IFR Altitudes

Question 1

Decision Altitude/ Decision Height

Answer 1

The altitude MSL above the runway threshold on the instrument approach procedure

Question 2

Maximum Authorized Altitude

Answer 2

Maximum height allowed prior to entering Flight Levels

Question 3

Minimum Crossing altitude

Answer 3

Is shown as the X in the box
The lowest altitude at certain fixes at which the aircraft must cross when proceeding in the direction of a higher minimum en route IFR altitude.

Question 4

Minimum Turning Altitude (MTA)

Answer 4

charted altitude providing vertical and lateral obstruction clearance based on turn criteria over certain fixes, NAVAIDs, waypoints, and on charted route segments

Question 5

Off-Route Obstruction Clearance Altitude (OROCA)

Answer 5

the off-route altitude that provides obstruction clearance with a 1,000-foot buffer in non-mountainous terrain areas, and a 2,000-foot buffer in designated mountainous areas.

This altitude doesn’t guarantee signal coverage from ground-based NAVAIDs, ATC radar, or communications coverage.

It’s the beige numbers on low IFR charts

Question 6

Minimum Obstruction Clearance Altitude (MOCA)

Answer 6

It is distinguished by having the asterisk next to the number

lowest published altitude in effect between fixes on VOR airways, off-airway routes, or route segments that meets obstacle clearance requirements for the entire route segment.

This altitude also assures acceptable navigational signal coverage only within 22 NM of a VOR.

Question 7

Minimum Reception Altitude (MRA)

Answer 7

MRAs are determined by FAA flight inspection traversing an entire route of flight to establish the minimum altitude the navigation signal can be received for the route and for off-course NAVAID facilities that determine a fix.

When the MRA at the fix is higher than the MEA, an MRA is established for the fix and is the lowest altitude at which an intersection can be determined.

Question 8

Minimum En Route Altitude (MEA)

Answer 8

The MEA is the lowest published altitude between radio fixes that ensures navigation signal coverage and meets obstacle clearance requirements between those fixes.

Question 9

MDA/ MDH

Answer 9

The lowest altitude MSL height above the runway threshold which descent is authorized on a non-precision approach until visual references for landing are met