When radar contact is established, ATC can watch your aircraft's position continuously on a display and provide separation without much pilot input. But in non-radar airspace — remote areas, mountainous terrain, oceanic routes, or simply when radar service is lost — the controller has no electronic picture of where you are. In those situations, your voice position reports become the primary tool ATC uses to build a mental model of traffic and maintain separation. Getting these reports right, on time, and complete is not a procedural formality; it is the backbone of instrument flight safety when radar is unavailable.
This article covers every element of a correct position report, the specific fixes where reports are mandatory, the additional reports required whenever something unusual happens, and the classic knowledge-test traps you need to avoid. All requirements stem from the Aeronautical Information Manual (AIM) Chapter 5 and 14 CFR Part 91.
Why Non-Radar Environments Still Exist
The continental United States has excellent radar coverage at most IFR altitudes, but gaps remain. Valleys, mountainous regions, and low altitudes near some rural airports can fall outside radar range. Offshore and oceanic routes are almost entirely non-radar. Additionally, radar equipment can fail, and when a controller loses your radar return, they must immediately revert to procedural separation — which depends entirely on position reports. Understanding when you are in a non-radar environment matters: ATC will typically tell you "radar contact lost" or "radar service terminated," and from that moment, your position reports carry full weight.
The Standard Position Report: Identification Plus PTATEN
When ATC requires a position report, the AIM (5-3-2) lists identification along with six additional elements. A reliable memory device used widely in instrument training for those six elements is PTATEN, which stands for:
- Identification: Your aircraft's call sign, given at the start of every report so ATC knows who is calling.
- P — Position: The name of the fix over which you are reporting. This should be an identifiable navaid, waypoint, intersection, or reporting point on your route.
- T — Time: The actual time you crossed the fix, in UTC (Zulu). Report the exact time, not an estimate.
- A — Altitude: Your actual altitude or flight level at the reporting point. If you are in a climb or descent, state the altitude you are passing through and indicate that you are climbing or descending.
- T — Type of flight plan: Confirm whether you are on an IFR or VFR flight plan. In practice, when operating IFR on an IFR clearance this element is sometimes abbreviated, but the AIM includes it as a formal element.
- E — ETA (Estimated Time of Arrival): Your estimated time over the next reporting point on your route. This is the forward-looking piece that allows ATC to project your position into the future and plan separation.
- N — Name of the next succeeding reporting point: The fix after the next one — essentially the fix after the one you just gave an ETA for. This gives ATC the full picture of your intended routing.
A complete report sounds like this: "Atlanta Center, November 4-5-2 Tango Foxtrot, over MACON at 1347 Zulu, 9,000, IFR, estimating LOGEN at 1412, then COLIN." Notice that identification is given first, followed by every PTATEN element in sequence. Practicing this structure until it becomes automatic is essential for any instrument pilot operating in non-radar airspace.
Where to Report: Compulsory vs. Non-Compulsory Fixes
Not every fix on a chart requires a position report. IFR en-route charts use a symbol system to distinguish between two categories:
- Compulsory reporting points are depicted with a solid triangle. Pilots operating in non-radar environments must report over every compulsory fix without being asked. These are typically major intersections or navaids that ATC relies on for procedural separation.
- Non-compulsory (on-request) reporting points are depicted with an open triangle. Reports at these fixes are made only when ATC specifically requests them. In non-radar environments, ATC may ask for a report at a non-compulsory fix for spacing purposes.
In radar contact, ATC generally suspends the requirement to make position reports at compulsory fixes because they can see you. The moment radar is lost, the compulsory reporting obligation is reinstated automatically.
Additional Reports: Mandatory Without Being Asked
Beyond passing compulsory fixes, the AIM identifies a set of events that require an immediate report to ATC regardless of radar status. These are not optional, and many of them become especially critical in non-radar environments because ATC has no other way to know something has changed.
- Vacating an altitude: Any time you leave a previously assigned altitude, you must report it. This includes leaving a cruise altitude during a descent as well as reaching a newly assigned altitude.
- Unable to climb or descend at 500 fpm or more: If your aircraft cannot maintain at least 500 feet per minute during an assigned altitude change, report it. ATC plans separation assuming normal climb and descent rates.
- True airspeed variation of 5% or 10 knots (whichever is greater) from filed: Per AIM 5-3-3, when operating on a direct route not flown by reference to radials or courses of an omnidirectional navaid (such as during non-radar or oceanic operations), a significant TAS change from that filed alters your ETAs and could create conflicts with traffic ATC has sequenced based on your filed speed.
- Missed approach: If you execute a missed approach, report it immediately. ATC must know you are climbing back into the traffic flow rather than clearing the runway environment.
- Loss of navigation capability: If any navigation equipment fails in a way that affects your ability to comply with your IFR clearance, report it at once.
- Security-related information: Any information the pilot believes should be brought to ATC's attention for safety or security reasons.
- Unforecast weather: Icing, turbulence, or wind shear not noted in the forecast must be reported. This protects other pilots operating in the same airspace.
- Aircraft emergency, including fuel emergency: Declare the emergency immediately. A pilot who has less fuel than needed to reach the destination safely should declare a fuel emergency and request priority handling.
- VFR-on-top altitude changes: If operating VFR-on-top and you change altitude, report the new altitude.
Key Numbers and Rules
- Position reports at compulsory fixes are mandatory in non-radar environments; in radar contact, ATC relieves this requirement unless they ask.
- Report the time you actually crossed the fix, not an estimate — accuracy matters for separation calculations.
- Airspeed deviation threshold (AIM 5-3-3, applicable on direct/non-radar routes): 5% of filed TAS or 10 knots, whichever is greater.
- Climb/descent rate threshold: 500 feet per minute. If you cannot achieve this, tell ATC.
- Compulsory fixes = solid triangle; on-request fixes = open (hollow) triangle on en-route charts.
- ATC declares radar contact lost with the phrase "radar contact lost" or terminates service with "radar service terminated" — both reinstate position reporting obligations.
Memory Aid
Give your identification first, then use PTATEN to build every position report in the correct order:
- P — Position (fix name)
- T — Time (actual Zulu time over the fix)
- A — Altitude (actual altitude or flight level)
- T — Type of flight plan (IFR or VFR)
- E — ETA over the next reporting point
- N — Name of the next succeeding fix after that
Say it mentally every time you cross a compulsory fix: Identification, Position, Time, Altitude, Type, ETA, Next. After a few actual approaches in non-radar areas, the sequence will feel completely natural.
Common Test Traps
- Forgetting the