June 2006 Cover Story:
Desert Disaster: TWA – United Mid-air Collision Over the Grand Canyon

By Michael McComb

The days of the Ford Tri-Motor were gone. The antiquated air space system, first established in 1929, had changed little by the summer of 1956. There were so many planes in the air and so little positive control. A major, mid-air collision was not only possible, it was becoming almost inevitable. It was just a matter of when and where.

The Crash
On Saturday morning, June 30, 1956, Los Angeles International Airport was alive with activity as crews worked to get two transcontinental flights out on time. United Air Lines Flight 718 was a Douglas DC-7 with first class service to Chicago’s Midway Airport, continuing to Newark. Each of the flight crew were qualified and well experienced. Captain Robert Shirley had nearly 16,000 hours and Co-pilot Robert Harms and Flight Engineer Gerard Fiore were both five-year veterans. Preparing the cabin were Stewardesses Nancy Kemnitz and Margaret Shoudt.

Across the ramp the scene was similar as Trans World Airlines readied their Lockheed Super Constellation, non-stop service to Kansas City and Washington D.C. The scheduled departure time had passed due to minor maintenance issues with one of the four engines. In command of TWA Flight 2 was Captain Jack Gandy. Gandy had been with TWA since 1939, starting his career with the airline on their DC-3s. He steadily advanced to captain and was qualified on all versions of the airline’s Constellations. To Gandy’s right was Co-pilot James Ritner, a 7,000-hour, WWII B-17 veteran, busy checking weather and flight planning their cross-country trip. Behind the pilots were Flight Engineers Forrest Breyfogle and Harry Allen. Allen was just along for the ride home, commuting back to his base in Kansas City. In the cabin were Hostesses Beth Davis and Tracine Armbruster. Both had been with the airline for several years.

The Constellation changed the face of commercial aviation. In May of 1952, TWA took delivery of their first Model L-1049 Super Constellation. With a pressurized cabin, it was able to cruise comfortably at 21,000 feet, above most weather and turbulence. Aside from a few small problems, the aircraft was a favorite among pilots and mechanics.

The Douglas answer to Lockheed’s Super Constellation was the DC-7. It flew for the first time on May 18, 1953. The DC-7 was powered by four Wright R3350 Turbo Compound Engines equipped with Power Recovery Turbines (PRT), with a range of 5,635 miles. It flew slightly faster and farther than the Super Constellation. In fact, the DC-7 became the first commercial aircraft able to fly coast to coast nonstop westbound against the prevailing winds. The DC-7 was Douglas’ largest and last piston aircraft.

The hostesses of TWA Flight 2 began seating their 64 passengers and preparing the cabin for departure. Many of the passengers were familiar to Davis and Armbruster; 31 were fellow TWA employees and their families traveling on reduced fare passes. Most were returning home from vacations in Southern California.

At 0901, TWA Flight 2, N6902C “Star of the Seine” began its takeoff roll from Runway 25 and climbed out over Dockweiller Beach. Three minutes later, Captain Shirley advanced the throttles of the DC-7 and United Flight 718, N6324C “Mainliner Vancouver,” accelerated down the 8,000-foot runway 25. Both aircraft turned east and climbed above the morning marine layer that covered the Los Angeles Basin. Taking a more southerly route near Palm Springs, United 718 climbed to its assigned altitude of 21,000 feet. Much like those on TWA Flight 2, the 53 passengers aboard the United plane were a mixture of business travelers and vacationers on their way to a Fourth of July holiday with family and friends.

Climbing to their assigned cruising altitude of 19,000 feet, TWA 2 made steady progress eastbound. As they flew across the Mojave Desert, Gandy and Ritner saw increasing cloud and thunderhead buildups. Captain Gandy made a request to Los Angeles Center Controllers for a climb to 21,000 feet. Initially, his request was denied due to conflicting traffic in the vicinity (United 718). However, an increase in altitude was approved when Captain Gandy requested a clearance for 1,000 feet “On Top” of the approaching cloud layer. Los Angeles Center approved his request and allowed TWA 2 to fly at its previously requested 21,000 feet, putting the responsibility, by regulation, to “see and avoid” traffic on the TWA crew. In addition to approving the request, Los Angeles Center notified TWA 2 that United 718 was in its vicinity. Captain Gandy acknowledged the traffic. ATC did not notify the crew of United 718 of potential conflicting traffic. Existing flight rules did not require such notification by ATC.

