Day or night strategic bombing?

[stona]

Harris, or rather the Air Ministry, did not jump to step 4.

Harris always acknowledged that a certain level of long range reconnaissance in convoy areas was essential. He didn't believe that flying thousands of hours over vast expanses of ocean to find (sink, report, force down, whatever) the U boats was the correct use of his strategic bombing force. It's target, entirely in line with RAF doctrine, was the means to produce the boats, which could be extended to the facilities which operated the boats,where they could surely be found

 

[Shortround6]

No the Air Ministry did not jump to step 4 but if Harris was advocating stopping production of the Halifax and switching to the Lancaster then he did jump to to step 4 and was turned down by the Air Ministry. Perhaps the Air ministry was slow to correct the problems with the Halifax?

Harris only got Bomber Command in Feb of 1942. At that time the need for using 4 engine bombers as maritime patrol planes was somewhat less than than earlier. No 120 squadron had been using Liberators for a while and were re-equipping with Liberator IIs.

However many people see only black and white. The need for 4 engine long range land planes was probably only 1-2 additional squadrons. Not anywhere near the whole of Bomber Command. It wasn't either or.

How much Harris had to do with earlier decisions about which planes to transfer to or equip Coastal command with I don't know. But Coastal Command went to war in 1939 woefully ill equipped for it's mission, and even it's supposed salvation (the Beaufort) may have been compromised by the intent to have them suitable for use as land bombers to make up numbers. What was needed were planes like the Wellington or Whitley, assuming they could be had with powerful enough engines and good enough propellers to allow safe single engine flight of water for long distances.

 

[swampyankee]

It's actually worse - except above 24,000ft where the B-24 gets more bombs inside a 1,000ft circle, but less inside a 500ft circle.

At all the other altitudes the B-24 has less bombs inside both a 500ft and 1,000ft circle.

Let me correct that post, but the basic question stands: why the difference? Was it a real difference or an error in test or data analysis?

 

[Shortround6]

It may relate to how steady the planes were. I believe (could be wrong) the B-24 had a reputation for hunting directionly/yawing.
While this may not affect the actual bomb release all that much it may make it harder to operate the bombsight, ie actually release the bombs at the proper point. It also meant that B-24 formations tended to be a bit looser than B-17 formations (more space between planes) which certainly does nothing for formation bombing accuracy.

 

[stona]

No 120 squadron had been using Liberators for a while and were re-equipping with Liberator IIs.

Harris considered the Liberator the ideal aircraft for this work. He was dismayed by the 8:1 ratio, fighters to bombers, proposed for purchases from the US, though the Liberator would not have been the principle reason.
Cheers
Steve

 

[stona]

why the difference? Was it a real difference or an error in test or data analysis?

It's not an error in analysis and the data sample was large enough to have smoothed out any anomalous results. It is, and was considered, a real difference.
There were many factors affecting accuracy. Relevant for the B-24 might be the size of the attacking force or where they were in that force. The first three Groups over a target in a large attack typically bombed between two times more accurately than succeeding Groups (11% and 5% within 500' of AP and 31.5% and 15.5% within 1000'.)
Cheers
Steve

 

[Ascent]

My youngest son has Aspergers - which makes life interesting.

Likewise. He takes after his father.

 

[Zipper730]

It may relate to how steady the planes were. I believe (could be wrong) the B-24 had a reputation for hunting directionly/yawing.

Like a slow snaking motion?

While this may not affect the actual bomb release all that much it may make it harder to operate the bombsight

I thought the Sperry was a little less accurate...

B-24 formations tended to be a bit looser than B-17 formations (more space between planes) which certainly does nothing for formation bombing accuracy.

Of course, bomb-bay of the most outboard planes on either side to the center plane sets the width of the bomb-trains; the interval of release sets the length based on speed, and the CEP is based on the ability to correctly predict all the release variables.

There were many factors affecting accuracy. Relevant for the B-24 might be the size of the attacking force or where they were in that force. The first three Groups over a target in a large attack typically bombed between two times more accurately than succeeding Groups (11% and 5% within 500' of AP and 31.5% and 15.5% within 1000'.)

Questions

• How big were the B-17 attack forces?
• How big were the B-24 attack forces?
• When you say groups, do you mean each box, or do you mean like an air-group (several squadrons)?

 

[Milosh]

Questions

• How big were the B-17 attack forces?
• How big were the B-24 attack forces?
• When you say groups, do you mean each box, or do you mean like an air-group (several squadrons)?

Maybe this will help, 8th Air Force Fighter and Bomber Unit Markings, Stations in WW-II

and

 

[fubar57]

Bookmarked, thanks Milosh

 

[nuuumannn]

It just wasn't anywhere near as bad as Harris claimed and if fitted with the big vertical stabilizers earlier operational losses might have been lowered sooner than waiting for the MK III.

Regarding the early Halifaxes, before the Mk.III, I'd be inclined to agree with Harris. We forget just how bad the early Halifax was because of its overall war record and how much of an improvement the Mk.III was over its predecessors - the Mk.III was a good aircraft and exhibited none of the dangerous characteristics and poor performance of the early examples; there was a war on and heavy bombers were required, so despite its many failings, the Hali was pressed on with. In the intervening years its many issues have been glossed over, but it was a basket case. Whilst undergoing trials at Boscombe Down, the service examples demonstrated a loss of speed of 20 mph over the prototypes because of turrets etc, maximum range during trials was decreased from 1,850 miles to 1,700 miles, rudder overbalance managed to destroy one aircraft, killing its crew - this issue alone took many hours and lives attempting to rectify over the subsequent couple of years. The scale of the effort undertaken to fix the type's persistent niggles took three years, in which time it consistently under performed, highlighted more so once the Lancaster began entering trial and service use, and in individual aircraft demonstrated dangerous handling, and shoddy workmanship, resulting in major performance deficiencies. This effort can be seen in the large number of types and sub-types of the Merlin engine examples that were built and the relatively small number of each that were built, after modifications were made on the production line after findings within the A&AEE.

It really was that bad. A good book to read detailing the issues surrounding the Merlin installation on the Halifax is Rolls-Royce and the Halifax by David Birch.

Here's a quote from The Secret Years, Flight Testing at Boscombe Down by Tim Mason;

"During 1942 and later the search continued for a solution to the problem of rudder overbalance thought in view of the Establishment's experience on the Mk.Is to be the cause of some unexplained service accidents and operational losses. The worst case considered was failure (and feathering) of the two port engines with the two starboard engines at take off power. The first modification, late in 1941, of reducing the rudder trimmer movement resulted in excessive foot loads until, on reducing speed to 160mph the rudders violently overbalanced to full travel and the resulting uncontrolled manoeuvre could only be overcome by throttling the starboard engines. 'Noseings', (bulbous nose to the rudders) improved matters such that control could be maintained down to a speed of 140mph with 10 deg bank without over balancing, but with very high foot loads.

Further changes, in mid 1942, to the balance tab and rudder tab settings reduced the foot loads to acceptable proportions, but reintroduced a mild tendency to rudder overbalance. It was decided to check the effectiveness on a representative aircraft. W7197 arrived in December 1942 from 102 Squadron; on the first handling test flight on 4 February 1943, the aircraft crashed fatally. The top half of one rudder had detached in flight - attributed to a violent overbalance leading to loss of control. Further investigation on HR679 (the first production aircraft incorporating the full range of aerodynamic improvements known as Series IA in service, but with rudders similar to W7917). Cautious reduction of speed during steady side slips caused no indication of overbalance until at 120 mph the rudders suddenly moved to full travel of their own volition. The pilot regained control at 150 mph after easing the control column forward; 4,000 ft had been lost in the spiral dive. On a second attempt control was regained by opening up the engines on the inside of the spiral. Later tests with restricted rudder movement reduced the speed at which less violent rudder overbalance occurred.

Cords on the trailing edge were tried but removed after it was found that they had no effect on overbalance and again made the rudders excessively heavy. HR727 had rudders with smaller balance areas which overbalanced at smaller angles; the modification was rejected. It was decided that larger fins were the only effective cure..."

The book goes on to describe the issues surrounding its loss of performance.

 

[Zipper730]

The first three Groups over a target in a large attack typically bombed between two times more accurately than succeeding Groups (11% and 5% within 500' of AP and 31.5% and 15.5% within 1000'.)

I'm guessing because the flak would build up increasingly accurate as the force progresses in. They can keep fine tuning things until they start increasingly hitting home right?

When was this realized?

 

[fubar57]

This is fantastic, clicked on the "People You Ignore" button and all the scrolling went away, back to learning. Good stuff Grant

 

[stona]

I'm guessing because the flak would build up increasingly accurate as the force progresses in. They can keep fine tuning things until they start increasingly hitting home right?

When was this realized?

I'm guessing because the flak would build up increasingly accurate as the force progresses in. They can keep fine tuning things until they start increasingly hitting home right?

