Procedures en route vary according to the proposed route, the traffic environment, and the ATC facilities controlling the flight. Some IFR flights are under radar surveillance and controlled from departure to arrival and others rely entirely on pilot navigation.
Where ATC has no jurisdiction, it does not issue an IFR clearance. It has no control over the flight, nor does the pilot have any assurance of separation from other traffic.
All pilots are required to report unforecast weather conditions or other information related to safety of flight to ATC. The pilot-in-command of each aircraft operated in controlled airspace under IFR shall report as soon as practical to ATC any malfunctions of navigational, approach, or communication equipment occurring in flight:
- Loss of VOR, tactical air navigation (TACAN) or automatic direction finder (ADF) receiver capability.
- Complete or partial loss of instrument landing system (ILS) receiver capability.
- Impairment of air-to-ground communications capability.
The pilot-in-command shall include within the report (1) aircraft identification, (2) equipment affected, (3) degree to which the pilot to operate under IFR within the ATC system is impaired, and (4) nature and extent of assistance desired from ATC.
Position reports are required over each compulsory reporting point (shown on the chart as a solid triangle) along the route being flown regardless of altitude, including those with a VFR-on-top clearance. Along direct routes, reports are required of all IFR flights over each point used to define the route of flight. Reports at reporting points (shown as an open triangle) are made only when requested by ATC. A pilot should discontinue position reporting over designated reporting points when informed by ATC that the aircraft is in “RADAR CONTACT.” Position reporting should be resumed when ATC advises “RADAR CONTACT LOST” or “RADAR SERVICE TERMINATED.”
Position reports should include the following items:
- Altitude or flight level (include actual altitude or flight level when operating on a clearance specifying VFRon- top)
- Type of flight plan (not required in IFR position reports made directly to ARTCCs or approach control)
- Estimated time of arrival (ETA) and name of next reporting point
- The name only of the next succeeding reporting point along the route of flight
- Pertinent remarks
En route position reports are submitted normally to the ARTCC controllers via direct controller-to-pilot communications channels using the appropriate ARTCC frequencies listed on the en route chart. Whenever an initial contact with a controller is to be followed by a position report, the name of the reporting point should be included in the call-up. This alerts the controller that such information is forthcoming. For example:
“Atlanta Center, Cessna 1230 Alpha at JAILS intersection.”
“Cessna 1230 Alpha Atlanta Center.”
“Atlanta Center, Cessna 1230 Alpha at JAILS intersection, 5,000, estimating Monroeville at 1730.”
In addition to required position reports, the following reports should be made to ATC without a specific request.
- At all times:
- When vacating any previously assigned altitude or flight level for a newly assigned altitude or flight level
- When an altitude change is made if operating on a clearance specifying VFR-on-top
- When unable to climb/descend at a rate of at least 500 feet per minute (fpm)
- When an approach has been missed (Request clearance for specific action (to alternative airport, another approach, etc.))
- Change in average true airspeed (at cruising altitude) when it varies by 5 percent or 10 knots (whichever is greater) from that filed in the flight plan
- The time and altitude upon reaching a holding fix or point to which cleared
- When leaving any assigned holding fix or point NOTE: The reports in (f) and (g) may be omitted by pilots of aircraft involved in instrument training at military terminal area facilities when radar service is being provided.
- Any loss in controlled airspace of VOR, TACAN, ADF, low frequency navigation receiver capability, global positioning system (GPS) anomalies while using installed IFR certified GPS/Global Navigation Satellite Systems (GNSS) receivers, complete or partial loss of ILS receiver capability, or impairment of air/ground communications capability. Reports should include aircraft identification, equipment affected, degree to which the capability to operate under IFR in the ATC system is impaired, and the nature and extent of assistance desired from ATC.
- Any information relating to the safety of flight.
- When not in radar contact:
- When leaving the final approach fix inbound on final approach (nonprecision approach), or when leaving the outer marker or fix used in lieu of the outer marker inbound on final approach (precision approach).
- A corrected estimate at any time it becomes apparent that an estimate as previously submitted is in error in excess of 3 minutes.
Any pilot who encounters weather conditions that have not been forecast, or hazardous conditions which have been forecast, is expected to forward a report of such weather to ATC.
Planning the Descent and Approach
ATC arrival procedures and flight deck workload are affected by weather conditions, traffic density, aircraft equipment, and radar availability.
