After nearly 50 people were hurt and a woman was paralyzed at McDonnell Douglas in 1991 during an evacuation test of a new high-capacity MD-11 jetliner, the company insisted that it would not repeat the government-mandated test.
Federal Aviation Administration officials concurred and last month quietly allowed McDonnell to conduct a new drill, in which test subjects ran from an MD-11 onto raised platforms. In the 1991 test, participants had jumped down a steep evacuation slide, just as the FAA has required for decades.
The new MD-11 tests permitted by the FAA have raised concerns among some air safety experts who say the procedures may not create a realistic simulation of an actual emergency evacuation. An estimated 30 to 50 actual emergency evacuations take place on airlines every year, making evacuation an important safety concern.
Although a special FAA panel is still considering new evacuation test guidelines, the agency created special interim rules for Douglas Aircraft in testing the MD-11. The company met those temporary requirements, Anthony Broderick, FAA associate administrator, said Tuesday.
Final approval, which is expected this month, will mark the first time that a new jetliner has received FAA certification without a drill in which passengers and crew jump down a slide and fully evacuate the plane in 90 seconds or less.
Douglas spokesman John Thom defended the new evacuation test, saying: "We believe that the demonstration is valid and useful. Coupling that data with separate slide tests can demonstrate that we can evacuate the plane safely and within the guidelines set by the FAA."
Douglas has sought FAA approval to increase the MD-11's capacity to 410 passengers, up from the current 399, a company spokesman said. The German carrier LTU already has taken delivery of some of the higher-capacity planes from Douglas.
Although some air safety experts criticized the new tests as unrealistic, Broderick said the modifications do not represent relaxed safety standards. Rather, he called the risk of conducting the tests "nuts."
"The tragic accident a year ago convinced us that that was it with these evacuation drills," Broderick said. "It is the realism, chaos and confusion that we don't want to simulate, and that led to this tragedy a year ago."
The U.S. aircraft and airline industries have conducted about 1,000 evacuation tests since the 1960s, causing hundreds of injuries, but none as serious as those at Long Beach-based Douglas Aircraft.
Douglas paid Long Beach resident Dorothy Myles $49 to participate in the daylong test in October, 1991. Along with 410 others, she was put in a darkened plane and, after a sudden, shrill alarm sounded, was ordered to evacuate the plane by jumping out the door. Chaos ensued, Broderick said.
Myles tripped at the top of the slide and plunged head-first into either the floor of the darkened hangar or into another test participant, Broderick said. Myles suffered a spinal fracture that paralyzed her from the neck down. She sued McDonnell last year, alleging that she was never told that 28 other tests subjects had been injured in another test conducted a few hours earlier.
In all, 47 people were injured in the two tests. Douglas twice failed to evacuate the plane in the required 90 seconds.
Despite those injuries, air safety experts expressed concern over the disclosure that the FAA has abandoned the evacuation tests.
"When you get to that door and look down at how far you have to slide, there is a little hesitation," said C. O. Miller, an air safety expert and the government's former chief accident investigator. "If you just hop out onto a platform, that might bias the results. If you look at past evacuations, you find case after case of people not wanting to jump."
But Broderick said the FAA built a hesitation factor into the new Douglas test, requiring that the passengers be off the plane in 62 seconds. That allowed a margin of nearly 15 seconds for the aircraft doors to open and slides to inflate and about 15 seconds for any hesitation that might occur. Broderick said Douglas performed the test in 56 seconds.