AC-47 (Italeri 1/72): What is the right angle for the miniguns?

[PIPboy]

Hey all, 

 

I'm currently building an Italeri AC-47. I just assembled the body and the wings and to my dismay the minigun closest to the cockpit would hit the wing if it started shooting. I followed the instructions so I'm not sure what's going on. I looked up pictures of real AC-47s on the internet and the barrels of the miniguns seem to be fixed in different positions: on some aircrafts they are almost parallel to the wing, on others they face downwards. Unfortunately I don't have good quality pictures of Vietnam era AC-47s, it's either a bad quality picture of a Vietnam era airplane or a good quality picture of a restored airplane so I can't really make the call myself.

 

Online sources say that the gunpods were attached to locally fabricated mounts. Were these mounts adjustable? If they weren't, what is the right angle and direction for the miniguns and what's the reason for the different angles?

 

I can't really change anything at this point but I'd love to know what's up.

[Dads203]

This might help ?

 

https://en.m.wikipedia.org/wiki/Douglas_AC-47_Spooky

[PIPboy]

15 minutes ago, Dads203 said:

This might help ?

 

https://en.m.wikipedia.org/wiki/Douglas_AC-47_Spooky

Thanks, I already checked the wikipedia but it didn't really help: 

 

On the Nha Trang Air Base picture the miniguns are aimed straightforward. However, on the last picture in this article https://warfarehistorynetwork.com/daily/military-history/vietnam-war-weapons-the-ac-47-gunship/ they are aimed downwards (similarly to the Italeri kit). Both aircraft seem to have the same setup (two minigun pods in the windows, one in the door) so I'm not sure why the pods are aimed so differently?

Edited May 31, 2019 by PIPboy

[Corsairfoxfouruncle]

Im thinking it has to do with the attitude of the aircraft. Straight guns would require a slighter steeper bank for the pilot to maintain. The guns angled down would mean the plane wouldn't need to bank as steeply. If that makes sense ? 

[spruecutter96]

I'm sure there's some Youtube footage of a Spooky mission - it might shed some light on the subject.  As previously stated, the gun-mounts were local modifications and so it seems logical there would be some variations in the guns' angles. 

 

Hope this helps. 

 

Chris.  

[PIPboy]

8 minutes ago, Corsairfoxfouruncle said:

Im thinking it has to do with the attitude of the aircraft. Straight guns would require a slighter steeper bank for the pilot to maintain. The guns angled down would mean the plane wouldn't need to bank as steeply. If that makes sense ? 

I guess that makes sense but the minigun closest to the cockpit still remains a mystery to me. (As far as I can tell) On some pictures it's aimed in angle where it would hit the wing. Was it also aimed slightly to the back of the aircraft?

[PIPboy]

7 minutes ago, spruecutter96 said:

I'm sure there's some Youtube footage of a Spooky mission - it might shed some light on the subject.  As previously stated, the gun-mounts were local modifications and so it seems logical there would be some variations in the guns' angles. 

 

Hope this helps. 

 

Chris.  

Yeah, I watched the few videos I could find on youtube. They show a similar variation in angles but they don't really spend time explaining how and why the miniguns were mounted.

[72modeler]

It does appear from the photo posted that the gun mount allowed for adjustment- you can see on the rear mounts the amount of adjustment and it appears the front mounts were pinned at the bottom to allow for the entire mount to be raised/lowered at the rear, giving two angles of fire. I have no idea why, though, but CCFFU's rationale makes sense. I have attached a link to a very interesting history of the concept and use of the AC-47's in SEA, but no mention of different angles on the miniguns, unfortunately. The second link also has very good information and specs and states that the guns were depressed twelve degrees to allow for a shallower bank angle and greater control.

Mike

 

https://www.ac119gunships.com/content/TWE/1_6_History_and_References/1_6_1_AC119_and_Gunship_Historical_Information/Stories The AC-47.pdf

 

https://www.456fis.org/AC-47D.htm

[thorfinn]

The differences in angle were likely tied to evolving tactics once the Spookies were in service. It took a while to develop the eventual favored tactic of a slow 'pylon turn' where the aircraft could circle what was essentially a fixed point on the ground (maintaining a steep angle), bringing its massive firepower to bear on a highly-localized area.

