Blackburn B.44

[PR19_Kit]

In WWII a Sunderland based at Milford Haven was damaged when it had landed in the Atlantic to rescue crews from a couple of other aircraft, so much so that it would have sunk if they'd tried to land normally. So the pilot put it down on the grass at RAF Angle, just west of its own base and everyone survived! That's more than can be said of the Sunderland as it was scrapped on site.

Not only that but there's a (silent) cine film of it happening here :- https://www.youtube.com/watch?v=0ZfVEoZmt-c&feature=youtube_gdata_player

[jcf]

While the retractable float is a great idea to reduce drag, it does rather give it the look of a pregnant guppy.   I'm wonder if a better idea might have been a retractable float with an inflatable top?   Make the bottom, planing surface of metal but make the top inflatable so when it's retracted, it collapses and folds down much smaller?

The Japanese tried that for the retractable wingfloats of the E15K1, never worked reliably.

[zenrat]

In WWII a Sunderland based at Milford Haven was damaged when it had landed in the Atlantic to rescue crews from a couple of other aircraft, so much so that it would have sunk if they'd tried to land normally. So the pilot put it down on the grass at RAF Angle, just west of its own base and everyone survived! That's more than can be said of the Sunderland as it was scrapped on site.

Not only that but there's a (silent) cine film of it happening here :- https://www.youtube.com/watch?v=0ZfVEoZmt-c&feature=youtube_gdata_player

Quick, quick, quick get out quickly...and then stand right next to it.  Behaviour I recognise from many a fire and evacuation drill.

I assume that if they had attempted to land in the traditional method (in the water) with that size hole in the hull then the whole hull could have been ripped off with disastrous consequences.

Why do we think one chap was showing us his long underwear?

[pyro-manic]

Not only that but there's a (silent) cine film of it happening here :- https://www.youtube.com/watch?v=0ZfVEoZmt-c&feature=youtube_gdata_player

What an excellent bit of footage! Thanks for that.

[KJ_Lesnick]

I'm curious about several things: Most of these are of course WHIF based

Firstly: Does anybody have any estimates as to its range?

Secondly: Could the prop have been increased in diameter about 10-12%?

• One thing I remember from the F4U was that it was designed with a ridiculously big propeller so as to maximize thrust and climb-rate: It even out-climbed the P-51's
  
• I'm not particularly sure about the give/springiness of the struts but it looks like such an enlargement of the props wouldn't nail the boat-hull below
  

[rickshaw]

While the retractable float is a great idea to reduce drag, it does rather give it the look of a pregnant guppy.   I'm wonder if a better idea might have been a retractable float with an inflatable top?   Make the bottom, planing surface of metal but make the top inflatable so when it's retracted, it collapses and folds down much smaller?

The Japanese tried that for the retractable wingfloats of the E15K1, never worked reliably.

Yes, I know but that doesn't mean it couldn't work just 'cause the Japanese couldn't get it work for them, Jon.

[jcf]

Yeah, but you see Brian the problem is basic to any inflatable object of that sort,
inflation is easy, the controlled deflation is the problem, and that's a problem
of physics, not technical ability nor nationality. Ask anyone who's had to repack the
inflatable floats on a Bell 206 or similar, damned if the things want to shrink back
down into the space from which they came. 

In the float scenario, to be useful it would have to be fast inflation from a pressurized
source and then be able to be equally quickly pump deflated, simply opening dump valves
to release the pressure wouldn't be fast enough, and then the fabric would somehow have
to be controlled so it goes back exactly into its storage cavity - which it would not be inclined
to do, and all of this has to happen on a very short cycle so yer not puttering about waiting
for the draggy, dangly bits to extend/retract. So you have the weight of the strut mechanism,
the weight of the bottles for quick pressurisation and the weight of the pressurization/de-pressurization
system, (which would probably use an engine driven compressor/air-pump that fills the tanks
in one mode, sucks the air out in the other) plus whatever gubbins are required to keep the fabric
under control as it is inflated/deflated, plus the fabric itself will be heavy.

So from a practical standpoint, a whole lot of weight and complexity for a relatively small return in
drag reduction.

[rickshaw]

I understand what you're saying, Jon.  It is a problem it seems with any rubber object which has to be folded to fit back into a box after you've used it, whether it's a 1500 litre rubber collapsable tank or the kids inflatable pool toy. 

However, there are ways around it.  You could design it so there is a fairing into which the collapsing float is dragged as it deflates.

As to the deflating mechanism, pumps work, so does external mechanical pressure with multiple release valves (ie, as the float is retracted, the pressure from the retraction forces the air out of the float).

I agree it would need some work but it might be an interesting solution to the drag problem.  Alternatively, you could go the way of the Macchi Schneider Cup races and use hydrofoils.

[PR19_Kit]

How about what SARO did with the SR/A1?

The wing floats on that turned 180 deg. on their longitudinal axis as they retracted so that the pointed end faced upwards into a suitably shaped hole in the wing's undersurface. The normal upper surface of the float then became the lower surface that presented to the airstream when retracted.

[Mossie]

rickshaw

If the figures I found were correct, I got

• Length: 39'4"
• Span: 50'0"

• Armament: 4 x 20mm cannon
  
• Engine: Napier Sabre
  

I'm curious if there have ever been figures for wing-area, operational empty weight, and loaded weight.

Finally got my copy of Tony Butler's British Secret Projects: Fighters and Bombers 1935-1950 back after loaning it to a friend.  Dimensions and cannon armament match those you quote Kendra, engine is given as a Sabre IV (Wiki gives 2,240hp for the Sabre IV).  The other values given are:

External stores: 2 x 500lb bombs or 2 x 90 gallon drop tanks
Wing area: 381ft²
Max speed: 360mph at 25,000ft
Ceiling: 38,000ft
Range: 1,000 miles

Initial studies showed problems with pontoon gave excessive spray and water drag making take off difficult even under normal loads.  Revisions to the design improved this.  A mock-up was built but the project didn't progress beyond the design stage.

[rickshaw]

Are there any pictures of the mockup?  That would be very interesting.  I assume they must have carried out tank tests?   Any pictures of the tank model(s)?

[Mossie]

There's a wooden wind tunnel model in the book, I can't post it unfortunately.

[KJ_Lesnick]

Mossie

Finally got my copy of Tony Butler's British Secret Projects: Fighters and Bombers 1935-1950 back after loaning it to a friend.  Dimensions and cannon armament match those you quote Kendra, engine is given as a Sabre IV (Wiki gives 2,240hp for the Sabre IV).  The other values given are:

External stores: 2 x 500lb bombs or 2 x 90 gallon drop tanks
Wing area: 381ft²
Max speed: 360mph at 25,000ft
Ceiling: 38,000ft
Range: 1,000 miles

Thanks

[Mossie]

You're welcome. 

[KJ_Lesnick]

Would the United States have had any use for a concept like this?

• Escorting B-29's over the ocean
  
• Providing fighter cover for flying-boats
  
• Other