Aug. 15 (Bloomberg) -- A United Airlines jumbo jet’s hull was punctured in a Chicago airport collision with another plane in July, four people familiar with the matter said, grounding the Boeing Co. 747 for weeks of repairs. No one was aboard.
The parked 747, one of only 24 jumbos at the carrier, was sliced open by the wing of a wide-body United jet that was being towed, said the people, who asked not to be identified because the details are private. A spokeswoman, Christen David, said the accident occurred July 28 near an O’Hare Airport maintenance hangar, while declining to elaborate.
Incidents like this one are rare, and are tracked closely by the U.S. Federal Aviation Administration. The agency will monitor the fixes to the 747 to ensure that they meet U.S. standards, said a person familiar with the agency’s operations.
“Usually tow accidents are a broken tow bar piercing the skin, not aircraft-to-aircraft violence,” said Robert Mann, a former American Airlines executive who is now an aviation consultant based in Port Washington, New York.
A message left for comment about the accident with the FAA wasn’t immediately returned. United’s Chicago-based parent, United Continental Holdings Inc., hasn’t publicized the collision, which occurred away from the terminals at the second- busiest U.S. airport.
The 747 involved in the collision is ordinarily operated by United on charter flights, and repairs by Boeing are still under way, David said. The other jet was a Boeing 777, a wide-body model used on long-haul international routes.
The 747 suffered damage to its radome, which houses radio antenna equipment in the nose, as well as a punctured pressure bulkhead, one person said. The fixes will cost almost $4 million, another person said.
The bulkhead is crucial because it seals the front of the plane from the atmosphere, ensuring proper air pressure at high altitudes. Faulty repairs to a bulkhead at the rear of a Japan Airlines Co. 747 were blamed for a 1985 crash that killed 520 people, according to the Aviation Safety Network website.
“Replacing a pressure bulkhead would be a major repair, pretty expensive,” with a bill running into the millions of dollars, Mann said in a telephone interview.
While rare, ground accidents with significant damage do occur. In 2003, a single-aisle Airbus A319 owned by Northwest Airlines plowed into one of the carrier’s Boeing 757s at a gate at New York’s LaGuardia Airport. The A319, which was being taxied by mechanics, also struck a concrete jetway support, shearing off its nose gear.
About 20 feet (6 meters) of the 777’s wing required repairs, two people said. The 777 is the world’s biggest twin- engine jetliner.
The 777 has been fixed and returned to commercial service, David, the spokeswoman, said in a phone interview. United substituted other aircraft for the long-haul jet, and was able to avoid disrupting the flight schedule, David said.
The 18-year-old 747, which stands out for its all-blue tail and white fuselage emblazoned with “United Charter,” is the airline’s only jumbo dedicated to ferrying troops under a U.S. military contract, two of the people said.
United’s David declined to identify any charter customers for the plane. The airline is using other jets to fulfill its charter flights while the jumbo is being repaired, she said.
Even as some carriers retire older, less-efficient four- engine jets that face expensive maintenance work, United’s decision to fix the 747 was probably made easier because the plane flies for the Civil Reserve Air Fleet, Mann said. Participating airlines are paid for their costs, including fuel, and a profit margin.
“I could see why they’d want to keep doing it,” Mann said. “It has a predictable value, much more so than the commercial scheduled business.”
--With assistance from Alan Levin in Washington.