Task VI.B
Navigation Systems and Radar Services
To determine the applicant exhibits satisfactory knowledge, risk management, and skills associated with navigation systems and radar services.
Note: The evaluator should reference the manufacturer’s equipment supplement(s) as necessary for appropriate limitations, procedures, etc.
References: AC 91-78; AIM; FAA-H-8083-2, FAA-H-8083-3, FAA-H-8083-25
Study Notes
Two big ones.
Range: each station's power output sets its class, and the standard service volumes run from 25 nm up to 130 nm depending on the class of the VOR and my altitude.
Line of sight: VHF signals don't bend over terrain, so a ridge between me and the station can block reception entirely — the lower I am, the shorter the usable range.
VOR standard service volumes (AIM 1-1-8)
| Class | Altitude above station | Range |
|---|---|---|
| Terminal (T) | 1,000 up to 12,000 ft | 25 nm |
| Low (L) | 1,000 up to 18,000 ft | 40 nm |
| High (H) | 1,000 up to 14,500 ft | 40 nm |
| High (H) | 14,500 up to 18,000 ft | 100 nm |
| High (H) | 18,000 up to 45,000 ft | 130 nm |
| High (H) | 45,000 up to 60,000 ft | 100 nm |
The newer VOR MON classes (VL and VH) extend low-altitude coverage: 40 nm below 5,000 ft and 70 nm at and above it.
From my flight notes on VOR tracking: listen to the Morse code — always positively identify the station before trusting the needle (no ident can mean the station is down for maintenance and the signal is unreliable). And fly the course TO and through the station, holding the heading through the cone of confusion at passage.
Position, not heading: the needle shows where I am relative to the selected course — my heading has no effect on the indication.
To/From flag: whether the selected course would take me to or from the station, regardless of which way I'm pointed.
Deflection: full-scale means I'm 10° or more off the selected course; centered means I'm on it.
Reverse sensing: if I track to the station with the reciprocal course set in the OBS, the needle deflects away from the course. Fix: always twist the OBS to the course I intend to fly.
Each dot ≈ 2° of course deviation on a standard VOR display.
1-in-60 rule: 1° off course ≈ 1 NM for every 60 NM from the station.
Example: 2 dots (≈4°) deflection at 30 NM from the VOR ≈ 2 NM off course.
GPS and radar services in brief
Receiver Autonomous Integrity Monitoring — the GPS receiver cross-checks extra satellites to verify its own solution is trustworthy. It needs at least five satellites in view (or four plus a baro input) to detect a bad signal. If RAIM is unavailable or flags a fault, the position can't be trusted for navigation.
VFR flight following from approach/center: traffic advisories and safety alerts on a workload-permitting basis. I stay responsible for navigation, terrain, and see-and-avoid — radar advisories help, they don't replace looking outside. A Mode C (or S) transponder with ADS-B Out is what makes me visible to those services in the airspace that requires it (91.215 / 91.225).
Official ACS elementsreference
Knowledge4 elements
The applicant demonstrates understanding of:
PA.VI.B.K1Ground-based navigation (identification, orientation, course determination, equipment, tests, regulations, interference, appropriate use of navigation data, and signal integrity).PA.VI.B.K2Satellite-based navigation (e.g., equipment, regulations, authorized use of databases, and Receiver Autonomous Integrity Monitoring (RAIM)).PA.VI.B.K3Radar assistance to visual flight rules (VFR) aircraft (e.g., operations, equipment, available services, traffic advisories).PA.VI.B.K4Transponder (Mode(s) A, C, and S) and Automatic Dependent Surveillance-Broadcast (ADS-B).
Risk Management5 elements
The applicant is able to identify, assess, and mitigate risk associated with:
PA.VI.B.R1Management of automated navigation and autoflight systems.PA.VI.B.R2Distractions, task prioritization, loss of situational awareness, or disorientation.PA.VI.B.R3Limitations of the navigation system in use.PA.VI.B.R4Loss of a navigation signal.PA.VI.B.R5Use of an electronic flight bag (EFB), if used.
Skills7 elements
The applicant exhibits the skill to:
PA.VI.B.S1Use an airborne electronic navigation system.PA.VI.B.S2Determine the airplane’s position using the navigation system.PA.VI.B.S3Intercept and track a given course, radial, or bearing.PA.VI.B.S4Recognize and describe the indication of station or waypoint passage.PA.VI.B.S5Recognize signal loss or interference and take appropriate action, if applicable.PA.VI.B.S6Use proper communication procedures when utilizing radar services.PA.VI.B.S7Maintain the selected altitude, ±200 feet and heading, ±15°.