|
|
|
Discussion
Hawker Henley (and Westland Whirlwind design)
To start on a personal note:
The realisation has been forming over recent months that my years of designing, building and flying may well be coming to an end as my time is increasingly taken up by attending to my wife's needs as her Alzheimer's become worse. I actually got out flying only twice during the early part of last year and time I can spend in the workshop dwindles. This leaves me with a small collection of part-finished plans which I have little practical hope of ever building, still less flying and getting to a stage where they can be published and become available to all my fellow modellers out there. Over the years I have had the plugging of some of the holes in the range of available plans as a general aim and this has fuelled my interest in those types less (or sometimes never) built. Which is where I am with the Henley. The Hawker Henley Designed in response to Air Ministry specification P.4/34 which called for a high speed light bomber, the Henley was first seen at the Hendon display of 1937 where it gave an excellent impression. However its' career then appears to have taken an inexplicable turn in that despite the type being far superior to the Fairey battle, capable of carrying 750 lbs of bombs internally and using the wing outer panels of the Hurricane to speed production it was sidelined to target towing. Certainly the RAF had a desperate need for a high speed target tug to meet the training needs for the new types of front line fighters and bombers coming on line at the time, but the conversion lost the very performance that it offered. The drag of the drogue meant that speed had to be limited to 220mph to limit engine wear due to overheating. At the outbreak of war the RAF had 122 on charge yet never issued it to front-line squadrons for use in its originally intended role despite the mauling the Fairey Battle received at the hands of the Luftwaffe. It can only be wondered what could have been acheived had it been. It was never used as a light bomber and was unable to fulfil its secondary role due to cooling limitations... which begs the question of why the cooling system was not redesigned to allow the latter. By the end of 1942 the Henley was phased out in favour of Martinets and Defiants. A far too brief history for a type that showed such promise at the outset. So, I start this thread to see what interest there is in the type and if folks would appreciate my posting the drawings for a 62" span conventional balsa model. If I never get round to building it there is at least no reason why someone else couldn't build a prototype and everyone else also benefit. Robin |
|
Last edited by eye4wings; Jan 31, 2018 at 07:14 AM.
|
|
|
|
|
But ......, but ....., it was a target tug
It's later incarnation, the Hotspur, at least had a Boulton Paul gun turret. You could have a rat-a-tat-tat machine gun sound, and a rotating turret. Ray |
|
|
|
|
|
Welcome - and a happy new year to all!
Jeff, I hope the PSA is still coming down - I'm still praying. The thought that nobody else would be likely to turn up of the field with another model just like mine has always been a driving force for me and the Henley was a very suitable subject from that point of view. Sufficiently like the Hurricane to cause a few head-scratchings and with a sufficiently different sit on the ground (rather like the Thunderbolt) to excite interest. Looking at my drawings for the first time in a long while I see that I drew them in 2014, and that this was my last all-balsa design before going onto foam board/balsa composite construction for cheapness and light weight. Hence in the same way that the Henley marked the end of an era being the last fabric covered rear fuselage type to see production so indeed was my Henley model design. The short section on the Henley in the book 'Aircraft of the RAF since 1918' does not go into such detail but it looks to me as if not only the outer wing panels were lifted from the Hurricane (as stated there), but the entire empennage looks to be from the same source. Interestingly the single short-lived prototype for the Hotspur you mentioned Ray had the rear fuselage underside slimmed down from the fattened profile of the Henley, which makes me wonder exactly what was going on in the Hawker design office. There may well have been some frustration that the Air Ministry were not using the Henley in the role for which it was designed and that the adaptation of the design to the same specification that produced the Defiant (which later took over the target tug role) was an attempt to rescue the Hawker name as producer of front-line aircraft following the sidelining of the Henley. My book tells me that the Henley had a top speed of 272mph with drogue fitted but had to be speed restricted to 220mph because of excessive engine wear due to overheating. This raises another interesting question in my mind. Since the cooler was moved to the chin position when the Hurricane had it under the wing centre section (due to compressibility?), why was the cooling not moved back to that position (just aft of the bomb bay? - or in it since the bomb bay was not being used) in an attempt to improve cooling and restore the operating speed of the Henley? Sheer disgruntlement in the Hawker design office? Maybe one of you guys has a more detailed history to hand that would cover this lack of development? Robin |
|
|
|
|
|
A much more detailed account is to be found here; http://dinger.byethost5.com/henley/h...henley.htm?i=1
Among details given are the actual top speed of the prototype light bomber version of 292mph at 17,100 ft and the fact that the prototype was dived to 395mph and a subsequent aircraft dived to 450mph and pulled out at 6.4g with no sign of structural defect. Also details are given of developments involving R.R Griffon and Vulture engine installations (in which instance the cooler was in fact moved back to the ventral position). Very telling are three quotes from pilots who flew the Henley given at the end of the article! Robin |
|
|
|
|
|
The Henley as described in Putnam's Hawker Aircraft since 1920 by Francis K Mason.
