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3 hours ago, Ben Brown said:

...  the nozzles would be open on takeoff because of the afterburners. They’d close at high power settings but out of afterburner. 

 

Basically, that's it.  The J79 in full burner "kicks you in the butt" with about 50% more power ... at the cost of 3 to four times normal fuel consumption (gulp). The burner lights off in three stages, and is finely adjustable in the entire burner range -- it's not just in or out. For example the range allows the leader in a formation takeoff  to throttle back a little when the wingman says, "Gimme a couple" to allow him to stay in position.  

 

Back in the waaaay old days when refueling behind a slow KC-97, there were situations (as altitude, and load) that required unhooking when the increasing angle of attack (read drag) needed for the added weight of fuel taken on, resulted in falling  behind the power curve at full throttle(s). Solution was to put one engine in min burner and use the other throttle to rehook and maintain position on the boom. So here's a situation where you could model one nozzle closed and the other open!  I'm sure ZM had that in mind. :whistle:

 

c99c5d027a38e1c74b848bfaf5aef6fb.jpg

 

The J-79, including AB operation, is shown and well explained  in excruciating detail in  a series of Youtube videos.  A lot is covered on general AB theory  (great!!) and  also  on the specifics of the J79 nozzle mechanics.  Very interesting when combined with the footage of the engine in operation on a test stand. 

 

The videos are also a great reference for modelers as regards colors and finish, for example here.

 

Gene K

Edited by GeneK
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1 hour ago, jpk said:

Why did the USAF opt for the flying boom v the drogue? It seems the drogue is much simpler and more widely compatible with our allies.

 

My understanding is that the flying boom moves a lot more fuel faster than the drogue method. Faster refueling.

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6 minutes ago, Mstor said:

 

My understanding is that the flying boom moves a lot more fuel faster than the drogue method. Faster refueling.


This.  I believe the main reason the USAF went to the flying boom was because they needed to refuel SAC’s long range bomber fleet.  Since they needed a lot of fuel,  it would have been too slow to use the drogue system.  Plus, I’d imagine it would have been difficult for something like a B-52 to try to capture a drogue. Interestingly, I believe they built the F-105 with both systems installed, so it could use either.

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...just to repeat my question:

can anyone shed a light on the vertical outboard pylon set included in the kit? There are two complete sets int he kit, a vertical and a canted set. The pylons are otherwise identical in design. Was the AF type outboard pylon originally vertical, and the design was then changed to canted?

 

(Edit: I have found the stabilator "fish plates" on one runner. As they are devoid of any rivets and quite thick it does seem that ZM themselves don't expect people to use them but use PE instead later on)

 

Cheers,

J

Edited by JeffreyK
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8 hours ago, Dave Williams said:


. Interestingly, I believe they built the F-105 with both systems installed, so it could use either.

Dave,

Very true, the boom method had a better fuel transfer rate but in the Thud when you connected to the boom you had to remind the operator to "one pump" transfer as that if he used both pumps the pressure could rupture your fuel tanks.

Begged fuel off Navy tankers twice in the late 60's. Being able to "go either way" can be a life saver.

Cheers :cheers:

Itch

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2 hours ago, JeffreyK said:

...just to repeat my question:

can anyone shed a light on the vertical outboard pylon set included in the kit? There are two complete sets int he kit, a vertical and a canted set. The pylons are otherwise identical in design. Was the AF type outboard pylon originally vertical, and the design was then changed to canted?

 

(Edit: I have found the stabilator "fish plates" on one runner. As they are devoid of any rivets and quite thick it does seem that ZM themselves don't expect people to use them but use PE instead later on)

 

Cheers,

J


The Jake Melampy book on the F-4 doesn’t really answer the question, other than saying the outboard pylon is canted when loading a HARM.

 

ETA:  Looks like Ben’s post below answered it.

Edited by Dave Williams
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1 hour ago, JeffreyK said:

...just to repeat my question:

can anyone shed a light on the vertical outboard pylon set included in the kit? There are two complete sets int he kit, a vertical and a canted set. The pylons are otherwise identical in design. Was the AF type outboard pylon originally vertical, and the design was then changed to canted?

