FAA Instrument Rating Airplane (IRA)Navigation SystemsMedium
A pilot is conducting a VOR operational check using an airborne checkpoint. The aircraft is 20 NM from the VOR station, and the published airborne checkpoint radial is 270°. The VOR receiver indicates a radial of 273°. What action, if any, should the pilot take?
- AContinue the flight; the VOR is within acceptable limits for IFR flight.
- BPerform a second airborne check at a different checkpoint to confirm the reading.
- CDiscontinue IFR flight using this VOR receiver, as it is out of tolerance.
- DRecalibrate the VOR receiver in flight before continuing IFR flight.
Show answer & explanationAnswer & explanation
Correct answer: C. Discontinue IFR flight using this VOR receiver, as it is out of tolerance.
For an airborne VOR check, the maximum allowable error is ±6 degrees. The indicated radial of 273° compared to the published 270° shows a 3-degree error, which is within the acceptable limits. Therefore, the VOR is within tolerance for IFR flight.
Why the other options are wrong
- A. The VOR is within tolerance; therefore, no action to discontinue IFR flight is required.
- B. While performing a second check might be good practice, it's not required if the first check is within limits, nor does it change the tolerance.
- D. VOR receivers cannot be recalibrated in flight by the pilot.
Airborne VOR Check Tolerance
The maximum permissible error for a VOR receiver when checked using an airborne checkpoint or a prominent ground landmark is ±6 degrees.
- Used for airborne operational checks.
- Tolerance is ±6 degrees.
- Can be performed using published checkpoints or prominent landmarks.
Memory trick: Ground = 4, Air = 6, VOT = 4, Dual = 4. Remember 'Fours for Floor, Six for Sky'!