Age-Old Issue Still a Concern for Most Carriers : Airlines: New regulations designed to upgrade the safety of aging U.S. aircraft go into effect this week. But as one veteran plane continues to prove, it’s mostly a matter of regular maintenance.
Ever since the Aloha Airlines accident in 1988, when part of the fuselage of a 19-year-old 737 ripped open in flight, the focus of many air-safety investigators, and the public as well, has been on the aging U.S. airline fleet.
New safety and maintenance regulations were ordered by the Federal Aviation Administration. Many were the result of the Aging Aircraft Task Force, a government/industry group formed after the Aloha accident.
Most recently, the FAA has ordered extensive structural modifications to older Boeing airplanes as part of a larger program designed to anticipate, and correct, metal fatigue in aging aircraft.
The new anti-fatigue rules, which go into effect Tuesday, involve 115 Boeing 727s, 737s and 747s. (Estimated cost for modifications: $142 million over four years.)
But do these new rules mean that the aging fleet is unsafe?
Not necessarily. The answer lies in each airline’s commitment to regular, thorough maintenance.
The first 727, more than 27 years old, still is operated by United Airlines. It has been well-maintained and flies virtually every day.
A more remarkable story is about another aging aircraft--the first 747, which is also still flying.
The jet, carrying serial number 19639, is owned and operated by Pan American, the first carrier to order the 747s from Boeing in the 1960s. It has flown longer, farther and harder than any other widebody aircraft in the sky.
An examination of this plane, which recently turned 21 years old, is a good example of how long an aircraft can fly if properly maintained.
The plane was completed in the factory on Feb. 28, 1969, and painted a week later. The aircraft’s first flight was April 11, 1969.
Actually, this widebody, dubbed the Clipper Juan Trippe after Pan Am’s founder, was the second 747 built. (The prototype aircraft, used by Boeing for test flights only, is also still flying. Boeing’s third 747, also delivered to Pan Am, was destroyed when a KLM 747 collided with it in Tenerife in the Canary Islands in 1977.)
The Clipper Juan Trippe, with the symbolic tail number of N747PA, holds all the records for commercial time, distance and endurance. It has averaged about 50 flights a month throughout the Pan Am system (about 400 flying hours) for about 20 years.
It was initially designed to hold 360 passengers . . . and now holds 414.
Its lifetime statistics are impressive: N747PA has flown more than 34 million miles (more than 63,000 hours), carried more than 3.4 million passengers, and made nearly 30,000 takeoffs and landings. It has gone through 1,890 tires and 330 brake systems, used more than 221 million gallons of fuel, had engine replacements 105 times and received more than 756,000 man-hours of routine maintenance.
But not everything about N747PA has been routine. After flying without incident for Pan Am for only nine months, the plane was nearly destroyed in a crash landing in San Francisco.
On July 30, 1971, the plane was operating as Pan Am Flight 845, bound nonstop for Tokyo with 199 passengers and 21 crew members.
When it was time to depart San Francisco (after beginning its journey in Los Angeles), the crew was notified that Runway 28 Left, 11,870 feet long, was temporarily closed, and the plane was diverted to the shorter 9,500-foot Runway 1 Right.
But as the 747, weighing 700,000 pounds (300,000 pounds of it fuel), roared down the runway, it soon ran out of concrete. The crew had no choice but to try to take off. The plane struck runway lights, ripping up a 75-foot section of the lighting pier.
In the cockpit, the crew fought to keep the plane airborne. The impact had knocked out three of the aircraft’s four hydraulic systems, outboard and inboard ailerons were torn from the wings, and parts of the elevator and rudder at the tail were missing.
Inside the passenger cabin, an 18-foot piece of iron from the pier had ripped through the fuselage and up through the floorboards at high speed. Two passengers were seriously injured.
Another piece of iron slammed into the rear of the cabin, pierced three restrooms and exited the ceiling.
Capt. Calvin Dyer stayed in the air for another two hours, circling the crippled aircraft over the Pacific while dumping most of his fuel. In the meantime, Pan Am technicians inside a U.S. Coast Guard HC-130 rescue plane caught up with the 747 to assess the damage from the air.
When the rescue crew flew alongside the plane, they couldn’t believe it was still flying. Among other damage, the right inboard main landing gear was jammed into a cargo bay and the left inboard gear was simply dangling.
But because it didn’t appear that any of the remaining 12 wheels had been damaged, the decision was made to try a landing. Runway 28 Left was reopened.
As emergency crews stood by, Dyer set down the 231-foot plane onto the runway, bounced once and veered off the runway into the dirt. The left inboard gear collapsed, the nose pitched up and the 747 sank back on its tail. Twenty-seven passengers were injured during the evacuation.
It was the first 747 accident to cause injury. Ironically, it was also the first opportunity for Boeing to demonstrate to the world the resilience of its newest jet.
A special Boeing team flew to the site from Seattle and assessed the damage. The plane was remarkably intact and repairable. Technicians, including metallurgical and structural engineers, were flown in. Three months and $4.84 million later, N747PA was certified as airworthy. It has been flying ever since.
“We learned a lot about the 747s from that incident,” one Boeing engineer said. “Much of what we learned we incorporated into the repair of that aircraft. In fact, we’re convinced the plane is stronger today than when it was first built.”
Later, investigators for the National Transportation Safety Board said that if it had not been for the “inherent structural integrity of the Boeing 747 . . . the accident could have resulted in a major tragedy.”
The plane continued flying for Pan Am until January, 1974, when it was leased for a year to Air Zaire. It returned to Pan Am in February, 1975. That March and April, N747PA handled the last charter flights out of Vietnam. Later it would perform similar service in Beirut.
N747PA is still flying today, with a few modifications. It has new, higher thrust engines. New landing gear has been added to accommodate more weight. Galleys have been changed twice. The passenger compartment has been refurbished four times. Lavatories have been replaced four times. The plane has received more than 4,000 modifications and repairs.
Structural inspections for metal fatigue and corrosion have used more than 9,800 frames of X-ray film.
The plane has received a number of heavy “D” service maintenance inspections (at a fee of about $1 million each), during which all movable parts are replaced. The plane also had “metal skin” replacements for structures such as wings and belly in 1972, 1976, 1981, 1985 and 1987.
And yet, N747PA is not known within the airline industry as a “hangar queen.” These statistics represent a normal maintenance history.
According to Pan Am, the total maintenance costs associated with keeping Clipper Juan Trippe in the air (numbers which the airline declined to reveal) have been worth the investment. To replace N747PA, which originally cost $22 million, would run Pan Am more than $130 million today.
