Investigation Summary
Flight 19 was a newly delivered Douglas DC-3A (MSN 2188), having been in service for only three months with 565 airframe hours. The flight departed Washington at 14:21 EST for a multi-leg journey to Detroit. While cruising at 6,000 feet, the aircraft entered a region of extreme atmospheric instability characterized by heavy rain and frequent lightning. At approximately 14:41 EST, witnesses near Short Hill Mountain observed the aircraft flying level before a 'blinding' flash of lightning occurred. Immediately following the flash, the aircraft entered a steep, near-vertical dive. The impact was so severe that the aircraft was largely destroyed, and the crash severed local telephone lines, delaying the arrival of emergency services. The investigation was significant as the first major probe conducted under the Civil Aeronautics Act of 1938. While initial theories suggested windshear or structural failure due to turbulence, the lack of structural breakup in flight and the consistent witness testimony regarding the lightning discharge led investigators to focus on electrical phenomena. The final report noted that while the exact mechanism of the lightning's effect on the crew or aircraft could not be definitively proven, it was the most probable initiating factor.
Final Conclusions
The Civil Aeronautics Board concluded that the probable cause of the accident was a lightning strike that occurred in the immediate vicinity of the aircraft. This discharge likely resulted in the temporary or permanent incapacitation of the flight crew or caused a sudden distraction or physical shock that led to a loss of control during severe turbulence. The investigation found no evidence of mechanical failure, engine malfunction, or structural deficiency prior to the lightning event.
Video Analysis
No video analysis linked for this case file yet.
Airframe & Maintenance
Crew Experience
Captain
Had a few hundred hours on the DC-3 type.
First Officer
Had a few hundred hours on the DC-3 type.
Systems & Failure Modes
Curtiss-Wright R-1820 Cyclone 9
The aircraft was powered by two G-102-A engines, which were found at the crash site with no evidence of pre-impact failure.
Static Discharge / Lightning Protection
1940s aircraft had limited protection against high-intensity electrical discharges, which could cause pilot blinding, acoustic shock, or magnetic interference with instruments.
Interesting Facts
- 01The accident was the deadliest in U.S. commercial aviation history at the time of its occurrence.
- 02U.S. Senator Ernest Lundeen was among the passengers killed in the crash.
- 03The aircraft was nearly new, having been delivered from Douglas Aircraft on May 25, 1940.
- 04The crash occurred during the first major investigation under the Civil Aeronautics Act of 1938.
- 05Heavy rain and flooded roads significantly hindered the initial recovery and investigation efforts.
Safety Actions & Advisories
Lightning Research
The accident prompted increased study into the effects of lightning strikes on all-metal aircraft and the potential for pilot incapacitation due to flash blindness.
Known Controversies & Unanswered Questions
FBI Investigation of Senator Lundeen
Reference ↗The presence of a U.S. Senator, two FBI employees, and a DOJ prosecutor on the flight led to public speculation, as the FBI was investigating the Senator's alleged ties to a German agent at the time. However, the official investigation found no evidence of sabotage.