At 0958, one minute ahead of schedule, United 718 reported “Over Needles at 21,000 feet” and “Estimating Painted Desert at 1031.” Trimmed and level, United 718 was making better time than anticipated. A minute later, TWA 2 radioed Las Vegas Control that it had passed Lake Mohave at 0955 and was also estimating the Painted Desert at 1031. It would seem that both aircraft reporting the same position at the same time would have triggered some concern with controllers, but it was only an interesting coincidence since the Painted Desert was not an actual physical position, but rather a line of position (LOP) extending northwest from the Winslow omni navigation station. In reality, the flights could cross anywhere along the line of position.

In an effort to make up time and fly more direct, the two airliners left their planned routes and flew off-airways as they crossed the Colorado River into Arizona. Their direct routes would take them over the Grand Canyon. A scenic view of the Grand Canyon was considered a high point of any transcontinental flight and airline crews often detoured a bit to give their passengers a view of the awesome spectacle. An hour or so earlier another TWA Constellation had also detoured to give passengers a view, and now Captain Gandy, as well as Captain Shirley, followed suit and began to weave around the towering thunderheads that covered the eastern half of the Grand Canyon. The time was 1031.

Captain Shirley made a slight left turn around a large buildup. He suddenly caught a flash of an object to his left. Collision: a convergence so sudden that there was nothing the stunned Captain Shirley or First Officer Harms could do. As the airliners collided, the left wing of the DC-7 made a crushing impact into the center vertical fin of the Constellation. The DC-7’s disintegrating left wing continued to cut and crush its way into the top of the aft cabin area of the fuselage of the Constellation, while the DC-7’s outboard 13-foot diameter propeller made a series of slicing cuts deep into the rear lounge and aft baggage compartment. Weakened by the impact and ruptured pressurized hull, the Constellation’s distinctive triple tail began to tear and fall away, taking with it most of the rear cabin interior. With the tail completely gone, or trailing momentarily, still-attached by a few control cables, the once aerodynamically balanced plane violently nosed over past vertical. On the flight deck of the doomed Constellation, Gandy and Ritner tried in vain to pull the nose up. The plunge through the clouds and into the canyon took a mere thirty-five seconds. For those on board each second was an eternity. Seventy lives ended on the slopes of Temple Butte in an explosion of metal, stone, and fire.

The collision destroyed nearly twenty feet of the DC-7’s left wing and aileron. Captain Shirley’s application of full right aileron and rudder had little effect as the Douglas pitched into a left rolling descent. First Officer Harms transmitted the final words from the flight. “Salt Lake…United 718…We’re going in!” Spiraling out of the cloud cover at nearly seven hundred feet per second, Shirley and Harms made one last effort to bring their ship under control. The end was brutal as the lives of 58 passengers and crew became a shattered memory on the jagged cliffs of Chuar Butte.

Air route controllers in Salt Lake City sat in stunned silence as they tried to understand what they had just heard on the radio. Realizing that TWA 2 was also in the area, message after message went out to both planes, met only by silence. Minutes turned into hours as it became clear that something had gone terribly wrong in the skies over Northern Arizona. The Civil Aeronautics Agency (CAA) issued a missing aircraft alert and Air Force Bases in the area organized search and rescue efforts.

Later that afternoon, Palen Hudgin, owner of Grand Canyon Airlines, flying his Piper Tri-Pacer on a scenic tour, noticed a column of smoke near the confluence of the Colorado and Little Colorado rivers. Believing lightning might have struck some brush the day before, he initially ignored it. It wasn’t until later that evening that Palen heard a report on the radio of the missing planes. He decided to take another look at the smoke in the canyon. With darkness approaching he flew just a few hundred feet above the river until he found the charred remains of the TWA Constellation.

