Comments on: Imperial Airways: now with extra airmail http://airminded.org/2009/10/18/imperial-airways-now-with-extra-airmail/?utm_source=rss&utm_medium=rss&utm_campaign=imperial-airways-now-with-extra-airmail Airpower and British society, 1908-1941 Thu, 09 Feb 2012 22:36:10 +0000 hourly 1 http://wordpress.org/?v=3.3.1 By: Brett Holman http://airminded.org/2009/10/18/imperial-airways-now-with-extra-airmail/comment-page-1/#comment-158707 Brett Holman Thu, 16 Jun 2011 12:51:19 +0000 http://airminded.org/?p=2683#comment-158707 I agree that this conversation has (I hope) run its course. I agree that this conversation has (I hope) run its course.

]]> By: Black Dog. http://airminded.org/2009/10/18/imperial-airways-now-with-extra-airmail/comment-page-1/#comment-158677 Black Dog. Mon, 13 Jun 2011 15:47:36 +0000 http://airminded.org/?p=2683#comment-158677 Trust me, I meant geocentric...! Trust me, I meant geocentric...!

]]> By: JDK http://airminded.org/2009/10/18/imperial-airways-now-with-extra-airmail/comment-page-1/#comment-158665 JDK Sun, 12 Jun 2011 13:52:59 +0000 http://airminded.org/?p=2683#comment-158665 It's 'Mr Tweed', it would be 'egocentric', not geocentric and it's de Havilland, with a space. Such minor errors (along with the failure to factually address <i>any</i> of the responses to the initial queries) are indicative. I agree that further discussion is pointless - in my case I feel with someone unable to provide evidence rather than insults. It is a pity that an obvious personal issue has spoiled an opportunity to have a useful educational discussion. I agree that we need have nothing more to say to each other. It's 'Mr Tweed', it would be 'egocentric', not geocentric and it's de Havilland, with a space. Such minor errors (along with the failure to factually address any of the responses to the initial queries) are indicative. I agree that further discussion is pointless - in my case I feel with someone unable to provide evidence rather than insults.

It is a pity that an obvious personal issue has spoiled an opportunity to have a useful educational discussion.

I agree that we need have nothing more to say to each other.

]]> By: Black Dog. http://airminded.org/2009/10/18/imperial-airways-now-with-extra-airmail/comment-page-1/#comment-158664 Black Dog. Sun, 12 Jun 2011 12:03:50 +0000 http://airminded.org/?p=2683#comment-158664 JDK;- 'Mr Tweedy' is YOUR own self-created epithet, not mine....as for the rest, you have simply underlined that you still 'don't get it' and are unlikely to do so. Further discussion is obviously pointless. Were deHavillands bothered about whether the Ratier was going to be certifiable in 2011..? Hardly. They just wanted to win the race. Which they did. Did the Ratiers do the job? Yes. - Res ipsa loquitur. Finito. Phew. There are a plethora of easily available expert test reports on historic a/c, and have been since flying began. I don’t think Mr.Tweedy has exclusive access. Yet. . 'As for relating to that, I'm not impressed at having my own research and writing fed back to me as an anonymous critique of my analysis' . .....My information on that came from an aviation business contact (Pilot, Aircraft Engineer etc etc.) who had spoken directly to the builders many years ago, not from your articles, which, like most people, I was blissfully unaware of. Again, JDK’s view is, to say the least, geocentric. JDK;- 'Mr Tweedy' is YOUR own self-created epithet, not mine....as for the rest, you have simply underlined that you still 'don't get it' and are unlikely to do so. Further discussion is obviously pointless. Were deHavillands bothered about whether the Ratier was going to be certifiable in 2011..? Hardly. They just wanted to win the race. Which they did. Did the Ratiers do the job? Yes. - Res ipsa loquitur. Finito. Phew.

There are a plethora of easily available expert test reports on historic a/c, and have been since flying began. I don’t think Mr.Tweedy has exclusive access. Yet.
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'As for relating to that, I'm not impressed at having my own research and writing fed back to me as an anonymous critique of my analysis'
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.....My information on that came from an aviation business contact (Pilot, Aircraft Engineer etc etc.) who had spoken directly to the builders many years ago, not from your articles, which, like most people, I was blissfully unaware of. Again, JDK’s view is, to say the least, geocentric.

