OK, silly question time...

Drzook

Drzook

Charter Member
Good evening all,
I just got the Alphasim F-84F package (yeah I know long time coming; BTW got the newer stuff and I am impressed but I digress) and something about this bird leaves me scratching my head. Why are the drop tanks at that crazy angle? That cannot possibly be good for aerodynamics.

On another note...OBIO's Loud and Rumbly jet sound goes fantastically with this plane :ernae:(that and I cannot find a Wright J65 engine sound anywhere).
Also love how it takes up all the runway before lifting off; apparently that story about the 'dirt sniffer' was true lol.
 
I believe the tank angle is authentic. The last thing you want when you want to drop them is to have one decide to fly back up into your belly. Big bang, fireball, not nice. I think they were pointed down to hasten their distance from the parent aircraft once cut loose. A considered trade off with aerodynamics. F-18 gas tanks also point down a little I presume for the same reason. A fighter jock or similar expert can verify or laugh at me and give the correct answer, either way is fine.
 
Drzook said:
Good evening all,
I just got the Alphasim F-84F package (yeah I know long time coming; BTW got the newer stuff and I am impressed but I digress) and something about this bird leaves me scratching my head. Why are the drop tanks at that crazy angle? That cannot possibly be good for aerodynamics.
Click to expand...

F-84F's usually sat in a tail down atitude when on the ground. If the tanks were paralell with the fuselage then they would hit the ground.

....at least I think thats the explanation.

edit: actually aeromed's explanation seems better, after looking at pictures.
 
I know the angle is probably spot-on. There's a Thunderstreak at the Kalamazoo Air Zoo and it has those 'drop' tanks (I use the term loosely; IIRC they rarely dropped them), again at that way-down angle. I also know that when on the ground the tanks were pretty much level. I like your theory Aeromed; also like yours too Kokoro; after all the tanks would be easier to top off this way. Still, you don't see that on an F-86 (OK maybe slightly downwards but not like the Thunderstreak's tanks).

In the meantime I am enjoying this plane very much; I would like to give out a shout-out to the guys at Alphasim for providing us with such wonderful virtual aircraft.:ernae: :salute:
 
With those tanks being slightly nose down would also likely help on take off and landing when the aircraft is flying much slower which is when the wing angle of attack is much higher. In slower flight they would be streamlined with the flight path of the plane.
 
Sorry if I step on any toes, but as far as looks go, the 84 is just too wonky looking for my taste, especially with those tangental tanks and the odd-looking rear fuselage. The 105 is a far better looking Republic product IMO. The only thing that ever endeared the F-84 to me was Richard Bach's "Stranger to the Ground" where he writes about flying it in the Air National Guard. I think the Section 8 Canadair Mk. 6 Sabre has spoiled me for life when it comes to 1950's jets :guinness:

N.
 
I can't remember where I found them, but I came across some Italian paints for this plane and it included a new MDL file with the drop tanks removed. Maybe on flightsim.com.
 
FS2004 (ACOF) - FS2004 Modern Military FS2004 Italian Air Force Republic F-84F
[SIZE=-1][ Download | View ] [/SIZE]
Name: f84f_am2.zip Size: 7,157,774 Date: 06-30-2008 Downloads: 315
f84f_am2.gif
[SIZE=-1] FS2004 Italian Air Force Republic F-84F Thunderstreak. Textures package with five different liveries for the Italian Air Forces aircraft of the period 1958/1968 (5 Aerobrigata, 6 Aerobrigata, 8 Stormo, 36 Stormo, 50 Stormo). These textures require the new Alphasim freeware package (F-84F_04.ZIP). This package includes also a new "clean" model (without wing tanks) by Michael Davies. By Manuele Villa.
[/SIZE]
[SIZE=-1]I think these are the repaints you need, they look really nice. ive try'd the no tanks mdl but i think the plane looks naked without them, incidently, im reminded of the old aviation gag,[/SIZE]
[SIZE=-1]If someone built a runway around the world, Republic would build an aircraft that would have difficulty taking of from it.[/SIZE]
[SIZE=-1] cheers ian
[/SIZE]
 
Now that no-tanks version of the Thunderstreak looks pretty cool to me; I will definitely have to give that a go. Any chance anyone knows about a no-tanks version of the Thunderflash?:jump:
ThinkingManNeil; I agree that the 'Streak looks a little wonky and that is what endears it to me. Now if I was going on a mission with a 1950's plane I would likely go with a Canadair Sabre too. According to what I read the engine on the F-84F was at some weird angle giving the exhaust a kink and for that reason losing some 700 lbs of thrust.
Another reason I like this plane so much: When I was very young one of the first 1/48 scale models I made was of a Thunderstreak (the first one was an F-80, followed by the F-84 then the F-86). Back then I would make them with the wheels up and no tanks and then me and my brothers would play 'Jets' with them. My brothers more often than not ended up with the 'Streak; however I still have to smile every time I see an old USAF jet from that time period.
 
On another note...

If anyone knows if this paint is available for the F-84F it would do a lot of good. My F-84 model didn't look this good but if we got this paint for FS2004 I could relive a lot of fond memories :D
 
Ok, I have to do what I always do when a thread get started on the F-84F. :kilroy: And that is to encourage you to read "Stranger to the Ground" by Richard Bach. It is a great book and you will really appreciate flying this old bird even more after reading it.
:ernae:
 
Here's a Thought- With the airplane sitting Tail down on the ground. Imagine trying to get ever last drop of gas in those tanks if they were'nt mounted in a neutral attitude. That would be a guess of mine.
 
Thought I would revisit this thread; another silly question...