The next morning Air Force and Army rescue helicopters began their descent into the canyon. Hovering in a Sikorsky S-55 near the still smoldering remains of TWA Flight 2, USAF Capt. Byrd Ryland discovered the smoking fragments of United 718 a little more than a mile away. The DC-7 had struck the south face of a vertical 1,000-foot cliff with such a terrific force that two of its four engines were still imbedded in the hard sedimentary rock. It was painfully clear from the utter destruction of both airliners that no one could have possibly survived.

Accident investigators and recovery teams were shocked by the devastation at the crash sites and the seemingly impossible recovery task they faced. The TWA Constellation had crashed upside down and disintegrated in a dry wash on the northeast slope of Temple Butte. On Chuar Butte, helicopters made several attempts to land on a small ledge near the impact point of the DC-7 but had to abort their attempts due to strong, gusty winds. When they were finally able to land, crews found only scraps of the plane and its occupants, many of which were on precarious ledges far below the main impact site. Evaluating the risks, the military nearly called off recovery efforts on Chuar Butte when W.A. Patterson, President of United Air Lines, accepted an offer by Swiss Air to fly in eight members of an alpine mountain-climbing team to help retrieve the victims and key pieces of wreckage that might be important to the investigation.

The small, quiet Red Butte Airport on the canyon’s south rim soon became a hub of activity as recovery and investigation efforts began. Air Force Piasecki H-21 helicopters began a series of 76 individual flights to the crash sites. Battling strong wind currents and hot July temperatures on the canyon floor, both craft and crew were pushed to their limits. At one point a rescue helicopter on the way back to the airport with several body bags was tossed so violently by turbulence that it lost one of its doors, and nearly one of its crew, to the canyon floor below.

Despite the heroic efforts of recovery crews, many of the crash victims were never positively identified. Of the 58 aboard United 718, only half were returned to their families for burial. The unidentified remains of the other 29 victims rest in a common grave on the canyon’s south rim near Grand Canyon Village. For TWA Flight 2 there was little left to send home. Only four victims were identified. The remaining 66 passengers and crew were buried in a mass grave at Citizens Cemetery in nearby Flagstaff.

The nation was stunned by the tragedy. Against almost impossible odds, two state-of-the-art airliners had collided and 128 people had lost their lives in a horrific air disaster. Public sorrow soon turned to anger. The public wanted answers. In response, the Civil Aeronautics Board (CAB) began a 10-month investigation of the accident. Recovery of several aircraft fragments with paint transfers, as well as pieces of the DC-7’s shattered left wing, proved that a collision of the two airliners had occurred. The question remained as to why and how they collided. With no witnesses, no radarscopes to show their final converging flight paths, and no flight recorders to record the flight crew’s last moments, only physical evidence recovered by the accident investigators and speculation could answer the questions.

In the months that followed the accident, blame was centered initially on the nation’s air traffic control system. In the final report released on April 17, 1957 though, the responsibility for the accident was placed squarely on the flight crews of the two airlines because of their failure to see and avoid each other. Aside from that primary finding of probable cause, five other factors were listed in the report: (1) intervening clouds, (2) cockpit window design, (3) preoccupation with cockpit duties or providing passengers with a view of the canyon, (4) physiologic limitations of human vision, and (5) insufficient air traffic advisory information.

It would take three other major mid-air collisions in the next four years (two involving military aircraft) before significant changes were made to the air traffic control system. There is little question that the Grand Canyon collision was a catalyst in the creation of an improved air traffic control system and the reform of the CAA into what is now the Federal Aviation Administration (FAA). The development of both the Mode C Transponder and the Traffic Alert/Collision Avoidance System (TCAS) has been attributed, in part, to the events of June 30, 1956 as well.

Aviation Archaeology
My eight-day trip to the crash sites had been planned for about a year, but preparations to make the fifty-mile hike took a little longer. In addition to food, water, and equipment, I carried an inflatable raft to cross the Colorado River, eighty-five pounds altogether. I made my way down the snow-covered Tanner Trail from the canyon’s south rim. Across the river from Temple Butte on the Beamer Trail, I discovered a metallic fragment reflecting amid the boulders. It was a small rectangular sign “PLEASE RETURN TO SEATS.” The combination of the Lockheed inspection stamp and part number impressed in the metal made it clear that it was from the Flight 2 and most likely fell from the aft lounge as the Connie’s tail separated. Considering the nearly four-mile fall and fifty years in the elements, the sign was in relatively good shape. Leaving the sign in place as I found it, I continued to the river crossing point. The river crossing was uneventful and soon after landing my raft on a sandy beach I discovered one of the DC-7’s four main tires in a dry wash. The tire was labeled “B.F. Goodrich Silvertown” and was complete with a deep gash from being blown out during the impact.

