Final answer:
When making transponder code changes, pilots must avoid inadvertently selecting code 7500, as it signifies a hijacking emergency. Codes 7200 and 7000 do not have emergency meanings, although 7000 is used under VFR in some regions.
Step-by-step explanation:
When making routine transponder code changes, pilots should avoid the inadvertent selection of certain codes that could signal an emergency situation to Air Traffic Control. Specifically, pilots should avoid the following codes:
- 7500 - which indicates a hijacking
Codes like 7200 and 7000 do not have universal emergency or alert meanings; however, 7000 is commonly used as a default squawk code in certain regions under Visual Flight Rules (VFR) when no other code has been assigned. It's crucial for pilots to exercise care when adjusting their transponder to prevent miscommunication and potential emergency responses from ATC due to inadvertent code transmission. Always follow the guidance of ATC and be familiar with regional transponder code protocols.