This question already has an answer here:

In the 911 terror attack the transponders were turned off. Who is to blame for the lack of foresight that has allowed another jet liner to shut off their transponders. This is a ¼ billion-dollar ship; it seems impossible that engineers would not be able to design a safe and reliable back up transponder system that would not jam other signals, and would not be a fire hazard.


marked as duplicate by voretaq7 Mar 15 '14 at 22:31

This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.

  • $\begingroup$ See the answers on the linked duplicate. There is no such thing as an infallible design, nor is there such a thing as perfect construction/assembly/installation. As long as there is imperfection there is a non-zero chance of a failure, and as long as the chance of failure is not zero there will be a need to be able to completely disable any electronic component installed on an aircraft. $\endgroup$ – voretaq7 Mar 15 '14 at 22:34

Browse other questions tagged or ask your own question.