[PIPboy]

11 hours ago, 72modeler said:

It does appear from the photo posted that the gun mount allowed for adjustment- you can see on the rear mounts the amount of adjustment and it appears the front mounts were pinned at the bottom to allow for the entire mount to be raised/lowered at the rear, giving two angles of fire. I have no idea why, though, but CCFFU's rationale makes sense. I have attached a link to a very interesting history of the concept and use of the AC-47's in SEA, but no mention of different angles on the miniguns, unfortunately. The second link also has very good information and specs and states that the guns were depressed twelve degrees to allow for a shallower bank angle and greater control.

Mike

 

https://www.ac119gunships.com/content/TWE/1_6_History_and_References/1_6_1_AC119_and_Gunship_Historical_Information/Stories The AC-47.pdf

 

https://www.456fis.org/AC-47D.htm

Thanks, great links!

[Graham Boak]

12 hours ago, thorfinn said:

The differences in angle were likely tied to evolving tactics once the Spookies were in service. It took a while to develop the eventual favored tactic of a slow 'pylon turn' where the aircraft could circle what was essentially a fixed point on the ground (maintaining a steep angle), bringing its massive firepower to bear on a highly-localized area.

It may have taken some time to perfect this tactic, but it was behind the very idea of these aircraft.  It stemmed from operations supplying missionaries in South American jungles, where supplies were placed in a bucket lowered on a rope.  Flying in a steady bank resulted in the bucket being effectively hovering in a clearing.

[72modeler]

3 hours ago, Graham Boak said:

It may have taken some time to perfect this tactic, but it was behind the very idea of these aircraft.  It stemmed from operations supplying missionaries in South American jungles, where supplies were placed in a bucket lowered on a rope.  Flying in a steady bank resulted in the bucket being effectively hovering in a clearing.

Guess that means the missionaries must have made a bucket list? (Sorry for that one, Graham- I will go sit quietly in the corner until it goes away.) 🤣

Mike

[Finn]

Here is one in action:

 

 

 

Jari

 

[CT7567]

@Graham Boak has the history on this correct, the technical term for the pylon turn delivery being a "long-line loiter."  

https://en.m.wikipedia.org/wiki/Pylon_turn

 

I believe if you look closely at this image from Wikipedia it appears that the forward minigun is slewed aft significantly with the other stations relatively centered. 

 

At the comparatively low altitudes these ships operated, there would be a notable angular difference between each station if firing on the same target, but keep in mind these were not "precision" weapons - especially by modern standards -  so it's doubtful all stations would be aimed at a pinpoint location.

[PIPboy]

56 minutes ago, CT7567 said:

@Graham Boak has the history on this correct, the technical term for the pylon turn delivery being a "long-line loiter."  

https://en.m.wikipedia.org/wiki/Pylon_turn

 

I believe if you look closely at this image from Wikipedia it appears that the forward minigun is slewed aft significantly with the other stations relatively centered. 

 

At the comparatively low altitudes these ships operated, there would be a notable angular difference between each station if firing on the same target, but keep in mind these were not "precision" weapons - especially by modern standards -  so it's doubtful all stations would be aimed at a pinpoint location.

Great picture, thank you! 

[Rob de Bie]

On 6/2/2019 at 5:36 AM, Finn said:

 

 

Wiki says modified SUU-11 gun pods were used initially - is that what we see here? I also noted that the last gun is positioned in the door opening, not in the last window. Italeri has the same gun positions, but on other Spookies the last three windows were used.

 

Rob

[JPuente54]

There is footage in "The Green Berets"(yes, the John Wayne movie) using an AC-47 attacking the camp taken by the VC. You might get some good shots there.

Joe

[J.C. Bahr]

One thing to bare in mind with that last pic... the window closest to the door I am pretty positive was a field mod and not a standard window.  Couple that with putting a gun in the doorway and there should not be the problem of potentially firing through the wing if not placed in the third window forward of the door.

 

I had often wondered about this too and this is where my research had lead me.  This is where pics are worth a thousand words on individual aircraft and their gun arrangements.

[PIPboy]

On 6/14/2019 at 7:15 PM, J.C. Bahr said:

One thing to bare in mind with that last pic... the window closest to the door I am pretty positive was a field mod and not a standard window.  Couple that with putting a gun in the doorway and there should not be the problem of potentially firing through the wing if not placed in the third window forward of the door.