]]> By: JDK http://airminded.org/2009/10/18/imperial-airways-now-with-extra-airmail/comment-page-1/#comment-158661 JDK Sun, 12 Jun 2011 08:22:58 +0000 http://airminded.org/?p=2683#comment-158661 It's a pity that 'Black Dog' is so determined to pick fault, rather than just bringing material (and debate) to the discussion. As well as being able to sign off as myself and back my own words, I'm happy to be corrected with factual analysis or data. Again, as well as patronisation ('Mr. Tweedy' - leave it elsewhere, thanks.) there's a telling scattering of caveats 'from memory' 'off the top of my head, I can’t recall' showing despite the time lapse since my last response to the points made, <i>no</i> actual research has been undertaken. I'm not guessing - as Black Dog is - about modern Comet pilot views, I've interviewed, written up and checked back articles with pilots of the US replica and the UK 'original'. Relating to that, I'm not impressed at having my own research and writing fed back to me as an anonymous critique of my analysis - viz the new washout on the US Comet replica and its efficacy or lack of - which I've written about in at least two articles. As to the long digression on the Sopwith Camel, I was recently chatting the a man who very reasonably reckons to be the world's highest time Camel pilot, and was putting on an excellent display of Camel flying, with an original rotary engine fitted. And that's the nub of my original point - you can certify an aircraft to fly with a rotary engine today, in a number of countries. I don't believe you could get a Ratier-prop (of the Comet's use) equipped aircraft certified in a first world country today. I would be delighted to hear that checked for a fact <i>either</i> way. But it <i>is</i> a fact there's not a single vintage aircraft <i>flying</i> with that mechanism. For that reason the Ratier can be filed along with the Messerschmitt Komet's engine as an acceptable technical solution at the time, just not acceptable now. We have airworthy-certifiable Comets and an airworthy glider Komet, but neither look likely to fly with the original power-setup. I'm well aware of the differences and difficulties of modern test-pilot expectations when applied to historic aircraft, and am in the process of assisting on that very matter for a period replica and modern test-pilots requirements. Anonymous opinion, without data, won't cut it there. I'm not sure of the point of saying "it is again rather futile to drop a modern frame of reference over these old machines and equipment", except that seem definitely to be the case when dismissing the DC-2 as failing modern airliner standards earlier in the same post! As I stated at the end of my last post, I regard the Comet and its crews achievements highly. You can see the KLM DC-2's performance as noteworthy or not, it is a personal rating if you wish. I'm well aware of the Comet's performance and how and why it wasn't an issue at the time. I'm not sure what point/s Black Dog is trying to make, except at base it's vital to attack me, whether I'm right or wrong. On that basis, my details are available, I can be contacted or corrected, but I don't propose to indulge anyone in anonymous personal attacks from someone hiding as a depression. It's a pity that 'Black Dog' is so determined to pick fault, rather than just bringing material (and debate) to the discussion. As well as being able to sign off as myself and back my own words, I'm happy to be corrected with factual analysis or data. Again, as well as patronisation ('Mr. Tweedy' - leave it elsewhere, thanks.) there's a telling scattering of caveats 'from memory' 'off the top of my head, I can’t recall' showing despite the time lapse since my last response to the points made, no actual research has been undertaken.

I'm not guessing - as Black Dog is - about modern Comet pilot views, I've interviewed, written up and checked back articles with pilots of the US replica and the UK 'original'. Relating to that, I'm not impressed at having my own research and writing fed back to me as an anonymous critique of my analysis - viz the new washout on the US Comet replica and its efficacy or lack of - which I've written about in at least two articles.

As to the long digression on the Sopwith Camel, I was recently chatting the a man who very reasonably reckons to be the world's highest time Camel pilot, and was putting on an excellent display of Camel flying, with an original rotary engine fitted.

And that's the nub of my original point - you can certify an aircraft to fly with a rotary engine today, in a number of countries. I don't believe you could get a Ratier-prop (of the Comet's use) equipped aircraft certified in a first world country today. I would be delighted to hear that checked for a fact either way.

But it is a fact there's not a single vintage aircraft flying with that mechanism.

For that reason the Ratier can be filed along with the Messerschmitt Komet's engine as an acceptable technical solution at the time, just not acceptable now. We have airworthy-certifiable Comets and an airworthy glider Komet, but neither look likely to fly with the original power-setup.

I'm well aware of the differences and difficulties of modern test-pilot expectations when applied to historic aircraft, and am in the process of assisting on that very matter for a period replica and modern test-pilots requirements. Anonymous opinion, without data, won't cut it there.

I'm not sure of the point of saying "it is again rather futile to drop a modern frame of reference over these old machines and equipment", except that seem definitely to be the case when dismissing the DC-2 as failing modern airliner standards earlier in the same post!

As I stated at the end of my last post, I regard the Comet and its crews achievements highly. You can see the KLM DC-2's performance as noteworthy or not, it is a personal rating if you wish.

I'm well aware of the Comet's performance and how and why it wasn't an issue at the time. I'm not sure what point/s Black Dog is trying to make, except at base it's vital to attack me, whether I'm right or wrong.

On that basis, my details are available, I can be contacted or corrected, but I don't propose to indulge anyone in anonymous personal attacks from someone hiding as a depression.

