Reading a four-digit IR military training route

Remote Pilot (Part 107) practice question 14 of 21 on Airspace / Classification. ACS element UA.II.A.K3 · difficulty: applied. Want to answer it in a timed quiz? Use the Remote Pilot (Part 107) practice mode.

Question bank updated 2026-09-22

QUESTIONA remote pilot notes a military training route identified as IR1206 near a planned operating area. What does this identifier indicate about the route?

AAn IFR route with no segment above 1,500 feet AGL
BAn IFR route with one or more segments above 1,500 feet AGL
CA VFR route flown only in visual weather conditions

Show the answer and explanation

Correct answer: A. An IFR route with no segment above 1,500 feet AGL

A — correct IR denotes a route flown under IFR, and a four-number identifier such as IR1206 means the route has no segment above 1,500 feet AGL.
B — incorrect Routes with one or more segments above 1,500 feet AGL are identified by three number characters, such as IR206, not four.
C — incorrect VFR military training routes are identified with VR, not IR; IR routes are conducted under IFR regardless of weather conditions.

BACKGROUND

Military training routes (MTRs) are used by military aircraft to maintain proficiency in tactical flying and are usually established below 10,000 feet MSL for operations at speeds in excess of 250 knots. Routes are identified as IFR (IR) or VFR (VR) followed by a number. MTRs with no segment above 1,500 feet AGL are identified by four number characters, for example IR1206 or VR1207, while MTRs that include one or more segments above 1,500 feet AGL use three number characters, such as IR206 or VR207. IR routes are conducted in accordance with IFR regardless of weather conditions. Because MTR traffic is fast and low, a four-digit route is especially relevant to a remote pilot operating near the ground.

STUDY TIP

Decode an MTR identifier in two steps: the letters give the flight rules (IR or VR), and the number of digits tells you whether any segment is above 1,500 feet AGL.

KEY POINTS

IR routes are IFR; VR routes are VFR.
Four digits mean no segment above 1,500 feet AGL.
Three digits mean at least one segment above 1,500 feet AGL.

SOURCES

remote_pilot_study_guide.txt Chapter 2 "Military Training Routes (MTRs)"

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