The Navy has grounded 90 light attack jets on as many as 11 aircraft carriers and at two flight training centers in California and Florida following the discovery of faulty turbine blades that caused two recent plane crashes and could be linked to as many as five others, The Times has learned.
Orders to halt flights of the A-7E Corsair IIs were sent Friday from Washington to aircraft carriers around the world, according to Navy spokesman Lt. Peter Johnstone in Washington. The orders included instructions that the planes were to be used, at risk, only for emergencies or wartime purposes.
Johnstone said it will take “a matter of months” before all of the suspected planes that require new engines are identified and the replacement work completed.
He said the grounding would have “minimal impact” on Navy operations.
But the deputy director of the Center for Defense Information in Washington said the idling of the A-7E, one of the oldest warplanes in the U.S. fleet and considered the backbone of the Navy’s conventional and nuclear ground-attack aircraft on carriers overseas, could significantly threaten national security.
“It’s a substantial loss of immediate combat capability when you have (that many) airplanes grounded out of a fleet of some 200,” said Eugene Carroll, a retired Navy rear admiral.
The engines, built by Allison Gas Turbine Division of General Motors, are failing because of blades that have an unusually high content of lead, which causes them to snap off during flight and damage the motors. Allison is working with the Navy to send eight maintenance experts to aircraft carriers around the world to repair engines found to have the faulty blades.
Eight A-7E jets have been lost in crashes this year, six since March 26. Of the eight crashes, two have been caused by the failed turbine blades, one is believed to be linked to the blades and four others are under investigation. In all but one crash, pilots successfully ejected. In the eighth case, not connected to the blade problem, a pilot was killed in a June 3 crash in Jacksonville, Fla.
‘Obsolescent at Best’
The Navy is gradually replacing the A-7E, which President Carter described in 1979 as “obsolescent at best,” with new, $32-million supersonic F/A-18 Hornets. The A-7E is expected to be phased out by the early 1990s.
Two aircraft carriers, the Constellation and the Coral Sea, are equipped with the new F/A-18s. The remaining 11 deployable carriers rely on the A-7E for ground attack. The A-7E carries a wide array of bombs and missiles and, according to retired military sources, is capable of dropping nuclear bombs.
The Navy would not release the number of planes that it has grounded on aircraft carriers or the availability of replacement engines on board. Johnstone said such information is “classified.”
The Navy operates 310 A-7E aircraft. Each aircraft carrier has 24 of the single-engine attack planes, bringing the total number of A-7Es on deployable carriers to 244. The rest of the planes are used in training at Lemoore Naval Air Station near Fresno and Cecil Field Naval Air Station in Jacksonville, Fla.
A Navy source in Washington told The Times that the bulk of the 90 planes that have been grounded are on aircraft carriers.
Not Enough Spare Engines
Johnstone said it takes about a day to replace an A-7E engine, but the Navy does not have enough spare engines to immediately refit all 90 planes.
The turbine blade problem was first discovered on July 10 by mechanics at a Navy rework facility in Jacksonville who were investigating a June 28 crash of an A-7E.
The faulty blade was sent to Allison’s Indianapolis offices. A chemical analysis of the blade on July 11 found 70 parts per million of lead--well beyond the allowable 10 parts per million, Allison spokesman Donald G. O’Brien said.
The high lead content reduces the ability of the blade to endure stress, causing it to crack and set off a sudden string of events that results in engine failure.
Crash Off California
The most recent crash of an A-7E jet occurred July 13 off the Southern California coast. The plane, based at Lemoore, was flying from the Miramar Naval Air Station in San Diego to the aircraft carrier Enterprise when it developed mechanical problems. The pilot ejected and spent 30 minutes in the water before he was picked up by a helicopter from the carrier.
On July 23, Allison notified Navy officials in Washington of problems with the A-7Es equipped with engine type TF41A-2B and gave them a series of recommendations, including conducting thorough examinations of all engines and returning suspect blades to the firm.
“We suspect something went awry in the original casting of material from which the blades are made,” O’Brien said. “That is where the excess quantities of lead cropped up. The cause is being sought so it doesn’t happen again. It sounds like a crazy, bad batch.”
Carroll, of the Center for Defense Information, said: “These engines are pulled out and reworked at regular intervals. Someplace at the rework cycle . . . they lost control of the situation. To suddenly start having an old workhorse fail in this fashion is very hard to understand.”
A Navy source in Washington said the blades were inspected on a random basis before they were installed. He said the high lead content was not detected.
O’Brien said the blades were manufactured by Wiggan Alloys Ltd. of England.
Responsibility for Costs
Navy officials said that responsibility for the cost of the repairs is being negotiated.
The Air National Guard has 57 A-7E planes based near Oklahoma City that may have faulty blades, O’Brien said. Those planes have also been grounded.
The attack planes, which were first sold to the Navy in 1968, also were sent to Portugal and Greece in the mid-1970s. But none of the foreign planes are believed to have the faulty blades, O’Brien said.
Times staff writers James Gerstenzang and Gaylord Shaw contributed to this story from Washington.