Canberra confusion
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Canberra confusion
Here's a real head-scratcher...
As Canberra experts will know, the Canberra PR9 carried tips tanks (when required) on the original B2/6 wing tip, so they were slightly inboard of the extended PR9 wing tip.
However, WH973 appears to be the one exception to the rule:-
The aircraft started-off as a PR7 and was modified to PR9 configuration (retaining the original B2 nose). Serving with the RAE, it was employed on gust research and on a few photos, the tip tanks appear to be fitted on the actual tips of the extended PR9 wing. Some of my colleagues insist it's an optical illusion but I'm convinced that the tanks (pods actually, as they didn't carry fuel) are indeed attached to the extended wing tips.
Anyone know any other photos that prove/disprove this? And if they really are in this odd position, then why?
As Canberra experts will know, the Canberra PR9 carried tips tanks (when required) on the original B2/6 wing tip, so they were slightly inboard of the extended PR9 wing tip.
However, WH973 appears to be the one exception to the rule:-
The aircraft started-off as a PR7 and was modified to PR9 configuration (retaining the original B2 nose). Serving with the RAE, it was employed on gust research and on a few photos, the tip tanks appear to be fitted on the actual tips of the extended PR9 wing. Some of my colleagues insist it's an optical illusion but I'm convinced that the tanks (pods actually, as they didn't carry fuel) are indeed attached to the extended wing tips.
Anyone know any other photos that prove/disprove this? And if they really are in this odd position, then why?
Last edited by WH904; 21st Jul 2013 at 22:04.
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I found the two images below on Google, although it's true to say that photos of PR9s with tanks/pods seem to be few and far between. I'm no type specialist, so you will have to decide if they are actually PR9s or not, but they are captioned as such in both instances.
No1 - PR9 with tanks/pods 'on' wing tip - similar to your photo:
No 2 - PR9 with tanks/pods well under wing tip:
No1 - PR9 with tanks/pods 'on' wing tip - similar to your photo:
No 2 - PR9 with tanks/pods well under wing tip:
Originally Posted by nacluv
I found the two images below on Google, although it's true to say that photos of PR9s with tanks/pods seem to be few and far between. I'm no type specialist, so you will have to decide if they are actually PR9s or not, but they are captioned as such in both instances.
No1 - PR9 with tanks/pods 'on' wing tip - similar to your photo:
IMAGE#1
No 2 - PR9 with tanks/pods well under wing tip:
IMAGE#2
No1 - PR9 with tanks/pods 'on' wing tip - similar to your photo:
IMAGE#1
No 2 - PR9 with tanks/pods well under wing tip:
IMAGE#2
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Unfortunately the picture In my copy of " A short illustrated History of the RAE Bedford" by Arthur Pearcy is cropped so doesn't show the wing tips however it does say that WH793 participated in the HICAT programme in 1967 and was based at NASAs Ames research centre at Moffat Field.
A quick Goggle on clear air turbulence test bed has thrown up a whole load of flight sim and model pictures but only one actual image which is here and by the looks of it copy righted up to the ying yang so I've posted the link instead
Canberra PR Mk.7 WH793 Masirah 06101972 D12606
It also shows zaps for project COLDCAT RAF Tengah, StormForm and Operations Rover 1967.
A quick Goggle on clear air turbulence test bed has thrown up a whole load of flight sim and model pictures but only one actual image which is here and by the looks of it copy righted up to the ying yang so I've posted the link instead
Canberra PR Mk.7 WH793 Masirah 06101972 D12606
It also shows zaps for project COLDCAT RAF Tengah, StormForm and Operations Rover 1967.
Last edited by Windy Militant; 22nd Jul 2013 at 18:21.
Originally Posted by Harley Quinn
TBH I can't see a difference that couldn't be explained by angle of view and shadow.
WH973 was written off twice following accidents
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WH973 was written off twice following accidents
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Canberra Confusion
WH904,
Aircraft flown by the RAE were often unique, despite their apparent resemblance to front-line types.
