Tuesday, October 18, 2011

How to Wreck a Perfectly Good Boeing 720

Another 707 on short final at Mojave over-flies the sad
remains of a perfectly good American 720. This photo
was taken by Bill Deaver, via Mojave Transportation
For the next few weeks, the mid-week update will feature photos from the archives of the Mojave Transportation Museum.

During the mid-1960s, there was little going on at the Mojave Airport, a hot and dusty place in the middle of nowhere. When the U.S. Marines left MCAAS Mojave for warmer digs in El Centro in 1959, they left behind acres of ramp (which central valley farmers used for drying grapes into raisins) and a really long runway, ideal for airline pilot training. Thus, four-engined Boeings were about all the frequented the place. American was one of the carriers to make use of the facilities.

Mojave's use as a training flight destination led to one of the more odd airliner incidents to happen at the desert airport. On June 29, 1966 at 8:10 in the morning, a 1960-model American Airlines Boeing 720-023B, registration N7534A, crashed on landing, just short of the runway at Mojave. The NTSB report simply says that the "pilot simulated 4 eng. flameout [on] approach with 4 engines in idle thrust position." What the dry NTSB report leaves out, though, local accounts more than make up for.

Evidently, on this day, there were two line pilots and two check pilots onboard, as well as a pair of flight engineers. Supposedly, the B720 and crew were in the vicinity of Oceanside, California, at cruise altitude, when a bit of a wager was made on whether they could make MHV from there with all four engines back at idle (as Google Earth crow flies, this is 137 miles). Evidently, about this same time in history, the FAA and American Airlines had done some similar flight testing to determine the glide range of the B707/720, and the results had been incorporated in the operating manuals. Whether this had any bearing on the Mojave incident is unknown, but the swagger factor certainly is a possibility. Assuming a 37,000 foot cruise altitude over Oceanside, a glide ratio of 19.57:1 would be required to reach Mojave, and the 707 family of aircraft are reported to have a 19.5:1 glide ratio with engines at flight idle, 15:1 with no power, so this seems to be a plausible explanation.

They almost made it.

In trying to stretch out the last bit of glide on final approach to the runway, the pilot stalled the aircraft a half mile short of Runway 30, and hit the ground hard, driving the right main gear up through the wing and tearing the number 3 engine off. According to the following day's Los Angeles Herald-Examiner, the only injury was to one of the flight engineers, who suffered a few cuts and bruises. The NTSB blamed the "dual student pilot", saying that he "misjudged distance, speed and altitude." The check pilot was blamed for "inadequate supervision of flight".

The American 720 sits outside the old Hangar 72.
Mojave Transportation Museum collection.
A professional house moving company from Santa Barbara was brought in, and the movers did additional structural damage in removing the plane from the field. The aircraft was taken to one of the old wooden hangars which was where Hangar 72, the National Test Pilot School now is, and rebuilding work commenced. Long-time Mojave resident, contractor and pilot Al Hansen loaned the AA crew some heavy equipment, and so got to know the project supervisor well. When asked why they would go to so much effort to rebuild the plane, the answer was that it would take $5 million and 6 months to rebuild it, versus $7 million and 18 months to get a replacement from Boeing, whose order books were backlogged. The right wing was replaced with a new unit from Boeing, and thus the bulk of the structural work was in the fuselage center section.

The aircraft reportedly left Mojave in December 1966 and re-entered service. But its troubles were not yet over. American retired N7534A in July of 1971, and the following March, it went to Middle East Airlines, of Beirut, Lebanon, who registered the aircraft as OD-AFT. On January 1, 1976 the aircraft as Flight 438 was in cruise flight at 37,000 feet and approximately 20nm northwest of Al Qaysumah, Saudi Arabia on a scheduled passenger flight from Beirut International to Dubai, when a terrorist’s bomb detonated in the forward cargo compartment. The aircraft crashed into the desert, killing all 66 passengers and 15 crewmembers on board. The terrorists were never identified.

(Special thanks to Bill Deaver and Al Hansen for research help. Today's piece is adapted from an article I co-wrote with Bill for the Mojave Desert News February 13, 2003 edition, and which also ran in 2008 in my old Mojave Skies blog.)

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