]]> By: Black Dog. http://airminded.org/2009/10/18/imperial-airways-now-with-extra-airmail/comment-page-1/#comment-158657 Black Dog. Sat, 11 Jun 2011 23:51:44 +0000 http://airminded.org/?p=2683#comment-158657 'Animus', what a lovely word Brett..... . Sure the DC2 put up a great show. I just find it rather irritating that people unfairly use this as a stick to beat the Comet with. It was a race after all… That said, the DC2 embodied a trend at the time, it was just bigger, but it wasn't pressurised, which is central to the concept of what we think of as a 'real' airliner - that ability to fly (Punters) over the weather. That and the arrival of the jet engine was the real quantum leap. The 1934 Comet didn't pretend to be an airliner, but it did show what could be done with a small amount of power and an aerodynamically efficient airframe. . Mr. Tweedy has again missed the point on the Ratiers. I’m perfectly well aware of the elementary issues with regard to the obvious limitations of those airscrews. The Ratiers were simple, reliable, efficient and available, and the pilots were well aware of obvious issues such as asymmetric deployment. Placing any sort of modern frame of reference over their shortcomings at that time is meaningless. At the time, they were just accepted attributes. The Camel suffered from a difficult to control engine and large amounts of torque and gyroscopic effects that some later Great War fighters such as the FD7 & the SE5a didn’t have – but it didn’t stop it being the Allies highest-scoring fighter. As far as the Ratiers greater efficiency is concerned, it’s worth noting that a number of the Schlesinger machines (Between 2 & 4 from memory.), a good two years later, swapped from the PD30 to Ratiers, albeit the electrically actuated version of the Helices Ratier product. As mentioned before, Alex Henshaw’s Mew was much faster with the Ratier fitted. Not only was the Ratiers blade design more efficient, but the available pitch range on the original PD30 was limited. The later PD30/211/1 fitted to the likes of the Queen II engined Proctors etc. had an increased availability of pitch range over the original PD30 of course. . At the risk of further ‘thread-drift’, I’d also make a couple of comments about the Comets flying characteristics, because they dovetail into the issue of the Ratiers. Some older a/c, and the Comet is a good example, have attracted a good deal of negative comment. This has accumulated over the years, bestowing such machines with quite undeserved reputations to the casual reader. There are two reasons for this. Firstly, when contemporary comments were made, most pilots were used to very simple, slow, basic draggy biplanes. Anything that didn’t slow-down quickly and easily was viewed as a hot-ship and such features as flaps and retracts were new territory for most pilots. None of these features in themselves would draw comment from the most basic pilot today. Now jump forward to today. Modern pilots, whilst well used to such complexities - and much more, are not used to some of the foibles of older machines. Many older aircraft exhibit characteristics that would be considered wholly unacceptable today, yet which hardly drew any comment when they were originally operated. (Interestingly, in the case of the Comet, the replica built it the USA incorporates, I have been told, added washout. The resulting ‘improvement’ was reputed to be zero..!). Neither, remember, was the Comet ever intended for any casual amateur to jolly around in. . Modern pilots flying the Comet have thus approached it with deserved caution. One may read their factual reports for the details. I know that some of these pilots were highly experienced test pilots and the like and one may suppose that an average-joe would come a cropper. However, remember this;- Back in the 1930’s, the Comets were flown with much, much higher loads, through appalling conditions and without the added bells and whistles fitted today. Indeed, deHavillands themselves were only able to give the Comet a very perfunctory evaluation, before they were all loaded with fuel and raced…..! Clearly they were not overly concerned. The Mollisons did manage to drop a wing on landing at Mildenhall for the start of the 1934 race, but otherwise, no one had any real dramas with the airframe, and off the top of my head, I can’t recall any adverse comments from the six pilots in the race, or, later, from Campbell Black or Clousdon, both of whom raced the a/c in meteorological conditions which no comparable a/c would be flown in today. In fact, what is remarkable, is what little comment Scott, Black & Clousdon et al made. They were almost exclusively ex-military pilots of course. Martlesham Heath, I think, later evaluated ‘SS, and I’m sure their report would be a good read, as they often still are. The original Gipsy Six’s (Not the ‘R’s of course.) had a TBO of much less than 500hrs, only 300 I think. This was later stretched, after a few mods and field experience, to about 1,000hrs (If you were lucky..!). Today, any old Continental or Lycoming is expected to last to at least 2,000hrs, and many go ‘On Condition’, for much longer. . My point is of course….it is again rather futile to drop a modern frame of reference over these old machines and equipment. If we go down that road, we’ll end-up castigating the Camel for it’s ‘shortcomings’, and the fact that it was an ‘interim’ design. Aren’t they all? . (As for the ‘anon’ issue. It’s a matter of choice. Just as adverting who you are on sundry forums.) . As they say in Brooklyn, - ‘Enough already’, - back to the aeroplanes. 'Animus', what a lovely word Brett.....
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Sure the DC2 put up a great show. I just find it rather irritating that people unfairly use this as a stick to beat the Comet with. It was a race after all… That said, the DC2 embodied a trend at the time, it was just bigger, but it wasn't pressurised, which is central to the concept of what we think of as a 'real' airliner - that ability to fly (Punters) over the weather. That and the arrival of the jet engine was the real quantum leap. The 1934 Comet didn't pretend to be an airliner, but it did show what could be done with a small amount of power and an aerodynamically efficient airframe.
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Mr. Tweedy has again missed the point on the Ratiers. I’m perfectly well aware of the elementary issues with regard to the obvious limitations of those airscrews. The Ratiers were simple, reliable, efficient and available, and the pilots were well aware of obvious issues such as asymmetric deployment. Placing any sort of modern frame of reference over their shortcomings at that time is meaningless. At the time, they were just accepted attributes. The Camel suffered from a difficult to control engine and large amounts of torque and gyroscopic effects that some later Great War fighters such as the FD7 & the SE5a didn’t have – but it didn’t stop it being the Allies highest-scoring fighter. As far as the Ratiers greater efficiency is concerned, it’s worth noting that a number of the Schlesinger machines (Between 2 & 4 from memory.), a good two years later, swapped from the PD30 to Ratiers, albeit the electrically actuated version of the Helices Ratier product. As mentioned before, Alex Henshaw’s Mew was much faster with the Ratier fitted. Not only was the Ratiers blade design more efficient, but the available pitch range on the original PD30 was limited. The later PD30/211/1 fitted to the likes of the Queen II engined Proctors etc. had an increased availability of pitch range over the original PD30 of course.
.
At the risk of further ‘thread-drift’, I’d also make a couple of comments about the Comets flying characteristics, because they dovetail into the issue of the Ratiers. Some older a/c, and the Comet is a good example, have attracted a good deal of negative comment. This has accumulated over the years, bestowing such machines with quite undeserved reputations to the casual reader. There are two reasons for this. Firstly, when contemporary comments were made, most pilots were used to very simple, slow, basic draggy biplanes. Anything that didn’t slow-down quickly and easily was viewed as a hot-ship and such features as flaps and retracts were new territory for most pilots. None of these features in themselves would draw comment from the most basic pilot today. Now jump forward to today. Modern pilots, whilst well used to such complexities - and much more, are not used to some of the foibles of older machines. Many older aircraft exhibit characteristics that would be considered wholly unacceptable today, yet which hardly drew any comment when they were originally operated. (Interestingly, in the case of the Comet, the replica built it the USA incorporates, I have been told, added washout. The resulting ‘improvement’ was reputed to be zero..!). Neither, remember, was the Comet ever intended for any casual amateur to jolly around in.
.
Modern pilots flying the Comet have thus approached it with deserved caution. One may read their factual reports for the details. I know that some of these pilots were highly experienced test pilots and the like and one may suppose that an average-joe would come a cropper. However, remember this;- Back in the 1930’s, the Comets were flown with much, much higher loads, through appalling conditions and without the added bells and whistles fitted today. Indeed, deHavillands themselves were only able to give the Comet a very perfunctory evaluation, before they were all loaded with fuel and raced…..! Clearly they were not overly concerned. The Mollisons did manage to drop a wing on landing at Mildenhall for the start of the 1934 race, but otherwise, no one had any real dramas with the airframe, and off the top of my head, I can’t recall any adverse comments from the six pilots in the race, or, later, from Campbell Black or Clousdon, both of whom raced the a/c in meteorological conditions which no comparable a/c would be flown in today. In fact, what is remarkable, is what little comment Scott, Black & Clousdon et al made. They were almost exclusively ex-military pilots of course. Martlesham Heath, I think, later evaluated ‘SS, and I’m sure their report would be a good read, as they often still are. The original Gipsy Six’s (Not the ‘R’s of course.) had a TBO of much less than 500hrs, only 300 I think. This was later stretched, after a few mods and field experience, to about 1,000hrs (If you were lucky..!). Today, any old Continental or Lycoming is expected to last to at least 2,000hrs, and many go ‘On Condition’, for much longer.
.
My point is of course….it is again rather futile to drop a modern frame of reference over these old machines and equipment. If we go down that road, we’ll end-up castigating the Camel for it’s ‘shortcomings’, and the fact that it was an ‘interim’ design. Aren’t they all?
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(As for the ‘anon’ issue. It’s a matter of choice. Just as adverting who you are on sundry forums.)
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As they say in Brooklyn, - ‘Enough already’, - back to the aeroplanes.

