Having survived more than three months in bombers, my father knew he was going to need all the luck in the world to make it four.
As soon as he woke on 1 August, he made a point of saying "rabbits" out loud. It was a superstition he had grown up with. The idea was that you would receive a month of luck if the first word out of your mouth, on the first day of the month, was "rabbits".
I well remember when I was growing up, Dad would creep into my room on the first morning of the month and mouth as quickly as he could, "say rabbits".
He would be delighted if I did and seemed almost convinced of the power of it.
Perhaps his experiences in August 1941 had given him good reason to believe in it. He had even written "Rabbits" at the top of the page in his diary on the first day of August. Curiously, it was the only month he ever wrote this in his 1941 diary.
Perhaps he knew, at some inexplicable level, that this month he was going to need all the luck in the world, and then some. He was probably also aware that Germany had been dramatically strengthening her air defences.
There were now many more defensive fighters for the allied crews to contend with over Europe. So many, in fact, that in the first 18 nights of August 1941, 107 British aircraft were lost.
August hadn't long begun when my father's crew were detailed for what would be his 15th op. The odds of surviving this many operations were heavily stacked against an airman. A great many bomber crews got shot down after only a few trips.
My father returned safely from his 15th op, describing it in his diary as usual. Some of his colleagues weren't so lucky during the raid, and my father had the shocking misfortune to witness the moment a nearby crew were blasted to eternity.
3-4 August, 1941 -"Our target tonight is Hanover. A real town blitz - with the post office as the objective. Took off into a thick fog and dirty weather. The weather was lousy for our little jaunt to Hanover. No searchlight opposition due to 10/10 cloud. There was plenty of flak but it was not very accurate. Passing Bremen I saw an aircraft receive a direct hit from flak. It was a ghostly sight " a huge flash then a ball of flame hurtled earthwards. Coming back we got lost and finished up with a wireless fix in the middle of the North Sea. Landed at an aerodrome near Hull at 06:00 hours, after having been in the air for nine and a half hours. I was pretty tired and glad to get to bed."
That was the last time my father made an entry in his red, pocket-sized 1941 diary. The pages from August 5 to December 31 remain ominously blank.
The diaries of the 55,000 men in Bomber Command who died during World War II must also have ended abruptly one day, blank pages the only thing remaining. Chills ran down my spine when I first saw all the blank pages in my father's 1941 diary. Even though I already knew what had taken place to prevent him from writing anything further, it made what followed seem all the more real - and all the more shocking.
On August 5, my father and his crew set off at 10.47pm in their Wellington bomber, serial number R1471. With half a tour under his belt, this was his 16th flight towards Nazi-occupied Europe. He had complete trust in the other members of his crew: their captain, Flight Lieutenant Frederick Lorne Litchfield; second pilot, Sergeant Richard Hammer Hilton"Jones; navigator, Sergeant Donald Arthur Boutle; wireless operator, Sergeant Alexander Scott Lawson; and front gunner, Sergeant Edward ("Ted") Frank Lambert.
Their lives were quite literally dependent on the vigilance and skill of each other. Alone in the sky, they were six men against the Reich.
The sun had already set in the west as they flew in near darkness towards the German coastline that night. They looked forward to seeing it rising in the east on their return. Flying over Germany, one of their engines began to give them some trouble. Despite this, they continued on towards their target. But it wasn't long before the pilot became sufficiently concerned that he announced they should jettison their bombs and head back as fast as possible. They chose a nearby bridge and rapidly unloaded their bombs.
As they were turning for home, they were caught in a searchlight cone. With no associated anti-aircraft fire they had good reason to be worried. Searchlights without associated flak meant there were certain to be German night fighters about. The pilot immediately took violent evasive action. Diving and turning to the left and right, the bomber hurtled through the air in a complex corkscrew manoeuvre.
But the highly skilled German searchlight operators were able to keep the illuminated aircraft firmly stuck in their cone of light. The pilot put the plane into another deep stomach-churning dive and this time, though not without considerable difficulty, managed to escape the searchlights.
No sooner had the men breathed a sigh of relief than a German fighter, flown by Lieutenant Hans-Joachim Redlich, seemed to appear out of nowhere. Now flying on only one engine, the Wellington crew knew they were in serious trouble. To add to their woes, my father discovered the hydraulic system that operated his turret wasn't working. The engine that had failed controlled this system. He was faced with a fighter right on his tail and no guns at his disposal.
Rendered defenceless, he knew it would take only one on-target shell to vaporise them.
The enemy fighter unleashed a burst of gunfire. The bullets whizzed towards them. Fortunately they were slightly off target. My father's highly skilled pilot took further evasive action trying to shake off their attacker. By nothing short of a miracle, he managed to evade the fighter. But by now, and with only one engine working, they had lost considerable height and were down to about 2000 feet.
With the fighter off their tail, my father tried to breathe deeply in an attempt to calm his harried nerves. Everything seemed relatively okay.
He knew the Wellington bomber was quite capable of flying on only one engine. Despite the gnawing apprehension deep within him, he tried not to let doubt infiltrate his mind. Getting back safely was all he needed to focus on.
On they flew. But it wasn't long before he heard front gunner Ted Lambert suddenly scream out.
'Let me out, open the door,' he cried, sounding highly agitated.
My father's heart began to pound. He had no idea what the problem was up the front, but things didn't sound at all good.
'Let me out, let me out,' Ted screamed again, this time even more urgently.
