Throughout the Second World War, guessing what the weather would do was a central preoccupation of Bomber Command, and considerable effort was devoted to predicting it. Dr Jennie Mack Gray describes Black Thursday, when failure to forecast dense fog led to unprecedented bad-weather crashes.
In The Right of the Line, the historian John Terraine wrote that Bomber Command’s “first and everlasting enemy” was the weather. Throughout the Second World War, guessing what the weather would do was a central preoccupation of the Command. Despite this, predictions could go seriously wrong. One such miscalculation was on 16 December 1943 when more personnel died trying to get home than were lost on the operation.
The most badly affected squadron was 97 Squadron of the Path Finder Force. Among their losses was the Thackway crew, which was almost certainly forced down by a petrol shortage and incorrectly guessing the location of their home airfield. They landed in a ploughed field which wrecked their heavy Lancaster aircraft, and killed or gravely injured six of them. Locals who lived near the site would remember for many years afterwards that the crash had occurred on “the night of the fog”.
The crew of 97 Squadron’s Flight Sergeant Ian Scott (seated centre), who crashed at Graveley. All were killed. © RAF Pathfinders Archive.
The Path Finder Force, also known as the PFF, or 8 Group, was the RAF’s only officially delineated wartime elite force. A small but vital facet of Bomber Command, it had been created in August 1942 to improve bombing accuracy. For the rest of the war, it led the other squadrons of Bomber Command, known as Main Force, by marking the routes and bombing targets. So vital was the Pathfinders’ job that on 1 April 1943, after some months of campaigning by their Air Officer Commanding, Donald Bennett, the PFF acquired its own meteorological flight.
1409 Met Flight was created when eight PAMPA Mosquitos (Photoreconnaissance and Meteorological Photography Aircraft) were withdrawn from Coastal Command’s 521 Squadron at Bircham Newton, Norfolk, to join the Pathfinders at RAF Oakington, Cambridgeshire. Over the next two years, the eight two-man crews and their successors would fly numerous reconnaissance missions over Europe, bringing back the data from which weather forecasts for bombing operations could be made.
Weather forecasting was even more important for the PFF than for Main Force because the weather over the target could dramatically affect the Pathfinders’ target-marking techniques. An entry in the Operations Record Book for 83 Squadron on 7 October 1943 illustrates this perfectly: “Unfortunately there was a Met boob and the warriors found ten-tenths cloud [complete cloud cover] over the target and reverted to Wanganui technique with somewhat doubtful success. We now await the PRU [Photographic Reconnaissance Unit] results to see what measure of success attended our efforts.”
Weather forecasting for Bomber Command had three elements: the forecast for the weather on the routes and over the targets; the forecast for the British Isles for when aircraft took off and returned; and the localised forecasts for groups and their squadrons. There were a number of weather hazards which the forecasters tried to anticipate. Strong head winds could slow the speed of the bombers, using up vital fuel which was often very tightly calculated for long journeys, such as to Berlin. Alternatively, strong winds behind a bomber could increase its speed, a good thing on the journey home, not so good when the time of arrival at a target had to be split-second accurate.
Icing could pose a considerable threat. On an operation to Duisburg on 18 December 1944, two 405 Squadron Pathfinder crews reported considerable icing difficulties when they returned. The Dailey crew stated: “Icing from French coast at 17,000 feet and increased until target. Perspex covered with ice at target.”
The Laing crew stated: “Grim weather conditions from French coast inwards and chiefly near target, icing severe, air frames and props static electricity.”
Under Air Ministry orders, a crew which encountered ice formation was duty-bound to report it on return to base, hence the very specific descriptions given by the crews of Dailey and Laing. The information about the icing would be passed by the Commanding Officer to the station’s Met Office and to Group.
It is impossible to tell how many crews were lost over Europe because of icing, which could cause an aircraft to crash or make it more vulnerable to flak or fighters.
A seemingly innocuous weather hazard was lack of cloud cover. This was particularly hazardous on nights when the moon was bright, leaving bombers exposed to enemy attack. The immense Bomber Command losses on the Nuremburg raid of 30/31 March 1944, when 545 men died, were due to two main factors: errors in route planning; and the lack of cloud cover, which horribly benefitted the German night-fighters. A 97 Squadron pilot, Charles Owen, noted in his Ops Diary:
“Moon far too bright for comfort, and the sky swarming with fighters. Saw combats all over the sky right from the coast to the target, and a very large number of aircraft shot down. […] Not at all a pleasant trip.”