]]> By: JDK http://airminded.org/2009/10/18/imperial-airways-now-with-extra-airmail/comment-page-1/#comment-158150 JDK Sun, 22 May 2011 12:08:30 +0000 http://airminded.org/?p=2683#comment-158150 'Black Dog' - Thanks for the additional information and some of the corrections. Someday I may well actually research and write up the background to the Ratier story after all, it's been on the list since this original discussion. As there seems to be some confusion - I don't call myself (or claim to be) an historian, I respect those who've earned the title through qualification, although it's not a requirement. For clarification, I'm a professional writer, as anyone can see from my linked details provided to the posts here. I also have never claimed to be a pilot or engineer, nor immune from error - nor am I anonymous. Having just returned from an overseas trip where I met - among others - several professional historic aviation pilots and engineers as a result of corresponding through online forums, while I may not agree or be agreed with, I'm certainly not "irritating all" although I accept annoying "sundry" does happen. I've also never claimed to be an authority - I just have based my opinions on the understanding of a number of people who are qualified to comment, including a couple of modern (post-Ratier) Comet pilots, and Comet re/builders. Regarding the much disputed facts - several points you are attempting to 'correct' me on aren't mine, but Erik's - where I was disputing his views. I'm not sure where that leaves your view in those cases. I'd suggest you are missing a core performance / safety issue of the air-pressure operated Ratier - as any twin-qualified pilot would observe on understanding the mechanism and its risks in the circuit. (Later Ratier developments remove the issue.) It <i>was</i> an 'interim' design, and bicycle-pump operation doesn't just seem Heath Robinson, it's a 'poor' (second-rate, if you prefer) engineering solution - if that were not the case, the technical approach would've been more widely (or longer) used. I agree it was the best solution available in that critical time window, but on your account because the other solutions (better and/or replacements) were not available. If you'd care to show otherwise - not anonymously, please - I'm interested. Regarding the correction on the engine issue/s over the Timor Sea - Scott's book, while a useful period account (I was looking at a copy last week in a friend's collection, incidentally, but didn't realise I was going to need to check the facts) may not state - as David Ogilvy's <i>The Racing Comets</i> does, that the Comet's engine ran roughly even after the clogged oil filter had been cleaned after landing at Darwin, after the Timor Sea crossing. Ogilvy wasn't writing for the popular media of the time. I certainly agree the Comet and the DH 'R' engine did a remarkable job at the time, as did the crews; but it remains a fact that G-ACSR's engines didn't run without issue on the way out, nor the way back, getting parts from G-ACSP at Allahabad. Referenced corrections welcome, but at the moment, my brief research stands. We could go on regarding appropriate adjectives and excusing performance shortfalls or recognising compromises as to the props; I think on your own argument the PD30s were evidently not the answer at the time. Conflating the benefits of feathering versus semi-controlled pitch changes is basic technical stuff, perhaps not best argued here given Brett's comment above. However non-anonymous properly-referenced corrections will be welcome on my blog when (if!) I get around to writing up the Ratiers. Finally, there seems some perhaps genuine misunderstanding of opinion. I'm not "dismissive" of the Comet's performance - in 1934 it was the fastest long distance aircraft on the planet, and deserved most of the accolades heaped upon it; and I rather like the type, personally. However the original point, disputed and re-disputed as it may be, was that a standard airliner was hot on its heels. Regards, 'Black Dog' - Thanks for the additional information and some of the corrections. Someday I may well actually research and write up the background to the Ratier story after all, it's been on the list since this original discussion.

