes of the same make and model as the accident airplane were examined, and instances of unsafe conditions in which electrical lines and hydraulic lines in the area of the main bus tie circuit breaker panel were in direct contact were found on all six airplanes. Some of the wires in the exemplar airplanes showed chafing between hydraulic lines and the electrical wires, which, if left uncorrected, could have led to electrical arcing and subsequent fire. Based on the unsafe conditions found during examination of the exemplar airplanes and the thermal damage to the area near the main bus tie circuit breaker panel on the accident airplane, including broomstrawing of the aluminum structure, electrical arcing damage to the wiring, and melting of the hydraulic lines, it is likely that an electrical wire near the tie bus circuit breakers chafed on a hydraulic line and/or airplane structure, which resulted in arcing and a subsequent in-flight fire that was fed by the hydraulic fluid.
Probable cause:
An inflight fire in the floor area near the main bus tie circuit breaker panel that resulted from chafing between an electrical wire and a hydraulic line and/or airplane structure.
Final Report: