Obscure Lancaster question...

[Troy Smith]

On 04/07/2022 at 17:21, SafetyDad said:

Another piece of evidence that I alluded to in my post above is here

 

https://www.iwm.org.uk/collections/item/object/205127070

 

A Mk VI following conversion awaiting delivery to squadron service - it's JB675. Note the caption describes four bladed props, but that's not what the picture shows!

 

SD

for ease of reference, note in the link posted, there is a zooms facility

 

AIRCRAFT OF THE ROYAL AIR FORCE, 1939-1945: AVRO 683 LANCASTER.. © IWM (ATP 11654B) IWM Non Commercial License

 

Fascinating pic I've not seen before

 

 

 

[AWFK10]

22 hours ago, SafetyDad said:

 

You mean like this?

 

https://discovery.nationalarchives.gov.uk/details/r/C3306580

 

 

SD

Pretty much! 😃 Thanks, I might think about asking for a quotation but I'ld better wait until the final bill comes in for our ongoing building work......

[SafetyDad]

A further twist:

 

Inspired by information in the Lancaster FE thread currently running, I  checked this data card for ND673 - the Lanc VI in that picture with the code F2@V and turrets removed. Thanks @Geoffrey Sinclair for the idea 

 

http://lancasterbombersinfo.ipage.com/Data/Form-78s/Lancaster/ND625-ND684/mobile/index.html

 

It appears that ND673 had a more complex history than I (at least) had realised. After service with 635 Sqn it went to the RAE on Dec 17 1944 (this I knew). BUT the card shows two return visits to Avro on June 4th and June 28th 1945. First for 15 days, then for 8 days. Then finally being SOC at the RAE on Jan 31st 1947.

 

So why return the aircraft to Avro? Twice? Does this signify relatively major work being undertaken on this airframe? All this before that picture was taken. 

This is new information for me - I understood that this airframe stayed at the RAE after service with 635 Sqn - I was not aware Avro undertook further work on it.. This information strengthens my suspicion that ND673 may not be a 'typical' Mk VI  (if such a thing exists!). 

 

Food for thought 

 

SD

 

[Geoffrey Sinclair]

I doubt the RAE had a full Lancaster servicing ability.  The trips to Avro could be routine inspection, say a 240 hour one, or other maintenance or repairs or modification, one of the published RAE histories may help.

[AWFK10]

Interesting! Thanks for this. It seems more and more likely that the photo shows ND673 after it had been extensively modified from its operational configuration to become a research airframe at the RAE. I'm reminded of an illustration in a certain book on the British air services in WW1. It has a section on the aircraft they used, which obviously wasn't the author's primary interest, and the photo used for the DH9 is of a machine that had started life as a standard bomber but had been modified in 1920 to test Handley Page leading edge slots. For that reason it had also been fitted with a disproportionately tall undercarriage and looked nothing like an ordinary Service DH9. If photos of the real thing were rare as hen's teeth, like the Lancaster VI, the received wisdom might well be that this was typical of operational DH9s in WW1.

 

I've had a look at the 7 Sqn ORB: they didn't undertake any operational flights with ND673.

 

I'm wondering about the electronics fit again. The photo doesn't actually show the aerials that Streetly identifies as being for Monica and Boozer. I can believe that ND673 might have been fitted with Monica while it was on 635 Squadron, as although the system was abruptly dropped when it was discovered that German night fighters were homing in on it that didn't happen until the end of August 1944. Streetly says that there was a single Monica aerial below the tail turret, which was the standard fit. He didn't have any photographic evidence for this, so perhaps he based it on Bowyer's account. But what Bowyer actually recorded was "bow and arrow aerials [plural] pointing at about 45 degrees from the base of the extreme rear fuselage". He does note elsewhere in Bombing Colours having a close look in May 1944 at a Lancaster II which had "beneath the rear turret....a Monica radar aerial to assist in gun laying [sic]", so it appears that he could recognise one even if he didn't know what it was for, yet he doesn't name either of the aerials that he saw on ND673 8 months later. His description of the one mounted on an arm above the tail turret certainly matches Boozer but if the other system really did have more than one aerial it's unlikely to have been Monica.

[SafetyDad]

46 minutes ago, Geoffrey Sinclair said:

I doubt the RAE had a full Lancaster servicing ability.  The trips to Avro could be routine inspection, say a 240 hour one, or other maintenance or repairs or modification, one of the published RAE histories may help.

 

Thanks for this. The card has a column headed Cat'y/Cause and another headed 'Contractor'  . The information given in the first column for both returns is Cat RC (might be 'HC' for the second visit to Avro. The information in the second column (Contractor) is R.O.S. A. V. Roe.

 

I could understand one return to Avro for a service/overhaul perhaps, but two within a month?

Modification now, that's a different thing. (However, as someone who has done research in the field for real and under scrutiny, I'm very aware of the dangers of 'cherry-picking' evidence to support a hypothesis, so I'm still open to the maintenance idea).

 

Any ideas what 'Cat RC' and 'R.O.S. A.V. Roe' might mean?

 

Edit: R.O.S. could mean 'Repaired on Site' 

http://www.associations.rafinfo.org.uk/acronyms.htm

 

SD

[AWFK10]

I think it's "Cat AC" in both cases, which is a damage category: http://www.airhistory.org.uk/spitfire/damage.html. "Repair is beyond the unit capacity, but can be repaired on site by another unit or a contractor."

[AWFK10]

Further to the presence of an extra navigator on some 635 Sqn missions. I've just been looking in 'Lincoln at War', which refers to "...the two navigator system as developed by Pathfinder Force during the war, which became known as the Nav-1 and Nav-2 or Nav and Set-Op. The two navigators worked alongside each other, [the nav radar's] job being to operate the Gee or Gee-H and H2S, complementing and aiding the plotter. The nav plotter was largely responsible for visual bombing and on nearing the target would vacate his seat and man the bombsight in the nose."

 

"The blind bombing H2S system worked out electronically the forward throw of the bomb to be dropped and presented the information to the nav radar [who] directed the pilot to fly the aircraft so that the target came down the track line and would order the opening of the bomb doors and the making of the release circuits before pressing the bomb release button situated by the side of the H2S equipment. Usually the visual bomb aimer would follow the nav radar through the target area from the nose. During co-ordinated attacks when a bomb had to be dropped visually or blind, the visual bomb aimer would be in the nose directing the pilot with the nav radar providing assistance on the H2S and if during the last stages of the bombing run the target could not be seen visually the nav radar would try to get the bomb away blind using the H2S."

 

If this description is also relevant to PFF Lancasters, then it's no longer necessary to postulate that the extra crew member was needed to manage unidentified defensive EW systems.