Investigation Summary
Flight 711 was a multi-stop service from Newark to Tulsa. During the leg from St. Louis to Springfield, the crew received weather updates indicating a 500-foot overcast ceiling and light drizzle. Although these conditions were above minimums for a VOR approach, they required strict adherence to instrument procedures. Instead of executing the full CAA-approved VOR approach, the crew proceeded directly from the VOR station toward the airport. Investigators found that the aircraft was flown visually below the overcast for several miles. The Board concluded that the pilots likely suffered from a sensory illusion or were so focused on looking outside for the runway lights that they neglected their flight instruments, allowing the Convair to descend until it impacted the ground. The captain survived with severe injuries, including the loss of an eye and a period of amnesia regarding the event.
Final Conclusions
The Civil Aeronautics Board (CAB) released its final report on September 22, 1955. The Board determined the probable cause was a descent to the ground while approaching the airport caused by the crew's inattention to their flight instruments and a possible sensory illusion giving them an erroneous impression of the attitude of the aircraft. The investigation found no evidence of mechanical failure or an emergency prior to impact.
Video Analysis
No video analysis linked for this case file yet.
Airframe & Maintenance
Crew Experience
Captain
Survived with severe injuries including loss of right eye.
First Officer
Fatal injury.
Systems & Failure Modes
VOR (VHF Omnidirectional Range)
A radio navigation system used by the crew to track their position relative to the Springfield station; the aircraft was on the 193-degree inbound radial when it descended into the ground.
Altimeter
The primary instrument for monitoring altitude; investigators concluded the crew failed to properly monitor this instrument during the final approach.
Interesting Facts
- 01The aircraft was a Convair CV-240-0, registration N94234, named 'Flagship Nashville'.
- 02The aircraft struck the ground approximately 1.25 miles north-northwest of the airport center, which was approximately 0.25 miles (1,320 feet) short of the Runway 31 threshold.
- 03The captain, Jack Pripish, survived but lost his right eye and suffered from amnesia regarding the crash.
- 04Weather at the time of the accident included a 500-foot ceiling and light drizzle.
- 05The flight did not execute the full CAA-approved VOR instrument approach procedure, proceeding directly from the station to the field.
- 06The First Officer had only 2 hours of flying time on the Convair CV-240 type at the time of the accident.
Safety Actions & Advisories
Instrument Adherence
The investigation emphasized the necessity of following approved instrument approach procedures even when ground contact is established, to prevent sensory illusions during night approaches in poor visibility.