Royal Canadian Air Force — Flight 3701H

A Royal Canadian Air Force Liberator III, serial number 3701 (individual aircraft letter 'H', callsign 'Harry'), collided with Black Mountain (Montagne Noire) on the night of October 19, 1943, during a routine transport flight in inclement weather, killing all 24 personnel on board. The aircraft was diverted from its original destination of Mont-Joli due to poor visibility and was attempting to reach Montreal or Ottawa when it struck the 875-meter peak. The wreckage remained undiscovered for over two years until it was spotted by chance during an unrelated search mission in 1946. Investigators determined that the mountain's height was incorrectly marked on contemporary navigation maps, contributing to the crew's failure to maintain adequate terrain clearance.

Aircraft

Consolidated Liberator III

Registration

3701

Phase

Cause

Souls on Board

Fatalities

Origin → Dest

Gander International Airport → Mont-Joli Airport

Report

Investigation Summary

The flight departed Gander at 22:16 GMT on October 19, 1943, after being delayed by weather. The mission was a routine domestic transport flight within the RCAF Eastern Air Command, carrying 20 passengers (mostly personnel from No. 10 Squadron returning for leave) and 4 crew members. Approximately three hours into the flight, the pilot contacted Mont-Joli tower but was informed the airfield was closed due to visibility. The aircraft was subsequently diverted to either Dorval in Montreal or Rockcliffe in Ottawa. At approximately 20:45 EST (01:45 GMT on Oct 20), the aircraft struck the summit of Black Mountain. A final distress call was reportedly heard by another aircraft near Grand-Mere, but no further contact was established. Despite an extensive search involving 728 sorties and 2,438 flight hours, the RCAF found no trace of the aircraft and eventually presumed it had crashed into the St. Lawrence River. The discovery in June 1946 revealed the aircraft had struck the summit of Black Mountain, the highest point in the region, and burned. The site was so remote that the original recovery team had to be guided by an observation plane performing nose-dives over the wreckage.

Final Conclusions

The accident was classified as Controlled Flight Into Terrain (CFIT). The primary contributing factors were severe weather conditions and a significant mapping error on navigation charts, which underreported the elevation of Black Mountain. This error likely led the crew to believe they were at a safe altitude for the region while navigating in low visibility.

Video Analysis

No video analysis linked for this case file yet.

Systems & Failure Modes

Navigation Charts

Contemporary maps used by the RCAF underreported the elevation of the terrain in the Saint-Donat region, leading to insufficient vertical separation.

Air Traffic Control Communication

The aircraft successfully communicated with Mont-Joli tower for diversion instructions before losing contact.

Interesting Facts

01The crash remains the worst accident in Canadian military aviation history.
02The wreckage was discovered 32 months after the disappearance.
03Navigation maps at the time of the crash incorrectly reported the height of Black Mountain.
04Only three of the 24 bodies could be individually identified due to the post-impact fire.
05The aircraft was a Consolidated Liberator III (B-24D), serial number 3701, with the individual aircraft letter 'H'.
06Several passengers were crew members from Liberator 586, which had sunk U-341 a month prior.

Safety Actions & Advisories

Cartographic Correction

Following the discovery of the wreckage and the identification of the mapping error, regional navigation charts were updated to reflect the correct elevation of Black Mountain.