Derek Piggott joined the Royal Air Force in 1942 as aircrew and made a first solo in a DH82 Tiger Moth after only six hours dual. He completed his training in Canada and was commissioned as a Pilot Officer in 1943. He was then sent on a multi-engine instructors' course and then on a course for elementary instructors before returning to England. By 1944 there was a surplus of trained pilots and he so volunteered to fly military gliders. After a short conversion to Airspeed Horsa, General Aircraft Hotspur and Waco Hadrians, he was posted to India and then on to Burma where he flew Dakotas dropping supplies to front-line troops. During his stay in India, he instructed Indian Air Force students and flew low anti-riot patrols just before partition.

Back in the UK he was posted as a Staff Instructor at RAF's Central Flying School at Little Rissington where he trained instructors and flew Harvard, Balliol, Athena, Meteor, Spitfire, Mosquito and Lancaster. After being awarded the A1 Instructor Rating, he joined the Home Command Gliding Instructors' School teaching civilian instructors for the Air Training Corps on Slingsby T21 and Slingsby Kirby Cadet gliders. As Chief Flying Instructor he introduced improved training methods. He also taught school teachers in the Combined Cadet Force how to teach flying in primary gliders. Flying with an ATC cadet as co-pilot in the National Gliding Championships, he established a British two-seater altitude record climbing to over in a thunderstorm over Sheffield. In 1953 Piggott received the Queen's Commendation for work on developing and introducing new instructional techniques for gliding in the ATC.

In 1953, he left the RAF as a Flight Lieutenant and joined Lasham Gliding Society and became its Chief Flying Instructor.

Derek Piggott is perhaps best known as a gliding instructor, and has written several instructional articles. In addition he had success as a competition glider pilot winning three regional championships, was the UK National aerobatic glider champion in 1961 and set several national gliding records including the single-seat altitude record of over in an active thunderstorm in a Slingsby Skylark. He holds the FAI Diamond Badge. Between 1953 to 1989, Derek Piggott was the Chief Flying Instructor at Lasham Gliding Society, though he took breaks during this time to do stunt flying.

He has travelled widely lecturing and advising gliding associations such as the Soaring Society of America and the Dutch gliding association on matters such as the use of motor gliders in training. As a leading authority on gliding, he has written seven books on the subject, an autobiography, several monographs and many magazine articles. His first book 'Gliding' was first published in 1958 and is still in print in its eighth edition. In 2003 at the age of 81, he completed a 505 km task in an Me7 glider with only a 12.7 metre span in a national competition in a time of 7hr 14min. (Several much younger pilots with superior machines failed to complete this task). He is an active glider pilot and competitor, though he no longer holds a full Private Pilot's Licence.

He was a member of a test group for the British Gliding Association and tested a number of prototype gliders and foreign machines for approval to be imported. He made a successful emergency parachute descent from a damaged Bocian making him a member of the Caterpillar Club. He researched the effect of sub-gravity sensations as a cause for many serious and fatal gliding accidents.

In 9 November 1961, flying Southampton University's Man Powered Aircraft (SUMPAC), Derek Piggott became the first person to make an officially authenticated take-off and flight in a man-powered aircraft. The longest flight was 650 yards (594 m). Turns were attempted, with 80 degrees the best achieved. He made a total of 40 flights in SUMPAC.

He took a break from being a gliding instructor to become a stunt pilot and was also technical advisor on several feature films. His role as a stunt pilot, began in 1965 with the film The Blue Max which tells the story of the competitive rivalry between two German pilots in the First World War. He was enlisted as one of several pilots who helped recreate the live dog-fight scenes for the film. However, he was the only stunt pilot to agree to fly for the climax of the film in which the two rivals challenge each other to fly beneath the spans of a bridge over a river. Taking the role of both German pilots and with multiple takes from contrasting camera angles, he ended up flying through the wide span of this bridge in Ireland 15 times and 17 times through the narrower span. The two Fokker Dr.I triplane replicas had about four feet of clearance on each side when passing through the narrower span. Piggott was able to fly through the arch reliably by aligning two scaffolding poles, one in the river and one on the far bank. The director had placed a flock of sheep next to the bridge so that they would scatter as the plane approached in order to demonstrate that the stunt was real and had not used models. However, by later takes, the sheep had become accustomed to the planes and continued to graze and, so had to be scared by the shepherd.

In Darling Lilli, he was responsible for the majority of the designs of six replica aircraft and for supervising their construction in a period of nine weeks. Some of the dog fight scenes are considered to be among the best made. However, they had to be re-shot the following year because the film was changed from being comic to serious.

Another notable film role, was Derek Piggott's contribution to Those Magnificent Men in Their Flying Machines in which he flew and advised on the construction of several of the early aircraft recreated for use in the film. Many of the planes employed wing warping for directional control, which involved re-discovering how to fly them safely. Several of the aircraft had dangerous features and he had a number of narrow escapes.

In Villa Rides he had to crash an aircraft that was flying towards a cliff by making the undercarriage collapse. This stopped it from 110 km/h in about 10 metres.

Derek Piggott flew some or all the aerial stunts in these other films:

• The Red Baron,
• Agatha,
• Slipstream,
• You Can't Win Them All,
• Chitty Chitty Bang Bang

and for several television programs. For one of these a replica of the Sir George Cayley's first heavier-than-air flying machine was built in the early 1970s. The machine was flown by Derek Piggott at the original site in Brompton Dale in 1973 for a TV programme and again in 1985 for the IMAX film On the Wing.

Derek Piggott also is the inventor of the "Piggott-Hook", which is to prevent air brakes opening on a launch. The system is installed in all new gliders built by DG Flugzeugbau

In 1987 Derek Piggott was appointed Member of the Order of the British Empire (MBE). In 2007 Derek Piggott was awarded the Royal Aero Club Gold Medal - the highest award for aviation in the UK. Also in 2007 the Royal Aeronautical Society appointed Derek Piggott an Honorary Companion of the Society. In 2008 he was awarded the Lilienthal Medal by the Fédération Aéronautique Internationale for outstanding service over many years to the sport of gliding

His monographs are:

• 'Sub-gravity sensations and gliding accidents'
• 'Stop worrying about stalling and spinning'
• 'Using motor gliders for training glider pilots'
• 'Ground launches'