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2 fatalities

Partial Loss of Engine Power on Left Engine Leads to Stall and Terrain Collision (N134FS)

Aguadilla, Puerto RicoTakeoff (climb)

On May 10, 1991, a Douglas C-47 Skytrain (DC-3) (registration N134FS) operated by Four Star Air Cargo was involved in an aviation accident near Aguadilla, Puerto Rico during takeoff. 2 people were killed. Investigators recorded the probable cause as: The pilot in command's failure to maintain airspeed (VS) after a partial loss of engine power on the left engine due to failure of the n°8 engine assembly cylinder. This resulted in an in flight loss of control (stall), and in flight collision with terrain. This summary draws on records from the Bureau of Aircraft Accidents Archives (B3A); 1 related events involving the same aircraft type or operator are linked below.

Sourcesthe Bureau of Aircraft Accidents Archives (B3A)Primary report: the U.S. National Transportation Safety Board (NTSB) historical archiveUpdated 2026-07-04Data APIEditorial standards

The airplane experienced a partial loss of left engine power during takeoff climb due to failure of the n°8 engine assembly cylinder. Maneuvering to return, the pilot lost control after a secondary stall, colliding with terrain and destroying the aircraft. Both pilots were killed.

Accident Sequence

During takeoff climb, the left engine experienced a partial loss of power. The failure was attributed to the n°8 engine assembly cylinder. Witnesses observed the airplane at approximately 400 feet above ground level (AGL) in a 20-degree left bank while maneuvering to return to the departure airport. The angle of bank subsequently increased to 60 degrees, accompanied by a noticeable decrease in airspeed as the airplane descended below 300 feet AGL. The left wing then dropped to a 90-degree angle to the left, and the nose pitched down vertically. The airplane appeared to regain elevator authority and leveled out before encountering a secondary stall. It then collided with the terrain and was destroyed by a post-crash fire. Both pilots sustained fatal injuries.

Probable Cause

The official investigation determined the probable cause to be the pilot in command's failure to maintain airspeed (VS) after a partial loss of engine power on the left engine due to failure of the n°8 engine assembly cylinder. This resulted in an in-flight loss of control (stall) and in-flight collision with terrain.

Engine failureLoss of control in flight

Related events

Same operator

Frequently asked questions

What happened in the 10 May 1991 Douglas C-47 Skytrain (DC-3) accident near Aguadilla, Puerto Rico?

The airplane experienced a partial loss of left engine power during takeoff climb due to failure of the n°8 engine assembly cylinder. Maneuvering to return, the pilot lost control after a secondary stall, colliding with terrain and destroying the aircraft. Both pilots were killed.

Were there any fatalities in the 10 May 1991 Douglas C-47 Skytrain (DC-3) accident?

The accident was fatal, resulting in 2 fatalities.

What aircraft was involved and where did it happen?

The accident on 10 May 1991 involved a Douglas C-47 Skytrain (DC-3), registration N134FS, operated by Four Star Air Cargo, at Aguadilla, Puerto Rico.

What was the probable cause of the accident?

The pilot in command's failure to maintain airspeed (VS) after a partial loss of engine power on the left engine due to failure of the n°8 engine assembly cylinder. This resulted in an in flight loss of control (stall), and in flight collision with terrain.

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