Airline pilots are dead set against putting cameras in cockpits as safety officials step up the pressure to require them as an aid to accident investigation and prevention.

The National Transportation Safety Board (search) launched a two-day hearing Tuesday to renew its call for all civilian planes to be equipped with crash-resistant cockpit image recorders (search).

Four years ago, the NTSB recommended that the FAA (search) require large aircraft to be equipped with cameras four years ago, but the FAA still hasn't done it. Subsequently, NTSB added small planes to their recommendation.

NTSB senior air safety investigator Frank Hilldrup said cockpit image recorders would produce faster and more accurate conclusions about the causes of aviation accidents.

"The technology exists, the costs are low and the need is here now," Hilldrup said during the hearing.

Supporting the idea was Ken Smart of the British Air Accidents Investigation Branch (search), who said cameras are used on military aircraft in the United Kingdom and are "very, very useful" in understanding the human actions that lead to airplane accidents.

Nonetheless, the idea of cameras in the cockpits drew strong opposition from airline pilots.

John David of the Allied Pilots Association (search), which represents pilots at American Airlines, said having a camera monitor everything they do would affect their ability to perform.

"It's going to be very intrusive," David said. "You always see the glass lens."

The Air Line Pilots Association (search), the largest pilots union, issued a statement saying "the benefits of video imaging are vastly overrated, because far more effective and efficient tools exist."

Advocates of the devices said there are ways to protect pilots' privacy — encrypting the information, for example, or pointing the cameras away from the pilots' heads and shoulders.

But one reason pilots oppose image recorders is that such promises were broken after they agreed to the introduction of cockpit voice recorders in the 1960s, the Air Line Pilots Association said in a statement submitted to the board.

Pilots had been told the tapes would be used for accident investigations only and wouldn't be publicly disclosed. But in 1989, a 6 o'clock news program played the cockpit voice recorder from Delta Flight 1141 (search), which crashed on takeoff at Dallas-Fort Worth International Airport. Out of the 108 passengers and crew aboard, 14 were killed.

Though laws were subsequently passed that limited the use of cockpit voice recordings, they are still used against pilots in criminal proceedings and disciplinary actions by employers, the statement said.

Airlines are skeptical of the cameras. They want a cost-benefit analysis done first before they have to pay for the devices.

The safety board maintains that cameras would have helped safety investigators understand the smoke and fire conditions in the cockpit of two deadly plane crashes: Swissair Flight 111 (search), which crashed off the coast of Halifax, Nova Scotia in 1998, and Valujet Flight 592 (search), which plunged into the Florida Everglades in 1996.

Cameras could have helped investigators understand how the fires started, what the crews did to put them out and whether the crew managed to clear smoke from the cockpit. The safety board said such information might steer them toward modifying firefighting training, procedures or systems.

Cameras would have also helped answer questions about what happened in the cockpit of EgyptAir Flight 990 (search) from New York to Cairo on Oct. 31, 1999, when the pilot apparently directed the plane into the Atlantic Ocean off the coast of Nantucket.

Safety board member Carol Carmody said cameras would have also saved time and money in determining what caused the twin-engine plane crash that killed Sen. Paul Wellstone (search) and seven others in Eveleth, Minn., on Oct. 25, 2002.

The safety board ultimately found the probable cause of the accident was the pilots' inattention to the aircraft's instruments. The Wellstone crash investigation gave rise to the recommendations that all small planes be equipped with crash-proof cameras.

The Federal Aviation Administration, the agency that would implement the NTSB's recommendations for aviation safety, has taken the first steps in developing technical standards for video recorders.

FAA spokeswoman Diane Spitalieri called the recorders "an extra level of safety for aircraft."