When was this realized?

The problem was caused by various factors, but the most important had nothing to do with the defences. It was simply the obscuring of the aiming point by smoke and dust raised by the first Groups to bomb.
It was realised quickly, you don't need a statistician to tell a bomber crew they can't see the target, but the analysis I quoted is from 1943.
Cheers
Steve

 

[stona]

As far as the Halifax's appalling handling, a 1942 ORS report noted

"A further case of a Halifax returning after being out of control and turning on its back occurred during the raid on Kreveld in October. It is therefore recommended that all possible means of improving performance and stability of the Halifax be given urgent priority."

This begs an unpalatable question. How many Halifaxes were going out of control and NOT returning to tell the story. Bomber Command's pilots were not all vastly experienced, and the ORS acknowledged that it was most likely that an experienced pilot would survive such an experience, less experienced ones might not.

On 14th November the AOC of 4 Group wrote to Saundby, effectively stating that he would give his new crews further on the job training on the Halifax, building up experience attacking 'fresher' (meaning easier) targets. This he acknowledged would mean a delay in getting new crews on operations (we can imagine what Harris thought about that) but was considered worthwhile. Saundby forwarded the letter to Harris whose comment was typically concise.

"He can try it. It is the aircraft not the crew that require improvement."

June 1943 it was established that 47% of Halifax crews lost between January and May had less than four operations. It was also established that losses in squadrons which had done fighter affiliation training was appreciably lower. For crews attacking easy targets when evasive manoeuvring was less likely the losses were similar to other aircraft types. The Halifax data highlighted the link between aircraft losses and defensive practices. The Halifax was a demanding aircraft to fly (politely... it was a dog) and its crews needed extra training in aircraft handling to acquire the skills necessary for evasive manoeuvres. So serious was the problem that the Command very nearly issued an instruction that the Halifax should abandon defensive manoeuvring as it actually increased the chances of the aircraft being lost!

In July 1943 Basil Dickins mad a personal visit to Handley Page. Various points about the shortcomings of the Halifax were raised, Dickins emphasised that the

"known rudder stall problem of the Halifax has possibly caused some casualties directly [he knew that it had] and others indirectly owing to induced lack of confidence in the machine."

Dickins reported on the company director's rebuttals, almost all based on the supposed performance of the Mk III which was due to enter service later that year. Dickins was sceptical.

"I was left with the feeling that the Handley Page organisation has said its last word in the Halifax III. We should therefore press on with consideration of the best results obtained with this type in order to see if they promise that the machine will meet future operational requirements. If they do not, then we know we have little more to expect from the Halifax and must act accordingly.
With regard to the new fin and rudder I feel we should immediately attempt to get the trial installation at present under test at Boscombe Down flight tested in an operational squadron. If the tests promise well, the greatest possible pressure should be brought to bear in order to speed up the introduction of this modification. Otherwise I fear that the promised introduction in August may be somewhat deferred."

When Dickins' comments were circulated it was not Harris but the CEngO Air Commodore Roach who replied that Dickins had been given

"exactly the sort of 'guff' that one would expect a stranger to the Handley Page firm to get from that firm, and I don't think I can answer the minute better than by the C-in-C's own words: "I don't believe one word of the firm's statement, and I have no faith in any promises made. "'

At the end of 1943 Bomber Command's ORS published its report on the new Halifax tail (ORS S 114, 'A Note on the Losses of Halifax Aircraft with Modified Rudders). It concluded that an analysis of the data had NOT pointed to any appreciable reduction in losses. It included a qualitative comment that there was some benefit to inexperienced pilots using the modified aircraft, but a slight disadvantage to experienced crews who were obliged to use new rather than 'seasoned' aircraft. This latter comment was based on comments by Wing Commander Smith Eng 3, to an earlier draft. He had noted that crew took a while to get a feel for a new aircraft and that newly assembled controls were

"stiffer so manoeuvrability may not be so good."

In view of this a slight diminution of the loss rate might be expected in the future.

In February and March 1944 figures were established showing that the comparative loss rates for the Halifax and Lancaster were still heavily weighted in favour of the Lancaster.
Harris received a report on the March losses which showed just how bad the new Halifax III was doing when compared to the Lancaster.

"The Halifax III is sustaining 30% higher loss rate than the Lancaster and having regard to the smaller bomb load of the Halifax the relative usefulness of these two aircraft may be given as 1: 2.6."

