Investigation Summary
The accident occurred during the final leg of a multi-stop route from Memphis to Bristol. During the previous leg into Nashville, the crew discovered that the ADF was malfunctioning, failing to provide aural or visual indications for compass locators. Despite this, the captain did not log the defect, and the new crew took over the aircraft for the Knoxville and Bristol legs without the instrument being repaired. Upon departing Knoxville, the flight was cleared via Green Airway 5. Investigators found that the crew likely did not use the low-frequency facilities defining this airway. As they approached the Tri-Cities area, the aircraft was east of its intended track. The pilot erroneously identified the Gray intersection and initiated an ILS approach. Because the ADF was inoperative, the crew could not receive the outer marker's compass locator. They missed the outer marker entirely and failed to use the available VOR facility to cross-check their position. The aircraft continued to descend while flying away from the airport, eventually striking Holston Mountain at an elevation too low to clear the terrain.
Final Conclusions
The Civil Aeronautics Board determined the probable cause was the pilot's failure to properly identify the Gray intersection and the decision to continue an ILS approach contrary to company and regulatory procedures. Contributing factors included the operation of the aircraft with known inoperative navigation equipment (ADF) and the failure to utilize alternative navigation aids like VOR to confirm the flight's position during the approach.
Video Analysis
No video analysis linked for this case file yet.
Airframe & Maintenance
Crew Experience
Captain
Robert L. Gollmier
First Officer
Robert M. Irwin
Systems & Failure Modes
Automatic Direction Finder (ADF)
A radio-navigation instrument that automatically displays the relative bearing to a radio station. The unit on N18941 was inoperative, preventing the crew from identifying the outer marker locator.
Instrument Landing System (ILS)
A precision runway approach aid. The crew attempted this approach without being able to verify their starting position at the outer marker.
Interesting Facts
- 01The aircraft was an intrastate Douglas DC-3A registered as N18941.
- 02The ADF (Automatic Direction Finder) was known to be inoperative prior to the final leg.
- 03The weather at Tri-Cities (18:59 special report) included 300 feet scattered clouds, a 900-foot broken ceiling, and 1,700-foot overcast, with 3 miles visibility in light snow and fog.
- 04The aircraft crashed 15 miles beyond the outer marker it was intended to use for the approach.
- 05All 7 passengers and 3 crew members were killed in the impact and subsequent fire.
Safety Actions & Advisories
Regulatory Compliance and Maintenance Logging
The investigation emphasized the necessity of logging all mechanical defects in the aircraft logbook. The failure of the previous crew to record the ADF malfunction prevented maintenance personnel from addressing the issue and left the succeeding crew with a known but undocumented safety deficiency.
Adherence to Instrument Approach Procedures
The CAB highlighted that continuing an ILS approach without positive identification of the required reporting points (such as the outer marker or Gray intersection) is a violation of standard operating procedures. Pilots were reminded to utilize all available navigation aids, including VOR cross-checks, when primary instruments like the ADF are unavailable.
Known Controversies & Unanswered Questions
Federal Pre-emption Jurisdictional Dispute
Reference ↗Following the crash, the airline argued in court that the Federal Aviation Act of 1958 pre-empted state law, claiming state courts lacked jurisdiction over the wrongful death lawsuits. The Tennessee Supreme Court ruled that the Act did not exclude state law remedies consistent with federal safety standards.