As there seems to be some confusion - I don't call myself (or claim to be) an historian, I respect those who've earned the title through qualification, although it's not a requirement. For clarification, I'm a professional writer, as anyone can see from my linked details provided to the posts here. I also have never claimed to be a pilot or engineer, nor immune from error - nor am I anonymous.

Having just returned from an overseas trip where I met - among others - several professional historic aviation pilots and engineers as a result of corresponding through online forums, while I may not agree or be agreed with, I'm certainly not "irritating all" although I accept annoying "sundry" does happen. I've also never claimed to be an authority - I just have based my opinions on the understanding of a number of people who are qualified to comment, including a couple of modern (post-Ratier) Comet pilots, and Comet re/builders.

Regarding the much disputed facts - several points you are attempting to 'correct' me on aren't mine, but Erik's - where I was disputing his views. I'm not sure where that leaves your view in those cases.

I'd suggest you are missing a core performance / safety issue of the air-pressure operated Ratier - as any twin-qualified pilot would observe on understanding the mechanism and its risks in the circuit. (Later Ratier developments remove the issue.) It was an 'interim' design, and bicycle-pump operation doesn't just seem Heath Robinson, it's a 'poor' (second-rate, if you prefer) engineering solution - if that were not the case, the technical approach would've been more widely (or longer) used. I agree it was the best solution available in that critical time window, but on your account because the other solutions (better and/or replacements) were not available. If you'd care to show otherwise - not anonymously, please - I'm interested.

Regarding the correction on the engine issue/s over the Timor Sea - Scott's book, while a useful period account (I was looking at a copy last week in a friend's collection, incidentally, but didn't realise I was going to need to check the facts) may not state - as David Ogilvy's The Racing Comets does, that the Comet's engine ran roughly even after the clogged oil filter had been cleaned after landing at Darwin, after the Timor Sea crossing. Ogilvy wasn't writing for the popular media of the time. I certainly agree the Comet and the DH 'R' engine did a remarkable job at the time, as did the crews; but it remains a fact that G-ACSR's engines didn't run without issue on the way out, nor the way back, getting parts from G-ACSP at Allahabad. Referenced corrections welcome, but at the moment, my brief research stands.

We could go on regarding appropriate adjectives and excusing performance shortfalls or recognising compromises as to the props; I think on your own argument the PD30s were evidently not the answer at the time. Conflating the benefits of feathering versus semi-controlled pitch changes is basic technical stuff, perhaps not best argued here given Brett's comment above. However non-anonymous properly-referenced corrections will be welcome on my blog when (if!) I get around to writing up the Ratiers.

Finally, there seems some perhaps genuine misunderstanding of opinion. I'm not "dismissive" of the Comet's performance - in 1934 it was the fastest long distance aircraft on the planet, and deserved most of the accolades heaped upon it; and I rather like the type, personally. However the original point, disputed and re-disputed as it may be, was that a standard airliner was hot on its heels.

Regards,

]]> By: Brett Holman http://airminded.org/2009/10/18/imperial-airways-now-with-extra-airmail/comment-page-1/#comment-158144 Brett Holman Sun, 22 May 2011 06:16:26 +0000 http://airminded.org/?p=2683#comment-158144 Wow, that's a comment and a half, Black Dog! Anyone who has read this blog for any amount of time knows that the finer technical points of aeronautical engineering are not my strong suit, so I won't (can't!) respond to most of this. But I will say a couple of things. I'm in the camp which argues that the DC-2 coming second was more significant than the DH-88 coming first. This is partly because that was a <a href="http://airminded.org/2009/10/23/the-great-air-race/" rel="nofollow">common reaction at the time</a>, but also because while the Comet-inspired Mosquito was a superlative light bomber, in the end it was just that, another bomber. Where are its descendants today? The DC-2 and DC-3, meanwhile, set the stage for the routinisation of long distance civil aviation, and that's something we all take for granted today. Secondly, it's clear that you have encountered JDK elsewhere and brought your animus against him to my blog. Whether he's right or wrong on this issue JDK is a friend of mine, so if you want to keep commenting here, I'd ask you to keep your feelings to yourself and stick to your technical arguments. In my experience, personal attacks (satisfying though they may be) don't help get a point across; quite the opposite. Wow, that's a comment and a half, Black Dog! Anyone who has read this blog for any amount of time knows that the finer technical points of aeronautical engineering are not my strong suit, so I won't (can't!) respond to most of this. But I will say a couple of things. I'm in the camp which argues that the DC-2 coming second was more significant than the DH-88 coming first. This is partly because that was a common reaction at the time, but also because while the Comet-inspired Mosquito was a superlative light bomber, in the end it was just that, another bomber. Where are its descendants today? The DC-2 and DC-3, meanwhile, set the stage for the routinisation of long distance civil aviation, and that's something we all take for granted today.

