Five potentially catastrophic incidents plagued Concorde in early years

Blown tyres on the European-built Concorde supersonic planes caused five "potentially catastrophic" incidents in the first two years of the luxury airliner's commercial life, including one that damaged an engine, punctured fuel tanks and left a large hole in the top of the wing.

Blown tyres on the European-built Concorde supersonic planes caused five "potentially catastrophic" incidents in the first two years of the luxury airliner's commercial life, including one that damaged an engine, punctured fuel tanks and left a large hole in the top of the wing.

That mishap, on June 14, 1979, sounded eerily similar to what authorities believe may have happened just before Tuesday's crash outside Paris killing 114 people.

The 1979 incident, and four less dangerous events involving Air France and British Airways Concordes over the next two years, resulted in adoption of strict inspection and emergency procedures. No similar failures had occurred in two decades of operation before Tuesday's crash outside Paris.

In a stern 1981 safety recommendation for the Concorde, the U.S. air safety authority described such incidents as "potentially catastrophic."

French officials have not ruled out human error in the Concorde crash and were also looking into the possibility of design or construction flaws. On Friday, officials concluded that at least one wheel had exploded, which could have damaged the plane's structure, triggered a fire and caused one of the engines to fail.

The first blowout in 1979 is not in the National Transportation Safety Board's databank of airliner safety incidents, but it is cited in a Nov. 9, 1981, NTSB safety recommendation that Air France agreed to follow.

"Tyre debris and wheel shrapnel resulted in damage to the No. 2 engine, puncture of three fuel tanks, and severance of several hydraulic lines and electrical wires," the board said in describing the 1979 mishap. "Additionally, a large hole was torn in the top wing skin which covers the wheel well area."

That flight returned safely to Dulles International Airport near Washington.

The five 1979-1981 incidents in NTSB records, all at New York or Washington airports, resulted in changes in strict inspection and emergency procedures.

The second mishap cited by the board in its 1981 recommendation was a blown tyre five weeks later, on July 21, 1979, during takeoff from Dulles.

"The similarity between the two incidents led to immediate voluntary corrective action by the appropriate authorities," the board said. This included an airworthiness directive by French aviation authorities that required detailed inspection of each wheel prior to takeoff and advice to crew members that when a problem is suspected, "particularly when a bang is heard," that the landing gear should not be raised.

But two subsequent incidents, more than a year apart, prompted the further action, including a mild rebuke of Air France for the ineffectiveness of its earlier directives.

"The repetitive nature of these incidents and, in particular, crew response to the more recent incidents is of serious concern," said the U.S. board, whose recommendations normally are adopted by foreign airlines using U.S. airports.

In October 1979, two tyres blew out on a Concorde at Kennedy International Airport in New York on a flight that safely continued on to Paris. No investigation of that incident occurred.

In February 1981, blown tyres at Dulles caused engine problems and forced a landing at New York. The board said no preparations of passengers were made for an emergency landing and the plane's cockpit voice recorder was inoperative and had been for several flights.

A fifth incident, recorded by the NTSB but not cited in the safety recommendation, occurred Aug. 9, 1981. A British Airways Concorde aborted takeoff in New York after the crew noticed a fuel leak. The report said two tyres "disintegrated, the hubs broken and the wheel rims broken and worn down," causing "minor airframe damage," including a one-inch (2.5-centimeter) hole in the left wing fuel tank.

The board called for a mandatory requirement that the landing gear be left down after a blown-tyre takeoff and that the plane immediately return to the airport from which it took off.

Just before Tuesday's crash, the pilot, Capt. Christian Marty, told the Paris control tower that he could not lift the landing gear.

The board in 1981 also called for Air France to better train its crews in following checklists and preparing for abnormal landings.

The French transportation ministry, in responding to the U.S. board on Jan. 7, 1982, said most of its recommendations were being implemented, and the NTSB later listed the recommendations as "no longer applicable" because of the airline's actions.

The then-chief of the French ministry's accident investigation bureau, J. P. Bonny, said in a letter to the NTSB that Air France was following its recommendations.