Underwing pylons on E.E. Lightning F.6?

[Doc72]

As far as I know, the RAF never intended to use its Lightnings for ground attack missions. The underwing pylons were normally an exclusive feature of the multi-role export model, the F.53. For marketing purposes BAC used the F.53s with the registrations G-AXEE and G-AWON that were on display at Farnborough and Le Bourget trying to convince potential customers. There are plenty of photos of these aircraft, sometimes carrying a bewildering amount of MATRA and Microcell rockets in the fuselage, under and above the wings. Both aircraft were later delivered to Kuwait and Saudi Arabia.

However, there are also photos of what seem to be standard F.6s on display at Air Shows with the underwing pylons of the multi role version. Such aircraft are XP697, XS903 and XS934. The last two even carried squadron markings of No. 5 and No. 11 Sqn, so it looks like BAC borrowed them from RAF squadron service for marketing.

So I wonder whether every RAF F.6 could carry underwing pylons although they probably never did so in squadron service? Any thoughts?

[SAT69]

I went on the internet and did a search for photos of the three airplanes you identified. I found photos of XS903 and XS934 where both carried outboard underwing stores pylons. However, I noted both were photographed at the Paris Air Show and I found no photo evidence that these F.6s were ever permanently equipped to carry outboard underwing external stores. Non-airshow photos of these two planes show them minus the pylons. I'm speculating that when photographed the planes were fitted with dummy pylons but I'm at a loss to explain how they would have been mounted. BAE worked some kind of temporary magic?

[Doc72]

I also thought about dummy pylons, but, as you said, how to fix them, even for static display? That's why I thought that maybe the F.6 and the F.53 wings were identical. The RAF just never saw the need to install these pylons in squadron service?

[Selwyn]

11 hours ago, Doc72 said:

I also thought about dummy pylons, but, as you said, how to fix them, even for static display? That's why I thought that maybe the F.6 and the F.53 wings were identical. The RAF just never saw the need to install these pylons in squadron service?

This is quite likely, why change the design of a wing? Design change  costs a lot of money  so a one size fits all design is the economic and sensible way to go.  Its a good selling point, OK the RAF never used pylons on lightning but the option was there if ever required in the future.

As an example of this principle, If you look at the Tornado F3 which was a missile armed interceptor design, the wing was exactly the same wing as  seen on the GR1 and had the outer pylon mounting points, although they were never used in normal F3 operations. When they explored the idea of using the F3 as a possible defence supression aircraft they were able to mount  outer pylons to carry Pods and Alarm missiles. In the same vein the F3 fuselage centre section was also the same as the GR1 so they could also fit the GR1 shoulder pylons with alarms to the F3 as well.

 

Selwyn

[kingcanberra]

The Daco book on the lightning says "The F.53 (not T.55) export version has additional internal structure to strengthen  the wing to allow for the provision of an underwing pylon". The accompanying photos show a distinct pylon shaped structure inset to the underwing surface.  This should show up on any underside photo

 

The Ian Huntley scale diagram in the Warpaint doesn't show these panel lines (not conclusive I know but certainly suggestive).

 

None of the photos I have access to show this area of the F.6 clearly.

[SAT69]

     I checked what references I have and managed to find a picture of an F.53, airborne, shot from below. Couldn't see even a hint of an inset area on the wing under surface. I made a point of trying to pinpoint where that would be and noted the pylon leading edge would be very close to the leading edge of the wing and the pylon itself is nearly centered on the ailerons. 

     Kingcanberra, I believe your reference answers the question for us, regarding the underwing pylon; additional structure was added to make provision for it, implying such structure was not present in previous marks of the Lightning. But we still don't have an answer as to how such pylons were mounted on static display F.6s at aforementioned airshows. Plastic (little weight) dummy pylons attached with industrial strength tape? For a display, they need only look like pylons, not necessarily be functional and the attached "weapons" might well be plastic too. I know, extreme speculation, but I have no other idea how they might have done it without making genuine modifications to the actual display aircraft. Don't think the RAF would have smiled kindly on that.

     Keep in mind too the RAF ordered the Lightning solely as an interceptor and put little enough into it to keep it up to date, much less adding anything to it to make it more versatile. 

