Avro 606 & 607 For Spec. 4/27

[hesham]

Hi,

here is a drawings to Avro 606 & 607,they were intended for Spec. 4/27,which needed a
three engined maritime and patrol flying boat.

 

[Schneiderman]

Hesham, what was your source for these? The second one looks like 'what-if' Supermarine rather than Avro, matching a Southampton-style hull to their 4/27 monoplane wing.

 

[hesham]

Avro Heritage is the source.

 

[Schneiderman]

Oh that's a pity, I was hoping you had found another source.
Jackson's description of these in Avro Aircraft since 1908 is clearly wrong and neither design appears to meet the requirements of 4/27 (or 5/27 or 6/27). As Avro had zero experience in building flying boats and there were four constructors (Blackburn, Short, Saunders and Blackburn) chasing the very few contracts available there has to be a story here that needs to be told.

 

[hesham]

Maybe rejected in early stage.

 

[Schneiderman]

Without a doubt, neither offered any obvious advantage over existing types or the designs of other companies. I suspect that they are speculative concepts/designs and not actually tendered to 4/27. This was also the time when Crossley sold the company to Armstrong Siddeley which caused Roe and other managers to resign, so the company was a little unstable.

 

[robunos]

As Avro had zero experience in building flying boats . . .

Just a wild guess, perhaps the Avro 607 was a proposal for a test bed for the Type 606 wing on a Southampton Mk.II hull?
I'm thinking along similar lines to the Saunders A.14, which was a Saunders hull, of a new type of construction, but using proven Southampton flying surfaces . . .

cheers,
Robin.

 

[Schneiderman]

There are very obvious Supermarine stylistic features but it was to be significantly larger than the Southampton II

 

[robunos]

As I said, just a wild guess . . . It was only later I realised that three Jupiters is way too much power for a Southampton . . .

cheers,
Robin.

 

[Schneiderman]

Not at all, it was a reasonable suggestion. Mitchell was thinking along the same lines

 

[Schneiderman]

The Avro Historical Research Group got themselves, and others, terribly confused over Avro's flying boat designs. In an article in Aeromilitaria (1996, #2) they commented on Air Britain's The British Aircraft Specification File but unfortunately made further errors of their own.
The Avro Types 606 and 607 they associate with spec R.4/22, but that is surely just a typing error for R.4/27 and is understandable. However they also refer to two other Avro flying boat designs tendered to spec 40/22, which has to be wrong as that spec was for a single-engine civil transport. Both of the designs they discuss are three engined flying boats, one a monoplane the other a triplane, which included 'fighting tops', that is defensive gun positions on the wings. Neither appear in the Avro Heritage list. Now, these 'fighting top' gun positions appear to have been a requirement of spec. 9/23, to which Vickers and Supermarine are known to have responded with designs that included them. However this spec was soon cancelled and replaced by completlely different specs. issued in 1924, which resulted in the Supermarine Southampton, amongst others.
We can see from the artwork of the Avro 606 in the Avro Heritage list that it features 'fighting tops', which by 1927 had dropped from favour having been tested in both a Vickers Virginia and a Southampton 1 and found wanting. Can we conclude that the Type 606 had started as a design to 9/23 and had been dusted-off and revised for R.4/27? Possibly, it certainly looks more akin to an early 1920s design. Both the Type 606 and 607 lack the side-by-side cockpit arrangement of the other 4/27 (5/27 and 6/27) tenders and also the Calcutta and look ill-equiped to meet 1927 standards.

 

[hesham]

I agree with that Schneiderman.

 

[hesham]

Hi,

I think the Avro Heritage was wrong as my dear Schneiderman explained,and those
two Projects were submitted to Spec. 14/26 for commercial seaplane.

 

[Schneiderman]

But that does not explain why both have defensive guns

 

[hesham]

But that does not explain why both have defensive guns

We can solve that by assume,the Avro-606 was for 14/26 and Avro-607 was for 4/27 ?.

 

[Schneiderman]

I think the story that works best, for me, is as follows.
The Air Ministry wished to assess 3-engine flying boats to either replace of suplement the Supermarine Southampton. Short were in the process of designing the Calcutta to meet an Imperial Airways requirement, similar in many ways to the Ministry's thoughts on a patrol flying boat. Unusually for a civil aircraft at this date they issued a specification around the Calcutta, which was 14/26, as they wished to assess the aircraft thoroughly. This was probably not put out to tender. It is known that the Calcutta spent more thime than was usual being assessed at Felixstowe before eventually being passed on to Imperial.
While the Calcutta was being constructed the Ministry issued Spec 4/27 for a 3-engine patrol flying boat and received tenders from Saunders, Blackburn and Supermarine. In an unusual move they decided to order all three; the Saunders Severn to 4/27 and then extra, but very similar specs. for the other two, 5/27 for the Blackburn Sydney and 6/27 for the Supermarine Southampton MkX. As we know Short produced military derivatives of the Calcutta while Blackburn built the Nile, a civil version of the Sydney. Supermarine planned several civil version of the MkX, mostly named Sea Hawk.
Avro may well have submitted the Types 606 and 607 for 4/27 but, as I said above, they look rather dated designs and may have originated earlier. They seem unlikely to have been suitable for 4/27. As with Saunder, Blackburn and Supermarine they no doubt had civil derivatives in mind and may have offered these to Imperial, but I doubt they were linked to 14/26 directly.

edit...One more thing. Supermarine tendered two designs to 4/27, a biplane and a monoplane. The biplane was revised extensively to become the Southampton MkX while the monoplane was used as the basis for the design of the Air Yacht

 

[hesham]

Hi,

I think the Avro-606 was submitted to Spec. 14/26 without guns,but later
they put canons for Spec. 4/27,and maybe both 606 & 607 were rejected
in early stage.

 

[Schneiderman]

But I do not see any indication that 14/26 was put out to tender, it was specific to the Calcutta

 

[hesham]

But I do not see any indication that 14/26 was put out to tender, it was specific to the Calcutta

But that means it was a mistake in the book; British Aircraft Specifications File ?.

 

[Schneiderman]

One of several.
The Calcutta was required for Imperial's Mediterranean to Karachi route. On a long distance flight it was important to have a side-by-side cockpit, and neither of the Avro projects are configured that way, just one reason why it did not fit requirements. That does not mean that Avro did not submit the projects to Imperial just that it was not part of 14/26, which was written around the Calcutta. Speculative tenders to Imperial happened all the time, many companies did so.

 

[Schneiderman]

Of course the REALLY interesting question is why a company in financial difficulty, with negligible experience of metal-skin construction (Avocet), and none of flying boat design would even consider submitting projects to either Imperial or the Air Ministry.

 

[hesham]

OK my dear Schneiderman.

 

[Schneiderman]

But it is a question worth asking as it is so out of character for the company. What were Avro doing?