If your Mode C transponder fails in flight, can you continue into Class B or C airspace?

The correct response highlights that if your Mode C transponder fails in flight, you can indeed continue into Class B or C airspace under IFR conditions, provided you obtain approval from air traffic control. This is because pilots operating under Instrument Flight Rules (IFR) are often granted more flexibility and can rely on air traffic control to maintain safe separation and guidance even when specific equipment is inoperative.

In this scenario, the controller may often provide instructions or clearances that ensure safety despite the malfunction of the transponder, as they have radar capabilities and additional information about the airspace and traffic. Therefore, obtaining this authorization is crucial to ensuring that safety standards are maintained.

The other options address various scenarios but do not present the allowances for IFR operations with controller approval. For example, it is not outright prohibited under all circumstances, as highlighted by the fact that IFR flight rules provide alternative pathways to ensure safety through controller liaison.