3The Operation on 17th and 18th April 1941
There can be no comprehensive description of this operation, first because many of the original records no longer exist, second because it has not been possible to trace any of the former members of 50 Squadron who participated in it. Reference to documents and people consulted are given in Appendix 5. The established facts of the flight are summarised in chapter 1.
On the night of 17/18 April 118 aircraft were detailed to bomb Berlin. Of these 50 were Wellingtons, 39 Hampdens, 25 Whitleys and 1 Stirling. Eight of these were lost: 5 Whitleys, 2 Hampdens and 1 Wellington. Records of three of the Hampden Squadrons 44, 50 and 83 which sustained casualties and which accounted for 50% of the total Hampdens involved were examined. (Details are given in Appendix 1). The Ministry of Defence confirmed to me and gave further details of the fix given to AD730 at 0217 hrs at Watton. The Commandant of Irish Military Archives was most helpful in supplying copies of all documents and records on file relating to the night of 17/18 April. Further substantial help was given by Mr Tony Kearns, the most knowledgeable Irish aviation historian for the period. It is unlikely that further documents or other direct information will become available.
To assess what may have happened to AD730 on its last flight the experience
of the three Hampden squadrons involved in the raid and which sustained
casualties needs examination.
Information from Records of 40, 50 and 83 Squadrons for night of 17/18 April
These records giving details of movements of all twenty aircraft (over 50% of all Hampdens involved in the raid) from these squadrons taking part in the nights operations are shown in Appendix 1.
All twenty aircraft took off within 40 minutes and set off for the same
target in Berlin so all would have experienced similar weather. The Squadron
records seem inconsistent about these conditions. 50 Squadron reports indicate
"Over Germany no cloud but a thick haze over Berlin probably due to fires
or smoke screen." Nos 44 and 83 Squadron reported difficulties in locating
the Berlin targets owing to cloud as well as haze and smoke. . . The report of
one of the 83 Squadron crews reads "Ground haze, cloud and darkness made
pin-pointing difficult. Bombs dropped on estimated position of target but
shortness of homeward flight led to doubt as to whether this estimate was
correct". Other planes reported similar great difficulty in locating the
targets and observing their bomb bursts.
Summary of the Operation
The reports are not all sufficiently specific to conclude whether the specified target was attacked. Table 3 summarises what appear to be the results.
At least two of the planes returning from Berlin reported problems in obtaining a radio fix which may have been due to static electricity from the cloud formations. One aircraft of 83 Squadron reported "target location obviously impossible. Bombs dropped on a large town estimated to have been in Ruhr district." Three crews of 44 Squadron reported excessive petrol consumption on the way out which suggest that there may have been strong headwinds (as does the 83 Squadron report quoted above). One aircraft (AD897 of 50 Squadron) reported "Spent 30 minutes over target. Return course uncertain until a fix obtained. Believed London overflown’. X3188 (83 Squadron) was airborne for 6 hrs 30 mins. It reported target location impossible and bombed an unidentified town believed to be in the Ruhr area.
Because of engine trouble, one aircraft diverted to Emden which it bombed
from 16,000 ft. It was attacked by a night fighter but returned safely to base.
Two aircraft made positive identifications of railway station targets—at
Flensburg and Hamburg—to which they diverted after abandoning the main
mission. This suggests that the weather fifty and more miles north of the direct
bearing to Berlin may have been clearer.
How far did AD730 penetrate into Germany?
To estimate how far any of the aircraft flew it is necessary to know the average speed and the time airborne. The only data available to calculate average speed is that of AD730 from the fix given to it from RAF Watton and its time over Southern Ireland. (Table 5) The only positive figure for this is 150 m.p.h which suggests that the aircraft was flying at between seven and ten thousand feet when it crossed the English coast. At a lower altitude, to maintain this speed it would be burning more fuel. If the crew believed that they were much further east of the base than they really were they would be maintaining the most economic fuel and altitude combination possible.
A Hampden carried a maximum fuel load of 650 gallons which it consumed at between seventy and eighty gallons per hour. Depending on military load, altitude and operational and weather conditions this would give a maximum duration of about nine and a half hours or up to 1450 miles. In exceptional circumstances one Hampden was airborne for an hour longer than this before ditching but it was generally accepted that, depending on conditions, Berlin—between 1200 and 1300 miles—was the extreme practical endurance limit for a target. Table 4 lists the seven aircraft known to have reached the Berlin area and calculates the miles flown on the basis of time flown at an average of 150 m.p.h.
The time difference between the fastest aircraft (X3144) and slowest (X3045) was 1 hour 15 minutes, equivalent to a distance of 187 miles at 150 m.p.h. Part of this difference could be accounted for by the fact that X3144 spent some time over the city before the crew pin-pointed the target whereas X3059 reported "target not located, dropped bombs on centre of city", but it seems that X3059’s target was probably the western boundaries rather than the city centre.
