F-16 (BMS) Flight model Stress Test, Wheel brakes to 15,000ft in 45secs
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Hi Guys,
Unrestricted Tactical Climbs are standard procedure in any High Risk Combat environment, mainly to protect from small arms fire and short range SAMs, however….in these environments, they are loaded down with lots of Gas and Weapons, and typically don’t have Delta Airlines flying overhead
This would be a Great Question for Haole, since he’s a certified Maintenance Test Pilot, which required a max performance tactical climb in a clean jet, after certain engine / maintenance was performed.
Let me text him and see if I can get him to jump in the conversation and verify the results or clear up the information.
I know enough to know that the vertical pull entry speed and the actual (G’s) in that pull are key to maximizing the climb performance. Too little and it takes too long to reach a max performance climb angle, thus adding time. Too much speed / (G’s) in the pull, and you’re depleting valuable potential energy. What’s the magic Speed / Vertical pull (G) wise…heck I don’t know… Haole Help Please!!
This is another reason we need a “Haoles Corner” here on the BMS Forums, so we can get real world data from an actual Viper driver with combat experience…who is available and likes to help simmer out!
Stang out
Yep, i’m trying to find that magic speed and g pull
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…try 1 G of pull for each 100 knots of speed at entry…also try pulling to the AOA limit until 75-80 degrees nose up. Just suggestions…
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My guess is 450 kts and then a “smooth” 4 G pull to 65-70 degrees.
The next question is how much fuel was on board for the test? I very seriously doubt it was “Full Fuel” so they could get the weight savings.
Haole is out Christmas shopping but said he would jump in when he gets home tonight and help out.
I just texted him the basics of this discussion to see if the 45 seconds is even in the realm of realistic or not.
I’ll let you know what he says.
Happy Holidays Guys
Stang out
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I could see full internal fuel…but nothing external - no EFT, no pylons, no armament. It’s not like a slick F-16 is that heavy.
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15,000 in 45 seconds is very reasonable with a climb rate of 50,000 ft/min on a clean jet. After 30 seconds of takeoff roll and 15" of climb you’re rolling out around 15,000’. Loaded down with weapons, fuel tanks, etc is a different story. We used to accelerate to about 400kts and blend in a nice 3-4G pull to 60 degrees nose high and climb to 10k’ on our combat departures with a full combat load. This allows us to roll out at 10,000’ and still have good maneuvering airspeed. Climb much higher and you piss your energy away.
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…I never doubted that for a second, Haole.
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15,000 in 45 seconds is very reasonable with a climb rate of 50,000 ft/min on a clean jet. After 30 seconds of takeoff roll and 15" of climb you’re rolling out around 15,000’. Loaded down with weapons, fuel tanks, etc is a different story. We used to accelerate to about 400kts and blend in a nice 3-4G pull to 60 degrees nose high and climb to 10k’ on our combat departures with a full combat load. This allows us to roll out at 10,000’ and still have good maneuvering airspeed. Climb much higher and you piss your energy away.
Thanks for that feedback.
I’m getting around 48-50secs right now (by flying the profile in the video). I’ve tried zero kts wind and changing other environment variables but have been unable to get 45s (with the climb done in 13s). I tried from a sea level similar to that in the video. Not sure if the environment variables are limiting me but do you think 45secs could be achieved more or less with common weather conditions (in real life)? Or do the weather conditions have to be absolutely perfect to acheive it?
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nice! but your climb took 22seconds. In the real world vid he did it in 12-13 seconds.
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I still think it’s not 15k feet. And before you say that Halle says it’s possible, just remember he’s a fighter jock and they’re prone to exaggeration. ;). [emoji3]
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nice! but your climb took 22seconds. In the real world vid he did it in 15seconds.
22 Seconds, probably. Remember, in bms, you start out with a fuel fuel load. Go with less than half a tank and less weight, and you can probably reach it in 15 seconds.
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I still think it’s not 15k feet. And before you say that Halle says it’s possible, just remember he’s a fighter jock and they’re prone to exaggeration. ;).
I’ve added a higher resolution video to main post, did you manage to read the article in the op? this was a feat performed by the well known Solo Turk. So they say…Maybe the video is not realtime?
22 Seconds, probably. Remember, in bms, you start out with a fuel fuel load. Go with less than half a tank and less weight, and you can probably reach it in 15 seconds.
I already tried with 1100lbs of fuel. I also made a mistake, the real life pilot did it in 12-13 secs not 15s as I said earlier. Most attempts take me 20secs for the climb given a 15s roll and 15s level flight.
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nice! but your climb took 22seconds. In the real world vid he did it in 12-13 seconds.
I was optimizing for brake release to 15k so I pulled up prior. If I wanted to optimize for 500’ to 15kft I would delay the pull until much faster. It’s a block 30 with 1817 lbs. of fuel.
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If that’s real time that would have been a 6 to 8G pull, I reckon. I might have a go at replicating this.
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Interesting topic and while browsing I thought of this documentary about the development of the Su-27 which also incorporated some interesting facts about the F-15’s rate of climb records. Apart from the common practice of stripping the paint down to reduce weight, tests were performed in winter time so the engines can produce a maximum thrust, apparently due to the air density being greater, as stated in the below video link . This apparently assisted in maximizing the best climb rate, starting at ground level !
So, as already stated by others we need to know the required environmental variables to plug into the equation, because that’s what this simulation really is, right One big equation. And therefore, as long as the HFFM can factor in these real variables then similar outcomes should be reached. Yes?
Anyway just my 0.0000002c and another excuse to post a another great aircraft doco.:D
@19:20 for the P-42 & F-15 climb records.
Found interesting links regarding engine thrust V’s density https://www.physicsforums.com/threads/jet-engine-performance-in-cold-weather.721313/ and http://forums.eagle.ru/showthread.php?t=83639&page=9
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Can anyone accurately recreate this event in BMS 4.33?
Need to know what was the air pressure, elevation of the field, air temperature (ISA) on different atmosphere layers …
Without those … you can’t compare anything.
EDIT: Sorry … already answered by Jp …
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simple ask where did that video was filmed and what date and time. Get from grib that date and hour weather data. Fire up falcon with Korea and put the weather data in a way to be the same on the area. have a two seater f-16 and try it out. Hope that the airfield doesn’t have a downslope to help runway wheels acceleration.
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Haole’s right…as usual
Tried this setup today 5 times and met or beat it every time.
You have to remember the Viper climbs at 50,000 + feet a minute That’s 830 - 1,000 a second, depending on load out, temp, altitude, lada lada lada.
My setup
Fuel 1,200 lb
Clean Jet
Start on the runway (no need to waste fuel taxing)
Brakes on
Full ThrottleThe moment the aircraft moves I release brakes and start the clock at the same time.
Pull up about 3 degrees up at 130 kts and immediately raise the gear while pushing the nose back level (10 - 15 feet off the runway) & Hold the nose level (it wants to climb)… now I’m accelerating like a “Bat …err Viper out Hell”.
Accelerate to 28 Seconds of time, then start a smooth pull (4 G’s max) to 70 degrees nose high.
At 15,000 feet, hit stop on the stop watch. Typically its between 41 - 44 seconds
Easy cheesy!!
I have Fraps, if I can figre out how to set it up and use it, I’ll post a video.
Stang out