 

I had often wondered about this too and this is where my research had lead me.  This is where pics are worth a thousand words on individual aircraft and their gun arrangements.

The sources I found say that an extra window was added but it was used to move the minigun from the door further inside the aircraft to make getting in and out (and I assume throwing flairs) easier. Consequently it didn't affect the position of the minigun nearest to the wing.

[RAGATIGER]

Hi there 

 

Regarding the use of Douglas AC-47 by Fuerza Aerea Salvadoreña during civil war 1980-1992, started support operations in December of 1984 the first two Douglas AC-47 (FAS 115 and 116) were received, which had a weapon system of three 0.50 machine guns, harmonized with an electric sight located in the ship captain's window, additionally counted in the compartment of loading with a system of evacuation of the smoke produced by the action of the machine guns or in case of smoke by fire inside the aircraft. It also included a manual device for lighting flares and missile evasion (flares and exhaust from motors with heat dispersers). Years before, the C-47 was adapted a weapon system of two 0.50 machine guns placed in the last window, before the loading door, on the left side of the fuselage. This system was complemented by a rustic set of sights, which consisted of a circle drawn in the pilot's window, which was aligned with a small antenna of the left wing.

In El Salvador at least two C-47s were modified locally, armed with two 12.7mm M2 machine guns. The Air Force of El Salvador used at least two AC-47D ex-USAF during the civil war. The airplanes were modified before being delivered in 1984 to El Salvador, receiving three Browning M3 machine guns of 12.7 mm caliber, and launchers of lighting flares. Some of the AC-47 (FAS 125)was shot down by a SA-7 missile in January 1989 during night operations and one of its crew survived 

In 1988, the first two C-47 aircraft (FAS 116 and 118) were sent to the United States to be transformed into DC3-TP67 (AC-47TP) aircraft by the Basler Turbo Conversions Inc. of Oshkosh, Wisconsin, changing their reciprocating engines. a turbo propeller Pratt & Whitney Canada PT6A-67R, also making other minor modifications. These aircraft were received on August 19, 1990. Two years later, two more aircraft were sent (FAS 117 and 119), which were delivered in October 1994.

 

http://www.fas.gob.sv/historiatransporte.html

 

You'll find some photos here

 

Best modeling you all

 

Armando

[Antti_K]

Hello all,

 

I guess that a "3-4-5 Triangle" was used on these operations. It is a flying technique where you fly at 3000 ft at a distance of 4000 ft around the center point (target). If you maintain a constant bank angle of 30 degrees the line-of-sight is 5000 ft. If you follow these figures your guns should point almost straight out and if you have to modify your altitude, bank angle or distance from target, the gunners have to change to gun angle accordingly.

 

Kind Regards,

Antti

[Seahawk]

On ‎6‎/‎26‎/‎2019 at 9:37 AM, Antti_K said:

Hello all,

 

I guess that a "3-4-5 Triangle" was used on these operations. It is a flying technique where you fly at 3000 ft at a distance of 4000 ft around the center point (target). If you maintain a constant bank angle of 30 degrees the line-of-sight is 5000 ft.

Good old Pythagoras.  You just never know when he'll come in useful.

[canberra kid]

I've just come across this.

https://m.youtube.com/watch?v=CZGx55B9Gyk&feature=youtu.be

John

[72modeler]

Interesting video, John- thanks for posting it. Guess they couldn't fit the third minigun in the doorway for safety reasons. Other than the modern avionics in the cockpit, she looks pretty close to original. Saw some original examples at military displays back in the day, but had no interest in building one back then, so only took a  few external shots....dumb, dumb, dumb!

Mike

[canberra kid]

5 hours ago, 72modeler said:

Interesting video, John- thanks for posting it. Guess they couldn't fit the third minigun in the doorway for safety reasons. Other than the modern avionics in the cockpit, she looks pretty close to original. Saw some original examples at military displays back in the day, but had no interest in building one back then, so only took a  few external shots....dumb, dumb, dumb!

Mike

Don't beat yourself up Mike, we've all been there and 'not' done that, when perhaps we should have! All the types I've passed by at air shows and museums that I now whis I hadn't, oh well, such is life. As for the video, it's always a risk setting to much trust in restored aircraft, but if nothing else it's a good thing to look around.

John