Colonel John Tillett: Soldier whose intensive preparations helped ensure the success of the Allied drive following D-Day

Tillett made possible the celebrated British "coup de main" at the bridges over the Orne river ("Horsa") and Orne canal ("Pegasus") in Normandy

Tillett in uniform as Commanding Officer of the 1st Ugandan Rifles in 1962; he left the country when the politics of the new regime became unacceptable

The 24-year-old adjutant who at 22.55 hours on 5 June 1944 waved off the six gliders that would begin the Allied invasion of Normandy was the man who, by his intensive preparations, made possible the celebrated British "coup de main" at the bridges over the Orne river ("Horsa") and Orne canal ("Pegasus").

The then Captain John Tillett was also to be the last-known surviving officer, more than 70 years later, of the D-Day contingent of the "52nd", 2Bn Oxf & Bucks Light Infantry, the battalion whose men, led by Major John Howard of "D" Company – portrayed by Richard Todd in the film The Longest Day – captured the two vital crossings.

On that overcast evening at RAF Tarrant Rushton in Dorset, watching the gliders' striped undersides disappear into the windy summer night, battalion adjutant Tillett had in his mind every detail of the six plywood Horsa transporters' loads, the disposal and weaponry of the 28 men that each lightweight craft, towed behind a Halifax bomber, could carry, and painful experience – a small bone broken in his neck during a training flight – of how hard an engineless landing could be. His work of the past weeks was about to face the test on the success of which the civilised world's hopes of smashing Hitler depended.

Within hours Tillett, married only a few months past, would leave his bride for France, following Major Howard's force of about 170 men with the rest of the battalion, also by glider. About 70 more of the flimsy aircraft went over; Tillett had arranged the contents, men and materiel, each one drifting between thick cloud above and choppy seas below, its fate decided by the strength of a tow-rope and a pilot's skill.

"John Tillett was a legend", a friend said, and command was soon to be his, in the shape of the legendary "D" Company itself, Major Howard having been badly injured in a road accident in autumn 1944 while on leave in England. Tillett, promoted Major, took over in November, and "D" Company helped to halt the German Ardennes offensive in the Battle of the Bulge, its men wearing snow-camouflage suits.

On 24 and 25 the following March, during Operation Varsity – the glider landings for the crossing of the Rhine into Germany at Hamminkeln – German rear area gun positions wrought carnage, leaving Tillett and "D" Company with only three officers and 58 other ranks after the Horsas came down amid a hail of incendiary bullets.

The depleted Company, advancing on foot, lost several more men when it came under heavy small-arms fire near Ladbergen, but on 1 April took an enemy position and captured more than a dozen anti-aircraft guns. They dealt with more weapons, makeshift cannon screwed in desperation to wooden blocks, placed at tactical points along their route.

On 8 April "D" Company took the hamlets of Friller Brink and Heinrichs Teich on the River Weser. Near Luneburg the discovery of a concentration camp shocked Tillett: "for the first time I experienced hate". He shielded his soldiers from it, lest it affect their fighting attitude, taking with him only one subaltern as a witness.

At the war's end Tillett was present when Field Marshal Montgomery met the Soviet army near Lubeck, and the 52nd formed the Guard of Honour for its commanding officer, Marshal Konstantin Rokossovsky. For his service in north-west Europe Tillett was Mentioned in Despatches in 1946.

That year he and "D" Company were transferred to British Mandate Palestine, and after attending the Middle East Staff College he progressed to posts at the War Office, liaising on intelligence matters with MI5 and MI6. He attended Staff College at Camberley in 1949 and was set to be Brigade Major of the Gurkha Brigade in Singapore before military cutbacks frustrated this, and he rejoined the Oxf and Bucks Light Infantry, re-formed, merged and renamed 1st Bn (43rd and 52nd), serving at Osnabruck, West Germany.

He was to pay a heavy personal price for Britain's determination in the 1950s to have a nuclear capability. A posting as instructor at the Nuclear Weapons Tactical Wing of the School of Infantry at Warminster led to his selection to observe an atomic weapons test at Maralinga in Australia. From a trench he saw the mushroom clouds of a 1 kiloton bomb and a few days later, a 5 kiloton device, and, with other witnesses, was driven to the site to see each bomb's effects.

Four years later he developed asthma and emphysema, which for the rest of his life gave him much difficulty. A scrupulously honest man, he refused to seek compensation, saying, "I stepped out of the box". In the excitement of the moment he had forgotten the advice given to stay down and had climbed out of the trench, taking the full radioactive effect of the blast wave that followed the flash.

His disability came to the fore when, after promotion to Lieutenant Colonel and a posting with HQ Allied Forces Southern Europe, he took on the preparation of Uganda's army for independence from Britain, becoming commanding officer of 1st Ugandan Rifles, formerly 4th Bn The King's African Rifles, and stayed on after independence in 1962. Mutinies erupted in 1964, and while he was giving out orders to control the crisis, a former comrade remembered, "he just lost all power of speech because he had no breath." A fellow officer continued the business of the day. Tillett went on to command the Ugandan Army as a Brigadier but left as Uganda's politics became unacceptable.

There followed posts in Canada and Britain before he retired in 1969. But ever loyal to the 52nd, Tillett forged a new career masterminding recruitment, as well as saving for posterity many of the regiment's artefacts in museums at Oxford and Winchester and writing a brief regimental history. He also founded a race for canoeists, inspired by army training.

Tillett had begun his career in the Territorial Army. The former pupil of Ipswich School, who returned to Normandy every year, told few of an unusual distinction: that on a school hockey team trip to Germany in 1936 he had been made an honorary member of the Nazi regime's young people's movement, the Hitler Youth.

ANNE KELENY

John Maurice Arthur Tillett, soldier: born Ipswich 4 November 1919; married 1943 Joan Lawson (one daughter, two sons; died Winchester 14 December 2014.