In a ground-floor research room at the Federal Aviation Administration Civil Aeromedical Institute in Oklahoma City are two cloth-covered dummies the size of a 6-month-old baby.
One is the weight of an average 6-month-old, 17 pounds. The other weighs 51 pounds, or what the same baby would weigh if a force was exerted on it three times the pull of gravity.When I picked up the heavy "baby," I was trying to imagine how hard it would be to hold that infant in my lap if I was strapped in and the baby was pulling away when a plane stopped abruptly.
When Cynthia Cofield, an in-flight service manager for American Eagle Airlines in Dallas, grasped the dummy, she was so taken aback she nearly dropped it.
"What a projectile!" she said. "Think of that loose in a cabin."
As participants in an aeromedical cabin safety workshop, we were both concerned with survival in an emergency, but I focused on the life of a child in my lap, and her training had taught her to think about all the passengers.
We observed the 15th test in a series on child safety seats aboard planes. The tests, to examine the effect of the flopping forward of the airplane seat back, or "seat-back breakover," on two types of child seats, were a joint project of the FAA and Transport Canada.
Two auto safety seats for children, a backward-facing model for infants and a forward-facing model for larger children, were placed in the front row of a two-row test sled. Child dummies were placed in the safety seats and adult dummies in the seats behind.
The dummies are wired to measure how much impact there is on the head. Videocameras recorded as the device was flung along the slide at 30 miles an hour and brought to a slamming stop. The impact created a force nine times the strength of gravity.
Viewed in slow motion, the tape showed seats in the second row flopping forward and the adult figures in those seats bumping into the backs of the front-row seats.
The "baby" in the rear-facing safety seat was bumped by the padded headrest of its seat; the forward-facing safety seat, acting as a diagonal between the seat and the seatback, kept its seat upright.
Both baby dummies stayed strapped in, and the seats remained attached to the plane seats.
Van Gowdy, head of the Biodynamics Laboratory at the institute, said the measurement of the impact on the dummies' heads could predict the likelihood of survival.
However, he said, there are no reliable data on child survivors of air crashes, so the laboratory could not accurately predict whether the impact would cause fatal abdominal injuries.
However, he said that the safety seats were performing as expected, adding that models approved by the National Highway Transportation Safety Administration since 1985 for use in autos were also acceptable for aircraft.
Passengers who want to be sure they can place a child in a safety seat will have to buy a ticket for the child, since the safety seat occupies a full passenger seat.
Buying a ticket for a child under 2 is not required on domestic flights, so this would mean an added expenditure. Infants held in the lap should be outside the adult's seat belt; if the child is inside, the force of the adult's body in a sudden stop will crush the child against the belt. But with the child outside, the strength of the adult's arms is all that will hold the child in turbulence or accident.
If a plane is not crowded, flight attendants may put a parent near a vacant seat for the child to use. But if there is no ticket for the child, there is often a dispute about bringing a safety seat aboard; many of them do not fit in overhead bins.
Another area of research at the FAA's institute is water safety. Gordon E. Funkhouser, the institute's specialist in this area, is planning to test flotation devices for small children and infants.
Current rules do not require child-size devices to be stocked aboard planes, although there must be one adult-size device for each seat.
A rule requiring child devices was proposed last year, and the Federal Aviation Administration is weighing comments. If a rule is approved, the airlines will have a certain amount of time to stock the devices.
Funkhouser said that in case of an emergency water landing and evacuation, it would be difficult to hold an infant in cold water very long.
In fact, Funkhouser said, after an hour it would probably be impossible to hold onto the straps of the seat cushion intended to keep a passenger afloat.
He said he believes that only an inflatable boat, or at least a lifevest, would avail a passenger much in the unlikely event of an emergency water landing.
Five pieces of child flotation equipment, ranging from a $500 Beaufort "infant cot" used by British Airways to an inexpensive lifevest of the sort given to a child in a rowboat, have been collected for tests that should start this summer.
The tests will find out the average time it takes to get a child into each one and how it works in the water.
An emergency procedure commonly recommended now, Funkhouser said, involves putting a child into an adult vest, attaching the waist belt under the crotch and inflating only half the vest. A child who does not have a seat would not have a lifevest.
Because scientists are not involved in creating safety rules, and probably because the researchers in Oklahoma City are blunt people, two anomalies were brought up.
One is the question of why auto safety belts and airline belts function in opposite ways. In a plane, passengers pull the latch up to release themselves. In an auto, they press a button. Charles B. Chittum, a specialist in fire safety, said that because people were more often passengers in cars, they might not think of lift-release in an emergency.
Chittum also discussed strip lighting along the aircraft floor. This has been mandatory in American aircraft since November 1986; the rule was put into force with unusual speed, three years after a fire and emergency landing in Cincinnati in which 23 of 46 passengers died.
When workshop participants joined in a test evacuation of a smoke-filled fuselage, all of the other exit lighting was obscured, even the sunlight outside the open door. But the strips in the floor remained clear and could be followed.
But Chittum, and Mark H. George, also of the safety research unit, raised the question of why the lights, which are white along the aisle, are red at the exit, reversing people's normal expectation of the meaning of red and green.
Which raised the question of why a regulation is not put into force to change the design or seat-belt latches and mandate green lights at the exit.
Federal Aviation Administration officials, among them Donell W. Pollard, who originated the workshops, cite the dual, and sometimes conflicting, FAA mandate: "regulating air commerce to foster" safety and "promoting civil aviation."
Promoting aviation, the experts made clear, means not adding to operating cost unless there is overwhelming public pressure.
Among the tools Chittum uses for his research are video records of rescue operations. These are filmed automatically from inside fire trucks and other emergency vehicles.
Workshop members watched what seemed an endless succession of people fleeing burning planes, clutching their carry-on luggage, even when it impeded their ability to go out the door.
"We are getting ready to research why people won't leave their luggage behind," Chittum said.
New air safety regulations are coming into force.
Passenger seats aboard new planes will be able to withstand a force 16 times the strength of gravity, called 16-G; seats in existing planes are required to withstand only 9 times the force of gravity.
The new seats are lighter than old ones because of new metals and technologies; they are also designed to bend and twist rather than break, absorbing impact rather than passing it along to the passenger's back.
It has yet to be resolved by what date existing planes must install 16-G seats.