Question for pilots (1 Viewer)

[Brian Perry]

Over the past few weeks I have been reading how transponders and even flight voice recorders can be easily switched off by pilots. Is there a reason for this? I would think that allowing the pilots to tamper with these items is a safety risk, but perhaps there are good reasons why these devices are not protected.
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Home Theater Pictures

 

[Ricky Hustle]

Interesting questions. I hope that there are some commercial pilots here who fly heavy aircraft that may have some insight that they can share.
I hold a private pilot's license (single-engine land). In the aircraft that I fly there are no cockpit voice recorders. The transponder is only switched on when preparing for takeoff. Air traffic controller's radar screens would be a mess if every aircraft on the ground was signalling its position and altitude. My guess is that you cannot link the transponder to automatically begin signaling when the engines are started due to the situation stated above. But, I may be completely off base here, and there are likely other reasons why transponders work the way they do.
Private aircraft also for the most part fly under VFR (visual flight rules) and use the squawk code 1200. This means that they are out of the air traffic control system and flying visually. But it is FAA law that while in flight, the transponder must be turned on.
As far as the flight recorder goes, sorry for the lack of insight.
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rickyhustle.com

 

[Jay Taylor]

I’m not a pilot, but I do have over 5000 hours as an airborne computer tech on E-3 AWACS aircraft. Besides the reasons mentioned by Rick are safety reasons.
Virtually all electrical devices on an aircraft must have an ON/OFF switch and circuit breaker to disable the device in case it starts smoking. Otherwise the plane could fill with smoke and or burn up if you couldn’t turn off a malfunctioning electrical device.
Jay Taylor
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"Any sufficiently advanced technology is indistinguishable from magic." - Arthur C. Clarke

 

[Philip_G]

as I understand it CVR's can not be switched off (well maybe if you find the breaker)
transponders are not required for all phases of flight, and they don't want them on for ground operations

 

[JamesKan]

Phil, Jay and Rick are all correct. Transponders can be shut off because they would interfere approach/departure control if they were used during taxi, preflight and other operations on the ground. Also, they can be shut off to determine a cause of an electrical problem. For example, say you smell smoke from an electrical fire. The procedure is to turn off all electrical components, and then turn them on one at a time until you determine where the problem is. Finally, the transponder can be switched off to save power in the event you need to run on battery power only. The transponder might not be as critical as another system if their is only limited power. The CVR cannot be turned off by a switch, but the circut can be pulled.
Hope that helps.
James
[Edited last by JamesKan on October 17, 2001 at 10:07 PM]

 

[Philip_G]

Bahahah when I got my private it was in an ancient C150 (N11261 still remember that after all this time and all those tail #'s) and the xponder never worked for shit, so whenever I went into a controlled field I always knew I'd be cycling the fucker over and over

curiousity, for airports that use ground radar (like for a cat 3 where ya land near 0/0 and they give taxi directions) HOW THE HELL DOES THAT WORK?
I think the dah 8's horizon flies are cat 3 in and out of sea-tac. That HAS to be fun

 

[Philip_G]

BTW you should have yelled at him for saying "identing" around here if you say more than you need to approach, tower, or departure they get pissy