Secondly, it's clear that you have encountered JDK elsewhere and brought your animus against him to my blog. Whether he's right or wrong on this issue JDK is a friend of mine, so if you want to keep commenting here, I'd ask you to keep your feelings to yourself and stick to your technical arguments. In my experience, personal attacks (satisfying though they may be) don't help get a point across; quite the opposite.

]]> By: Black Dog. http://airminded.org/2009/10/18/imperial-airways-now-with-extra-airmail/comment-page-1/#comment-158130 Black Dog. Sat, 21 May 2011 15:28:24 +0000 http://airminded.org/?p=2683#comment-158130 This is a very old thread now, but I thought it worthy of a few comments, as there is some highly misleading ‘information’ being disseminated here. Firstly with regard to the Comet. There is a wealth of information available if one roots around. All my library and archives are in storage as I'm relocating at present, so this is all from memory, but it's easy enough to verify. The Comets were ALWAYS intended to fly with the DH PD30 airscrews. Period. DH's always intended to produce two versions of the Gipsy Six. The original Six had a tapered, solid crankshaft, suited to fixed-pitch airscrews. The Six Series II, had the SBAC1 splines to suit the PD30, and was of course hollow. The 'R' engines were simply a hybrid to save time in the few months that they had as the DHGSix Series II wasn’t quite ready. The ‘R’s were Six's, with a raised compression-ratio and a few other minor tweaks, but fitted with the DH Gipsy Six hollow crankshaft with the SBAC1 splines to accept the new PD30. DH's had sent a team to tour the USA to look into VP airscrews some time before, and, as a consequence, had reached an agreement with Hamilton's to produce the units under Licence in the UK. There was NEVER for any moment any reason to doubt that they would not work on a smaller power unit. To suggest otherwise is utter nonsense. The fact was, however, that all the off the shelf units from Hamiltons were for the much larger American engines, the DH Gipsy Six being a relative minnow. DH's settled upon the SBAC1 splining to suit the size of the DHGS's crankshaft. (Many years later enlarged to the SBACII for the DHGQ30 et al.) That's why the Comets engines had that spline fitted, and NOT specifically for the Ratiers. The first Comet to fly in fact had the PD30 units fitted and they worked perfectly. In truth, all the development work took longer than anticipated. DH's proved very consistently that they could magic-up an a/c from paper to flying prototype in double-quick time over and over again – one of the advantages of wooden construction. Getting engines and airscrews working reliably and optimally was always going to take longer. This was still all quite new technology at the time after all. Despite the fact that the PD30's worked, they were simply not sufficiently tested. Additionally, owing to the very wide speed-range of the Comet, it exceeded to original design parameters, both in terms of the blade-form and the pitch-range. (This was precisely the problem that affected the Mew Gulls of that era.) They needed speed and they needed range. JDK's comments about the Ratier units are very ignorant. The Ratier units were simple, efficient and well engineered. Clearly, after all the effort to get the Comets ready for the race, to develop the ‘R’s and rush through the PD30, the change to the Ratier, for such a prestigious event, upon which DH’s had their reputation riding, was not taken lightly. It was an informed and well reasoned decision, and, in the circumstances, the decision was entirely logical. Both the Ratier airscrews and the ‘R’ engines performed very well under the circumstances. Much has been made of the apparent failure of ‘SS’s engine(s). After the event, I’m pretty sure that it was simply found to be a faulty oil pressure gauge. The other Comets engines worked well – when not supplied with the wrong fuel….! Remember Cathcart Jones flew directly back to the UK with the same engines. JDK;- I think that you will find that ‘SS’s engine didn’t ‘Lose Power’ over the Timor Sea, as you state, but that, rather, C.W.A.Scott throttled it back because of the faulty gauge. He wrote all that-up in a book just after the even. ‘Scotts Story’ it may have been named. Still on the subject of the Ratier airscrews; Jump forward to 1936 and the Schlesinger Race. Several machines changed to Ratier airscrews (Albeit the electrically actuated version.) at the last moment. Why? Efficiency. Ratiers were faster. Alex’ Henshaw fitted the same unit to’XF for exactly the same reason. Ironically, he was forced to remove it for the Kings Cup and fit a DH PD30, as only British units were allowed at that time (Bloody good job that rule doesn’t apply today..!). Consequently, his machine was around 34mph slower. Res ipsa loquitor. Henshaw would have re-fitted the Ratier for the Cape Record too, but the basic simplicity and reliability of the PD30 won out, as it was another long flight. There was also an issue with the spinners for the Schlesinger event, but I digress. Thus;-“ "DeHavilland ... leveraging its developmental effort into an attack on the airscrew market." Not true in any aspect. They didn't have a propeller to do the job, there was not a British design that could, and so they chose what can politely called an 'interim' design from Ratier.” JDK as usual, pontificating - and wrong. "The Ratier was certainly a peculiar design. It was more aerodynamically efficient and more useful than the two-pitch on the Douglas." I would be interested in where you get the data to suggest the Ratier was a better propeller than the DC-2's Hamilton Standard. Not only was the Ratier inferior to the DC-2 propellers, it was actually compromised in performance and safety (due to the Heath-Robinson airflow pitch-change mechanism) and irreversible, so could jam, act asymmetrically, and critically, in the case of an aborted take-off or landing or a go-around, was unable to regain course pitch. They were replaced on the Comet type as soon as possible and when the Comet Racer was restored at Shuttleworth, there was no question of using this poor interim design. Further, de Havilland (note spacing and capitalisation) did not develop their own propeller design pre-war, they set up de Havilland Propellers in 1935 (note date) by licencing Hamilton Standard designs from - America. As far as I’m aware, JDK isn’t a pilot, or an engineer, as the above clearly shows. Seems he’s not much a a historian either. Neither am I, but I don’t pop-up on every forum on the web promoting myself as such to the irritation of all and sundry…. We aren’t talking about an Airfix kit or correct colour schemes here. The words ‘better’, ‘poor’ or ‘inferior’ are quite irrelevant in this context. As for the pitch change mechanism itself, yes, it was a well known characteristic that the pitch-change initiation could, and probably would occur asynchronously. Every pilot flying them was well aware of that. Duh. DH’s decision to use the Ratiers was a