     For what it's worth, I have three Lightning reference books and none of them give any detail regarding possible modifications made to the Lightning 6 late in its career. Sorry.

[Irish 251]

XS903 still exists, at Elvington, so when movement bans are lifted maybe someone can go and inspect it.

[SAT69]

I sent a message to the Yorkshire Air Museum and asked for clarification in this matter. Will let you folks know when I get a reply.

[rossm]

This is what it looks like on the Norfolk Air Museums F.53

 

[Hook]

Great pic, thanks!

 

Cheers,

 

Andre

[Duncan B]

I am sure, but have no evidence to that effect that, the export aircraft's wings would have been modified structurally from F.6 standard to carry pylons and they would also have required associated wiring for this pylons. I see no reason why BAC would have added the structural strengthening and wiring to the RAF F.6s for free (but at a weight cost to the airframes) without a specification asking them to do so. Unlike the Tornado F.3 example stated above the F.6 came first then the export versions so it wouldn't have been cheaper to use existing tooling.

As I say I have nothing to support this other than the knowledge that the MOD always considered the Lightning to be a stopgap and anticipated it's withdrawl to be sooner rather than later. They were hard pushed to add any upgrades to the RAF Lightnings in service so wouldn't have requested and paid for capability that they never intended using.

 

Duncan B

[sloegin57]

1 hour ago, rossm said:

This is what it looks like on the Norfolk Air Museums F.53

 

...and this is an f.6 wing :-

 

 

Dennis

 

[JagRigger]

If you look at the wings pictures of XR728 on the Thunder and Lightnings site, there appears to be a banking plate over what looks like the pylon spigot mount

 

https://www.thunder-and-lightnings.co.uk/lightning/walkaround.php

[David Womby]

Just speculating here but does anybody know the build dates for XS903 and XS934?  I am wondering if it is possible that they were built AFTER introduction of the F.53 on the production lines and F.53 wings were fitted without the necessary wiring in the fuselage to support use of the pylons?  Or that XS903 and XS934 had wings replaced at some time for this display?

David

[sloegin57]

19 minutes ago, David Womby said:

Or that XS903 and XS934 had wings replaced at some time for this display?

David

Basically No.  The two wings were bolted together on the centre line and then the rest of the aircraft was built around the complete unit :-

 

Cheers

 

Dennis

[71chally]

1 hour ago, JagRigger said:

If you look at the wings pictures of XR728 on the Thunder and Lightnings site, there appears to be a banking plate over what looks like the pylon spigot mount

 

https://www.thunder-and-lightnings.co.uk/lightning/walkaround.php

Unless I'm missing what you're looking at, it looks like the standard access panels to me.

 

XP697 was one of the late version development aircraft, converted from an F.3, that might explain why that had pylons, haven't seen references to the other two showing pylons fitted.

[Doc72]

Another point worth considering might be that the F.6 could carry overwing tanks unlike the earlier marks IIRC. This means that the wing of the F.6 had received some kind of reinforcement and additional wiring. These overwing pylons at least are something only the F.6 and the F.53 had in common. Of course, this doesn't proof that both marks had identical wings.

Another wild guess would be that BAC produced surplus F.53 wings and used them for some F.6s when anticipated export orders did not materialise.

[rossm]

From an article on the Export Lightning in Flight International 5th September 1968:-

 

Like the F.6, the F.53 is a
long-range aircraft with a low-drag, cambered leading edge, a
large ventral fuel tank, provision for a flight-refuelling probe
and carrying additional fuel for ferrying in two 260 gallon
jettison-tanks mounted on overwing pylons. There have been
few structural changes other than local strengthening of the
wing for the carriage of underwing stores.

[Doc72]

56 minutes ago, rossm said:

From an article on the Export Lightning in Flight International 5th September 1968:-

 

Like the F.6, the F.53 is a
long-range aircraft with a low-drag, cambered leading edge, a
large ventral fuel tank, provision for a flight-refuelling probe
and carrying additional fuel for ferrying in two 260 gallon
jettison-tanks mounted on overwing pylons. There have been
few structural changes other than local strengthening of the
wing for the carriage of underwing stores.

