Saro Sr.177 Gun Pack

[Mossie]

I'm very much thinking of tackling Colins Freightdog SR.177 soon, it'll be my first go at a resin kit so should be interesting.  I'm thinking along the lines of early to mid eighties air defense & was wondering what mods it might have had.  One thing that I thought of would be a gun, the SR.177 was designed without one like other fighters of it's time & of course Vietnam lessons showed that this was an oversight.

My main idea is to add it on the centreline, similar to the ventral pack on the Lightning, but not as large (not planning on extra fuel).  Possibly underwing pods (although I'd prefer to keep the pylons free) or even wing root conformal packs.  I was thinking of modifying a Hawk gun pod, I guess the supersonic speeds of the SR.177 would require that it be faired into the fueslage?  Do the 1/72 Airfix or Italeri Hawks have a gun pod?

Cheers!

Simon.

[kitnut617]

The Italeri Mk.100 Hawk I have, has a single gun pack Simon if that helps.  It's quite large though, bigger than the Harrier gun packs.

Robert

[Hobbes]

I checked the layout drawing found in Project Cancelled, and you'd have a hard time installing an internal gun pack. The jet engine sits in front of the wheel wells, and in front of that you've got the intake and nose wheel bay.
Having the guns behind the cockpit is an option, but I don't think the pilot would like that. You may have to resort to a wing root fairing.  

[Mossie]

Cheers guys!

Robert, after what you said I compared 1/48 Hawk & Harrier guns & found the Hawk gun may be a little on the large side, there might not be much clearance.  I'd discounted the Harrier gun because it's assymetric, but then I thought I could easily combine two opposite halves to form one gun, or there should even be enough room to combine the pair.  I've got a spare 1/72 pair, this might be the way to go.

Hobbes, I see what you mean, there's a definate lack of space in that fuselage!  A thouroughbred, built for it's purpose with no space left unfilled.  Trouble is, as aircraft like this are developed, they tend to develop lumps & bumps which defeats the early objective.  I think your right, wing root fairings would be the best bet, for an integral mounting, although I assume this would have some effect on the lift properties of the wing?

[GTX]

Simon,

What about an arrangement similar to the F-8 Crusader (though probably with only one or two 30mm aden cannon) with the cannon on the sides?

Regards,

Greg

[Zen]

Retracting InFlight Refueling probe is on the left side, but persumably there might be space on the right side of the fusilage for a cannon. A slight bulge might be visible externaly if you go that route.

Ventral is a poor choice with this type IMO.

[Mossie]

Seems theres no perfect soloution so I've thought through the options & added some more:

1 Ventral external pack
Pluses: Aerodynamically clean, room between forward & main gear.
Negs: Lack of ground clearance
Soloution: Extend gear

2 Underwing root fairings
Pluses: No need to free up fuselage space.
Negs: May reduce lift & cause other aerodynamic problems
Soloution: Increase wing area or live with it

3 Pylon mounted pods
Pluses:  No need to free up fuselage space.
Negs: Takes up space on pylon that could be used for other stores, draggy
Soloution: Add extra pylons, possibly overwing

4 Fuselage mounted beside cockpit 'F-8 style'
Pluses: Fairly clean, space beneath cockpit, also equipment bay.
Negs:  Only one gun due to refueliing probe on left side, some slight bulge.
Soloution: One gun is acceptable for an interceptor, if not remove refueling probe

5 Fuselage mounted beside air intake 'Hunter style' with large fairings
Pluses: Easy to service
Negs: Would have to be mounted almost wholly externally, draggy
Soloution: Hmmm..... scratches head

6 Turret 'Defiant style'
Pluses:  Very Radish!
Negs: Very Radish!
Solution: Start wearing stockings & suspenders.....

Number 4 is looking good from a 'real' world practicality verus modelling skill required.  3 isn't bad either, although I'm reluctant to go down the 'Lightning' route.  1 might be good from a real world point of view, but I'd have to think about the size of the undercarriage bay, no way I'm going to do any work to them on my first kit.

What do you think guys, have I got it about right?

Oh, nearly forgot, number six, my legs are very hairy & would need serious waxing, no chance!

[jcf]

The 'lessons of Vietnam' are somewhat overstated vis-a-vis armament.
Guns made a comeback because of the particular Rules of Engagement used in that conflict, and if your SR.177 scenario includes that sort of 'limited conflict' then finagling a gun into the package may be necessary...for Cold War Europe or Far East bomber defense duty, missiles make more sense.

