Why are pilots able to turn off aircraft transponders?

Claire Billegas: The transponder mission is to allow a WILLING crew to have its plane tracked.And the capability to turn a unit off is vital if the transponder has a short circuit that could burn the airplane.

Bianca Lannier: There are hundred of gauges, and lights or switches in a cockpit -And all of them are controlled by a switch with ON/OFF or STBY position -If there is an electrical short, there must be a means to shut down the faulty item -If no ON/OFF switch just pull the circuit breaker -ALL electrical items have circuit breakers controlling them -There are a couple of "Y!A" aeronautical experts who say "fuses" -I think the last fuses in airplanes were found on DC-3 in the 1940s......Show more

Donte Hamme: I'll just copy and paste my answer from another question asking the exact same thing.What if the transponder surged? It's better to turn it off than let it burn the electronics of the rest of the cockpit. Everything in a plane needs to be able to be ! turned off, in fact in a certain FedEx hijack attempt the hijacker managed to turn off the Cockpit Voice Recorder before the plane left (he was jump seating), thankfully, the hijack was unsuccessful and the flight engineer noticed the CVR was turned off and turned it back on again....Show more

Coleman Deliberato: You don't activate the transponder until you are ready for takeoff, and have the correct transponder code entered. You don't want radar to display transponder responses from every aircraft sitting on the ramp or taxiway. You also would not want it to activate with the code assigned to another plane. Since the transponders are also the basis of traffic avoidance systems, if you had them activated on the ground the cockpit of every plane on the ground would be inundated with traffic alerts. If the transponder malfunctions, it could interfere with radar coverage of the entire area. And turning off the transponder does not mean you can not be tracked on ! radar - while ATC radar is designed to work with a transponder! , it still has some ability to track primary (non-transponder) targets. The larger the target, the easier it is to track. An airliner is not a stealthy aircraft....Show more

Ruthe Real: Makes no legal sense to me.

Lyman Gauld: The complications are endless.....makes ya give 9/11 a 2nd thought doesn't it??