Interesting! If I understand this correctly, it says that both versions had different wings.

[SAT69]

XR728 also doesn't have the forward panel located just aft of the leading edge. I believe, and could well be very wrong, the article on Export Lightning is saying that there have been few structural changes of the wing between the F.6 and the F.53 other than local strengthening of the wing for the carriage of underwing stores. Lightning F.6 and Lightning F.53 aircraft were both built in 1966 but I couldn't determine if the F.53s were interspersed on the F.6 production line or came at the end of F.6 production. 

On 5/1/2020 at 2:24 PM, Doc72 said:

Another point worth considering might be that the F.6 could carry over wing tanks unlike the earlier marks IIRC. This means that the wing of the F.6 had received some kind of reinforcement and additional wiring. These overwing pylons at least are something only the F.6 and the F.53 had in common. Of course, this doesn't proof that both marks had identical wings.

Another wild guess would be that BAC produced surplus F.53 wings and used them for some F.6s when anticipated export orders did not materialise.

This is an interesting possibility, but wouldn't those F.6s built or retrofitted with F.53 wings have had a different Mk identifier, perhaps F.6A representing a minor modification or F.7 representing the fact it's an F.6 with an F.53 wing? I'm confident, though not certain, the RAF would have wanted some way to distinguish the standard F.6 from its somewhat more sophisticated brother.

Here's another possibility: The F.6s at the Paris Airshow were actually modified to carry the external stores, for show purposes, then returned to their standard configuration after the show. If you're an aircraft manufacturer bent on selling your wares in large numbers, it seems logical you'd spend the money to make the modification and then demodify the airplane, if the chances are reasonably good you'll get a good return on your investment.

[sloegin57]

On 02/05/2020 at 22:15, SAT69 said:

XR728 also doesn't have the forward panel located just aft of the leading edge. I believe, and could well be very wrong, the article on Export Lightning is saying that there have been few structural changes of the wing between the F.6 and the F.53 other than local strengthening of the wing for the carriage of underwing stores. Lightning F.6 and Lightning F.53 aircraft were both built in 1966 but I couldn't determine if the F.53s were interspersed on the F.6 production line or came at the end of F.6 production. 

  

On 01/05/2020 at 20:24,  Doc72 said: 

Another point worth considering might be that the F.6 could carry over wing tanks unlike the earlier marks IIRC. This means that the wing of the F.6 had received some kind of reinforcement and additional wiring. These overwing pylons at least are something only the F.6 and the F.53 had in common. Of course, this doesn't proof that both marks had identical wings.

Another wild guess would be that BAC produced surplus F.53 wings and used them for some F.6s when anticipated export orders did not materialise.

 

This is an interesting possibility, but wouldn't those F.6s built or retrofitted with F.53 wings have had a different Mk identifier, perhaps F.6A representing a minor modification or F.7 representing the fact it's an F.6 with an F.53 wing? I'm confident, though not certain, the RAF would have wanted some way to distinguish the standard F.6 from its somewhat more sophisticated brother.

Here's another possibility: The F.6s at the Paris Airshow were actually modified to carry the external stores, for show purposes, then returned to their standard configuration after the show. If you're an aircraft manufacturer bent on selling your wares in large numbers, it seems logical you'd spend the money to make the modification and then demodify the airplane, if the chances are reasonably good you'll get a good return on your investment.

Hi All,

 

As has everyone else in this thread, and for that matter in the aeronautical press down the years, you all appear to have made the assumption that the F.Mk.53 was the export version of the F.Mk.6.  It was not.

 

The F.Mk.53 was the export version of the F.Mk.3 and the T.Mk.55 was the export version of the T.Mk.5 which in turn was essentially an F.Mk.3 with a two seat nose bolted onto the front.

 

Although externally the F.Mk.53 and the F.Mk.6 look almost the same, internally they were two entirely different beasties.  Had there been an export version of the F.Mk.6 it would have been designated F.Mk.56.

