Accident Howard Cargo Harpoon N7428C,
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Date:Sunday 16 September 1990
Type:Silhouette image of generic L37 model; specific model in this crash may look slightly different    
Howard Cargo Harpoon
Owner/operator:Confederate Air Force
Registration: N7428C
MSN: 15-1228
Year of manufacture:1957
Total airframe hrs:1900 hours
Engine model:Pratt & Whitney R-2800-31
Fatalities:Fatalities: 0 / Occupants: 4
Aircraft damage: Destroyed, written off
Location:Conroe-Montgomery County Airport, TX (CXO) -   United States of America
Phase: Taxi
Departure airport:Conroe-Montgomery County Airport, TX (CXO/KCXO)
Destination airport:Lafayette Regional Airport, LA (LFT/KLFT)
Investigating agency: NTSB
Confidence Rating: Accident investigation report completed and information captured
During taxi to takeoff the crew sensed an odor similar to an electrical fire, and smoke became apparent in the cockpit. Both generators and the battery master were secured. The right generator would not accept a load and smoke was coming from the right wing accessory jbox in the right wheel well. Three occupants deplaned and initially extinguished the fire, which reignited due to hot metal and compromised fuel/oil lines. All systems were secured and the pilot then evacuated the airplane, which was consumed by the fire. The pilot estimated that fire fighting equipment did not arrive for 20-25 minutes after the fire began. FAA inspectors were unable to determine the fire source from the burned wreckage. However, the operator's report stated that the right starter solenoid did not open after engine start causing the starter to remain linked to the electrical system. this resulted in a system overload and subsequent electrical fire. Both fuel and oil lines were routed through the right wheel well for cockpit indications.

PROBABLE CAUSE: "The engine starter remained engaged after engine start and the electrical system overheat."

Accident investigation:
Investigating agency: NTSB
Report number: FTW90DRA10
Status: Investigation completed
Duration: 2 years and 5 months
Download report: Final report



Revision history:


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