That is completely unrelated.
In the tests you mentioned the plane was nowhere even close to producing that much thrust. Producing that amount would have made landing impossible since you’d be accelerating insanely fast.
You are seeing two different things done by the same plane and conclude they are done at the exact same time.
A car can have 1000HP, can you still park your car into tight spaces in reverse? Do you think the car uses 1000HP in that moment?
See the issue? It’s not wrong to say that the plane has that amount of thrust. It’s also not wrong to say that it can maneuver with it’s engine at slower speeds, but it’s not possible for the plane to have both at the same time.
I mean sure… You CAN use 1000HP to park your car… But I guess you can see why that would not be an ideal situation.
The Thrust of the F-15 is pretty much correct within a small margin of error depending on the sources. What you suggest would mean that the F-15 should have a Thrust to Weight ratio of almost 3, when approaching Mach 1 at low fuel.
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An argument made from conjecture can be dismissed with conjecture.
On top of that, the document addresses PW-100, not PW-200.
AKA F-15A’s engine.
And the sentence that uses PW-100’s paper stats AB thrust is unconnected to the landing test sentence. @DocUSMC
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Thank you Alvis, but i’m worried that regardless of how much you might explain to him that he’s wrong he’ll keep on making these crazy claims.
F15s newer engines are even more powerful than this. F-15 Flight Research Facility - NASA
Initial ADECS engineering work began in 1983. Research and demonstration flights with the ADECS system, which began in 1986, displayed increases in engine thrust of from 8% to 10.5% (depending on altitude), and up to 16% lower fuel consumption at 30,000 feet and constant thrust.
The increased engine thrust observed with ADECS improved the aircraft’s rate of climb 14% at 40,000 feet, and its time to climb from 10,000 feet to 40,000 feet was reduced 13% at an airspeed of 350 knots (15% at 250 knots). Increases of 5% to 24% in acceleration were also experienced at intermediate and maximum power settings, depending upon altitude. Overall, engine performance improvements (rate of climb and specific excess power) were in the range of 10% to 25% at maximum after-burning power.
Proving we still don’t have enough thrust. Further more. If they were correct, then we could perform this:
I would love to see anyone do this within even 10% of the stated times with the in game aircraft. Do it clean, with minimum fuel (you can’t).
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The correct procedure is:
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Takeoff in 400 feet.
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Hold on runway to 500mph
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Pull 5G vertical to 80 degrees.
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accelerate to Mach 1.0 within 23 seconds.
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Reach 20,000ft at Mach 1.05 39 seconds.
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Reach 30,000ft at Mach 1.0 in 49 seconds.
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Reach 39,000ft at Mach 0.9 in 59 seconds.
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At the time of that test engine #P680063 was configured as a PW1128 EMD demonstrator engine, meaning it had significantly more thrust than the engines used on production F-15s.
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No F-15 can do 28,653 pounds, all will be heavier.
Since we cannot remove the Vulkan, and we cannot drop fuel below minimum, ours will always be heavier than that test.
4021 pounds of fuel.
28,204 pounds of aircraft.
My testing is sadly done at less than ideal conditions. I won’t bother doing an exact test for the simple reason of my F-15A being completely stock. When I chose the “reference” option I have either drop tanks which I can’t drop until I am in the air or I have weaponry slowing me down. I also pulled up way too hard at 9G’s.
Yet you can see that even with all those screw-ups, my time to altitude isn’t that far off. I also took too much fuel as I still have a ton of fuel left at the end.
I am not sure how heavy the F-15A at that fuel amount is but I reckon the F-15 used in that test had no weaponry installed, they sometimes even remove the radar and non-needed systems for those trials.
Without seeing all the details for the test it’s really hard to compare it to the ingame model. If we can match the weight it should be quite close though.
I guess the WT model is a bit heavier and since I lost more speed during the harsher pull-up I reckon you can gain a couple seconds from that alone.
EDIT: Also note my struggle with the brakes at the beginning, I was trying to hold them but for some reason my keybindings got messed up therefore there is some weird beginning to the video on the runway. I also couldn’t drop the weapons because I forgot to select them.
EDIT2:
Timestamps
-Start on runway at 22seconds
(That’s when I engaged the afterburner and released the brakes)
-Take-off at 32 seconds
(Could have been earlier if I pulled up earlier)
-Reach 30.000ft at Mach 0.92 at 1:19
-Reach 39.000ft at Mach 0.8 at 1:29
Taking away the 22 seconds idle on the ground we get:
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Take-off at 10 seconds
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Mach 0.7 at 21-22 seconds
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Reach 20K ft at 46 seconds
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Reach 30K ft at 57 seconds
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Reach 39K ft at 1:07 seconds.
