ATR 11A

Overview

The ATR-11A was a Canadian-built HF aircraft radio set used extensively during the later years of the British Commonwealth Air Training Plan (BCATP). Manufactured principally by Canadian Marconi Company (CMC), with components also produced by Northern Electric and RCA Victor (Canada), it served as the standard radio equipment for Harvard Mk II, Mk IIA, and Mk IV advanced trainers during the 1940s and early 1950s.

The designation ATR means Aircraft Transmitter/Receiver.
The “11A” suffix denotes a mid-war improved model with autotune capability and a more compact, serviceable layout compared to earlier pre-war AT/AR combinations.

Role and Function

The ATR-11A provided two-way voice communication between training aircraft and ground stations. In BCATP operations, instructors relied on it for:

  • Contacting control towers

  • Receiving practice “vectoring” or navigation instructions

  • Communicating with navigation beacons

  • Emergency procedures and position reporting

  • Air-to-air coordination with other Harvard trainers

It was not a long-range strategic radio—its purpose was stable, reliable communication within local training zones.

Summary: The Core Aircraft

Primary / Standard User

  • North American Harvard Mk II, Mk IIA, Mk IV

Secondary (Refits / Postwar Use)

  • Avro Anson Mk II (late refits)

  • Avro Anson Mk V (postwar training)

  • Fleet Canuck (civil postwar)

  • Noorduyn Norseman (limited postwar)

  • Cornell / Crane refits (very rare)

Typical layout:

  • Main ATR-11A unit: behind rear cockpit on right-hand side

  • Dynamotor: either adjacent to the main unit or on the mount frame

  • Remote head: left cockpit wall (front cockpit)

  • Headphones/Microphone: plugged into the intercom system, often a Gosport-type or later wired helmet

  • Antenna: fixed wire mast behind the rear cockpit canopy

This arrangement allowed instructors in the rear to manage the radio while students practiced flying in the front.