Spirfire X & XI Aerial Masts

[fishplanebeer]

In anticipation of receiving my new KP Mk.X and XI from Hannants can anyone please explain why the X is shown with no mast but the XI has such given that I'm assuming they would have carried the same radio? All the pics I have of the X confirm its absence but I'm curious as to why, unless it had something to do with the cabin pressurisation although I can't think why this would be the case.

 

Regards

Colin.

[gingerbob]

Possibly because the X entered service in mid-'44, and somewhere along the way the whip antenna replaced the mast, as slightly less drag.  This is not to say that the whip was commonly retrofitted- I don't know that.

[fishplanebeer]

I must admit most of my Mk.X pics are not highly detailed but there is a nice pic of MD191, the first production MK.X, in Shacklady which has the aerial mast. However there is also another pic of a Mk.X in Shacklady where the mast is missing but there's what appears to be a small appendage on the under side of the fuselage aft of the cockpit area, so possibly some form of aerial possibly? There doesn't seem to be any evidence of a whip aerial on the rear fuselage of this particular machine which makes me think this might be the case but just not sure.

 

Regards

Colin.

Edited April 5, 2022 by fishplanebeer

[gingerbob]

Here's a shot of SR396- note that you can "view full size" - when you do so, you can just make out the whip aerial.  I suspect that the "small appendage" you speak of is the beam approach antenna- also on SR396, slightly aft of the fuselage roundel?

 

bob

[Phoenix44]

39 minutes ago, gingerbob said:

Here's a shot of SR396- note that you can "view full size" - when you do so, you can just make out the whip aerial.  I suspect that the "small appendage" you speak of is the beam approach antenna- also on SR396, slightly aft of the fuselage roundel?

 

bob

I think that's an artefact of the camera/film/printing. The other photo of that aircraft in the series has a very similar line but not where there would be a whip aerial. There's quite a lot of marks on the photos.

[fishplanebeer]

Many thanks for the extra photo and the link which has a wonderful collection of Spitfires, now book marked!

 

The underside appendage is much clearer in this photo but it then begs the question why the XI didn't have it as well?

 

I must confess I'm struggling to see evidence of a whip aerial on the top of the fuselage so I'm still unsure as to why any form of aerial is missing from the X apart from MD191?

 

Regards

Colin.

[fishplanebeer]

Just another quick question about the PR.X.

 

The PR.XI had a curved windscreen with no armoured glass whereas the PR.X seems to have retained this feature even though it came off the production line after the XI so wondered why this was the case?

 

Regards

Colin.

[Graham Boak]

This was the normal PR windscreen, other than for the low-level work.  Predated both the X and XI.

[Andy Fletcher]

The Spitfire PR.X was based on the high altitude F.VII airframe retaining the pressurised cockpit and armoured windscreen.

[gingerbob]

2 hours ago, fishplanebeer said:

The PR.XI had a curved windscreen with no armoured glass whereas the PR.X seems to have retained this feature even though it came off the production line after the XI so wondered why this was the case?

 

As Andy suggests, the PR.X was a bit of a "lash-up" to get a pressurized PR Spit ASAP.  Mk.VII fuselages [the design/structure, not "recycled fuselages"] were adapted, since they were already built for pressurization. 

 

I'm not convinced one way or the other about the (possible) whip antenna, I just did a quick search, thought I got lucky, and put it on here!  PR.XIXs (eventually?) did have a whip, which was further back on the fuselage.  I'll try to poke around a bit more to see if I can find anything out- I like this sort of question.

 

bob

[fishplanebeer]

Aha, that now begins to make sense .

 

I know that the availability of the F.VII airframe, upon which the X was based, was an issue and explains why the X came after the XI as this was based upon the more readily available F.IX airframe, with later examples having the retractable tail wheel fitted. 

 

This still leaves me puzzled by the aerial on the X and also why the underside appendage, possibly some form of beam approach system, doesn't seem to appear on the XI or be on the MD191 example of the X. I may be way off beam (no pun intended) but this appendage only seems to be present where there is no aerial mast evident/present or could this just be a coincidence perhaps?

 

Regards

Colin.

[Chuck1945]

Probably coincidence. The beam approach fitting can also seen on many IX photos though it wouldn’t be a complete surprise for it to also have been censor removed.

[fishplanebeer]

Just to add something else to the mix if I may. 

 

In 'The Spitfire Story' by Alfred Price on page 154 there is a pic of EN149 which is described as being one of 15 IX's converted to PR.IX's in late 1942 but according to Shacklady the PR.VIII and PR.IX were abandoned in favour of the PR.X. However Shacklady also has the same pic of EN149 and confirms that it was indeed a PR.IX but that it was then converted to PR.XI standard presumably along with the other 14 of the type?

 

BTW the pic in Shacklady which I thought was of MD191 (with an aerial mast) is in fact EN149 so I no longer have an actual pic of a X with an aerial mast in place which sort of confirms that this was the case with all X's. However this still leaves the question of 'why' given that the X had the same/similar radio equipment installed.

 

Apologies for any confusion.

 

Regards

Colin.

Edited April 7, 2022 by fishplanebeer