Date & Time:
Jul 22, 1986 at 1353 LT
Type of aircraft:
Douglas DC-3
Operator:
Registration:
N27PR
Flight Phase:
Takeoff (climb)
Flight Type:
Cargo
Survivors:
Yes
Site:
Lake, Sea, Ocean, River
Schedule:
San Juan - Basseterre
MSN:
11776
YOM:
1943
Country:
Puerto Rico
Region:
Central America
Crew on board:
2
Crew fatalities:
1
Pax on board:
0
Pax fatalities:
0
Other fatalities:
0
Total fatalities:
1
Captain / Total hours on type:
2000
Aircraft flight hours:
44394
Circumstances:
Shortly after takeoff, the aircraft's climb performance began to deteriorate and the right engine started to overheat. Subsequently, the right engine was feathered and the crew attempted to return to the airport. The radio transmitter became unintelligible, so the tower personnel cleared the aircraft to land on runway 10 and asked the crew to key their mike twice, if they understood. The mike waskeyed twice. The aircraft entered a right downwind for runway 10 at a very low altitude. According to witnesses, the aircraft went into a steep bank as it was turning onto a base leg over water, the right wing tip hit the water and the aircraft cartwheeled and crashed. The copilot reported that after feathering the right engine, the vmc of 84 kts was maintained; however, he believed the aircraft stalled just prior to impact. A teardown of the right engine revealed the edge of the #8 piston and its piston rings had failed. Metal filings were found in the oil and the oil pump was scored. There was evidence of oil starvation to the crankshaft journal, as well as piston slap associated with the ring failure.
Probable cause:
Occurrence #1: loss of engine power (total) - mech failure/malf
Phase of operation: climb - to cruise
Findings
1. (f) engine assembly, ring - failure, total
2. (f) engine assembly, bearing - failure, total
3. (f) engine assembly, master rod - failure, total
4. Propeller feathering - performed
5. Precautionary landing - initiated
----------
Occurrence #2: airframe/component/system failure/malfunction
Phase of operation: approach
Findings
6. (f) comm/nav equipment, transmitter - failure, total
----------
Occurrence #3: loss of control - in flight
Phase of operation: approach - vfr pattern - base turn
Findings
7. Maneuver - initiated
8. (c) airspeed - inadequate - pilot in command
9. (c) aircraft handling - improper - pilot in command
----------
Occurrence #4: in flight collision with terrain/water
Phase of operation: descent - uncontrolled
Findings
10. (f) terrain condition - water, rough
Phase of operation: climb - to cruise
Findings
1. (f) engine assembly, ring - failure, total
2. (f) engine assembly, bearing - failure, total
3. (f) engine assembly, master rod - failure, total
4. Propeller feathering - performed
5. Precautionary landing - initiated
----------
Occurrence #2: airframe/component/system failure/malfunction
Phase of operation: approach
Findings
6. (f) comm/nav equipment, transmitter - failure, total
----------
Occurrence #3: loss of control - in flight
Phase of operation: approach - vfr pattern - base turn
Findings
7. Maneuver - initiated
8. (c) airspeed - inadequate - pilot in command
9. (c) aircraft handling - improper - pilot in command
----------
Occurrence #4: in flight collision with terrain/water
Phase of operation: descent - uncontrolled
Findings
10. (f) terrain condition - water, rough
Final Report:
N27PR.pdf91.33 KB
