Posts Tagged ‘airplane accident investigation’

The “Black Box” Revealed: History of Flight Data Recorders

How many time have we heard that investigators are searching for the “black box” after an aviation accident? This refers to the flight data recorder (FDR) which all commercial and corporate airplanes in the United States are required to carry. They are also required to be equipped with a cockpit voice recorder. It might seem like the FDR is an extremely modern, space age device, but in fact, the earliest type of flight recorders date back to 1939. Developed in France by François Hussenot and Paul Beaudouin, their “type HB” flight recorder used a photographic record. Another early version was developed in the UK during World War II by Len Harrison and Vic Husband. Their technology used various styli which indicated readings of various instruments / aircraft controls and were recorded on copper foil. Modern FDR technology was invented by Dr. David Warren at the Aeronautical Research Laboratory in Melbourne, Australia. In the mid-1950s he took part in the investigation of a mysterious crash involving the world’s first jet-powered commercial aircraft, the Comet. It occurred to Dr. Warren that if there had been some kind of recording of what was happening on the aircraft just prior to the crash—that would have been a huge help to the investigation. His first demonstration unit was produced in 1957. In 1960, an unexplained plane crash in the northern part of Australia prompted that government to make the Black Box mandatory for all commercial aircraft. They were the first country to do so. The media was quick to adopt the term, “black box.” Although the origins of the term “black box” are uncertain, what is certain is that having them onboard aircraft has revolutionized the accident reconstruction industry. Black Box Facts: • FDRs are not located in the cockpit of an aircraft, but rather in the rear, typically in the tail. Why? It’s unlikely that a plane would go down tail first. The entire front and midsection of the plane acts as a buffer, to reduce the shock reaching the recorder. • Today’s black box is not black at all, but a bright orange for ease in spotting it among the wreckage in case of an accident. • Black boxes emit an underwater locator beacon for up to 30 days, in case of a water crash. They can operate in depths of up to 20,000 feet.

NTSB Reports on Airplane Accidents Caused by Wildlife

Much is made in the news about terrorist attacks on airplanes, of course with good reason. But there are other, somewhat “hairier” things that can also take a plane down (no pun intended). Take a look at these two reports from the NTSB (National Transportation Safety Board):

In the first incident, the NTSB reports that a plane was attempting to land on a small airport runway, when a deer ran onto the pavement right toward the oncoming plane. The pilot attempted to climb, but couldn’t accomplish it before the deer struck and substantially damaged the left horizontal stabilizer. The pilot was able to stop without further incident, and no mention is made of what happened to the deer.

For an incident like this, the NTSB didn’t send an investigator, but depended upon reports from the FAA and the pilot to make its determination: The probable cause(s) of this accident—An inadvertent collision with a deer during landing. This raises the question of whether or not the airport should have had a fence, however, no fence could have prevented what happened in the next incident.

The second reported incident took place between a student pilot and our national bird, the bald eagle. According to the flight instructor, the plane was 1,000 feet above the ground when the eagle hit the right horizontal stabilizer. The instructor immediately took over and landed at the nearest airport. He reported that the rudder controls were impaired on final approach, but he managed to land without incident. Again, nothing was mentioned as to what happened to the bald eagle.

However, the plane showed a large indentation on the right horizontal stabilizer with bird feathers embedded in it. The tail cone was shoved upward into contact with the rudder, which had impeded the rudder’s movement.

For those of you unfamiliar with NTSB, it’s an independent branch of the government charged with advancing transportation safety. The NTSB’s mandate is to investigate every civil aviation accident, as well as major accidents in other types of transportation, including train accidents, marine accidents, and even pipeline accidents. They attempt to determine the probable causes and issue recommendations for safety improvements that could prevent future accidents.

Click here for more information about the NTSB.