VFR Weather Minimums

Visibility and cloud clearance under 91.155, class by class, day and night.

13 min read · Regulations: FAR and AIM

After this lesson you can

  • Recite the visibility and cloud clearance for any airspace class from memory.
  • Explain why Class G minimums change at the 1,200 ft AGL and 10,000 ft MSL thresholds.
  • Apply the 91.155(c) ceiling rule and the 91.155(d) ground-visibility rule to a takeoff decision.
  • State the condition under which Special VFR may substitute for basic VFR minimums.

91.155 is probably the single most tested table on the FAA written exam. Its logic, though, is one idea applied consistently: keep enough distance between a VFR aircraft and an IFR aircraft breaking out of a cloud, given how fast the two can be closing.

That logic explains the numbers. Where traffic is slow and sparse, 1 mile and clear of clouds is tolerated. Where a jet can appear at 250 knots, the rule demands 5 miles and a full mile of horizontal separation.

The rest of this lesson

  1. 1.The 91.155 table
  2. 2.Why Class G is different
  3. 3.Takeoff and landing: the 3-mile ground rule
  4. 4.Special VFR
  5. 5.Two worked scenarios

These 5 sections, their figures, the checks along the way and the end-of-lesson quiz come with the PPL track. Paid once, yours for good.

See what the PPL track costsEvery module 1 is free to read, no account, no card.

Key terms

Try to recall each definition before turning the card.