Engine failure and loss of control during approach

1 fatality • San Juan-Luis Muñoz Marín (Isla Verde), Puerto Rico • Takeoff (climb)

An aircraft experienced engine overheating and subsequent power loss shortly after takeoff, leading to a fatal crash into the water during a turning maneuver.

What happened

During the initial climb phase following departure, the aircraft experienced deteriorating climb performance accompanied by rising temperatures in the right engine. In response to the overheating, the crew feathered the right engine and initiated an emergency return to the airport. During this period, the onboard radio transmitter malfunctioned, rendering communication unintelligible; air traffic control confirmed the crew received instructions by requesting they key their microphone twice.

While executing a right downwind pattern for runway 10 at a very low altitude, the aircraft transitioned into a base leg over water. Witnesses observed the plane enter a steep bank during this turn, resulting in the right wing tip striking the water surface. The impact caused the aircraft to cartwheel and crash. While the co-pilot noted that the airspeed remained above the minimum controllable speed of 84 knots following the engine feathering, he indicated that a stall likely occurred just before the collision.

Findings

An investigation into the right engine revealed significant mechanical failures, specifically involving the failure of the #8 piston and its associated rings. The presence of metal shavings in the oil and scoring on the oil pump suggested internal damage. Furthermore, evidence indicated that the crankshaft journal suffered from oil starvation, and the engine experienced piston slap related to the ring failure.

Additional findings identified a total failure of the communication and navigation transmitter. Regarding the loss of control, investigators concluded that the pilot maintained inadequate airspeed and engaged in improper aircraft handling during the maneuver. The crash was ultimately characterized by the aircraft striking the water surface during an uncontrolled descent.

Probable cause

The accident was caused by engine mechanical failure leading to power loss, compounded by insufficient airspeed during a low-altitude turn.

Frequently asked questions

What happened in the 1986-07-22 Douglas DC-3 accident near San Juan-Luis Muñoz Marín (Isla Verde), Puerto Rico?

An aircraft experienced engine overheating and subsequent power loss shortly after takeoff, leading to a fatal crash into the water during a turning maneuver.

Were there any fatalities in the 1986-07-22 Douglas DC-3 accident?

The accident was fatal, resulting in 1 fatality.

What aircraft was involved and where did it happen?

The accident on 1986-07-22 involved a Douglas DC-3, registration N27PR, operated by Borinquen Air, at San Juan-Luis Muñoz Marín (Isla Verde), Puerto Rico.

What was the probable cause of the accident?

The accident was caused by engine mechanical failure leading to power loss, compounded by insufficient airspeed during a low-altitude turn.

Loading the flight search…