The next morning I began my trek up the steep talus slope. I could see large portions of wreckage still lodged in a 300-foot crevasse on the cliff face. The fragments were not removed in 1956 nor were they removed during the 1976 cleanup operation. The accessible slope below the cliff face provides some interesting fragments that testify to the severity of the airliner’s impact with the cliff. The first item that caught my eye was the aft lounge emergency exit door that was sheared in half by the impact into the canyon wall. I sat there on a rock for a moment, contemplating the incredible force that destroyed such a strong component near the tail of the aircraft.

Continuing my hike along the slope, I saw other objects and fragments: a crushed serving tray, a fragment of a shoe, and a passenger seat armrest, all torn by the impact. A fragment painted white with black lettering caught my eye. Pulling it free from the boulders, I knew exactly where it came from. On the plane it would have been located on the aft fuselage, just below the vertical stabilizer and would have read: “UNITED AIR LINES.” The fragment still had most of the lettering. The destruction of this piece along with the severed aft emergency exit, made it clear that United 718 suffered an impact so severe that nothing, from the nose to the tail, was spared almost complete disintegration.

The next day I camped next to the northeast slope of Temple Butte, the final resting place for TWA Flight 2. The area near my camp was still littered with wreckage debris from both the initial collision and the in-flight separation of the Constellation’s tail section. Mostly small pieces, wreckage could be found virtually everywhere in the nearly eight square miles of the debris path. The area between the two crash sites is similar to the steep slopes of Chuar Butte with even steeper canyons and more vertical cliffs.

Hiking near where the Connie’s giant triple tail came crashing down, I located a fragment with Lockheed stamps, numbers and, seatbelt attach points. It appeared to be a seat fragment. Further on, I discovered more evidence of the Connie’s in-flight breakup. A few pieces of window Plexiglas, cabin ceiling panels and a few strands of severed steel control cables. On the upper slopes of Temple Butte, I found the most surprising and largest fragment located during my four-day stay. Up a boulder-strewn gulley was a cabin interior bulkhead about seven feet tall. Painted in Lockheed’s green-blue interior paint, the fragment includes a folding work desk and multiple switches and rheostats that controlled cabin lighting and audible chimes. The bulkhead/work station would have been located immediately to the passenger’s right as they boarded the aircraft.

Unlike the crash site of United 718, where most of the wreckage is perched on a nearly impossible-to-reach 1,000-foot cliff, the charred remains of TWA Flight 2 are accessible by foot from the river. The rocks and boulders are chipped and scarred in the direction of travel that the plane took as it disintegrated in the dry wash. I found small coins nearly torn in half by the impact, airline silverware embossed with the TWA logo, twisted and burned. It was possible though, amid all the destruction, to find an unbroken ball point pen or a wristwatch with its minute hand stopped at exactly thirty-one minutes past the hour.

I made my way back to camp as afternoon shadows descended on Temple and Chuar Butte. The silence of the canyon was broken by a lone jet airliner tracing across the Arizona sky. I thought about the innocent passengers of the two airliners who perished in this desolate wilderness half a century ago. I wondered if the passengers in the airliner miles above me knew about the contribution, albeit unknowingly, that the 128 people who died here made to their safety.

The accident site is a protected historical site, overseen by the National Park Service.

Michael McComb is chief pilot for Grand Canyon Airlines. He holds a degree from Embry-Riddle Aeronautical University in Aeronautical Science with a minor in Aviation Safety/Accident Investigation. Mike has also co-authored a book entitled Wreckchasing 2. Mike formed Airesearch in 1992. The organization has located and documented many notable military and civilian crash sites throughout the Western Hemisphere. Mike also enjoys flying antique aircraft including the Beechcraft Super 18 and Grand Canyon Airline’s 1929 Ford 5-AT Tri-Motor.