IFR - IFR Charts

IFR Airways

Low Altitude (1,200 ft to FL 180):

• V (black): Victor Airways (Low Altitude) VOR airways
• T (blue, RNAV): Low Altitude RNAV Routes (T-Routes)

High Altitude (FL 180 through FL 450):

• J (black): Jet Routes
• Y (RNAV): U.S. offshore or over southern Florida.
• Q (blue, RNAV): High Altitude RNAV Routes (Q-Routes)

More Airways

• TK: Helicopter RNAV Routes (TK Routes) Two helicopter RNAV routes (TK-routes) exist in the northeast corridor between the Washington, DC, and New York City metropolitan areas.
• Joint Victor/RNAV Routes (Low Altitude)
• Joint Jet/RNAV Routes (High Altitude)
• Unusable Route Segments
• Military Training Routes (MTRs): All IR and VR MTRs are shown on enroute charts, except VRs at or below 1500' AGL. They're numbered and published in brown.

Flags

The X in a flag for a intersection, waypoint or fix regardless of if it is a NavAid means there is a Minimum Crossing Altitude. An MCA present means you must be at or above a certain altitude when passing over the fix in the direction specified.

Altitudes

Along the airway:

• MEA: the topmost number, in black.
• GNSS MEA: the middle number, in blue, ends with a G.
• MOCA: the bottom bumber, in black, with a *.
• MAA: Maximum Authorized Altitude.

At a fix:

• MRA: Minimum Reception Altitude (a flag with an R); the lowest altitude at which an intersection can be determined; normally above the MEA.
• MCA: Minimum Crossing Altitude (a flag with an X); start the climb early, BEFORE the fix.

Each quadrant of the chart:

• OROCA: off-route obstruction clearance altitude (similar to the max elevation figures on the VFR sectional chart)

On Approach Plates:

• MSA: Minimum Safe Altitude.

For ATC:

• MVA: Minimum Vectoring Altitude; the lowest that ATC is allowed to assign you heading vectors.