It's a Boys' Own tale of amazing derring-do - the First World War pilot who shot down the German ace who flew with the Red Baron.

Chris Lloyd recounts the story of the Richmond schoolteacher whose story has been a secret for over half a century.

IT was supposed to be Erwin Boehme's big day. In a few hours time, the Kaiser himself was coming to present him with Germany's highest award for gallantry. This was his recognition for shooting down 24 enemy aircraft; it was also his absolution for bringing down his country's most famous air ace of the day.

But before the presentation, Boehme had one more mission to fly.

And that mission would bring him into conflict with a British flier named Captain John Pattern. In later life, Pattern was known to generations of schoolboys in Richmond, North Yorkshire, as "Joe". But it wasn't until he had retired from teaching and reached his eighties that Joe was persuaded to tell how he ruined Boehme's big day and brought him crashing down to earth.

Darlington author and military historian Robert Jackson, a former pupil at Joe's Richmond Grammar School, recorded the story and now tells it in his new book.

On the day in question - November 29, 1917 - Boehme's thoughts were on the Ordre Pour le Merite, the "Blue Max" as it was nicknamed. For him, receiving it from Kaiser Wilhelm II would help erase the memory of a dreadful mistake which had taken him to the brink of suicide.

A year earlier, on October 28, 1916, Boehme had been flying with his squadron commander Oswald Boelcke. Boelcke was regarded as the father of the German air corps, the pioneering pilot who had written the rules of aerial combat.

Boelcke had himself won the Ordre Pour le Merite for his feats in the skies in January 1916 and then, within a few days, had won a lifesaving medal for rescuing a drowning French schoolboy from a canal.

Boelcke was an all-action hero but, on October 28, 1916, Boehme had made a fatal error of judgement. The two pilots were in a dogfight with some British planes when Boehme's wingtip had touched Boelcke's.

The ace's aircraft fell from the skies, breaking up as it went. Boelcke, who had a record 40 kills to his name, died instantly.

As soon as Boehme landed, he went to his tent, took out his revolver and put it to his head. He was prevented from killing himself by another young pilot, another protg of Boelcke: Manfred von Richthofen who would, using Boelcke's tactics and techniques, become famous as the Red Baron.

Some 18 months later, Boehme was still carrying much of this baggage. He was now in command of Boelcke's old unit, Jagdstaffel 2, and having shot down 24 British and French aircraft, he was due to be presented with the Ordre Pour le Merite on November 29, 1917.

But he had one more mission to complete before his big moment. So he set off from an airfield near Lille for the front line, accompanied by five more Albatros Scouts, in good spirits. Another quick kill, and then decoration from the Kaiser.

But taking off at practically the same time from an airfield 30 miles away at Abeele in Belgium, was Capt John Pattern. He was with No 10 Squadron, and was flying an Armstrong-Whitworth FK8 reconnaissance aircraft. It was his seventh mission with his observer, Lieutenant Leycester.

"I was due to go home on leave the following day," Capt Pattern told Jackson in 1979, four years before he died aged 92. "And when you had been warned for leave you weren't supposed to fly. But after several days of fog and rain the weather had finally cleared and there were reports of large enemy troop movements south of Passchendaele, so as the Squadron's most experienced pilot I was detailed to go out and get the photographs that were urgently needed.

"It wasn't that I was a particularly good pilot; it was just that most of the others who had been on the Squadron when I joined it six months earlier were dead. On average, a crew doing our sort of job, flying straight and level over the enemy lines, could expect to last three weeks before being shot down."

Pattern rose to about 5,000ft, and crossed into enemy airspace just north of the Belgian town of Westhoek.

"About a quarter of a mile on the enemy side of the lines, I turned south-east and Leycester started to work his camera," said Pattern, who was Mayor of Richmond in 1958 and was awarded an MBE in 1968. "The anti-aircraft fire, which had been intense, had not stopped, but I didn't take much notice. I should have known better; it was a sure sign that enemy fighters were in the vicinity.

"Suddenly, I heard the clatter of Leycester's machine gun above the roar of the engine. I looked round to see what he was shooting at, and nearly had a heart attack. Slanting down from above, getting nicely into position 30 yards behind my tail, was an Albatros.

"I immediately heaved the old A-W round in a turn, tighter I think than I had ever turned before. I felt a flash of panic as I lost sight of the Hun, but Leycester must have been able to see him all right as he kept on firing.

"My sudden turn had done the trick. The Albatros overshot and suddenly appeared right in front of me. Because of the relative motion of our two aircraft, he seemed to hang motionless, suspended in mid-air. I could see the pilot's face as he looked back at me."

It was, of course, the face of Erwin Boehme, the man just hours from receiving the Ordre Pour le Merite.

"I sent a two-second burst of Vickers fire into him," continued Pattern, sitting in his home in Gilling Road, Richmond, at the time. "His aircraft seemed to flutter, then slid out of sight below my starboard wing. I was pretty certain that I had hit his petrol tank.

"Behind me, Leycester was still blazing away. He was using tracer, and it may have been one of his bullets that ignited the petrol pouring from the Hun's ruptured tank. When I caught sight of the Albatros again, it was burning like a torch and side-slipping towards the ground, trailing a streamer of smoke.

"For an instant I saw the German pilot, looking down over the side of the cockpit. Then the smoke and flames enveloped him."

For Boehme, that was that. He was buried with full military honours in a cemetery near Keerselaarhoek, but his grave is now lost. In his pocket when he went down was his last letter from his fiancee Annamarie Bruening - she never got to see him wear the Blue Max.

Pattern completed his story: "I pushed the A-W's nose down and headed flat out for home, aware that the other Hun scouts were coming down after me. They would probably have got me, too, if some friendly fighters had not come along just in time and driven them away.

"To say that I was relieved would be the understatement of the century."

Pattern's luck ran out less than two months later. Flying solo, he was returning home from a bombing mission on the Somme when he was hit by anti-aircraft fire.

He was knocked unconscious and when he came round he realised he was flying upside down perilously close to the ground. He recalled righting the aircraft and spotting the Abeele beacon, but crash-landed into some trees. It was while he was recovering in a military hospital that he met an attractive young nurse called Dora - the woman who was to become his wife.

He never flew operationally again. After the war, he went to Cambridge University and joined Richmond Grammar School in 1923. He taught there for 34 years - none of his pupils knowing of his extraordinary war story.

* Captain John "Joe" Pattern's story is told in Army Wings - A History of Army Air Observation Flying 1914-1960 by Robert Jackson (Pen and Sword, £19.99.