FAA Private Pilot Helicopter (PRH)Navigation and AirspaceMedium
A pilot tunes a VOR, sets the OBS to 270°, and the CDI centers with a TO indication. On what radial from the station is the helicopter located?
- A270° radial
- B180° radial
- C090° radial
- D000° radial
Show answer & explanationAnswer & explanation
Correct answer: C. 090° radial
A TO indication means the OBS setting points toward the station, so the aircraft is on the reciprocal radial. The reciprocal of 270° is 090°, so the helicopter is on the 090° radial.
Why the other options are wrong
- A. 270° would be the radial only if the indication were FROM, not TO.
- B. 180° is not related to the reciprocal calculation for this setting.
- D. 000° is also unrelated to the correct reciprocal math.
VOR TO/FROM Indication
The TO/FROM flag shows whether the selected OBS course leads toward or away from the station; when FROM, the radial equals the OBS setting, and when TO, the radial is the reciprocal of the OBS setting.
- FROM = radial equals OBS setting
- TO = radial equals reciprocal of OBS setting
- CDI centered confirms you are on that course line
- Reciprocal = OBS ± 180°
Memory trick: TO means you're 'Turned Opposite' the radial you dialed.