June 18, 1986: Grand Canyon Airlines, Inc. / Helitech Inc., deHavilland DHC-6 (N76GC) / Bell 206B III (N6TC) Mid-Air Collision, Grand Canyon, AZ
June 18, 1986. The morning was clear and sunny when a deHavilland DHC-6-300 Twin Otter "Vistaliner" (N76GC) operated by Grand Canyon Airlines departed for it's hour long air tour. On board were 18 passengers, many of whom were Dutch citizens booked through a tour company promoted by American Express. The two crew members were seasoned air tour pilots with several years flying the Grand Canyon.
Less than a mile north of the airport, a Bell 206B Jet Ranger helicopter (N6TC) operated by Helitech Inc. was preparing for a 40 minute tour flight with four passengers. The pilot of the helicopter was also highly experienced.
Both flights proceeded normally on their prescribed air tour flights even though no set regulations or standardized routes existed at the time. All flights within the airspace of Grand Canyon in regards to routes and altitudes were conducted by a "gentleman's agreement" with the various air tour companies. A suggested five hundred foot altitude separation of helicopters and airplanes was the safety cushion.
At about 9:30 AM, the two flights were approaching a geologic formation known as Mencius Temple. The Twin Otter, call sign "Canyon 6" from the west and the Bell Jet Ranger, call sign "Tech 2" from the north. For reasons undetermined to this day, both aircraft collided in a horrific impact at an altitude of 6,500 feet. The collision separated the main rotor mast from the helicopter while the disintegrating rotor blades tore into the Vistaliner's tail section causing it to separate in-flight. Both airplane and helicopter pitched over and fell inverted onto the southwestern slope of Mencius Temple. All 25 persons on both aircraft perished, making this accident the second deadliest air disaster in the Grand Canyon to date.
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HISTORICAL SUMMARY:
Unlike the June 30, 1956 accident, the wreckage from this collision was for the most part entirely removed from the national park. The wreckage materials from both airplane and helicopter were taken to a private property location near the town of Tusayan, Arizona and discarded.
During 1990, I was given permission by the land owner to take what I wanted as he was frustrated by the salvage company that never removed the wreckage. Within the debris I found many identifiable personal effects which were overlooked by the initial recovery efforts. I was able to return these items to very grateful surviving family members. The other fragments of wreckage that I have collected and documented provide a tangible historical record to this tragic event in the aviation history of Arizona.
In November 2010, I hiked into the crash site area from the Grand Canyon's North Rim. It was an opportunity to actually see the accident site first hand and to document any remaining wreckage. The crash sites are located on the Tonto Plateau nearly 1,200 feet above the Colorado River and almost 6,000 feet below the canyon's North Rim. The area is designated by the National Park Service as "Wild" since there are no trails, no services, and very few water sources.
This accident was a catalyst event that led the Federal Aviation Administration (FAA) to require that all turbine commercial passenger aircraft be required to have Traffic Collision Avoidance Systems (TCAS) installed. This accident also led the FAA to develop a rules and regulations for standardizing air tour routes and altitudes within the Grand Canyon National Park as well as other selected national park boundaries. The result was an increase in air safety and a reduction of aircraft noise levels within the park.
GRAND CANYON AIRLINES - SUMMER 1986
Grand Canyon Airlines (GCA) had been in operation since 1927. Founded as Scenic Airways, the company is considered the oldest air tour operator in the world.
During the summer of 1986, Grand Canyon Airlines operated two "Vistaliner" converted deHavilland DHC-6-300 Twin Otter aircraft as well as two Cessna 207 aircraft.
Pictured is a GCA air tour brochure from the summer of 1986. This was the last year that this particular brochure was used by the airline. (2008 Lostflights)
The above 1986 GCA brochure folded out to this picture of the accident aircraft "N76GC".
After the accident these brochures were removed from public circulation. (2008 LostFlights)
N76GC (s/n: 248) - DHC-6-300 "VISTALINER"
deHavilland Twin Otter "N76GC" seen passing 7,400 foot Vishnu Temple was purchased in May 1982 and after modification work was delivered to Grand Canyon Airlines during February 1983. This was the first aircraft of it's type to be operated by the airline.
Dubbed a "Vistaliner", the deHavilland DHC-6-300 Twin Otter was a 19 passenger turbo-prop specifically designed for the air tour industry. The modified aircraft featured large passenger windows, air conditioning, and a quiet insulated cabin. The verbal tour was provided to the passengers over headphones and was narrated by the non-flying pilot. (Photo courtesy of LostFlights)
HISTORY OF AN AIRCRAFT
Before deHavilland Twin Otter "N76GC" flew tours over the Grand Canyon, it lived a different life in the Northeast United States as a commuter airliner.
