WASHINGTON – Airplane accident investigators this week recommended tracking equipment and black-box recorders be made tamper-proof, going far beyond the measures industry groups have supported to avoid repeats of aviation disasters like the unresolved disappearance of Malaysia Air Flight 370.

The National Transportation Safety Board also said airlines should put video recorders in cockpits so investigators can see what the gauges showed at the time of an accident. The recommendations are among eight released Thursday in Washington designed to help accident investigations in remote regions and combat acts of pilot sabotage.

The recommendations are significantly broader and more costly for airlines than an existing proposal that the United Nations' International Civil Aviation Organization will consider next month.

"Cockpit voice recorder and flight data recorder data are some of the most important information sources available to help determine causes of aviation accidents," the NTSB said in its recommendation letter. "Recent events have highlighted that recovering flight data can be costly and difficult when an accident occurs in a remote area, outside of radar coverage."

The NTSB also said aircraft flying over oceans should be capable of reporting their position within at least one minute of a crash, which would allow searchers to pinpoint an accident site to within 7 miles.

Either automatic flight tracking or devices transmitting a location during an emergency would suffice, said Joseph Kolly, NTSB research and engineering chief.

The NTSB didn't provide cost estimates for its changes and it would be up to the U.S. Federal Aviation Administration or Congress to decide whether to force them on the industry. Costs would vary depending on what equipment was used. Retrofitting electrical components would also take years to complete, based on previous safety mandates.

The proposal for potentially expensive retrofits of all existing airliners stems from one of the most unusual aviation incidents since the dawn of the jet age in the 1950s. On March 8, Malaysian Airline's Flight 370 turned off its northerly course to Beijing and instead flew west toward the Indian Ocean with 239 people on board. It has never been found.

The plane appears to have been deliberately turned around and equipment that would have recorded its path was switched off, according to Malaysian Prime Minister Najib Razak. A search led by Australian authorities is looking for the Boeing 777 along an arc in the Indian Ocean based on cryptic electronic signals sent from the plane's non-working satellite phone.

That event "made us really take a new look at where we were," Kolly said.

While the NTSB letter didn't refer to the Malaysia investigation, it cited other airline accidents in which pilots intentionally crashed. In a 1997 crash of a SilkAir Singapore plane in Indonesia, the NTSB concluded that a pilot intentionally switched off recorders capturing cockpit sounds and flight data before crashing into a river, killing all 104 aboard.

An NTSB recommendation in 2000 that pilots shouldn't be able to shut off black box recorders was resisted by the FAA on grounds that flight crews should be able to cut power to equipment in an emergency.

The NTSB countered in Thursday's letter that the latest generation of aircraft have many circuit breakers that aren't accessible to pilots.

Planes over oceans or the poles, where ground radar doesn't function, currently radio their position to air traffic controllers or send it via satellite data links. They can go for an hour or more without reporting their location.

An industry task force proposal to improve aircraft tracking, which will be considered at the U.N. safety conference starting Feb. 2 in Montreal, called for similar tracking technology but without any tamper-proof measures.