ULB Questions of the Week - 06-05-2009

Air France's loss of Flight 447 has raised obvious forensic questions. The world would like to rule out terrorism, though such an act has not been claimed according to news reports. Investigators never located the 'black boxes' from the 2 planes that crashed into the World Trade Center on 9/11.

What are the basic specs on the Underwater Locator Beacon (ULB) of modern, transoceanic airliners?

The ULB device is usually attached to the flight data/cockpit voice recorder. Unless catastrophically damaged, ULBs are designed to pulse a 37.5 Khz (ultrasonic) signal once a second upon immersion for at least the next 30 days, and at depths up to at least 20,000 feet (6 km).

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Considering the time and expense of underwater searches (tens - hundreds 0f million $$) are there better ways to locate and recover vital flight data and cockpit voice information? Two of the following proposals ignore major failure modes connected with their implementation:

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***Transmit real time records of cockpit conversations and flight data directly to a storage facility via satellite.

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***Redesign 'black boxes' so that they float.

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***Redesign 'black boxes' so their beacon life is longer.

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QUESTIONS of the WEEK:

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1 - Which two proposals are impaired by major failure modes and what are those modes?

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2 - One of the two proposals also suffers from a current technological problem and the other raises serious U.S. labor issue with pilots. What are the problem and issue, respectively?

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BONUS

3 - Were the black boxes from the two planes that crashed into the world trade center on 9-11 ever located?

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Answers MONDAY

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Submarines are always silent and strange.