When landing at an airport with approach control services and where two or more IAPs are published, information on the type of approach to expect is provided in advance of arrival or vectors are provided to a visual approach. This information is broadcast either on automated terminal information service (ATIS) or by a controller. It is not furnished when the visibility is 3 miles or more and the ceiling is at or above the highest initial approach altitude established for any low altitude IAP for the airport.
The purpose of this information is to help the pilot plan arrival actions; however, it is not an ATC clearance or commitment and is subject to change. Fluctuating weather, shifting winds, blocked runway, etc., are conditions that may result in changes to the approach information previously received. It is important for a pilot to advise ATC immediately if he or she is unable to execute the approach or prefers another type of approach.
If the destination is an airport without an operating control tower and has automated weather data with broadcast capability, the pilot should monitor the automated surface observing system/automated weather observing system (ASOS/AWOS) frequency to ascertain the current weather for the airport. ATC should be advised that weather information has been received and what the pilot’s intentions are.
When the approach to be executed has been determined, the pilot should plan for and request a descent to the appropriate altitude prior to the initial approach fix (IAF) or transition route depicted on the IAP. When flying the transition route, a pilot should maintain the last assigned altitude until ATC gives the instructions “cleared for the approach.” Lower altitudes can be requested to bring the transition route altitude closer to the required altitude at the initial approach fix. When ATC uses the phrase “at pilot’s discretion” in the altitude information of a clearance, the pilot has the option to start a descent at any rate and may level off temporarily at any intermediate altitude. However, once an altitude has been vacated, return to that altitude is not authorized without a clearance. When ATC has not used the term “at pilot’s discretion” nor imposed any descent restrictions, initiate descent promptly upon acknowledgment of the clearance.
Descend at an optimum rate (consistent with the operating characteristics of the aircraft) to 1,000 feet above the assigned altitude. Then attempt to descend at a rate of between 500 and 1,500 fpm until the assigned altitude is reached. If at anytime a pilot is unable to maintain a descent rate of at least 500 fpm, advise ATC. Also advise ATC if it is necessary to level off at an intermediate altitude during descent. An exception to this is when leveling off at 10,000 feet mean sea level (MSL) on descent or 2,500 feet above airport elevation (prior to entering a Class B, Class C, or Class D surface area) when required for speed reduction.
Standard Terminal Arrival Routes (STARs)
Standard Terminal Arrival Routes (STARs) (as described in Chapter 1) have been established to simplify clearance delivery procedures for arriving aircraft at certain areas having high density traffic. A STAR serves a purpose parallel to that of a DP for departing traffic. [Figure 10-3]
The following points regarding STARs are important to remember:
- All STARs are contained in the Terminal Procedures Publication (TPP), along with the IAP charts for the destination airport. The AIM also describes STAR procedures.
- If the destination is a location for which STARs have been published, a pilot may be issued a clearance containing a STAR whenever ATC deems it appropriate. To accept the clearance, a pilot must possess at least the approved textual description.
- It is the pilot’s responsibility to either accept or refuse an issued STAR. If a STAR will not or cannot be used, advise ATC by placing “NO STAR” in the remarks section of the filed flight plan or by advising ATC.
- If a STAR is accepted in a clearance, compliance is mandatory.
Substitutes for Inoperative or Unusable Components
The basic ground components of an ILS are the localizer, glideslope, outer marker, middle marker, and inner marker (when installed). A compass locator or precision radar may be substituted for the outer or middle marker. Distance measuring equipment (DME), VOR, or nondirectional beacon (NDB) fixes authorized in the standard IAP or surveillance radar may be substituted for the outer marker.
Additionally, IFR-certified GPS equipment, operated in accordance with Advisory Circular (AC) 90-94, Guidelines for Using Global Positioning System Equipment for IFR En Route and Terminal Operations and for Nonprecision Instrument Approaches in the United States National Airspace System, may be substituted for ADF and DME equipment, except when flying NDB IAP. Specifically, GPS can be substituted for ADF and DME equipment when:
- Flying a DME arc;
- Navigating TO/FROM an NDB;
- Determining the aircraft position over an NDB;
- Determining the aircraft position over a fix made up of a crossing NDB bearing;
- Holding over an NDB;
- Determining aircraft position over a DME fix.