Googling Canberra WH793 brings up quite a bit of relevant info, ie it was a HAPR.9 converted by Napier from a PR7 with the new proposed PR9 wing configuration, which first flew 8 July 1955.
The following link has a different image in the RAE Aero Flt Bedford livery with a better indication of the Tip Tank fit:
Topic: HAPR.9 WH793, this time at the end of the story - IPMS UK Canberra SIG
lm
Aircraft flown by the RAE were often unique, despite their apparent resemblance to front-line types.
Googling Canberra WH793 brings up quite a bit of relevant info, ie it was a HAPR.9 converted by Napier from a PR7 with the new proposed PR9 wing configuration, which first flew 8 July 1955.
The following link has a different image in the RAE Aero Flt Bedford livery with a better indication of the Tip Tank fit:
Topic: HAPR.9 WH793, this time at the end of the story - IPMS UK Canberra SIG
lm
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The above link/s highlight the problem! The chap who has carefully built the model firmly believes that the aircraft was re-winged with standard B2 wings, but only because he thinks it would have been ludicrous to have fitted the tanks in a non-standard position (I asked him about this).
Likewise, the flight simulator people have made the same assumption, probably because they've picked-up the same assertion off the internet. It becomes a sort of Chinese whisper and if we're not careful it will become fact, even though photographs clearly show it isn't fact at all.
However, examination of photographs clearly shows that the tanks are attached to the tips of a PR9 outer wing. There's no logical reason why the tanks (pods in this case) would be attached here, as they could have been attached on the standard PR9 position on the original B2 wing tip inboard. So there must have been a good reason why they were not.
Even Adrian Balch's magnificent book "Testing Colours" doesn't solve the mystery. Two lovely photos in there, but they only show the starboard tank (pod) attached to a wing tip, but no clarification as to what wing tip it is. But close examination of the shape and the navigation light suggests it's a PR9 wing.
So... this is where I came in. Logic suggests that the tanks should be fitted to a standard B2 outer wing but even on the above photo, you can see that it isn't a B2 outer wing, it's a PR9 wing.
It's a very odd machine!
Likewise, the flight simulator people have made the same assumption, probably because they've picked-up the same assertion off the internet. It becomes a sort of Chinese whisper and if we're not careful it will become fact, even though photographs clearly show it isn't fact at all.
However, examination of photographs clearly shows that the tanks are attached to the tips of a PR9 outer wing. There's no logical reason why the tanks (pods in this case) would be attached here, as they could have been attached on the standard PR9 position on the original B2 wing tip inboard. So there must have been a good reason why they were not.
Even Adrian Balch's magnificent book "Testing Colours" doesn't solve the mystery. Two lovely photos in there, but they only show the starboard tank (pod) attached to a wing tip, but no clarification as to what wing tip it is. But close examination of the shape and the navigation light suggests it's a PR9 wing.
So... this is where I came in. Logic suggests that the tanks should be fitted to a standard B2 outer wing but even on the above photo, you can see that it isn't a B2 outer wing, it's a PR9 wing.
It's a very odd machine!
Last edited by WH904; 22nd Jul 2013 at 19:19.
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nacluv thanks for the photo links. That helps to explain what I'm getting at. The top machine is a PR9, the lower aircraft is also (technically) a PR9 although it's designated as an SC9 (it was a non-standard RAE machine). As you can see, the tip tanks are not actually on the wing tips, they're attached to the tip of the original B2 wing structure, just inboard. However WH973 has the same longer wings, but the tanks (they're actually equipment pods) are on the actual tips. This is the mystery - why would they be there?
Last edited by WH904; 22nd Jul 2013 at 19:23.
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This is my first post, I've been trying to get to the bottom of this conundrum for some time, I am the person responsible for the model of WH793 on the link, my reasoning for the modified or should that be de modified wing tip is as follows.