Seen here in February 1971 at Boston/Logan, MA, flying for Executive Airlines originally registered as "N386EX". (Photo courtesy of Werner Fischdick)
By 1972, the Twin Otter made it's way out west to Colorado flying passengers for Frontier Airlines. Shown here awaiting passengers at Denver's Stapleton Airport. The aircraft remained with Frontier until 1974.
The demand for commuter aircraft in the northeast U.S. brought "N386EX" back to the east coast flying passengers for Air New England. Seen here in Lebanon, New Hampshire during August 1977.
By 1983, the aircraft was re-registered as "N76GC" by Grand Canyon Airlines and was operated with the radio call sign "Canyon 6".
The big window modification is clearly visible as well as its new distinctive terrain blending earth-tone paint scheme.
The interior cabin of "N76GC" was photographed shortly after it's completion in 1983 by the modification facility, RW Martin.
The passenger cabin of "N76GC" was designed to carry a maximum of 19 passengers. The air conditioning outlet vent can be seen attached to the upper aft cabin bulkhead. The air conditioner was another modification added to the "Vistaliner" design.
HELITECH, INC. - SUMMER 1986
Helitech's Bell 206B III Jet Ranger was manufactured in 1980 and was very similar in configuration to this one operated by Grand Canyon Helicopters.
Helitech was in operation for only two weeks when the accident occurred. At the time, the company was not operating under an FAA 135 air-taxi program nor were they required by federal regulation at the time. (2008 LostFlights)
JOHN THYBONY (Pilot of "Tech 2")
With several thousand hours of flight experience in the military and civilian world, Thybony was considered by his peers to be one of the most experienced helicopter pilots flying the canyon.
Employed just five days prior, June 18th was John's first day flying air tours over the canyon for Helitech. (Courtesy of Scott Thybony)
During the early 1980s, Thybony began flying Grand Canyon helicopter air tours on a regular basis with Madison Helicopters. He also served as their Chief Pilot. (Courtesy of Scott Thybony)
GRAND CANYON - JUNE 18, 1986 - 8:55 AM
Passengers boarding Vistaliner "Canyon 4" for a morning air tour of the Grand Canyon. Both N74GC and N76GC utilized a drop down airstair door to board passengers.
On the morning of June 18th, both "Canyon 6" and "Canyon 4" were flying the popular "Canyon Highlights Tour" about ten minutes apart. (LostFlights Photo)
Marcus and Katrina Christian were passengers on Canyon 6. They celebrated their 30th wedding anniversary on June 16,1986. They traveled to the Grand Canyon to celebrate this milestone anniversary. Prior to making this trip they told their family they absolutely would not take an air tour of the canyon. But at the last minute they decided to take the 9:00 AM flight.
Twin Otter "N76GC" seen here in a promotional photo over the canyon was the first Twin Otter "Vistaliner" to be delivered to Grand Canyon Airlines.
To offer the passengers a slow, comfortable ride over the canyon, the pilots would normally fly the air tour at around 90 knots indicated air speed with the wing flaps extended to 10 degrees.
Passengers aboard a Grand Canyon Airlines Vistaliner received an unparalleled view of the Grand Canyon and a live tour narration by one of the two pilots. In most cases, the non-flying pilot.
This aircraft, "Canyon 4" (N74GC) was about 10 minutes behind "Canyon 6" during the 9:00 AM air tour. Although the flight crew of "Canyon 4" never witnessed the accident, they made several attempts to contact "Canyon 6" after seeing fire and smoke in the canyon.
The aircraft was later used by NTSB Accident Investigators to help establish a probable flightpath and timeline of events preceding the collision.
The GCA Vistaliner, operating under call sign "Canyon 6" was approaching Crystal Rapids from the west as the Helitech Bell 206B, call sign "Tech 2" was flying southbound near Mencius Temple.
A vertical separation of 500 feet was supposed to be maintained by both aircraft per the informal agreement with "Tech 2" at 6,500 feet and "Canyon 6" at 7,000 feet. A recent change in helicopter tour routes strongly encouraged by the National Park Service and based primarily on the reduction of noise pollution was implemented two weeks prior.
The change in the helicopter route brought both fixed-wing and helicopter tour traffic into potential conflict. (2008 LostFlights)
COLLISION!! - APX. 9:26 - 9:33 AM MST
With no radar, cockpit recorders, or witnesses, the details of the collision are vague.
The NTSB's official investigation revealed that the collision occurred at approximately 9:30 AM at about 6,500 feet.
