IFR Altitudes

Question 1

DA / H

Answer 1

Decision Altitude / Height: the Altitude (MSL) / Height (above runway threshold), on an instrument approach procedure
at which the pilot must decide whether to continue the approach or go around.

Question 2

MAA

Answer 2

Maximum Authorized Altitude. Annotated “MAA-17000” (17,000ft as an example) on IFR charts.

Question 3

MCA

Answer 3

Minimum Crossing Altitude

Question 4

MDA / H

Answer 4

Minimum Descent Altitude / Height: The lowest Altitude (MSL) / Height (above runway threshold) to which descent is
authorized on a non-precision approach until the pilot sees the visual references required for landing.

Question 5

MEA

Answer 5

Minimum En route Altitude: The lowest published altitude between radio fixes which assures acceptable navigational
signal coverage and meets obstacle clearance requirements. An MEA gap establishes an area of loss in navigational coverage
and annotated “MEA GAP” on IFR charts.

Question 6

MOCA

Answer 6

Minimum Obstruction Clearance Altitude: Provides obstacle clearance and navigation coverage only up to 22 NM of the VOR.

If both an MEA and a MOCA are prescribed for a particular route segment, a person may operate an aircraft lower than
the MEA down to, but not below the MOCA, provided the applicable navigation signals are available. For aircraft
using VOR for navigation, this applies only when the aircraft is within 22 NM of the VOR. (§91.177)

Question 7

MORA

Answer 7

Minimum Off Route Altitude (Jeppesen):
▷ Route MORA provides obstruction clearance within 10NM to either side of airway centerlines and within a 10NM radius at
the ends of airways.
▷ Grid MORA provide obstruction clearance within a latitude / longitude grid block.

Question 8

MRA

Answer 8

Minimum Reception Altitude. Minimum altitude the navigation signal can be received for the route and for off-course NAVAID facilities that determine a fix

Question 9

MTA

Answer 9

Minimum Turning Altitude: Provides vertical and lateral obstacle clearance in turns over certain fixes. Annotated with the
MCA X icon and a note describing the restriction.

Question 10

MVA

Answer 10

Minimum Vectoring Altitude: The lowest altitude at which an IFR aircraft will be vectored by a radar controller, except as
otherwise authorized for radar approaches, departures, and missed approaches. MVAs may be lower than the minimum
altitudes depicted on aeronautical charts, such as MEAs or MOCAs.

Question 11

OROCA

Answer 11

Off Route Obstruction Clearance Altitude: Provides obstruction clearance with a 1,000 ft buffer in non-mountainous
terrain areas and 2,000 ft in mountainous areas. OROCA may not provide navigation or communication signal coverage.
*Designated mountainous areas are defined in 14 CFR part 95 by lat / long coordinates.

Question 12

Excluding takeoff and landing what is the lowest an aircraft can be operated under IFR?

Answer 12

▷ Minimum altitudes prescribed for the flown
segment, or if none:
▷ Mountainous areas: 2,000 ft above the highest
obstacle within a horizontal distance of 4 NM
from the course.
▷ Non-mountainous areas: 1,000 ft above the
highest obstacle within 4 NM from the course.