Ray |
|
|
|
|
|
Gosh, I think I've only seen a couple of pictures of the Henley before.
The historical context is all fascinating stuff and it would be interesting to find out the Ministry thinking on the Henley. Of course, the Henley wasn't alone in being sidelined. Many requirements were spur of the moment. With the leads and lags in design, prototyping, proving, gearing up and production, many proposals were already outmoded by the time they had taken only a few steps down the chain. By the time the weaknesses in light bomber equipment and tactics were laid bare in May 1940 there would be other priorities for production capacity and superior options in the pipeline. A stock of 122 aircraft may have been seen as insufficient basis for commitment of an additional type (there were more than 2000 Battles). By the following Spring, offensive fighter operations had commenced and the light bomber concept had been displaced by the fighter-bomber. But it makes a great subject and I'm looking forward to you giving the Henley its moment in the sun. Alec |
|
|
|
|
|
Welcome to the thread Alec!
The link I included in post #8 makes a point of the difference between the strategic thinking of the RAF planners and the Luftwaffe. RAF thinking was centred on the bombing of strategic targets to deny war materials to the front whereas the Luftwaffe was geared up to close support at the front. The Battle, although slower and more vulnerable did have the longer range, but was stopped from ever attempting to fulfil its intended function by the French fear of reprisals - an understandable reaction in view of the German disregard of the Geneva convention evident even at that early stage. The wonder is that nobody seems to have thought 'hang on we already have a type that will plug the gap - tell Glosters to produce more Henley Mk.1s'... Robin |
|
|
|
|
|
Hello Robin
Indeed, the John Dell article suggests the light bomber was a poor fit with the RAF’s strategic thinking of the time. Commitment to the Fairey Battle had been expedient, based on concerns that heavier types would be outlawed by Treaty. This appears to explain why the RAF was no longer interested in a further light bomber once this risk was seen to be out of the way. This was probably when the Henley missed its moment. Although 220 Henleys were built, Dell describes these as meeting an order for target tugs rather than being reassigned light bombers. He doesn’t elaborate upon their equipment. Anyway, my curiosity is truly piqued. Let's be seeing your stuff Alec |
|
|
|
|
|
At this point my memory is dragged back to the discovery of an inexplicable quirk of my copy of CorelDraw7 - that without my telling it to (or being able to find a setting to stop it doing so) it chooses to convert from its own CDR to PDF not at full size, but reducing the drawing's size by a few percent so that it is not at the full size as designed. This has been a continued source of frustration as I have repeatedly trawled through drop-down menus to find a way of getting the software to behave itself and be sensible.
The files below I believe are ones I took down to my local printers where this misbehaviour was first spotted. They kindly corrected them back to full A0 size and saved them back to my memory stick. SO, IF my memory is right the three drawings below SHOULD not require correction for size. However there is always the possibility that my PC has tinkered with then again and does so every time they are saved, so the way to check them before printing is to make sure that the height of each drawing is 841mm - and if not, to increase it so it is. Then the model will be 1:8 scale as intended. You will notice that I have not included the fourth drawing (templates) at this stage, which is because it is not sufficiently complete to be of any use. I have begun re-drawing the template drawing in the hope of making it complete at some stage. In the meantime feel free to download and print the drawings here free of any copyright. And IF any one of you wish to build from them and be the first onto the field with a Hawker Henley my only request would be that you post progress here so that the rest of us can chip in and help in whatever way we can. Does that sound fair? What do you think? Robin |
|
|
|
|
|
More than fair!
I just opened the Fuselage plan in Adobe Reader - and it looks good at first glance. Then I opened it in Inkscape - and there's something strange: there are items outside the page that look like they belong in parts sheets. They are to the right, above, and below the page. Measuring page height in Inkscape, I got only about 808 mm. I did not check the other sheets. |
|
|
|
|
|
Greetings and welcome perttime!
The bits you are seeing are indeed extracted ready to go on parts sheets - arranged on half-length 100mm (4") wide balsa for postage purposes from a possible laser cutter. I never got round to grouping them all and doing the cut and paste onto the new sheet. I had thought that it was the over sheet length that caused the scaled-down conversion quirk but it seems to happen whether there are those extra bits or not so I haven't yet sussed out the logic the software might be using. The height of 808mm sounds like the usual discrepancy. IIRC I used a multiplication factor of 104% to restore the size. Does that work for you? My problem is that every time I convert to PDF the stupid machine reduces the size so it will need someone else to correct the sizes of the sheets and repost them at correct size. Is that something you could do for us? Robin |
|
|
Thread Tools | |
Similar Threads | |||||
Category | Thread | Thread Starter | Forum | Replies | Last Post |
Video Link | Alan Henley/J3 watersports! | Ranfred Radius | Humor | 2 | Feb 06, 2009 07:23 PM |