Archive for June, 2021

A History of Vickers VC10 Aircraft Accidents

June 15th, 2021

As one of four long-range, quad-engine, first-generation jetliners, along with the Boeing 707, the McDonnell-Douglas DC-8, and the Ilyushin Il-62, the Vickers VC10 was one of only two to feature uninterrupted wings, aft-mounted Rolls Royce Conway turbofans, and a t-tail to maximize its short-field, high-lift performance.

Although it was praised by passengers and crew members alike, its overweight, overengineered design, produced in both short-fuselage Standard and long-fuselage Super versions, limited its sales to just 54 aircraft, including those to the Royal Air Force, and rendered it a technological success, but a financial failure.

This study looks at its brief accident history.

Other than initial stall and drag deficiencies encountered during the VC10′s flight test program, the type experienced few airframe and powerplant failures, reflecting both its superior engineering and the relatively few in operation.

Initial teething troubles, however, surfaced in December of 1964 when an undercarriage warning light illuminated on a BOAC Standard 1101 while it executed its approach to Manchester. Although it landed safely after the landing gear was gravity-extended, the anomaly was identified as the gear-down lock, which was subsequently changed. The true culprit, however, would later surface.

The same aircraft flashed the same warning three weeks later when it was approaching Jan Smuts International Airport in Johannesburg, South Africa. Despite several extension attempts, it would not lock in place. During its ensuing circle to burn fuel and reduce its fire risk after touchdown, the crew finally succeeded in lowering the gear and landed without incident.

Its more permanent grounding, during which time engineers were flown in to discover the real snag, led to the discovery that a corroded spindle had been behind the incident and it was recommended that increased corrosion protection be subsequently applied. Although all VC10 operators were advised of the find, no further incidents occurred.

Another, although relatively minor, incident occurred on August 9, 1967 when a BOAC Super 1151, enroute from Lima, Peru, to New York-JFK, with an intermediate stop in Jamaica, shed a four-by-eight-foot wing flap section, which traveled behind the wing and then plunged to the ground, puncturing the roof of a house at 214 North Street in Manhasset Hills, Long Island. There were neither injuries to those in the house nor even awareness of those on board, leaving Flight 500 to safely land at 19:56 local time. While the passengers disembarked from what they considered a “routine” fight, the incident attested to the aircraft’s design, since the absent flap did not even affect its lift during approach or touchdown.

Of far greater reach was its September 9, 1970 aerial hijacking, along with that of a TWA Boeing 707 and a Swissair McDonnell-Douglas DC-8, carried out by the Popular Front for the Liberation of Palestine, or PLFP, to Jordan’s Dawson Field, history’s single, largest-scale event of its kind. Since the passengers had been allowed to leave the aircraft, there were no fatalities.

Nevertheless, the type suffered two fatal accidents during the 15-year period between 1964 and 1979.

The first of these occurred on November 20, 1969 with aircraft 5N-ABD operated by Nigeria Airways on a multi-sector flight from London to Lagos with intermediate stops in Rome and Kano. The aircraft itself, the first production Standard VC10-1101, had originally been registered G-ARVA and had served BOAC for five years, between 1964 and 1969. Nigeria Airways only operated it for two months and it had 18,431 hours on its airframe at the time.

The crew was hardly without experience. Captain Val Moore, 56, had himself flown for BOAC on several notable piston and pure-jet types, including the Halton, the York, the Hermes, the Argonaut, the Comet 4, and the VC10. Of the 15,173 hours in his logbook, 3,323 of them had been in command of that very Vickers design.

First Officer John Wallis, 30, had also flown the type with East African Airways for two-and-a-half years. Of his 3,500 hours, 900 of them had been on the VC10.

Also in the cockpit were Flight Engineer George Albert Baker, 50, and Navigator Basil Payton, 49, both of whom were serving Nigeria Airways, but were employed by British United.

The four crew members operated all three sectors.

