Investigation Summary
The accident highlighted a dangerous lack of oversight in the booming Grand Canyon air tour industry, which at the time operated under a 'gentleman's agreement' regarding routes and altitudes. In the years leading up to the crash, the National Park Service (NPS) had been pushing to move air tour routes to mitigate noise pollution. These noise-abatement efforts resulted in the relocation of helicopter routes into areas where they intersected with fixed-wing flight paths, specifically near Crystal Rapids. On the day of the accident, Canyon 6 (the Twin Otter) was flying east-southeast while Tech 2 (the Bell 206) was flying south-southwest. The aircraft approached each other at nearly right angles. Because neither aircraft was equipped with a Cockpit Voice Recorder (CVR) or Flight Data Recorder (FDR), and there was no radar coverage in the canyon, investigators could not determine exactly why the pilots failed to spot one another in the clear morning sky. The investigation also noted that the pilots' attention might have been divided between navigating the complex terrain and providing narration to their passengers.
Final Conclusions
The National Transportation Safety Board concluded that the probable cause was the failure of the flightcrews of both aircraft to see and avoid each other for undetermined reasons. Contributing factors included the FAA's failure to exercise oversight of Grand Canyon airspace and the National Park Service's influence on route selection, which led to the convergence of rotary-wing and fixed-wing flight paths near Crystal Rapids.
Video Analysis
Natural Points of View: The story of the 1986 Grand Canyon Midair Collision — A detailed analysis of the regulatory and environmental factors that led to the collision of a Twin Otter and a Bell 206 over the Grand Canyon.
If playback is blocked, the owner has disabled embedding — use the link above.
Airframe & Maintenance
Grand Canyon Airlines Canyon 6 — de Havilland Canada DHC-6 Twin Otter · N76GC
Crew Experience
Captain
Copilot
Pilot
Experience figures for the Helitech pilot are approximate based on NTSB records for this event.
Systems & Failure Modes
See-and-Avoid
The primary method of collision avoidance in Visual Flight Rules (VFR) flight, which failed due to undetermined reasons, possibly including cockpit workload or blind spots.
TCAS
Traffic Collision Avoidance System; this accident was a primary catalyst for the FAA mandating TCAS on turbine-powered commercial passenger aircraft.
Air Tour Management
The lack of standardized routes and altitudes (Special Federal Aviation Regulation 50) was identified as a systemic failure prior to the crash.
Interesting Facts
- 01The collision was the second deadliest air disaster in Grand Canyon history at the time.
- 02Neither aircraft was required to carry, nor did they carry, CVR or FDR equipment.
- 03The Twin Otter was carrying 18 passengers, including 11 Dutch and two Swiss citizens.
- 04The wreckage was located approximately 1,200 feet above the Colorado River.
- 05The accident occurred in perfect visual meteorological conditions with unlimited visibility.
Safety Actions & Advisories
SFAR 50 Implementation
Source ↗The FAA developed new rules and regulations standardizing air tour routes and altitudes within the Grand Canyon National Park to ensure separation.
TCAS Mandate
Source ↗The accident served as a catalyst for the FAA to require Traffic Collision Avoidance Systems (TCAS) on all turbine commercial passenger aircraft.
Flight and Duty Time Regulations
Source ↗The NTSB recommended new regulations to limit flight and duty times for pilots conducting scenic air tour flights.