bold move and was utterly vindicated. I might also add, that, the Hamilton/PD30 airscrews were also unfeatherable, as were all ‘Bracket-Type’ airscrews. ‘SS now uses the PD30, but the rebuilt ‘Black Magic’ will, on good advice, use the Hydromatic which is fully featherable, as it’s using Q30’s. All the DH Hydromatics on Gipsys need an SBACII ya see. JDK has allowed the 1935 date of the setting-up, administratively, of DH’s separate airscrew division to mislead him. The tour to the USA and the agreements probably date to 1933 from memory. Check Flights archives, it’s all in there. The Centenary Race; A minor point first – I seem to recall that the DC2 did have extra fuel capacity fitted. I don’t think it had a standard interior either, but as I was never much interested, I may well be wrong on these two points. I also seem to recall that the Comet actually won both the Speed AND the Handicap race, but the rules prevented Scott & Black from claiming both, so, understandably, they opted for the speed prize. JDK is quite right to point-out that the DC2’s performance was very respectable, and a portent of things to come. He is however wrong, as he often is, to be so dismissive of the Comets performance. The Comet would have arrived in Oz even sooner had the (Bogus.) oil pressure issue not delayed them significantly. In previous years, aircraft arriving in the antipodes took weeks and made dozens of stops. Some even had to be rebuilt several times along the way. I think ‘SS made just four stops. Formula One races are won by hundredths of a second. This wasn’t a sprint special for a few minutes around the pylons, it was the other side of the globe, in all weathers, and, in the case of Cathcart Jones, all the way back. The effort required to increase speed is basically always exponential, so at the time, given the relatively tiny engines fitted to the Comet, it was somewhat akin to the 1969 moonshot. The DC2 may well have given birth to the DC3, but the Comet gave birth to the Mosquito, a much more significant leap. Just because one has ridden-in and crawled all over a/c doesn’t make one an authority, no matter how tiresomely enthusiastic one is. There is more. I could go on but I have much more pressing aviation matters to address. This is a very old thread now, but I thought it worthy of a few comments, as there is some highly misleading ‘information’ being disseminated here.
Firstly with regard to the Comet.
There is a wealth of information available if one roots around. All my library and archives are in storage as I'm relocating at present, so this is all from memory, but it's easy enough to verify.
The Comets were ALWAYS intended to fly with the DH PD30 airscrews. Period. DH's always intended to produce two versions of the Gipsy Six. The original Six had a tapered, solid crankshaft, suited to fixed-pitch airscrews. The Six Series II, had the SBAC1 splines to suit the PD30, and was of course hollow. The 'R' engines were simply a hybrid to save time in the few months that they had as the DHGSix Series II wasn’t quite ready. The ‘R’s were Six's, with a raised compression-ratio and a few other minor tweaks, but fitted with the DH Gipsy Six hollow crankshaft with the SBAC1 splines to accept the new PD30. DH's had sent a team to tour the USA to look into VP airscrews some time before, and, as a consequence, had reached an agreement with Hamilton's to produce the units under Licence in the UK. There was NEVER for any moment any reason to doubt that they would not work on a smaller power unit. To suggest otherwise is utter nonsense. The fact was, however, that all the off the shelf units from Hamiltons were for the much larger American engines, the DH Gipsy Six being a relative minnow. DH's settled upon the SBAC1 splining to suit the size of the DHGS's crankshaft. (Many years later enlarged to the SBACII for the DHGQ30 et al.) That's why the Comets engines had that spline fitted, and NOT specifically for the Ratiers. The first Comet to fly in fact had the PD30 units fitted and they worked perfectly. In truth, all the development work took longer than anticipated. DH's proved very consistently that they could magic-up an a/c from paper to flying prototype in double-quick time over and over again – one of the advantages of wooden construction. Getting engines and airscrews working reliably and optimally was always going to take longer. This was still all quite new technology at the time after all. Despite the fact that the PD30's worked, they were simply not sufficiently tested. Additionally, owing to the very wide speed-range of the Comet, it exceeded to original design parameters, both in terms of the blade-form and the pitch-range. (This was precisely the problem that affected the Mew Gulls of that era.) They needed speed and they needed range.
JDK's comments about the Ratier units are very ignorant. The Ratier units were simple, efficient and well engineered. Clearly, after all the effort to get the Comets ready for the race, to develop the ‘R’s and rush through the PD30, the change to the Ratier, for such a prestigious event, upon which DH’s had their reputation riding, was not taken lightly. It was an informed and well reasoned decision, and, in the circumstances, the decision was entirely logical. Both the Ratier airscrews and the ‘R’ engines performed very well under the circumstances. Much has been made of the apparent failure of ‘SS’s engine(s). After the event, I’m pretty sure that it was simply found to be a faulty oil pressure gauge. The other Comets engines worked well – when not supplied with the wrong fuel….! Remember Cathcart Jones flew directly back to the UK with the same engines. JDK;- I think that you will find that ‘SS’s engine didn’t ‘Lose Power’ over the Timor Sea, as you state, but that, rather, C.W.A.Scott throttled it back because of the faulty gauge. He wrote all that-up in a book just after the even. ‘Scotts Story’ it may have been named.
Still on the subject of the Ratier airscrews; Jump forward to 1936 and the Schlesinger Race. Several machines changed to Ratier airscrews (Albeit the electrically actuated version.) at the last moment. Why? Efficiency. Ratiers were faster. Alex’ Henshaw fitted the same unit to’XF for exactly the same reason. Ironically, he was forced to remove it for the Kings Cup and fit a DH PD30, as only British units were allowed at that time (Bloody good job that rule doesn’t apply today..!). Consequently, his machine was around 34mph slower. Res ipsa loquitor. Henshaw would have re-fitted the Ratier for the Cape Record too, but the basic simplicity and reliability of the PD30 won out, as it was another long flight. There was also an issue with the spinners for the Schlesinger event, but I digress.
Thus;-“ "DeHavilland ... leveraging its developmental effort into an attack on the airscrew market." Not true in any aspect. They didn't have a propeller to do the job, there was not a British design that could, and so they chose what can politely called an 'interim' design from Ratier.” JDK as usual, pontificating - and wrong.