Flight WT 925 had departed London the previous evening at 22:10, experiencing routine operations to both Rome and Kano. But, before it left the latter city, the captain requested 30,000 kilos of additional fuel, fearing that civil unrest presently raging around Lagos would preclude his landing and force his Kano return.

Takeoff for the short, 66-minute segment at 06:24 resulted in an estimated time of arrival (ETA) of 07:28.

At 07:11, or six minutes after the aircraft made its initial air traffic control (ATC) contact, it requested descent clearance from its current 35,000-foot altitude to 14,000 feet, the latter to avoid interference from a Lagos-departing Fokker F.27 Friendship turboprop. After it visually verified and passed the Nigeria Airways quad-jet, the VC10 itself was given further permission to descend and maintain 5,000 feet.

Its subsequent request for a straight-in approach to Runway 19 was granted, although it was required to report reaching 2,200 feet.

Misunderstanding of local weather conditions seems to have played a crucial factor in the event. While the airport was under clear skies, the area surrounding it was not. Thick fog, from treetop level to some 2,000 feet, blanketed the ground one mile north of it, and poor visibility rose as high as 5,000 feet.

Descending through 2,200 feet at 07:29, the VC10 complied with its previous reporting request and the tower asked it to do so again when it reached a point six miles from touchdown. No further transmissions were received.

Shortly after the 08:05 departure of two Nigeria Air Force aircraft from Lagos, they saw smoke rising through the clouds on the approach path to Runway 19.

Almost in its final landing configuration, with 35 degrees of trailing edge flap, extended undercarriage, and a 6.7-degree nose-up tailplane setting, aircraft 5N-ABD had brushed the treetops at 207 feet above the ground, shedding its number two and three port wing flaps and left, main undercarriage bogie. After another 350 feet, it lost its entire port wing.

Careening through three other trees over the next 250 feet, it lost more of its structure-in this case, the number two, three, and four right wing flap panels. After covering a 1,700-foot distance from its initial tree-strike, it impacted the ground in a nose-up, left-wing-down profile, losing its tail and four aft-mounted engines, before the remainder of the aircraft came to rest 300 feet beyond this point.

Fuel ruptured from the tanks ignited a survivorless fire.

Although the aircraft was not equipped with a flight data recorder and no definitive cause in the sequence of events that led to the aircraft’s destruction was determined, it evidently failed to clear obstructions in its approach path and monitor its altitude and sink rate during what was, but should not have been, a visual approach during instrumental meteorological conditions (IMC) at the end of a tri-sector high flight, which placed the crew at the fringes of its legal duty time.

The second fatal VC10 accident occurred three years later, on April 18, 1972, when a Super 1154, registered 5X-UNA with 18,586 hours on its airframe, crashed during takeoff from Addis Ababa, Ethiopia.

Operating East African Airways Flight EC 720 to Rome and eventually to London, it had been granted its start-up clearance at 09:21 and subsequently followed the eastern taxiway to Runway 07. The winds, it had been advised, were out of variable directions at five knots.

Cleared for takeoff at 09:38:40, it executed its acceleration roll. But, just before reaching its V1 speed, or the moment at which its takeoff either had to be aborted or continued, it plowed through a steel jacking pad shed by an earlier-departing Cessna 185 with its nose wheel, resulting in the puncture of the right of its two tires. The cockpit crew experienced the collision as both a loud bang and a vibration.

The nose briefly rose, but resettled to the ground.

Aborting the takeoff, the captain pulled the throttles back to the idle position and engaged the thrust reversers, while the t-tailed quad-jet veered slightly to the right and one of its main gear tires burst. Now veering to the left, it hit an embankment, causing the port wing to momentarily rise and then intercept Runway 25′s steel lattice approach light stanchion.

The impact, rupturing the 1A fuel tank, unleashed a cascade of igniting liquid as the aircraft dropped 10.6 meters to the lower ground beyond the runway and broke up. Eight of the 11 crew members and 35 of the 96 passengers perished.