Eight PAMPA Mosquitos joined the Pathfinders at RAF Oakington, Cambridgeshire. Over the next two years their crews flew over Europe, bringing back the data from which weather forecasts for bombing operations could be made. © Met Office/Crown
For crews on bombing operations who survived both the weather and the enemy, there were also potential weather hazards on return to base. The greatest of these was fog. Fog could obscure the lights of the airfield circuit, which ended in a funnel pinpointing where the landing should be made. It could also blank out the angle of glide indicators which ensured the correct approach to the runway — an amber if too high, a red if too low, a green if on the correct glide path.
At the end of 1943, technical aids for landing in fog were in their infancy. Gee, a radio navigational aid which was very accurate over England, could help the returning aircraft to locate their home airfield, but it was too imprecise to direct them down onto a runway. The only real facilities available to land in low cloud and fog were FIDO and a system known as SBA.
SBA was Standard Beam Approach. Referred to as ‘landing on the beam’, SBA employed signals emitted by beacons in line with the main runway. These beacons sent out a code to the pilot which showed if he was straying off course, dots to one side, dashes to the other, and just a steady note if he was right on track. Unfortunately, using SBA was very difficult when crews were returning home exhausted after a long operation. SBA had a minute margin for error, and each mistake meant that an aircraft had to go round and try again. Inevitably, fuel shortage became a threat. There was also the added stress of other squadron aircraft being stacked up at different height slots on the circuit, all wanting to get down as quickly as possible.
FIDO was the Fog Investigation and Dispersal Operation. At the end of December 1943 it was only operational at three RAF airfields: Graveley and Downham Market, both Pathfinder stations, and Fiskerton, close to Lincoln, about 95 miles to the north. The official statement on FIDO, put out by the Air Ministry shortly after the war ended and the need for secrecy had passed, summarises what had become a desperate situation:
“The electrical beam [SBA] could help the pilots to approach to within 100 or 200 feet of the runway but they were then still flying absolutely blind at over 100 miles an hour with the imminent danger of crashing the aircraft, and killing themselves and all their crew, because they could not actually see to land. Fog over British airfields [had become] more of a menace than flak over Germany.”
FIDO was designed to disperse the lethal cloud and fog, but the mechanism by which it accomplished this was somewhat terrifying. Vast pipes, carrying thousands of gallons of petrol, were installed down the sides of a runway on the host airfield. The pipes were pierced with holes from which a fine jet of petrol spurted forth when the pumps were in operation. To fire up each section of the system, a man manually set a light to the first burner and then ran like hell when it ignited with a whoosh. The heat dispersed the fog and cloud, and the glow of the flames provided a flarepath.
FIDO: heat from its fire dispersed the fog and cloud, and the glow of the flames provided a flarepath. © Met Office/Crown.
At the end of 1943, FIDO was still a young and comparatively untested system, and SBA had its considerable drawbacks. Local weather forecasting, which ran alongside national forecasting, was the best way of stopping accidents even though it might mean the complete grounding of operational aircraft.
Every Pathfinder station had its own Met Office, which monitored local weather and forwarded the data for collation at Pathfinder and Bomber Command HQs. From these local reports an assessment would be made of what the weather would be like at base, both at take-off and on return. Many bombing operations were cancelled, even when the crews were on the aircraft ready to leave, because the weather was thought to be too threatening. Spells of bad weather could produce multiple cancellations over consecutive days or lead to operations not being planned at all. One such period occurred in December 1943.
The Battle of Berlin had commenced the previous month on 17 November. The campaign was deemed critically important; it was an all-out effort to win the war by bombing alone. So when many days were lost to bad weather in early to mid-December, there was great pressure to resume operations as soon as possible.
At RAF Bourn in Cambridgeshire, the base of 97 Squadron flying Lancasters, bad weather had severely curtailed all forms of flying that month. By Thursday 16 December, there had been a gap of almost a fortnight since the last operation had been flown. But now the waiting came to an end.
