Using the System
Once you understand the overall operation of the traffic control system, the many procedural details can be put into the appropriate sequence as you learn them. The problem now is to review the regulations and procedures involved in using the system under Instrument Flight Rules. Pilot responsibilities relating to air traffic control are stated in the Federal Aviation Regulations, Part 91, General Operating and Flight Rules.
More detailed procedures can be found under "Air Traffic Control" in the AIRMAN'S INFORMATION MANUAL. The instrument pilot should purchase copies of the Regulations and the AIM and maintain them with current revisions which are included in the subscription prices.
IFR Flight Plan
As specified in FAR 91, if you plan to operate an aircraft in controlled airspace under Instrument Flight Rules, you must file an IFR flight plan and receive an appropriate ATC clearance. If your flight is to be in controlled airspace, your initial contact with Air Traffic Service involves your flight plan. The "Preflight" section of the chapter titled "Air Traffic Control" in the AIRMAN'S INFORMATION MANUAL provides guidance for completing the FAA Flight Plan, Form 7233-1 (Fig. 12-1). The forms are available at FSSs, flight planning rooms in airport terminal buildings, and at other convenient locations.
Filing in Flight
An IFR flight plan may be filed in the air under various conditions,
a. An IFR flight outside of controlled airspace prior to proceeding in to IFR conditions in controlled airspace.
b. A VFR flight expecting IFR weather conditions enroute in controlled airspace.
c. A flight on a VFR flight plan enroute to a destination having high air traffic volume. Even in VFR weather conditions, more efficient handling is provided a flight on an IFR clearance. However, acceptance of an IFR clearance does not relieve the pilot of the responsibility for maintaining separation from other traffic when operating in VFR conditions.
Figure 12-1. Flight plan form.
d. A flight departing under VFR conditions from an airport where no means of communication with Flight Service is available on the ground.
In any of these situations, the flight plan may be filed with the nearest FSS or directly with the Center. A pilot who files with Flight Service submits the information normally entered during preflight filing, except for "point of departure," together with present position and altitude. The Center will then clear the pilot from present position or from a specified navigation fix. A pilot who files direct with the Center reports present position and altitude, and submits only the flight plan information normally relayed from Flight Service to the Center. You should be aware that traffic saturation frequently prevents Center personnel from accepting flight plans by radio. In such cases, you will be advised to contact the nearest FSS for the purpose of filing your flight plan.