Beagle redesignated the Model 6A to A.61, and 82 of the AOP.6 and T.Mk.7 were converted into:
17 A.61 Tugmaster glider tugs,
18 A.61 Terrier 1, featuring electrical starter, civil trim, new exhaust and arear bench seat
46 A.61 Terrier 2, Terrier 1 with flaps, larger tail, differential ailerons, new undercarriage
1 A.61 Terrier 3, fitted with an 160 hp Lycoming O-320-B2B.
G-ATDN was original an AOP.6, s/n TW641 c/n 2499, converted to A.61 in 1965 and is still registered as of this day."