 

(Edit: I have found the stabilator "fish plates" on one runner. As they are devoid of any rivets and quite thick it does seem that ZM themselves don't expect people to use them but use PE instead later on)

 

Cheers,

J

Here’s something on Tommy’s blog that might help:

LINK

 

Ben

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Jeff, 

Conjecture on my part, but perhaps other users, in particular the JASDF which lacks an offensive mission and therefore not ever carry MERs and TERs, would opt for conventionally mounted (“straight”) outer pylons on their aircraft. I noticed that ZM’s next release is the F-4EJ Kai.

Rich

Edited by RichB63
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48 minutes ago, RichB63 said:

Jeff, 

Conjecture on my part, but perhaps other users, in particular the JASDF which lacks an offensive mission and therefore not ever carry MERs and TERs, would opt for conventionally mounted (“straight”) outer pylons on their aircraft. I noticed that ZM’s next release is an F-4EJ Kai.

Rich

 

Possibly to give the towed target dart a bit more room under the wing:

 

aF42j-13.jpg

 

Jari

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On 8/31/2020 at 7:43 PM, JeffreyK said:

Thanks Ben!

Edit: I just did a search and found that the ARN-101 mod was introduced in '77, so it might not be applicable to this early hard-wing F-4E?

 

Further investigation: I didn't find any parts for the TISEO, nor any for the longer Midas gun fairing.

 

Can anyone shed a light on the vertical outboard pylon? Was there such a thing? Were the pylons originally mounted vertically before the canted pylon was introduced?

 

ZM included a set of closed J79 nozzles as well as the open ones and there is an extended nose gear strut in plastic as well. Also, you can mount the stabs in three positions now, there's already a cutout in the fuselage for the inserts to go in.

 

J

This could be in anticipation of theF-4G.  When the G's mounted 4 AGM-88 HARMs ( one on each pylon) the outboard pylons had to be canted so the fins on the missiles would clear the landing gear.  

 

Geoff M

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All I know (and that's not all that much by all means) is that USAF outboard pylons were canted 7.5°. Hence my recently released pylon set 

is designed just like that. The straight pylon, as found in the ZM kit is an entirely new thing to me. I've tried finding JASDF F-4EJ's with pylons but they very rarely carry outboard pylons and three pictures I've found are inconclusive regarding an outboard cant.

 

Edit: Just found this video here: 

Looks distinctly canted to me, same as the USAF pylon.

 

J

Edited by JeffreyK
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1 hour ago, cemdogut said:

I think pylons are same, spacer is placed according to the load. 

 

jdkDdP.jpg

The Sgt Fletcher tank pylon is something entirely different and has nothing to do with the weapons pylon, neither Air Force nor Navy type. The tank pylon was integral with the tank and was not used for anything else but the tank. On theory I think tank and pylon can be separated but they usually weren’t  (at least that’s what I remember reading). It’s a different story for the early McD tank and pylon, but that’s  not relevant here at the moment....

The outboard cant of the AF weapons pylon is in the structure of the pylon body itself, not in the mounting. The top surface and the stabiliser braces are all at an angle.

Cheers,

J

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9 minutes ago, JeffreyK said:

The Sgt Fletcher tank pylon is something entirely different and has nothing to do with the weapons pylon, neither Air Force nor Navy type. The tank pylon was integral with the tank and was not used for anything else but the tank. On theory I think tank and pylon can be separated but they usually weren’t  (at least that’s what I remember reading). It’s a different story for the early McD tank and pylon, but that’s  not relevant here at the moment....

The outboard cant of the AF weapons pylon is in the structure of the pylon body itself, not in the mounting. The top surface and the stabiliser braces are all at an angle.

Cheers,

J

https://tailspintopics.blogspot.com/2013/06/things-under-wings-f4h-f-4-phantom.html

 

Note the lack of sway braces on the attachment of the Sergeant Fletcher tank to the pylon,  a result of that tank being bolted directly to the pylon.

Edited by Tailspin Turtle
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1 hour ago, JeffreyK said:

The Sgt Fletcher tank pylon is something entirely different and has nothing to do with the weapons pylon, neither Air Force nor Navy type. The tank pylon was integral with the tank and was not used for anything else but the tank. On theory I think tank and pylon can be separated but they usually weren’t  (at least that’s what I remember reading). It’s a different story for the early McD tank and pylon, but that’s  not relevant here at the moment....

The outboard cant of the AF weapons pylon is in the structure of the pylon body itself, not in the mounting. The top surface and the stabiliser braces are all at an angle.

Cheers,

J

 

Thank you for information.

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