Last flight

A longer version of this account appears in Chapter 9 of Breaking the Dams
Early in September 1943 new 12,000 lb thin-cased bombs were delivered to RAF Coningsby. It had been decided that 617 Squadron was to continue its role as a specialist low-level bombing unit and deliver this, the biggest bomb the RAF had yet carried, in an attempt to breach another German key industrial target, the Dortmund-Ems canal. This waterway stretches over 150 miles, linking the Ruhr valley to the sea. At Ladbergen, near Greven, just south of the junction with the Mittelland Canal, there is a raised section where aqueducts carry the canal over a river. This had long been a target which the RAF was keen on attacking, but so far had failed to breach. Now it had a new weapon, three times the size of the normal 4,000 lb ‘cookie’. The plan was to drop these from very low height into the soft earth embankments of the raised waterways. A delayed fuse would give the Lancasters time to get away before the huge explosion.

The eight Lancasters detailed for the operation were to be accompanied by six Mosquitoes, specially brought in from 418 and 605 Squadrons. Their role was to deal with searchlights, flak and any fighter opposition met along the way or over the target. The force was to be divided into two sections of four Lancasters and three Mosquitoes each, with the force leader commanding the first section and the deputy force leader commanding the second.

The raid was important enough to be given its own code name, Operation Garlic, and was scheduled for Monday 14 September. The new squadron CO, who had replaced Guy Gibson, Sqn Ldr George Holden was to lead the first section of four, with Les Knight, Ralf Allsebrook and Harold Wilson. David Maltby would lead the second section: David Shannon, Geoff Rice and Bill Divall. Three Mosquitoes would fly with each group. As deputy force leader, David Maltby was due to drop the special parachute beacons which would mark the target.

Each aircraft also carried an extra gunner, to operate the mid-upper gun turret. WO John Welch was allocated to David's crew, so there were eight people aboard when they took off.

The weather was not good but a separate Mosquito designed for meteorological work had already been sent to the target area and was due to report back. If it found that conditions over the canal were poor, then Group command could call the strike force back.

The aircraft took off and set course for their crossing point on the Dutch coast, south of Texel Island. About an hour later, came the news from the Mosquito on weather-spotting duty. The target was badly obscured by mist and fog. At 0038, a recall signal was sent from the operations room at 5 Group in Grantham. Just as, or just after, the recall signal was received, disaster struck and, somehow, David’s Lancaster went down in the sea.

But what happened?
Most of the explanations derive from what Paul Brickhill wrote in The Dam Busters, six years after the war:

They were an hour out, low over the North Sea, when the weather Mosquito found the target hidden under fog and radioed back. Group recalled the Lancasters and as the big aircraft turned for home weighed down by nearly 6 tons of bomb David Maltby seemed to hit someone’s slipstream; a wing flicked down, the nose dipped and before Maltby could correct it the wing-tip had caught the water and the Lancaster cartwheeled, dug her nose in and vanished in spray. Shannon swung out of formation and circled the spot, sending out radio fixes and staying until an air sea rescue flying boat touched down beneath. They waited up at Coningsby till the flying boat radioed that it had found nothing but oil slicks. (The Dam Busters, Evans, 1951, pp. 117-118)

There are several inaccuracies in Brickhill’s account: the air sea rescue service sent two launches, not a flying boat. One of the launches recovered a single body, David’s, although there was no trace of the rest of the crew.

Official documents and other contemporary accounts tell a slightly different story, and have a number of significant variations. David Shannon’s logbook entry reads in full:

Operations – Dortmund Emms [sic] Canal. 1 x 12,000. 4 incends. (90x4). 2 marker beacons. Recalled weather u/s. Jettisoned. S/L Maltby crashed in sea. All killed. Directed Air Sea Rescue launches which arrived in about 11/2 hours. Circled 3 hours in touch with 5 Group.
Total flying time: 4.15 (Imperial War Museum archives)

The next official account was written in the ‘operation summary’ section of the 617 Squadron Operation Record Book. This would have been written by the Squadron Adjutant, Harry Humphries. It reads:

... At approximately 0040 hrs, on the 15th, a recall message was sent to all aircraft, on account of unfavourable weather. The aircraft were then over the North Sea, and in turning to make the homeward journey the aircraft piloted by S/Ldr Maltby was seen to crash into the sea. Nothing definite is known of the cause of this accident, but it is possible that the aircraft struck the water. .. (National Archives: AIR 27/2128)

A week or two later a formal Accident Card was prepared by a small panel, or perhaps even just one officer. The panel would have considered the information sent in by the squadron in writing and then summarised its findings:

