On July 8, 1917, a young medical student from York travelled down to the royal naval depot at Crystal Palace in London to sign up for a fledgling new branch of the British armed forces: the Royal Naval Air Service.

Hugh Mortimer Petty was just 17. He had been a first-year medical student in Leeds. But instead of waiting to be called up to join the men fighting in the trenches, he opted instead to volunteer for the new-fangled air service.

In a speech he gave to medical colleagues ten years later, he recalled the day he signed up.

"It was a Sunday," he said. "I well remember appearing at Victoria Station wearing His Majesty's uniform for the first time, feeling extremely uncomfortable, but greatly relieved to find a good many other people feeling uncomfortable too."

Though he didn't know it at the time, he had good reason for feeling uncomfortable. Of the 23 teenagers who joined him for pilot training at RNAS Cranwell, only three were to survive the war.

After initial training at Cranwell, the young Pilot Officer Petty was posted to Freiston, to learn more about gunnery, then to East Fortune near Edinburgh. "Here we stayed for some time," he recalled in that speech ten years later, "flying over the Firth of Forth, getting our sea knowledge and learning about the silhouettes of the ships of the Grand Fleet and the enemy."

York Press:

Pilot Officer Hugh Mortimer Petty

He was ready to begin work as a naval reconnaissance pilot - a duty that, over the next nine months, was to see him crash-land no fewer than six times - at least one of them into the North Sea itself.

We know all this, because Pilot Officer Petty's speech to his colleagues has been included in full in a book published by his son, Dr Richard Petty.

It is a remarkable tribute to the young First World War airman - made all the more remarkable by the stunning photographs used to illustrate it.

That has been possible because, against all military regulations, the young pilot officer carried with him, slipped into a pocket, a Kodak camera. Throughout the war, he and his comrades used it to capture a series of extraordinary photographs depicting their life at sea and in the air.

This may be starting to sound familiar to some readers.

That is because an exhibition of Pilot Officer Petty's photographs is currently on display in the Community Room at theYork Castle Museum.

The book written by his son, however, provides a wonderful insight into the man who took those photographs - and the risks and dangers of the life he led as a young naval pilot.

In 1917, flying was still in its infancy. The aircraft that Pilot Officer Petty flew - Sopwith Pups and Camels - were fragile bi-planes ill-suited to taking off from the bucking decks of a ship at sea.

York Press:

A First World War biplane of the kind flown by Pilot Officer Petty

At one point, Pilot Officer Petty was posted to HMS Nairana, which gloried in the name of an aircraft carrier, though it was in truth a converted meat packing ship from New Zealand.

"We were sent to this ship in order to practice taking off the deck," the former pilot officer recalled in his speech ten years later.

"This business was rather complicated. The machine was put on the deck so that the tail was lifted up...The tail skid had a small knob on the end: this fitted into a long piece of tubing placed in a stand.

"The machine was tethered... to the deck by a wire rope, and a special release gear fitted.

"The engine was put at full speed and, on the signal from the pilot, the machine was released, and shot into the air. Whilst this was being done the ship was manoeuvred so that it was steaming directly into the wind - and therefore when the machine was released, the pull of the ... propeller and the resistance of the wind gave the machine a chance to 'rise' straight into the air..."

Remarkably, Pilot Officer Petty survived numerous take-offs and crash landings, including a ditching in the North Sea. After the war, he resumed his medical studies and went on to become an ear, nose and throat surgeon.

But this book, and the extraordinary photographs it contains, stands as a unique record of the early days of naval flying, and the terrible risks the young men of the Royal Naval Air Service took.

York Press:

  • The Boy Airman: An Absolute Stranger to Fear by Richard Petty. Pen & Sword, £19.99
  • An exhibition of photographs taken by Hugh Petty and his colleagues during the First World War, also entitled The Boy Airman, remains on display in the Community Room at the York Castle Museum until February 29