FAA Private Pilot Helicopter (PRH)Navigation and AirspaceEasy

A helicopter pilot departs at 0915 Mountain Standard Time (MST) for a flight requiring a UTC (Zulu) departure time for a flight plan. Mountain Standard Time is UTC-7. What is the correct departure time expressed in UTC?

  1. A0215Z
  2. B0915Z
  3. C1015Z
  4. D1615Z
Show answer & explanation

Correct answer: D. 1615Z

To convert MST to UTC, add 7 hours: 0915 + 0700 = 1615Z. This accounts for the -7 hour offset of Mountain Standard Time from Coordinated Universal Time.

Why the other options are wrong

  • A. This subtracts 7 hours instead of adding, giving an incorrect earlier time.
  • B. This simply relabels local time as Zulu without converting.
  • C. This adds only 1 hour instead of the required 7-hour offset.

UTC (Zulu) Time Conversion

Coordinated Universal Time is the standard time reference used in aviation; local times must be converted by adding or subtracting the appropriate zone offset.

  • Mountain Standard Time (MST) = UTC-7
  • Mountain Daylight Time (MDT) = UTC-6
  • Add the zone's offset number of hours to local time to get UTC

Memory trick: Go west, add more — the farther west, the more hours you add to reach Zulu.

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