This is the summery for the test flights carried out by WH793 in 1967 in the USA
SUMMARY
In a number of flights in the stratosphere over mountainous terrain in
the western U.S.A., much valuable data was collected. Flights "are planned
on the basis of tropospheric lee wave forecasts and were usually made along
wind at heights from the tropopause to about 50000 ft over California and
Nevada. Mountain waves, deduced from an analysis of the temperature along
the flight track, were moderate or strong on four flights. Moderate or severe
turbulence and marked temperature changes were encountered on three flights.
The results give an insight into the severity of the stratospheric environment
and the meteorological conditions in which the severe disturbances occur.
My reasoning behind the standard wing tips on 793?
The extended wing span would serve no advantage in a gusty turbulent environment, indeed it would only amplify any airframe buffet and add to crew discomfort.
The PR.9 wing tip is not and was never intended to support any
weight, it is purely an increase in span. All the electrical wiring and fuel
goes to the same point as it dose on the standard PR.7 wing and any other
Canberra wing. The wing on the production PR.9's are basically that of the
B(I)8 but with the area increased. There would be no advantage in increasing the strength or re designing the tips on 793.
The wing tip of the Canberra is relatively easy to remove and the two types of wing tip and they are quite interchangeable.
I have closely studied photos of 793 from this time
and I can see no evidence of modifications to the tip tanks that would
indicate that they are fitted to anything other than the standard Canberra
wing tip. In order for the tanks to fit the PR.9 wing the tip tanks need a
fairing to modify the shape to the new wing profile.
I wouldn’t fancy flying through CAT with two hefty pods hanging off a relatively flimsy structure. The small increase in altitude gained from the extra span wouldn’t warrant the extra work involved in all the cost and effort in redesigning and beefing up the PR.9 wing tips, that for me is one of the biggest clues to the normal wing tips being re fitted, you wouldn’t go to all the trouble of ignoring a perfectly serviceable electrical connection and a designed attachment point for the tank/pod, to move them out to hang on a structure that was never designed for, or intended to carry anything other than a light. it can’t see it being for any radar related purpose either as I said before the SC.9 didn’t need to have it’s pods moved and other R&D Canberra’s flew with standard tip mounted pods. I just wish my WH793 PN’s had a three view and measurements!
John
This is the summery for the test flights carried out by WH793 in 1967 in the USA
SUMMARY
In a number of flights in the stratosphere over mountainous terrain in
the western U.S.A., much valuable data was collected. Flights "are planned
on the basis of tropospheric lee wave forecasts and were usually made along
wind at heights from the tropopause to about 50000 ft over California and
Nevada. Mountain waves, deduced from an analysis of the temperature along
the flight track, were moderate or strong on four flights. Moderate or severe
turbulence and marked temperature changes were encountered on three flights.
The results give an insight into the severity of the stratospheric environment
and the meteorological conditions in which the severe disturbances occur.
My reasoning behind the standard wing tips on 793?
The extended wing span would serve no advantage in a gusty turbulent environment, indeed it would only amplify any airframe buffet and add to crew discomfort.
The PR.9 wing tip is not and was never intended to support any
weight, it is purely an increase in span. All the electrical wiring and fuel
goes to the same point as it dose on the standard PR.7 wing and any other
Canberra wing. The wing on the production PR.9's are basically that of the
B(I)8 but with the area increased. There would be no advantage in increasing the strength or re designing the tips on 793.
The wing tip of the Canberra is relatively easy to remove and the two types of wing tip and they are quite interchangeable.
I have closely studied photos of 793 from this time
and I can see no evidence of modifications to the tip tanks that would
indicate that they are fitted to anything other than the standard Canberra
wing tip. In order for the tanks to fit the PR.9 wing the tip tanks need a
fairing to modify the shape to the new wing profile.