The Berlin raid of 16/17 December went ahead despite the possibility that visibility would be poor on return. The Commander-in- Chief of Bomber Command, Air Chief Marshal Sir Arthur Harris, seems to have gambled on his aircraft getting back before the weather clamped down. It was an error of calculation for which 97 Squadron and 405 Squadron, based at RAF Gransden Lodge, three miles from Bourn, would pay dearly.
By eleven o’clock that night, as the bombers began to return from Germany, the light mist of the afternoon had turned into a deadly peasouper of a fog which blanketed the country as far up as Yorkshire. At Bourn and Gransden Lodge, conditions were among the worst in the country. Both squadrons would suffer a large number of casualties as crews unable to land sought different airfields, or were forced into taking hazardous risks because their fuel was running out.
Among those who died were Squadron Leader Ernest Deverill and his crew; their petrol ran out as they tried to land at RAF Graveley using FIDO. Deverill, a highly decorated pilot, had survived many dangerous operations, including the costly daylight raids on Augsburg and Le Creusot in 1942. Of his long-serving crew only one survived — James Benbow, the mid-upper gunner, who suffered multiple injuries, including serious burns.
The shock of receiving this telegram caused Edward ‘Ted’ Thackway’s mother a violent emotional collapse. Ted was her adored eldest son, and a pilot with 97 Squadron. His aircraft crashed near their home airfield on Black Thursday, with the loss of five of the crew. © RAF Pathfinders Archive.
Throughout Bomber Command, the fog resulted in a large number of aircraft crashes, involving many fatalities and serious injuries. Twenty-five Lancasters were lost during the Berlin operation but a further thirty-one were lost due to the fog over England; crashed or abandoned when their crews bailed out, or, in the case of two unfortunate crews, collided over Lincolnshire. Other types of aircraft also crashed due to the fog. In total, Bomber Command suffered 327 deaths and lost 70 aircraft on 16/17 December. night became known as Black Thursday. The Pathfinder squadrons were badly affected: 97 Squadron lost 28 men, 405 Squadron lost 15, 156 Squadron lost 6, and 83 Squadron lost one. In total, 50 Pathfinder aircrew were killed. Moreover, survivors of the crashes had often been so seriously injured that they would never fly on operations again.
Interestingly, 1409 Met Flight had no losses that night. Their Mosquitoes were tiny, nimble aircraft which needed far less room to land than the heavy Lancaster. The fog is scarcely mentioned in their Operations Record Book. However, 7 Squadron, the heavy bomber squadron at the same base, Oakington, also had no bad weather losses, although it can have been little consolation as they had lost four crews on the Berlin raid.
The inevitable conclusion is that the Berlin operation should have been cancelled. The Met Officer at Bourn stated that he thought it would be, but the order to scrub never came through. Sending the force out on such a night was a huge tactical blunder, but no commander whose operations so closely depended on the weather could hope never to make such a mistake.
Shortly after the war, Harris was to write in his study of the campaign, Bomber Offensive, that amongst the very worst strains of his command had been ‘the continuous and fearful apprehension about what the weather may do’ and stating:
“Meteorology is an inexact science; in fact it is still in the condition of being an art rather than a science. This being so, and our climate being what it is, I should have been able to justify myself completely if I had left the whole force on the ground, if I had done nothing whatever, on nine occasions out of ten […] The whole of the responsibility, the final responsibility, for deciding whether or not to operate falls fair and square on the shoulders of the Commander-in-Chief and falls on them every twenty-four hours. For all he knows he may lose the whole of a very large proportion of the force by weather alone, to say nothing of enemy action.”
There was apparently no detailed enquiry into the night’s events, and no blame was ever attached to Harris. There was a war on and the true enemy was Germany. The accidents due to the thick fog had to be put down to terrible bad luck. Even today the effects of that disastrous night can be seen in a line of graves at Cambridge City Cemetery. Twenty Pathfinders are buried in a row, most of them Australians, Canadians, and New Zealanders. Among them are two members of the Thackway crew – Tony Lawrence, who was English, and Sandy Grant, a Canadian.
The three other dead members of the crew, including the pilot, Edward Thackway, are buried in Yorkshire near their family homes. Many hearts were broken that year just before the fifth Christmas of the war.
Dr Jennie Mack Gray is a historian and author of ‘Pathfinder Aircrew: Courage, Love and Loss in Bomber Command’s Elite Force’,. She is also Chairperson of the RAF Pathfinders Archive: rafpathfinders.com.