It was obvious that Ted desperately wanted someone to open his door. The bulkhead door behind his front turret could only be opened by the pilots on the other side. My father listened for the pilot. Nobody responded. The lack of response gave him further cause for concern. He sucked in sharply, looking below as he tried to gauge their altitude. The pitch darkness encompassing the enemy territory below stared back at him, providing no clues as to its depth. From the rear turret, he didn't know exactly what was going on in the rest of the aircraft.
'What's the trouble Ted?' my father said through the intercom, although, from his position in the rear, completely isolated from the rest of the crew, there was precious little he could do.
He listened again. Still no one said a word. He tried to ignore the suppressed fear building inside. But it was impossible. Something must be very wrong. He looked anxiously out into the endless blackness all around him. But there were no clues as to the nature of their predicament.
All of a sudden, with no warning whatsoever, there was a thundering, almighty graunch. The plane was careering through tall trees and into a potato field. With no idea of their position, my father was horribly surprised by the deafening "rending crunch on impact with Mother Earth" in the fleeting moments before he passed out. Complete blackness followed as he lost consciousness.
In the wee small hours of the morning in the nearby village of Glabbeek, the commotion startled some of the local Belgians. They jumped out of bed.
Regaining consciousness, my father tried to exit the wreckage. If he was injured, he didn't know it. He managed to open the turret door manually.
Dropping a large distance to the ground, and a lot further than he'd anticipated, he felt a shattering pain in his leg, so intense, he passed out again. Shattered bones protruded through the flesh below his knee.
Astonishingly, Ted Lambert's front turret had been knocked off the aircraft on impact and had rolled around and around eventually coming to rest. Ted, who miraculously emerged with scarcely a scratch, dashed over to check on the others.
The rest of the aeroplane was in two pieces, each ending up about 50 feet apart. Pieces of wreckage were strewn chaotically among broken branches and scattered leaves.
My father drifted in and out of consciousness. Ted and the two pilots, who were also largely unharmed, dragged the injured crewmen away from the aircraft, over to the edge of a clearing. It was pitch black and they could hardly see a thing. The pilot explained that tall trees had broken their fall. Without trees to cushion their impact, it is unlikely any of them would have survived the crash.
(Perhaps this was the genesis of my father's deep-seated love of trees.)
Sergeant Boutle was in the worst shape. He had a fractured skull. Sergeant "Jock" Lawson had an injury to his face. The pilots went back to the aircraft and, as they had been trained to do, set fire to it by exploding the oxygen bottles. Nearby, villagers spotted the fire and rushed out to help. The crewmen heard them coming but didn't recognise the language they were speaking, although they sounded friendly enough.
The airmen asked the villagers where they were and learned that they had arrived, unannounced, in the middle of Belgium.
Their rescuers helped them back to the village, carrying the injured men on stretchers. It was a five-minute walk to the home of Franz and Bertha Willems-Harry on Kersbeekstraat in Glabbeek - Zuurbemde, and they ushered the airmen inside, along with neighbour Mr de Becker and mayor Victor Mertens. Bertha cut Boutle's parachute off him as he lay on a stretcher, to ease his laboured breathing. Local doctor Dr Homans gave my father some medication for the pain emanating from his left leg. Everyone was most concerned about Donald who, apart from being helped to sit up to vomit, lay motionless on a mattress with his eyes closed.
His face was swollen and covered in blood. Mr de Becker could see that the other airmen were young and handsome, but couldn't tell if Donald was a man of 25 or 55. He was in such a bad way that it didn't look as if he was going to survive.
None of the locals spoke English but the airmen managed to make themselves understood when they asked if there was a priest nearby.
Pastor Van Maegdenbergh arrived with holy oil and administered last rites.
As morning approached, Franz and Bertha gave the men some breakfast. My father felt ever so grateful for the kind way they willingly shared what little they had and hungrily devoured his food.
Mr de Becker was amazed at my father's appetite despite his badly fractured leg. Word of the airmen's presence soon spread and most of the village filed in to see their "RAF heroes".
With three of the crew badly injured, the villagers had no option but to notify their German occupiers to arrange for an ambulance to take them to the nearest hospital.
With a compound fracture of the leg, my father was about to officially become a prisoner of war. But he was alive. He breathed a huge sigh of relief. Not just because he had survived the crash, but also because the horror of night raids to Germany was finally over.
Having left England abruptly in the dead of night, he realised that, ironically, crashing into a field in Belgium had just preserved his life, releasing him from further perilous bombing raids.
Now however, instead of being in a plane that dropped the bombs, he was on the very ground that would be subjected to heavy bombardment for the next few years. But he didn't concern himself with that right now.
He just felt a strange sense of relief. Having already survived something akin to Russian roulette, he certainly had good reason to be relieved.
The work he had been doing was so hazardous that, throughout 1941, more RAF aircrew were lost over Germany than German civilians killed on the ground.
I'll always remember how palpable Dad's relief still seemed when he told us about surviving his plane crash in Belgium.
He hadn't known how he could have endured the horror of night raids indefinitely, yet carrying on had seemed his only option.
I always marvelled at this man who, despite being bound for a prisoner of war camp with shattered bones to boot, seemed to have been profoundly grateful to have arrived on a foreign field, alive.
• From Battle of Britain Airman to POW Escapee: The Story of Ian Walker RAF by Angela Walker. Distributed by South Pacific Books and available in bookshops nationwide. RRP: $60