I wouldn’t fancy flying through CAT with two hefty pods hanging off a relatively flimsy structure. The small increase in altitude gained from the extra span wouldn’t warrant the extra work involved in all the cost and effort in redesigning and beefing up the PR.9 wing tips, that for me is one of the biggest clues to the normal wing tips being re fitted, you wouldn’t go to all the trouble of ignoring a perfectly serviceable electrical connection and a designed attachment point for the tank/pod, to move them out to hang on a structure that was never designed for, or intended to carry anything other than a light. it can’t see it being for any radar related purpose either as I said before the SC.9 didn’t need to have it’s pods moved and other R&D Canberra’s flew with standard tip mounted pods. I just wish my WH793 PN’s had a three view and measurements!
John
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As described in the previous post, there is no plausible reason why the tip tanks would be fitted on PR9 outer wing tips. So why were they fitted thus?
Just in case anyone isn't convinced that the aircraft does have PR9 wings, take a look at this photo:-
I've added a red line to show the obvious similarity between a standard PR9 wing and WH793.
Then there's this illustration:-
Standard Canberra B2 wing in the top picture, and WH793 below. I think anyone can see that the wing tips, aileron trailing edge (no trim tab) and tank fairings are not the same.
So, given that it is a PR9 wing, why on Earth would the tanks (pods) be attached outboard of the normal attachment point?
Just in case anyone isn't convinced that the aircraft does have PR9 wings, take a look at this photo:-
I've added a red line to show the obvious similarity between a standard PR9 wing and WH793.
Then there's this illustration:-
Standard Canberra B2 wing in the top picture, and WH793 below. I think anyone can see that the wing tips, aileron trailing edge (no trim tab) and tank fairings are not the same.
So, given that it is a PR9 wing, why on Earth would the tanks (pods) be attached outboard of the normal attachment point?
Last edited by WH904; 23rd Jul 2013 at 07:19.
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There is no doubt it is the increased cord PR.9 wing complete with power control surfaces, this is confirmed by my copy of the pilots notes. It's just the tips that were changed back to the standard version, I hope 
!
This is not without precedent the following photo is of 793 obviously before the it's modification at Bedford but after the larger cord was reduced to that of the "standard" PR.9 wing with short/standard span tips fitted.
Until we can find a photo or drawing that confirms or denies that the radar and camera pods were attached to the extended PR.9 tips I'm sticking with my theory.
I've copied some info from my PR.9 AP's, I'm sure it was not beyond the whit of the highly skilled guys at Bedford to engineer a way of attaching and beefing up the PR.9 tips but the big question is why?
!This is not without precedent the following photo is of 793 obviously before the it's modification at Bedford but after the larger cord was reduced to that of the "standard" PR.9 wing with short/standard span tips fitted.
Until we can find a photo or drawing that confirms or denies that the radar and camera pods were attached to the extended PR.9 tips I'm sticking with my theory.
I've copied some info from my PR.9 AP's, I'm sure it was not beyond the whit of the highly skilled guys at Bedford to engineer a way of attaching and beefing up the PR.9 tips but the big question is why?
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Pure speculation on my part (I have no knowledge of Canberras apart from one back seat flight from St Mawgan in 1972) so I have my hat and coat ready!
Could it be that the tanks were attached to the normal points BUT the wingtips were shortened? One reason for doing that might be to reduce the flexing moment in turbulence!
I now await incoming!
Could it be that the tanks were attached to the normal points BUT the wingtips were shortened? One reason for doing that might be to reduce the flexing moment in turbulence!
I now await incoming!
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Well this is the debate really. A lot of people (including John above) think that the aircraft must have had standard B2 wings re-fitted (or more likely the extended PR9 tips simply removed) so that the structural, fuel and electrical attachment point could be used as normal. I see the logic in this, but the problem is that the photos (including those above) clearly show that this isn't the case.
It's all just very odd. There's no reason why the tanks couldn't be attached in the proper position, and yet they evidently were not. I'd just like to find out why as it seems like a very strange arrangement. I'd also like to find a nose-on picture of the aircraft just to clearly confirm this absurdity once and for all!
It's all just very odd. There's no reason why the tanks couldn't be attached in the proper position, and yet they evidently were not. I'd just like to find out why as it seems like a very strange arrangement. I'd also like to find a nose-on picture of the aircraft just to clearly confirm this absurdity once and for all!
