Which set of specifications correctly describes Black Box and Underwater Locator Beacon requirements?

• A. Black Box must withstand deceleration 3200 Gs and 1000 C for 80 minutes; ULB depth 15000 feet and 20 days
• B. Black Box must withstand deceleration 3600 Gs and 1200 C for 70 minutes; ULB depth 18000 feet and 25 days
• C. Black Box must withstand deceleration 3400 Gs and 1100 C for 60 minutes; ULB depth 20000 feet and 30 days
• D. Black Box must withstand deceleration 3000 Gs and 900 C for 40 minutes; ULB depth 25000 feet and 60 days

Answer: (C)

Crash survivability and beacon endurance hinge on two linked ideas: how harsh a crash the flight data recorder must endure, and how long the underwater beacon must keep transmitting to aid recovery. The correct set matches the standard crash-survivability targets: the black box is designed to withstand about 3400 g of deceleration, exposure to roughly 1100 °C, for 60 minutes. The Underwater Locator Beacon is built to operate down to about 20,000 feet and remain functional for about 30 days. This combination ensures the device can survive a severe impact and heat while still providing a signal long enough to locate the wreckage.

Other options alter those key values—whether the g-load, temperature, or duration for the crash, or the depth and days for the beacon—so they don’t align with the common regulatory/industry benchmarks.