Now, we might think that the Halifax III became a competitive aircraft and that most of the issues were solved, but we are not among the extra 30% of men dying bombing Germany.
It was following this that Harris sent his 'Top Secret and Personal' letter to Freeman at the MAP, copies to the CAS and Secretary of State, in which he argued for the replacement of the Halifax with the Lancaster. Harris, most senior officers in Bomber Command and the boffins of the ORS now knew that the Halifax was not, and never would be, the aircraft that the Lancaster was. Harris concluded.

"On the whole, therefore, it is apparent that my prognostication that the Halifax III would be in the same position by next Autumn as the Stirling and Halifax II and V are today, shows every indication of coming true."

We can look at performance figures and argue from the safety of our armchairs that the Halifax III was an aircraft in which Handley Page had largely solved the issues with the type, but the simple fact is that the substantially higher loss rate of the type was costing Bomber Command more young lives than was the Lancaster. That's why Harris (and others) argued so vehemently against the Halifax and for the Lancaster.

Cheers

Steve






"

 

[fubar57]

Thanks Steve, was totally unaware of the issues surrounding the Halifax. I'm surprised that over 6000 were made

 

[stona]

Thanks Steve, was totally unaware of the issues surrounding the Halifax. I'm surprised that over 6000 were made

In fairness to the Mk III it did do better than Harris' worse fears in the latter stages of the war. On 26th October 1943 Harris confided in Portal that he hoped he might be mistaken about the Halifax III, the opinion he formed based on the data from February and March 1943. In truth he wasn't, the Halifax always suffered higher loss rates for a lower return on investment than the Lancaster.
A Halifax consumed 60 man months of effort per ton of bombs dropped, three times as much as the Lancaster's 20 man months.
An analysis of operations against targets in Germany between 1st June and 15th September 1943 showed that the Lancaster suffered a loss rate of 3.5% and dropped 112.6 tons of bombs per aircraft lost. The figures for the Halifax were a 5.4% loss rate and just 45.5 tons of bombs dropped per aircraft lost.

Harris' attitude to Handley Page, the firm and the man, was certainly based in some kind of personal antipathy, but his opinion of the Halifax was always based on the best data he had available. ALL the data showed that the Lancaster was a superior aircraft to all Marks of Halifax in every respect.

Eventually, on 21st December 1943, there was a formal meeting at the MAP (chaired by Portal who, whilst less critical of the Halifax III supported Harris in his convictions about the superiority of the Lancaster, which could hardly be disputed) to discuss the vexed question of heavy bomber production. To cut a long story short, it was clear that only if the war lasted well into 1945 would switches in production start to have significant effects. The MAP agreed to investigate the options available, but it was made clear that Harris would be operating through 1944 with the types and quantities of aircraft he had and was expecting to receive.This is why nearly 6,200 Halifaxes were eventually built.

I think Harris was correct about the Halifax, but he could be wrong, and when he was he could be very wrong! Writing to Freeman in April 1942, about the Mosquito, he reckoned that it would suffer

"a still grimmer fate than has always been the lot of such naive attempts to produce an aeroplane so much faster than anything the enemy posses that it requires no armament. It will go down in history in consequence as a second 'Battle' as far as its bombing role is concerned."

Actually Arthur, no it won't

Cheers

Steve

 

[pbehn]

It just shows that pilots recollections of an aircraft should be viewed for what they are. I have read pilots saying they preferred the Halifax to the Lancaster, obviously unaware of the statistics posted above.

 

[stona]

It just shows that pilots recollections of an aircraft should be viewed for what they are. I have read pilots saying they preferred the Halifax to the Lancaster, obviously unaware of the statistics posted above.

I have too. On the bright side, if they did get shot down, which was more likely statistically, they did have a better chance of escaping their doomed aircraft.
Cheers
Steve

 

[buffnut453]

It just shows that pilots recollections of an aircraft should be viewed for what they are. I have read pilots saying they preferred the Halifax to the Lancaster, obviously unaware of the statistics posted above.

For the most part, pilots will defend the aircraft they are currently flying. After all, they must have faith that the aircraft will do its job and bring the crew home safely. If the pilots doubt that simple fact, then they wouldn't get in the aircraft in the first place. Some of it may well be bravado and some self-motivation (perhaps even self-deception). However, pilots are human beings and confidence in the tools they are given is vital to them doing their job successfully. It is precisely that confidence that enables pilots of lower-performing types to go into combat against better aircraft and strive to succeed through better tactics or other non-performance measures (eg outright numbers).