 

HTH

 

Dennis

[rossm]

32 minutes ago, sloegin57 said:

Hi All,

 

As has everyone else in this thread, and for that matter in the aeronautical press down the years, you all appear to have made the assumption that the F.Mk.53 was the export version of the F.Mk.6.  It was not.

 

The F.Mk.53 was the export version of the F.Mk.3 and the T.Mk.55 was the export version of the T.Mk.5 which in turn was essentially an F.Mk.3 with a two seat nose bolted onto the front.

 

Although externally the F.Mk.53 and the F.Mk.6 look almost the same, internally they were two entirely different beasties.  Had there been an export version of the F.Mk.6 it would have been designated F.Mk.56.

 

HTH

 

Dennis

 

Flight certainly seems to have got it wrong, their article of 5th Sept 1968 has a sub-heading "The potent F.53 development of the F.6 Lightning for interception, strike and reconnaissance" and in the text "These export Lightnings are derived from the F.6 intercepter".

 

The text also refers to a "developed F.3" as being part of the line leading to F.6 and F.53 - perhaps they just missed the point at which they diverged?

 

[sloegin57]

1 hour ago, rossm said:

 

Flight certainly seems to have got it wrong, their article of 5th Sept 1968 has a sub-heading "The potent F.53 development of the F.6 Lightning for interception, strike and reconnaissance" and in the text "These export Lightnings are derived from the F.6 intercepter".

 

You may well have uncovered the root source of the misunderstanding @rossm. That is all it can be called as as far as I am concerned Flight, or Flight International, as it is now, have a reputation for accurate reporting.  If I were writing that last sentence and with the beauty of hindsight, I would have written :- "These export Lightnings are derived from the development aircraft that has led to the F.6 interceptor".  The development aircraft I am referring to are P.1A WG760, which first proved the cambered "kinked" outer wing and F2/3/3A XN725 a photo of which has already appeared on BM else where (see below)

P-1A WG760 :-

 

2 hours ago, rossm said:

The text also refers to a "developed F.3" as being part of the line leading to F.6 and F.53 - perhaps they just missed the point at which they diverged?

 

The "developed" F.3 referred to above was this one :-  

 

together with it's history from a BARG "Spotlight" feature :-

 

The only thing that puzzles me about Flight's misunderstanding is that they seem to have missed the obvious connection and that is in the Mark Number for the export single seater.  The first figure '5' refers to the fact that it is an export aircraft and the second figure refers to the fact that it was derived from the Mk3..  That was standard practice throughout the British aircraft Industry in those days. 

 

One of the major problems with all the early Lightnings was maintainability - it was a pig, in fact it was a pigs father.  During my time in the service, there were only three organisations that had requests published on Station Standing Orders for technical volunteers to fill vacancies and request postings to them.  They were - The Red Arrows, The Queens Flight and Lightnings.  Don't get me wrong - some people loved them.  They were superb in the air but maintenance was a horror. With the F6, BAC attempted to right the wrong bits by completely redesigning the component, pipework and electrical layout inside the fuselage and a few bits in the wings in order make life just a little easier for techies.  In the view of many, myself included, a posting to any of the above three was considered to be a career killer.   

 

We seem to have wandered off the OP's question a touch.  How did BAC manage to hang underwing weapons on two RAF F.6 Lightnings when there were no pickup points for them. ?

 

I've no idea  

 

HTH

 

Dennis

 

  

[rossm]

7 minutes ago, sloegin57 said:

We seem to have wandered off the OP's question a touch.  How did BAC manage to hang underwing weapons on two RAF F.6 Lightnings when there were no pickup points for them. ?

 

I've no idea  

 

HTH

 

Dennis

 

  

 

I've not seen any of the photos from Air Shows but could the access panels be used to attach lightweight dummies? Just a question, I've really no idea either.

[John B (Sc)]

'sloegin' - that picture of XN725 is fascinating, and may give us  a clue.  It appears to have a dummy (I presume) weapon attached to a short pylon on the side of the ventral tank. Surely a temporary lash up to determine what would be needed structurally and in terms of equipment  services reshuffle etc.  I think as 'rossm' says use of the access panels to hang temporary pylons for show seems reasonable.  No structural impact likely in doing that.

 

John B