I suppose one could do two variants...all-missile defense interceptor and gun-equipped tactical strike fighter. Lose the rocket on the tac version and the added weight of the guns is less of an issue, also that would allow expanding the aft equipment bay to take the kit that would have to be relocated from the fwd bay to make room for your guns.
Under-wing pods would probably be the worst scenario as everything I've read states that they are notoriously inaccurate...OK for ground-attack but almost useless for air-to-air.

Cheers, Jon

[Mossie]

No patrolling the iron curtain, just making sure the neighbours don't cause too much trouble in a minor tiff over garden boundaries in the South Atlantic.  A gun in that situation would be a must.  I've been thinking about a strike version, but I've only got the one kit.  If I get one of the other versions I may well bomb it up.

Yeah, even the Aden cannon on the Harrier is notoriously bad for accuracy, they were still having problems with it in the mid nineties & I don't know if it's ever been solved fully.  With the Harrier being the exception, IIRC all British frontline aircraft have had a main gun, so I think if one could be fitted internally, it would be.  Option number 4 is starting to look good.

[jcf]

'Rapid Fire' gives a length of 159cm for the Aden Mk 4.

[Mossie]

Cheers John, 2.2cm in 1/72 definately do-able, same position as the re-fueling probe but on the right-hand side.

Anyone think of any other mod's that an early eighties British interceptor might require?  Updated radar maybe, but again, I don't want to chop anything!  If the Lightning was anything to go by, probably very little due to the neglect the British forces got in the  seventies.

[Zen]

I'd stick with the F8 style solution. Theres no room for Hunter style guns under the intake. Though you could cant the gunpods to give some greater clearence, I have worries over interference with the main gear doors.

It maybe possible to have guns on both sides and not impact the IFR probe, but to do so is likely to impact the HTP tankage, though not by much if the weapons slightly bulge out either side of the fusilage.
In that case we're talking up on the flat sides further back, front ends of the barrels behind the avionics bay doors. Which is a nice rigid postion, and good for sighting for the pilot as you can effectively have them firing at head hight either side of the plane.

If the plane has ditched the rocket for jet only then I see little problem.

Adopt RB106 or Spey for the jet only solution, increases intake size (suck in doors would help) and a afterburner diameter.
Radar could be set back further to allow increased diameter of dish, but you need more cabling as parts of the system would have to be behind the cockpit.

The dish seems to be the 18 inch one, they might replace it with Blue Fox in the late 70's along with integration of Sea Eagle. The wing looks like it can be strengthened to take such a heavy weapon.
Setting back might permit a dish of 20-24 inches.
Sidewinder or SRAAM instead of Red Top?
Blue Dolphin SARH equipped Red Top missiles? Limited in range due to the radar dish's size.

You stick all sorts of arials on the fusilage. Its likely the orriginal would get the Ferranti auto-interception system, and a datalink. Updates for that in the late 70's.
You might even add a ram air inlet for some more advanced avionics?
Perhaps a twin seater EW version?

The avionics bay might be extended back into the fuel take space (orriginaly for HTP) to add SLAR for example, externaly you'd see dialectric panel and perhaps a ram air inlet for cooling.

[Mossie]

Thanks Zen.  I'll keep to one gun as I don't intend to make any major mods like engine or radar changes, being my first resin kit I haven't enough confidence to chop chunks out.  I'll go along the premise that although the SR.177 got into service, the timeline remained largely unchanged & the forces were neglected throughout the sixties & seventies, so major mods got sidelined.  If I get the Naval version, I may well include a Blue Fox radar nose.

I'd been thinking about aerials, I might stick a few on for various systems.  Air scoops are a good idea too, I might introduce those around the equipment bays.

I'm not familiar with Blue Dophin SARH.  Can you fill me in?

[GTX]

I'm not familiar with Blue Dophin SARH. Can you fill me in?

Blue Dolphin (also known as Blue Jay Mk.5) was a proposed SARH variant of the De Havilland Red Top air to air missile. This was to have an active continuous wave radar seeker and was intended for Sea Vixen and TSR.2. It was to be similar in capability to the US AIM-7 Sparrow.  If you have any Red Tops, you could probably modify them into a Blue Dolphin.  Personnally, I'd go for equal numbers of each variant being fitted similar to the way the Soviets did.  Alternatively, you could try fitting Sidewinders and Skyflash for an updated '80s weapons fit.

You might also add a IR sensor just in front of the cockpit - again similar to that on the F-8.

Regards,

Greg

[Mossie]

Cheers Greg, I guess Blue Dolphin would have been similar in appearance to Red Top then, but with a radar cone instead?

I think I'll include both Red Top & Blue Dolphin like you suggest, maybe make a few mods to the missiles to suggest updated versions, slightly different fins etc.  I'd quite like to keep the 'Made (& developed) in Great Britain' theme.