Quoted from The Spifire Society Website:
Vb AB910
Originally ordered among a batch of Mk I's, the production run coincided with the arrival of the Rolls-Royce Merlin 45 engines, and the batch were delivered as Mk V. It was delivered to 222 Squadron at North Weald in August 1941. With intervening periods of repair it also served with 130, 133, 242 416, 402 and 527 Squadrons.
While at 53 OTU it had its most famous (infamous?) flight. It was common practice for pilots using high power settings while on the ground to avail themselves of any convenient passerby to lie over the tail of the aircraft to prevent the aircraft from nosing over. Flt Lt Neil Cox was detailed to fly AB910, and was aided in his ground running by Leading Aircraftswoman Margaret Horton acting as a tailweight. After the ground run, the pilot lined up into wind and took off. In the circuit it was clear that the trim of AB910 was not normal, and flew in a tail-down attitude. After the remainder of the 1000 feet circuit, AB910 returned to the ground. On stopping, Margaret Horton was seen sliding off the tail unit where she had been determinedly clinging for the whole of the circuit!
After the War, AB910 was used for air racing before being purchased by Vickers-Armstrongs. After a career of air shows in the hands of Jeffrey Quill, she was presented in September 1965 to the Battle of Britain Memorial Flight, who operate her to this day. (10/02)
If you Google her name, you'll find other interesting info, including that she was allegedly charged the cost of her lost beret!