@NuclearWeapon
The black box will send out the last position reading in lat and long format to a distress box on any aircraft within say 100 miles.
Unfortunately, the black box is currently
not connected to a radio transmitter.
Read the Malaysian Airlines thread. It's all been discussed before:
ELT (electronic locator transmitter): activated with high g's. Fuselage mounted antenna. Battery powered. Will not work underwater (uses VHF and UHF(satellite) frequencies). More useful for crashes on land. Satellite comms can be impeded by metallic structures (does your mobile phone always work indoors?). Transmissions are generally line-of-sight. If you're in a deep valley, you may not have a clear view of the satellite. Thunderstorms can also interfere with the signal. Can be destroyed by fire or very hard impacts.
Black boxes (CVR/FDR). Located inside the fuselage. Not connected to antennas, but will transmit an ultrasonic signal when in contact with water. Ultrasonics can be detected by sensors placed in the water by search teams. Stop
recording when certain aircraft electrical busses are unpowered (doesn't help if aircraft power is lost in flight as would happen in a break up )
Portable beacons: In stowages throughout the cabin). Battery-powered. Usually removed from stowages and activated by crew after a survivable impact with land/water. Automatically activated by contact with water. Will not work
underwater (VHF) and won't work very well if stuck in the fuselage (Google Faraday Cage).
Satellite communication systems: Usually found on larger aircraft for various reasons. Can use small antenna (for data transmission), but for reliability and voice transmission, large fuselage-mounted antenna are used. These require aircraft main bus electrical power and, of course, a functioning navigation system, for transmitting position information.
ACARS: Is capable of using Satellite or VHF to send position information (see limitations above). However, for economy reasons, this data is not transmitted continuously.
We don't need transmitting black boxes. We just need passengers to pay more for their tickets and use existing technology