This drawing depicts the violent midair collision between "Canyon 6" and "Tech 2" near Crystal Rapids. With the tail separated, The Twin Otter pitched over and fell inverted. The helicopter, missing it's main rotor mast also fell in an inverted attitude.
The main impact site of "Canyon 6" was on the southwest slope of Mencius Temple. The wreckage of "Tech 2" came down nearly one half mile to the southwest of the "Canyon 6" impact site at the eastern edge of Tuna Creek.
At 9:52 AM, National Park Service helicopter pilot Tom Caldwell with NPS Rangers; Ernie Kuncl and Charlie Peterson (EMT) were the first to respond to the accident scene.
Upon arrival, both tour aircraft were completely engulfed in flames. Ranger Peterson remained at the site as the interim Accident Scene Coordinator. No attempts were made to extinguish the fires which burned for several hours.
The next day, the gutted wreckage of "Canyon 6" was still smoldering on the canyon floor. (Photo courtesy of Brad Gray)
Photos such as this were printed in newspapers around the world. (2013 LostFlights)
THE INVESTIGATION BEGINS
A team of federal investigators from the NTSB, FAA as well as other federal agencies spent several days working at the crash site in temperatures that exceeded well over 100 degrees Fahrenheit.
It wasn't long after the accident before Arizona Republic's newspaper editorial cartoonist, Steve Benson ran his viewpoint of air tour safety at Grand Canyon.
THE WRECKAGE DUMP SITE - 1990-1992
The NTSB and other officials conducted their initial on-site investigation in the canyon.
Once completed, the wreckage debris from both helicopter and airplane impact sites were removed from the canyon by helicopter and brought to this site on the canyon's south rim near the town of Tusayan, Arizona.
In the foreground are the remains of the Bell 206B helicopter. The wreckage of the Vistaliner is piled in the background. (1990 LostFlights)
The remains of one of the Vistaliner's two three-blade propeller assemblies lay amid other debris.
The dump site for both helicopter and airplane contained most of the wreckage from both impact sites. Certain key pieces to the investigation were retained by the NTSB for further analysis. (1990 LostFlights)
During my 1990 examination of the wreckage dump site, I was able to locate the pilot's flight control assembly from "Canyon 6". (1990 LostFlights)
The Vistaliner's wings were one of the few recognizable parts remaining after the collision. The dump site contained both wings from the aircraft. (1990 LostFlights)
In this 1990 photo, Paul Richfield, a pilot for air tour company Air Grand Canyon stands next to the vertical stabilizer of "Canyon 6".
The rudder and horizontal stabilizer were virtually undamaged during its separation and free-fall into the canyon. (1990 LostFlights)
Burned and bent passenger seat frames from the Twin Otter made up some of the debris found at the dump site.
With the accident investigation long concluded, I received permission from the land owners in 1990 to remove articles from the dump site that I felt were of future historical importance. (1990 LostFlights)
Covered in four years of pine needles, the inverted interior side (cabin ceiling) of the Twin Otter lay next to a Ponderosa Pine Tree. In my hand is one of the actuator arms for the overhead power,prop, and fuel controls. (1990 LostFlights)
The National Park Service wanted all traces of the accident wreckage removed from the canyon. This not only included the wreckage, but also these wooden numbered marker (victim) stakes the accident investigators left behind.
The helicopter's tail boom, landing skid, and engine power section were some of fragments of "Tech 2" left at the dump site. (1991 LostFlights)
Just small fragments are all that remains of a passenger's 35mm film camera located in the debris of the helicopter. (1990 LostFlights)
THE RE-CONSTRUCTION OF "TECH 2"
There were enough fragments of the helicopter lying around that a partial re-construction was possible.
From the upper bends in the doors and minimal damage to the landing skids, it was becoming obvious that the helicopter had also impacted in an inverted attitude. (1990 LostFlights)
The re-construction was nearly complete with the tail fin, tail boom, landing skid and doors.
The cabin was mostly consumed in the post crash fire and many of the key impact pieces had been removed during the NTSB investigation. (1990 LostFlights)
VISTALINER "CANYON 6" STORAGE
Stored in an airport hangar attic were various salvaged fragments of "Canyon 6".
These components, the largest being the rudder, are mostly from the tail section which separated during the collision and fell to the canyon floor with minimal damage.
The left elevator flight control surface from "Canyon 6" had it's home in the upper ceiling of the hangar since the accident.
During August 2013 and over 27 years after the disaster, the rudder and elevator flight control assemblies were brought down from the attic to the floor of the hangar.
For several days maintenance personnel contemplated what to do with the components.