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WH904
Have you contacted FAST at Farnborough:
FAST - Farnborough Air Sciences Trust - Farnborough Museum - Hampshire
Most of the RAE documentation, Reports etc were passed to FAST following the destruction of the RAE. Possibly they may have the relevant RAE Mod Drawings etc that should clarify how and why the Pods are attached as they are. Failing that, the relevant trial(s) would have been reported and RAE Reports usually contained the engineering aspects of the trial installations.
lm
Have you contacted FAST at Farnborough:
FAST - Farnborough Air Sciences Trust - Farnborough Museum - Hampshire
Most of the RAE documentation, Reports etc were passed to FAST following the destruction of the RAE. Possibly they may have the relevant RAE Mod Drawings etc that should clarify how and why the Pods are attached as they are. Failing that, the relevant trial(s) would have been reported and RAE Reports usually contained the engineering aspects of the trial installations.
lm
Last edited by lightningmate; 23rd Jul 2013 at 09:21.
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I emailed them a couple of days ago so I'm hoping they might be able to shed some light on this. So far no news but if I hear anything I'll post it here
As for the above photo of the aircraft in PR7 guise, I'm not convinced that it is a PR9 wing with the tips removed. You'd need to see the upper surface to be certain of that (ie- are the power controls there) but as you can see, it has a standard aileron with a trim tab. That suggests that it's a standard wing, not a PR9 wing with the tip removed. I'm guessing that the underside shot shows the aircraft before it had PR9 wings fitted. Or did it have PR9 wings and then have B2 wings fitted, and then go back to PR9 wings?! It gets more absurd the more you look into it!
As for the above photo of the aircraft in PR7 guise, I'm not convinced that it is a PR9 wing with the tips removed. You'd need to see the upper surface to be certain of that (ie- are the power controls there) but as you can see, it has a standard aileron with a trim tab. That suggests that it's a standard wing, not a PR9 wing with the tip removed. I'm guessing that the underside shot shows the aircraft before it had PR9 wings fitted. Or did it have PR9 wings and then have B2 wings fitted, and then go back to PR9 wings?! It gets more absurd the more you look into it!
Last edited by WH904; 23rd Jul 2013 at 10:19.
If I can enter the argument as a very long time serving Canberra PR9 man, the PR7 prototype in the photographs have the PR9 wing root cord extension but not the square PR9 wing tip extension.
The PR9 tip tanks fit at the original B2 / B6 mounting point and are identical to all other Canberra wing tip tanks.
Although many were modified to fit chaff dispensers/ radar heads and other bits of trial equipment all remain the same three point mounting with explosive bolts. The PR9 wing tip extension, which is not readily removable, is not primary structure and is supported by an extended internal spar which will not carry the weight of a full drop tank.
The PR9 tip tanks fit at the original B2 / B6 mounting point and are identical to all other Canberra wing tip tanks.
Although many were modified to fit chaff dispensers/ radar heads and other bits of trial equipment all remain the same three point mounting with explosive bolts. The PR9 wing tip extension, which is not readily removable, is not primary structure and is supported by an extended internal spar which will not carry the weight of a full drop tank.
Last edited by scorpion63; 23rd Jul 2013 at 11:54.
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I'm in agreement on all that (apologies - I think I should have been more clear and said "outer wing" when referring to the photos) but, as I keep saying, what about the photos? I guess it's possible to misinterpret the pictures but on the other hand it would be unwise to dismiss them just because logic says they must be wrong.
Hope somebody out there has a picture of the aircraft taken front-on so that the wing span can be established. I guess that's the only way to settle the mystery?
Hope somebody out there has a picture of the aircraft taken front-on so that the wing span can be established. I guess that's the only way to settle the mystery?
Last edited by WH904; 23rd Jul 2013 at 13:38.
Last edited by scorpion63; 23rd Jul 2013 at 14:21.