Dudley Smith, 78, took to the skies on Sunday, May 1, and raised an impressive £2,250 in aid of the medical emergency charity.
The brave grandfather - who isn't a huge fan of heights - visited Damyns Hall Aerodrome, Upminster, for his challenge and selected the 'Extreme' option to really test his nerves.
Dudley laughed: "When I was sat on the wing and he revved up the engine of the 81-year-old plane I said to myself, 'This is another fine mess you've got yourself in!'
"In my case it really was 'extreme' - they can't give you a loop-the-loop on the first go, but they can come pretty jolly close to it.
"The view was superb. I could see right across to the docklands, Dartford Bridge and the River Thames.
"Then he started climbing - and diving at 135mph!"
Daring Dudley completed a tandem parachute jump for the charity during 2019, while he has also abseiled the Spinnaker Tower, Portsmouth, in 2018 to aid research into Parkinson's Disease.
Both challenges raised £1,500 each, while Dudley was first inspired to help Magpas because the charity gave a talk to the Rotary Club of Sandy, of which he is a member.
Dudley said: "Magpas was started in 1971 by a couple of GPs in Huntingdon because in those days a lot of people died in road accidents - about 8,000 a year in England.
"They persuaded around 120 colleagues to join the service and used to ride around in their cars - but they are now on their second helicopter and celebrating their 50th anniversary."
To take to the skies himself, Dudley had to lose over a stone to be within the wing walk weight limits, dropping from 14 st down to 12 st 8lbs in just two months.
He achieved this by exercising more, cutting down his food intake, and resisting the temptation of Easter eggs!
On charity challenges, Dudley advised: "Don't let your age be a barrier. Find something you can do and set yourself a goal."
Dudley would like to say a heartfelt thank you to everyone who donated, and to Magpas representative, Annette, who came to watch his wing walk.