Final answer:
None of the provided transponder codes (1200, 7500, 7700, 2200) are standard for IFR flights in high-level airspace, as they correspond to VFR flying, hijacking, general emergency, and an unrecognized code, respectively. In controlled airspace, IFR flights are assigned unique squawk codes by ATC.
Step-by-step explanation:
The IFR transponder code in high-level airspace is not explicitly mentioned in the question. In aviation, certain transponder codes (squawk codes) are universally recognized and used in specific emergency situations or for specific flight conditions. None of the codes listed (1200, 7500, 7700, 2200) are typically used for IFR flights in high-level airspace as a standard code. Here are what the codes generally stand for:
- 1200: Used in the United States for VFR (Visual Flight Rules) flight, not for IFR (Instrument Flight Rules).
- 7500: Universal code for hijacking.
- 7700: Universal emergency code, used to indicate a general emergency.
- 2200: This is not a commonly recognized transponder code for IFR or any other standard aviation use and might be either incorrect or specific to a certain region or procedure.
In controlled airspace, IFR flights will be assigned a unique squawk code by air traffic control when they file their flight plan or during communication with ATC.