"The Ratier was certainly a peculiar design. It was more aerodynamically efficient and more useful than the two-pitch on the Douglas." I would be interested in where you get the data to suggest the Ratier was a better propeller than the DC-2's Hamilton Standard. Not only was the Ratier inferior to the DC-2 propellers, it was actually compromised in performance and safety (due to the Heath-Robinson airflow pitch-change mechanism) and irreversible, so could jam, act asymmetrically, and critically, in the case of an aborted take-off or landing or a go-around, was unable to regain course pitch. They were replaced on the Comet type as soon as possible and when the Comet Racer was restored at Shuttleworth, there was no question of using this poor interim design. Further, de Havilland (note spacing and capitalisation) did not develop their own propeller design pre-war, they set up de Havilland Propellers in 1935 (note date) by licencing Hamilton Standard designs from - America.
As far as I’m aware, JDK isn’t a pilot, or an engineer, as the above clearly shows. Seems he’s not much a a historian either. Neither am I, but I don’t pop-up on every forum on the web promoting myself as such to the irritation of all and sundry…. We aren’t talking about an Airfix kit or correct colour schemes here. The words ‘better’, ‘poor’ or ‘inferior’ are quite irrelevant in this context. As for the pitch change mechanism itself, yes, it was a well known characteristic that the pitch-change initiation could, and probably would occur asynchronously. Every pilot flying them was well aware of that. Duh. DH’s decision to use the Ratiers was a bold move and was utterly vindicated. I might also add, that, the Hamilton/PD30 airscrews were also unfeatherable, as were all ‘Bracket-Type’ airscrews. ‘SS now uses the PD30, but the rebuilt ‘Black Magic’ will, on good advice, use the Hydromatic which is fully featherable, as it’s using Q30’s. All the DH Hydromatics on Gipsys need an SBACII ya see. JDK has allowed the 1935 date of the setting-up, administratively, of DH’s separate airscrew division to mislead him. The tour to the USA and the agreements probably date to 1933 from memory. Check Flights archives, it’s all in there.
The Centenary Race; A minor point first – I seem to recall that the DC2 did have extra fuel capacity fitted. I don’t think it had a standard interior either, but as I was never much interested, I may well be wrong on these two points.
I also seem to recall that the Comet actually won both the Speed AND the Handicap race, but the rules prevented Scott & Black from claiming both, so, understandably, they opted for the speed prize. JDK is quite right to point-out that the DC2’s performance was very respectable, and a portent of things to come. He is however wrong, as he often is, to be so dismissive of the Comets performance. The Comet would have arrived in Oz even sooner had the (Bogus.) oil pressure issue not delayed them significantly. In previous years, aircraft arriving in the antipodes took weeks and made dozens of stops. Some even had to be rebuilt several times along the way. I think ‘SS made just four stops. Formula One races are won by hundredths of a second. This wasn’t a sprint special for a few minutes around the pylons, it was the other side of the globe, in all weathers, and, in the case of Cathcart Jones, all the way back. The effort required to increase speed is basically always exponential, so at the time, given the relatively tiny engines fitted to the Comet, it was somewhat akin to the 1969 moonshot. The DC2 may well have given birth to the DC3, but the Comet gave birth to the Mosquito, a much more significant leap.
Just because one has ridden-in and crawled all over a/c doesn’t make one an authority, no matter how tiresomely enthusiastic one is. There is more. I could go on but I have much more pressing aviation matters to address.

]]> By: Ian Evans http://airminded.org/2009/10/18/imperial-airways-now-with-extra-airmail/comment-page-1/#comment-136281 Ian Evans Tue, 13 Apr 2010 16:17:33 +0000 http://airminded.org/?p=2683#comment-136281 Yes, the Hamilton-Standard unit wasn't used because no one knew how it would behave on such small engines and there was no time to test it. No, three Comets were entered, two finished, and the one that came fourth in the race turned round and flew back to the UK with newsreel films of the finish to the race. Yes, the Hamilton-Standard unit wasn't used because no one knew how it would behave on such small engines and there was no time to test it.
No, three Comets were entered, two finished, and the one that came fourth in the race turned round and flew back to the UK with newsreel films of the finish to the race.

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