Time: 00.45. Ops night. Recall to base.
A/c missing. Presumed hit sea. Investigators consider the accident was due to aircraft hitting the sea after some obscure explosion and fire had occurred in the aircraft. It is possible that the pilot partially lost control in a turn when the bomb doors were opened to jettison the bombs. Explosion and fire may have been caused by bouncing on the water. None of the equipment is likely to have exploded in the air.Cause obscure.Only e/a [enemy aircraft/action] could have set bombs or incendiaries on fire in the air. NB Large bomb doors affect aircraft stability when lowered.
[Conditions] Night, moon, dark. (RAF Museum)

Another theory
However, author Len Cairns has discovered that there is a good chance that an errant Mosquito was involved. Most people have discounted this theory since the six Mosquitoes seconded to the mission from 418 and 605 Squadrons all returned safely. However another Mosquito on a completely different operation to attack Berlin did not come back. And it may be this one that collided with David’s Lancaster.

The first piece of evidence is in the Operations Record Book for 278 Squadron, the Coastal Command squadron which was responsible for air sea rescue on the Norfolk coastal area. Its account is quite different from that recorded by 617 Squadron:

DUTY: Search position H.0374 for Lancaster and Mosquito reported to have COLLIDED.
TIME OF SEARCH: 06.38 – 07.56 hours.
Aircraft searched this position and found an oil patch approximately one mile long and 200 yards wide in which were small pieces of wreckage. Nothing further was seen and a ‘FIX’ was transmitted to operations after which A/C returned to base.
(National Archives: AIR 27/1605)

Later that day a report had reached London. Every afternoon a group of senior officers would convene in a meeting room at the Air Ministry to discuss technical and administrative matters concerning Bomber Command. It was called the Air Officers Administration Conference (usually abbreviated in the files as the AOAs Conference). They would note details of the numbers of squadrons available, the ferrying of aircraft to and from different stations and the mechanical and other problems that had occurred. But they also looked at the numbers of operations flown, the losses incurred and, particularly, since they were interested in ironing out any repeated mechanical failures, which might be the cause of crashes. That very day, probably within 15 hours of the incident occurring, they noted that there had indeed been a crash the night before. The minutes of the conference state, quite baldly:

1 Lancaster of 617 Squadron and 1 Mosquito of 139 Squadron are believed to have collided N.E. of Cromer. No survivors yet reported. (National Archives: AIR 24/259)

According to the records, one Mosquito of 139 Squadron, DZ598, had been recorded as ‘did not return’, as nothing had been heard from it after it took off from Wyton in Cambridgeshire at 1936 hours on 14 September. The pilot was Flt Lt M W Colledge and the navigator Flg Off G L Marshall.

Unfortunately this is where the trail goes cold because the 139 Squadron records are not very informative. The RAF Wyton ORB gives a little more detail about the raid:

This trip was made unusually difficult by heavy cumulonimbus, which caused several crews to return early and made the operation longer and more arduous for those who pressed on to the target.
F/L Colledge did not return; nothing was heard of him after take-off. (National Archives: AIR 27/960)

There is no further information about what happened to Flt Lt Colledge’s Mosquito. As nothing had been heard from him after take-off, and no wreckage was ever found, it has always been assumed that he was lost over the sea on the outward trip. However, it is possible that his radio failed, but he decided to press on to Berlin regardless. And, on the way home, his aircraft collided with David’s.

It’s certainly plausible. If Colledge had gone onto Berlin, he would have been coming back across the North Sea between 0030 and 0100, and his route from the northern end of Texel Island off the Dutch coast to landfall at Cromer would have intersected with the 617 Squadron Lancasters’ route, which was due to take them from Coningsby to landfall on the Dutch coast just north of Petten. Plotted out on a map, the intersection point is very close to where we know the accident occurred.

We will never know for certain what caused David Maltby's final crash. But many people would agree with his uncle, Aubrey Hatfeild, who had himself been an RFC pilot in the First World War. David was too experienced a pilot to make a mistake while turning an aircraft around, even one laden down by a new six ton bomb. Aubrey told other family members during the war that a Mosquito 'which shouldn't have been there' was involved in the crash. And there is some evidence in the official files which backs him up.

Charles Foster 2008.
Many thanks to Len Cairns for help on this article.



Map showing the routes allocated to the Lancasters and their Mosquito escort of 617 Squadron and the separate Mosquitoes of 139 Squadron, on the night of 14-15 September 1943. The 617 Squadron detachment was divided into two sections, with David Maltby leading the group taking Route B. This was to take them directly from Coningsby to landfall on the Dutch coast a little way south of Texel Island. The 139 Squadron Mosquitoes were following the ‘Whitebait’ route, the return leg of which runs from the northern end of Texel island to landfall at Cromer. The two routes intersect very near to where David Maltby’s Lancaster crashed into the sea.