Hey all,
turns out the paintjob that I referred to a couple of posts back is in Alphasim's base package. Also turns out there's a real Thunderstreak painted up like that at the Kalamazoo Air Zoo. I've been really enjoying this plane lately. I do have another silly question however: I can't seem to get this plane much over 30,000 feet, and at that altitude it is not going fast, even with the thrust lever all the way forward. All sources say it has a service ceiling of 46,000 feet but at anything over 17000 feet I might as well be trying to coax a Bonanza higher. Any ideas?
 
Actually, all of the reasons proposed for the angled tanks are correct. Everyone's right!

I like the no tanks model, but I don't recall ever seeing a real 'Streak or even a photo of one without the tanks.

If you're installing the no-tanks model, keep it and its paints in the separate aircraft folder with separate aircraft.cfg files. The contact points are slightly different, and if you use the same contact points one or the other won't sit quite right on the ground.

If you don't want to clutter up your computer with duplicate copies of all your texture folders, you can alias them from one model to the other. The texture lines in the aircraft folder without the texture folders looks like this:

texture=..\..\..\Aircraft Name Where The Textures Are\texture.Whatever

You can use the same technique to alias panels, sounds or model files. The only things that must be present in a folder for FS to recognize it as an aircraft are the aircraft.cfg file and the AIR file. And I'm not even sure about the AIR file; I think you could alias that, too.

I still have a scar from where I ripped my upper arm on the sharp projecting twisted wires of a chain link fence I was hanging on to watch an element of Mass. Air Guard F-84Fs take off from Barnes Airport in Westfield. I was in college then, and now I'm retired, so that's been a persistent scar!
 
Alphasim models were not known to be very accurate when it came to the Flight Model.

If you enjoy it fly it that way if you want to tweek it...

:running:

Start purchasing Pilot manuals and doing research on how it flew. Putting together an accurate FM really takes research and is very challenging and rewarding. It may also make you loose all of your hair if you let it. :icon_lol:

http://www.flight-manuals.com/fth.html

The base air file will be the place to start as I believe they got the take off right.

When you do your research you might find that the F84 was a low altitude fighter that flew better at lower altitudes. It still should get to the service ceiling though so something is still off. Remember that the service ceiling is the point at which the aircraft can no longer maintain a 100 fpm climb. This will be affected by load out as the service ceiling should be lower with full tanks and weapons loaded.
 
The tank angle seems to be beneficial both on the ground for refueling, though that could potentially be done before connecting them to the wing, but also in the air.
When the aircraft is flying at a slower ferry or on station holding speed, possibly at higher altitude to increase efficiency of the turbine and with extra weight from the tanks and fuel it would likely have a definitive positive AoA.

Service ceiling does not mean you can get there in any condition....with full fuel you definitely won't be able to get there.
:ernae:
Stefan
 
Sunny9850 said:
...Service ceiling does not mean you can get there in any condition....with full fuel you definitely won't be able to get there...
:ernae:
Stefan
Click to expand...
I kind of figured that with full fuel I couldn't get too high; I had it so I just had a full tank of internal fuel (570 gallons) and 500 lbs ordinance instead of the default 4500 (I'm guessing 500 lbs would cover the .50 cal ammo). Still doesn't want to get much over 25000' in that config, although it seems most happy about 15000' and lower.
I know that piston engines have a line in the cfg file, something like 'critical altitude' which is the maximum altitude the turbocharger can emulate sea level oxygen levels. I don't see anything in this turbine engine config concerning critical altitude, however. Perhaps I'm missing something?
DD, I know putting together realistic FD is both rewarding and frustrating at the same time; back in the good ol days (FS98, CFS2) it seemed so much easier (granted those old efforts were probably way off).
Other from the inability to get up past the tropopause the only quibble I had about the Alpha 'Streak's flight model was the fuel capacities. I have replaced them with the following lines in the CFG file:
[fuel]
//Longitudinal (feet), Lateral (feet), Vertical (feet), Usable(gallons), Unusable (gallons)
fuel_type = 2
number_of_tank_selectors = 1
//Center1 = 0, 0, 0, 800, 0 <--original
//LeftMain = 0, -3.9, -3.75, 300, 0 <--original
//RightMain = 0, 3.9, -3.75, 300, 0 <--original
Center1 = 0, 0, 0, 570, 0
LeftMain = 0, -3.9, -3.75, 230, 0
RightMain = 0, 3.9, -3.75, 230, 0
electric_pump=0

I also used the model from the NATO 'Streak in conjunction with the 'clean' model, not only because of contact point issues but also because the animation on the front wheel on the US 'Streak seems off. There's also been some mods in the panel as well; the VC now has all the gauges that the 2D cockpit has. At some point I'll upload the mods when everything seems right.
 
I just went for another flight doing what I love most with jet fighters--harassing airliners. I had my doubts--after all the Thunderstreak is not the happiest bird at high altitudes. Turns out I may've been wrong in my initial assessment--it just takes some time to get up there is all. I was chasing down a 737 at 33000'--groundspeed was over 470kts which is pretty close to the actual F84F's cruise speed (465kts). Granted it took place over three states (Michigan, Indiana, and Ohio south of Dayton) but I managed to pull it off! This was done with just internal fuel and no ammo on board (also assumes I only weigh 200 pounds with flight gear haha). Nevertheless it can be done and I still get a respectable range of around 900nm. I'm not sure if I can get to 40k and beyond but for the most part everything 'seems' right on this plane. Now after this flight the major take-away from it is 'where can I find better contrail effects?' At some points it felt like I was on a white road to the airliner and I know that ain't right.:kilroy:
 
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