F-14 low speed prowess vs Other Aircraft - Page 40 - ED Forums
 


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Old 05-09-2015, 05:56 PM   #391
BlackLion213
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Originally Posted by captain_dalan View Post
Pretty much this. Above angels 25, the PW's would hardly hold you airborne, let alone accelerate (in MIL power).
Although, if you load up an F-15C to ~50-55K lbs, the F100's also have a hard time accelerating above 25K and its best to climb in steps (I just tried this out).

I've heard that the GE engines in general (in both the Tomcat and Viper) are much better at altitude with lower airspeed. PW engines seem to want more airspeed to make thrust.

-Nick
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Old 05-09-2015, 06:06 PM   #392
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The only comparisons you can make with real aircraft are the clean birds in-game.

Stores drag is quite excessive in-game. An eagle with two bags and eight missiles will happily go M1.6-1.8, and that performance is part of its air sovereignty mission. That doesn't mean you shouldn't climb in steps, but that's a schedule that pilots plan based on the aircraft's Ps curves, fuel flow, and desired time-to-distance.

LN may possibly deal with stores drag differently so it won't affect their aircraft.
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Old 05-09-2015, 07:28 PM   #393
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The only comparisons you can make with real aircraft are the clean birds in-game.

Stores drag is quite excessive in-game. An eagle with two bags and eight missiles will happily go M1.6-1.8, and that performance is part of its air sovereignty mission. That doesn't mean you shouldn't climb in steps, but that's a schedule that pilots plan based on the aircraft's Ps curves, fuel flow, and desired time-to-distance.

LN may possibly deal with stores drag differently so it won't affect their aircraft.
Good to know, though it seems that the F-15C can still reach very high speeds with stores, including fuel tanks. I was surprised that it could reach M1.6+ with 3 fuel tanks. Plus, part of the acceleration/climb changes is the fact that thrust relative to mass really drops off with altitude. Engine thrust drops by ~ 50% by 20,000' and drag decreases considerably also, but mass is constant. It's no surprise that an aircraft operating at twice it's empty weight with with less than half of it's sea-level thrust would have underwhelming acceleration up in the stratosphere.

One nice characteristic of the F-14 was that all of is stores are conformal/semi-conformal in the center tunnel. Placing large stores in the center tunnel was chosen for drag benefits and the fuselage lift that resulted was unexpected. It was discovered during aerodynamic testing. Many Tomcat pilots would move to the ANG after retiring from the USN and fly the F-16C. One Tomcat pilot that I spoke to (via the Sunset forum several years ago) was flying Block 32 wide-mouth F-16Cs. He was impressed by the Viper's abilities, but surprised by how much performance deteriorated when they strapped on fuel tanks or ordinance. The Tomcat, in contrast, had little performance changes from it's stores.

-Nick
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Old 05-09-2015, 07:40 PM   #394
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The F-14's stores between the engines are incredibly draggy, at least if the manual is correct. As you mentioned, the good thing is that up there, drag doesn't count as much. There are more effects than just drag when you add stores, the F-14 just seems to suffer less from such. Also, the F-16's intake isn't as good at recovering thrust as an F-14 or F-15, so I suspect those play a huge role.
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Old 05-09-2015, 07:54 PM   #395
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The F-14's stores between the engines are incredibly draggy, at least if the manual is correct.
I actually got the opposite impression. At least relatively, the F-14A seams to have less penalty from stores then the F-15/16/18 or Su-27. With 8 AAMs, even the A still reaches mach 2.15 at 35+ kft (out of max 2.41+ clean) unlike the F-15 wich struggles to break through mach 2.0 with similar load (out of max 2.5 clean). The Su us even worse.

I think it has something to do with the conformal stores, or how much submerged the missiles were inside the funnel.
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Old 05-09-2015, 07:59 PM   #396
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An F-15 will go pretty fast with stores onboard, but 'not permitted' AFAIK. Put it another way, they'll fly it M1.8 with two bags, those are about the value of the drag of all the AAMs put together ( ... minus pylons of course )

Conformal stores help, and both the F-15 and F-14 use them. Drag index of F-15 stores is pretty small. Drag index of F-14 stores is relatively quite large, but also realize the F-14 changes its wing sweep to drop overall drag to begin with. In other words, it's probably a bit beyond trying to pin it on any single thing.
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Old 05-09-2015, 08:33 PM   #397
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In other words, it's probably a bit beyond trying to pin it on any single thing.
Probably so

Makes me wonder why they never came up with some less draggy solution for the Sidewinders though
I mean, those Sparrows could depending on station and plane go from 25% to over 75% recessed.
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Old 05-09-2015, 08:37 PM   #398
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Sidewinders need to lock-on before launch, and a relatively wide FoV helps

The draggiest part about the sidewinder, IMHO, is the pylon it's attached to.
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Old 05-09-2015, 08:41 PM   #399
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Sidewinders need to lock-on before launch, and a relatively wide FoV helps

The draggiest part about the sidewinder, IMHO, is the pylon it's attached to.
Good point about the seeker, i never thought of it.
Why do the drag indexes on the winders are then often larger (by quite the margin) then the ones for AMRAAMs and Sparrows (in the store managers in the manuals)?

EDIT: because of the adapter/pylon?
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Old 05-09-2015, 09:48 PM   #400
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Good point about the seeker, i never thought of it.
Why do the drag indexes on the winders are then often larger (by quite the margin) then the ones for AMRAAMs and Sparrows (in the store managers in the manuals)? EDIT: because of the adapter/pylon?
For which plane and for which station? E.g. on the F-15's, both can be carried under the wings using the same pylon so it's probably not the pylon? Maybe due to the blunt seeker head of the Sidewinder (vs the thicker, but more aerodynamic AMRAAM I guess but I'm no aerodynamics expert)?
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