And the test was actually done at “current settings” so the plane is indeed stock.
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You can make a clean preset without weapons
IIRC you can also disable automatic refuel and rearm on runway
They stripped literally everything they could out of that F-15:
The aircraft was modified by McAir between April 27 and June 11, 1974 for the tests by deleting all non-mission critical systems including: the flap and speed brake actuators; internal armament; the radar and fire-control system; non-critical cockpit displays and radios; one of the generators; the utility hydraulic system; and, of course, the 50 pounds of paint (hence its name)
Yeah, I can’t because I didn’t buy it yet^^.
Test was also performed on “current” which seems to mean “stock” when I compare it against the “reference” setting in local:host.
The engine is real. The engine exists. We have great test data on it. This should be the engine we have in game. This is a demonstration of what is possible. I also provided the NASA article where even more advancements were made later on, including even more thrust improvements, climb improvements, and fuel efficiency. The MSIP program used this knowledge to improve the F15. This means we should have far more power.
The standard set by the snail is that only 1 needs to exist for it to be in game. The Yak-141 is a great example of this. The R-79-300 for the Yak-141 never left the test stand. The R-79V-300 was the only engine to fly. Proof that we only need the stats from one for it to be in game.
The world record for that kind of plane is 90,000ft in 3 minute and 27.8 seconds. The games aircraft is way too weak to do this.
This is a failed test. Took 1 Min 10 seconds and you reached altitude at Mach 0.56 (Should be Mach 0.9). For the test to pass, you would have to make 40,000ft and be at Mach 0.9.
Also keep in mind, they were able to improve the engine performance later on by 25% at maximum AB. So you should be beating the time not falling behind it.
So I get a difference of 8 seconds to 39K feet with a plane that is vastly heavier, had to pull a much harder turn to 80° because of my incompetence and is carrying draggy missiles at the start?
That seems to be perfectly within the margin of error to me considering I got within 15% of the actual data with a much heavier plane and while it’s “stock” so Gaijin stole a couple seconds from me anyway =)
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For the test to be a success you would have to arrive at 40,000ft at Mach 0.9. You arrived at Mach 0.55. The Missiles aren’t going to slow you down to half speed. The aircraft is a 1.6+ Thrust to Weight ratio. Make it work in game. You shouldn’t be losing speed.
It’s not a failed test at all.
If the plane stayed any faster while climbing up, the times would have been much faster as well. The plane was also vastly heavier so it will naturally lose more speed while climbing.
I bled a lot of speed during my pull-up with means I got less ram-air and less intitial thrust during my climb phase.
Your claim is for a plane that is barely 1 ton heavier than the empty weight of the F-15A… If I had taken only 1 ton of fuel I would have still been vastly heavier from the ammunition, weaponry I had with me and the fact that it’s not a demonstrator used for climb records…
The fact that the F-15 arrived at 40K feet at Mach 0.9 makes no sense to me. How is that supposed to work by the way?
My time was barely off and I was at 0.54M at the end. If I still had that much speed I would have undershot that target drastically.
I will do another test after walking my dogs, with a reference aircraft and with better management. Let’s see the times we get then and compare those.
EDIT: Also: at 40K feet the F-15 in my video was still going Mach 0.77… I don’t know where you get the 0.54 from…
0.77 with a gimped stock plane that’s not a specialized test variant vs 0.9 on a heavily modifed test aircraft seems pretty okay to me…
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I am not the one who programmed the game and needs to fix it.
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They made improvements into the 90s which increased the engine performance by 25% (per NASA).
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They reduced fuel consumption in the same process (per NASA).
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The benchmark is. 40,000ft @ Mach 0.9. Not up to me to make it work. But clearly they have entirely too much drag going on as well.
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8 x AMRAAM = 2850lbs. Or 10% of the vehicles weight.
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The Aircraft is a 1.6+ Thrust to Weight ratio clean.
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10% of 1.6 = 1.44 Thrust to Weight Ratio.
This means its still a positive TWR. So the aircraft should arrive at 40,000ft near Mach 1. Even with armament. If we can’t do this in game, then the game has the aircraft modeled wrong.
Lastly… Now take the ADECS and DEEC improvements which NASA talks about. Add the 25% performance increase and the 16% lowered fuel consumption.
In short, we should be climbing faster, retaining more speed, and using less fuel all around.
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Where did you find this source?
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The empty weight of the standard F15A is listed at 28,000lbs. The Climb graph I gave you is 28,653lbs when it rolls. Minimum fuel, clean configuration, should be at Mach 0.9 at 40,000ft. Read my other post on why it should actually be BETTER due to improvements in the engine in the late 80s/90s. We have the 2000s model, so these should be reflected.