[MAP 1- Taken from inside cover of the book Portrait of a Bomber Pilot]
In considering these figures it must be remembered that they relate only to
the weather and other conditions applying to a specific operation at a
particular time. Their sole purpose is to provide a rational basis for
estimating how far into Germany AD730 penetrated.
AD730 From Lindholme to Watton
There is some ambiguity in the Squadron Record which makes the actual take off time of AD730 uncertain. The number quoted against the description of the fate of AD730 appears in the Record as AD853. Its take off time was recorded as 20.30, the same as that of AD797.
The take off times in the original record are listed in time sequence and ADF853 (assumed to be AD730) is the first. If the take off times of all other aircraft were reported correctly AD730 may have taken off either at 20.10 (first away) or 20.40 (last away apart from AD897). As the first mentioned aircraft in the report it has been assumed that it was the first aircraft to have taken off. The amendments have been made in Appendix 1.
The first step is to estimate how far AD730 would have travelled had it returned safely to base. The relevant figures are: (estimated figures in italics)
Three available timings (below) for AD730 are precise. They are taken from the archives of the Ministry of Defence in London, the Look Out Posts and Defence Ministry in Dublin:
The average speed of all aircraft returning from Berlin is assumed as 150 m.p.h. The figure of 155 m.p.h. in Table 5 is certainly feasible but for consistency the figure of 150 m.p.h. will be used. (At a total flying time of just over eight hours the difference in distance covered is only 40 miles). The mileage Lindholme—Berlin and return on these assumptions is 1,200.
The distance from Lindholme to the fix given at Watton is 100 miles. Had AD730 received and acted on the Watton fix and returned safely to base its total distance covered would have been 1010 miles and its airborne time 6 hrs 47 mins just 13 minutes (33 miles) less than the time of X3119 of 83 Squadron, whose crew first thought they had bombed Berlin but decided that they had not because of the apparent speed of the return journey. (see below and Appendix 1)
My brother’s operational flights record (Appendix 3) shows that he made three raids on Hamburgh of which one occupied 6 hrs 45 mins, one 7 hrs 5 mins and the third (in which weather conditions were ideal but heavy searchlight and flak was encountered and evasive action was not successful) 7 hrs 25 mins.
The tentative conclusion from the foregoing is that AD730 probably reached the Hamburgh area, with which the crew would have been familiar, decided to abandon the mission there, released its bombs and turned back.
Why the crew decided to abandon the mission will never be known. Enemy action is possible. One aircraft, X3121 of 83 Squadron whose airborne time was only nine minutes longer than the theoretical time of AD730’s return time to Lindholme (6 hrs 47 mins), reported "Ground haze made target location impossible. Heavy flak. Bombs released over this". Excessive petrol consumption was reported by two aircraft of 44 Squadron, both of which abandoned the mission, one of them having diverted to bomb Hamburg. Two aircraft of 50 Squadron reported flames coming from their starboard engines so they attacked alternative targets, one of which was Emden. Two aircraft from 83 Squadron, who airborne times of 6 hrs 58 mins and 7 hrs were similar to AD730’s , reported target identification impossible. One (X3121) released bombs over heavy flak. The other (X3189) reported "Ground haze made target identification impossible. Bombs dropped on target ETA (Estimated Time of Arrival) but speed of return journey led to doubt if estimated bombing position correct" (Appendix 1) This report raises the problem as to why, after only three and a half hours flying time they thought they had reached Berlin. It would have been an average speed of 171 m.p.h.—possible but not likely unless they had assumed, from Met. reports at their briefing, a following wind which, owing to weather conditions, they had been unable to check while airborne.
Weather reports from the British and Irish Met. Offices for the period that AD730 was over England and Ireland indicate that there was a low pressure system extending from Stornoway in the north to Gibraltar in the south, and from west of Ireland over Britain and the North sea thence to an estimated line through northern Germany via the Weilhemshaven and Frankfurt areas then curving S.W. across central France to join with the recorded reading at Gibraltar.
Cloud over the North Sea to Dublin area was 9/10ths all the way with a base of 1500 ft over East Anglia dropping to 800 ft at Holyhead where AD730 crossed the coast. Wind speeds at ground level were between 10 and 15 m.p.h. and E or S.E. Over Ireland and the Irish sea the depression maintained a north-easterly airstream. Conditions were mostly overcast with outbreaks of rain and occasional clear intervals. Cloud base was estimated at 700 -1500 ft.
These reports confirm the clearer visibility noted over Emden by AD728 of 50 Squadron and over Flensburg and Hamburg by AD747 and AD767 of 44 Squadron (Appendix 1).
The Hampden Bomber 1939