M197 Cannon Turret Diameter? (For OV-10 NOGS)

[Hoops]

Good afternoon! 

 

I have two questions that hopefully somebody can help me with pretty easily.

 

1. What is the diameter of the of the M97 turret (uses the M197 Three-barreled 20mm gun) on the AH-1. I've done a bunch of searching online, but can't find an answer. If someone has a kit in 1/72 and just wants to measure it, that would also work fine.

 

I'm looking at the possibility of converting a 1/72 ICM OV-10D to the late Night Observations Gunship (NOGS) which incorporated a modified version of the turret

 

2. How long was the fuselage extension behind the cockpit of the Tornado ADV? I've found that the extension for the longer engines was 14", but how large was the extension behind the cockpit?

 

I happened to pick up a Hasegawa 1/72 Tornado ADV as a junk kit with no decals for super cheap and am kitbashing it with the Revell kit in the same scale. The kits break down differently so it's not easy to figure the size of the forward plug. 

 

Thanks!

Hoops

Edited February 16 by Hoops
One Question Answered!

[Hoops]

I was able to find a copy of the Aeroguide volume on the Tornado F3 Variant. In the book it is stated that the the fuselage extension behind the cockpit is 21" long. Problem solved!

 

Still looking for the diameter of the AH-1 Turret though,

 

Cheers,

Hoops

[CT7567]

20 hours ago, Hoops said:

Still looking for the diameter of the AH-1 Turret though,

 

Cheers,

Hoops

 

When you say "diameter of the turret," can you clarify exactly what measurement you're looking for?

 

AFAIK all AH-1s with the M197 mount directly under the nose:

 

A cylindrical shroud was used on early Army variants with this cannon, which the twin-engine versions (J/T/W/Z) seem to retain even with the latest "Zulus" (J variant pictured):

 

The OV-10D NOGS turret has an adapter fairing below the center fuselage (similar in shape to the shroud) with the turret itself (base of rotation) mounted to the bottom of the fairing.

 

 

 

The 1:72 Airfix OV-10D (which is otherwise pretty awful) includes a belly fairing nd turret for the NOGS M197 - I don't think this has been offered in any other kits or aftermarket to date. If using that kit just for the turret, I would also plan on investing in a metal barrel set from Master.

[Hoops]

On 2/15/2024 at 10:14 AM, CT7567 said:

 

When you say "diameter of the turret," can you clarify exactly what measurement you're looking for?

 

 CT7567,

 

This is the diameter that I am looking for:

 

Bell_AH-1J_Sea_Cobra_2_(4685837287) by J2Hoops, on Flickr

 

From that I think I can interpolate the rest of the measurements close enough to look the part in 1/72 scale.

 

On 2/15/2024 at 10:14 AM, CT7567 said:

A cylindrical shroud was used on early Army variants with this cannon, which the twin-engine versions (J/T/W/Z) seem to retain even with the latest "Zulus" (J variant pictured):

 

The OV-10D NOGS turret has an adapter fairing below the center fuselage (similar in shape to the shroud) with the turret itself (base of rotation) mounted to the bottom of the fairing.

The 1:72 Airfix OV-10D (which is otherwise pretty awful) includes a belly fairing and turret for the NOGS M197 - I don't think this has been offered in any other kits or aftermarket to date. If using that kit just for the turret, I would also plan on investing in a metal barrel set from Master.

 

There seems to be two versions of the turret that were installed on OV-10s for various "NOGS" tests. The first version that deployed to Vietnam, has the turret mounted at the very aft of the center fuselage. This version had a larger aerodynamic fairing between the fuselage and the turret itself. The turret seemed to be mounted at a slight downward angle, and is the version depicted rather basically in the Airfix kit. It seems to have had the same shroud around the gun itself as the AH-1, but the bottom rounded "pan" was sometimes removed it seems (see your third photo)

 

yov-10d_canon by J2Hoops, on Flickr

 

There also seems to be a later version of the installation, where the turret was mounted immediately behind the rear seat. This version had only a very short (vertically) spacer between the fuselage and the turret, which had a much deeper, hemispherical, shroud around it. Link! as well as your 4th photo.

 

There are also some images of this version of the installation without the lower "pan" portion of the shroud installed either. This later turret is the one that I'm more interested in, as I really don't like the look of the three color camouflage or the early FLIR. I think that the later AAS-37 FLIR is more visually appealing, as well as either the overall dark green, or dark green over light grey camouflages. I would be designing the turret in CAD and 3D printing it, but would use the Master M197 Barrels.

 

Cheers,

Hoops

[Hoops]

OK, down the rabbit hole we go...

 

I have no confirmation of this as an amateur internet sleuth, but I think that there was at least a static installation of the M197 turret on a line OV-10D (i.e. not the two YOV-10Ds 155395 or 155396) with VMO-2 at Camp Pendleton in the 1980s.

 

See this link to an archive of an old Ebay slide auction

 

Looking at the background there are a few other aircraft visible 155483 and 155484 (side number 27). Another picture of 155484 can been seen here on Facebook from Detail and Scale, showing the 27 side number on the nose.

 

This photo on Flickr shows a whole line up of VMO-2 Aircraft on the Pendleton flightline. Of note 155484 is all the way down at the end, and can been seen with the same tail markings as seen in the background of of the ebay slide above. The aircraft with the M197 turret installation is side number 22, but it's BuNo cannot be seen in that photo. In this Flickr photo, the tail for "22" is visible and is clearly BuNo 155466 and the machine gun sponsons have been removed from the fuselage!

 

With both aircraft are painted the same across the multiple photos and interpolating from incomplete data, and I think that the slide previously sold is of 155466 with a M197 at least temporarily and statically installed. I doubt any of us have it, but it would be amazing to see more information.

 

Cheers,

Hoops

Edited February 16 by Hoops