First Air Corps rocket-assist takeoff

[freeflight]

On August 12, 1941, a Wright Field test pilot, using a small civilian-type aircraft, made the first Air Corps rocket-assist takeoff. Subsequent refinements of this technique were made for assisting heavily loaded aircraft in taking off from limited space.

What was the aircraft used?
I'm looking for the military designation.

[JohnKachenmeister]

The airplane used was an Ercoupe.  I don't think that there ever was a military designation for the Ercoupe.

[BillB]

There was a military designation for the Ercoupe Here is the info from the Air Force Museum.
Model 415-C Military Service Construction
Number Construction
Date Civilian
Registration Purchase
Date Army Air Force
Designation Army Air Force
Serial Number Service
Date
11 December 4, 1940 NC28655 January 4, 1941 YO-55 41-18875 February 26, 1941
110  NC37143 August 19, 1941 XPQ-13 41-25196 December 8, 1941
XXX unknown unknown unknown XPQ-13 41-39099 unknown

So the original USAAC designation was Yo-55, later changed the same year to XPQ-55. Only a total of three were purchased by the USAAC

[freeflight]

Correct the it was Erco Ercoupe.  The military designation was a PQ-13.