What fuel requirements must be met for a flight under IFR?

The correct choice indicates that a flight conducted under Instrument Flight Rules (IFR) must include enough fuel to reach the first airport, proceed to an alternate airport if necessary, and still have an additional 45 minutes of fuel reserve. This requirement is established to ensure that the aircraft has the necessary fuel reserves in the event of changes in the flight plan or unexpected delays, particularly when weather or other conditions may affect the ability to land at the intended destination.

When operating under IFR, pilots are often faced with less flexibility due to the nature of instrument flying and air traffic control requirements. The 45-minute reserve is a critical safety margin that allows for contingencies, such as the need to hold or divert to a different airport due to weather or mechanical issues.

The other options do not meet the established fuel requirements under IFR. For instance, simply flying to the first airport with only an hour of reserve does not account for the possibility of needing to reach an alternate airport, which is a key consideration under IFR regulations. Similarly, not including additional reserve fuel beyond the direct flight to the alternate fails to provide sufficient safety for unanticipated circumstances.

Therefore, ensuring that the flight has adequate fuel not only enhances safety but also complies with regulatory standards for IFR operations.