The record thread: How fast can you go...

[S77th-GOYA]

this is actually a bit less than 2.4.

 

Yep, that's what I thought. Thanks for checking.

[peterj]

You say the F-15's porked?? never heard that before :)

 

 

Su-27

Time: 24:30 (stationary 24:46)

Fuel: 0 KG (ran out on approach)

 

Climbed to 10000 on full AB, then lowest AB to 13200 and maintained mach 2.2, until descend.

[pappavis]

Any1 for a Su-25T race from Sukhumi to Razdolnoye? no mac there, just plain 650km/h or so ;).

[peterj]

Any1 for a Su-25T race from Sukhumi to Razdolnoye? no mac there, just plain 650km/h or so ;).

I did an attempt with the Su-25, however managed to overshoot the airport, it's a handfull at mach 0.9 :)

Will try the Su-25t, atleast it has autopilot.

[britgliderpilot]

I did an attempt with the Su-25, however managed to overshoot the airport, it's a handfull at mach 0.9 :)

Will try the Su-25t, atleast it has autopilot.

 

I did some Su25 pylon racing online once . . . . after a while all it is is everyone wrestling with the Mach buffet!

 

 

Now, racing the Ka50 . . . . that should be a bit more fun. Grin.

[peterj]

Su-25T

 

12:46:00

 

Cruise: 977 km/h @ 6078 m

Instruments says mach ~0.97, calculated: 0.86

 

Start 5010 KG

End 1010 KG

 

I found that the amount of fuel is not the same on the ramp as you set in the mission editor. 5310 KG -> 5010 KG on the ramp. , less difference without ext tanks, 3090 KG -> 3070 KG.

[golfsierra2]

 

12:46:00

 

 

Is that 46 minutes or 12 minutes 46 sec or 12 hours 46 mins ?? I guess it's the local time when you landed...

[mikoriad]

Here's the track. After viewing it though, it looks like something is hosed. My Mach meter was well above 2.4 when I went to the outside view. In the outside view, my TAS reached 2518km/h, possibly 2519. But, according to Mach at 29,000', this is actually a bit less than 2.4. I very rarely fly the F-15C, so I hadn't noticed before, but the RPM gauges are porked too. Has anyone else noticed how they read "Percent PRM", instead of "Percent RPM". And what's with the fuel flow gauges? Mine topped out at around 9200 pounds per hour, each. So, according to those gauges, I should have been able to fly to Sukhumi and turn right around and go back to Razdolnoye, on burners the whole way, and land with about 5000 pounds of fuel left. What's the point of the fuel flow gauges if they don't show actual fuel flow? :( Heh...I noticed that eye-sore again on the UFC too. A transponder cannot produce a mode A code of 8 in any of the four digits.

 

Anyway...here's the track.

 

 

The fuel consumption for the F-15 is just screwed the way all around. In mulitiplayer I can load up with 3 tanks and max internal fuel. I then takeoff and head in the opposite direction of the "fight" and climb to about 40,000ft. I turn around and fly back to the fight at around that alt and slowly climb as I use up fuel, all of this is done in full AB. Basically I can tool around at around 45 or so thousand feet and just stay there forever on full AB plucking the bogies 1 by 1.... as long as I don't get shot down too soon.:joystick:

[GGTharos]

This is actually how it should work ;) Fuel consumption up there is low, even in AB.

[peterj]

Is that 46 minutes or 12 minutes 46 sec or 12 hours 46 mins ?? I guess it's the local time when you landed...

Good guess ;)

 

Take off 12:00:32

Land 12:46:00

[britgliderpilot]

Is that 46 minutes or 12 minutes 46 sec or 12 hours 46 mins ?? I guess it's the local time when you landed...

 

If you can find an Su25T that'll do that distance in 12 minutes, I want to know about it!

 

 

. . . . I need to fly higher. I didn't record how high I was flying, and attempts to beat my previous time flying at 11,000m all, um, ran out of fuel.

 

I reckon a cruise at 15,000m or higher is the way to go, and then it's just figuring out the compromise between fuel burn to get up there and time spent getting to that altitude . . . .

 

Constant climb, or go ballistic from a very high speed at low level?

Longer you're at low level accelerating, the more fuel you burn. Constant climb the fuel burn's dropping off all the time, but you're climbing slower. Tricky.

[britgliderpilot]

22 minutes 30.

 

Which is still slower than GGTharos and his F-15, dammit . . . .

[GGTharos]

Listen, you need to go about 1000kph faster than that frog can fly at to catch up with me ;)

[hitman]

Meanwhile it took me 10 minutes to walk to 7-eleven to get me a cold beer and back and exactly 30 seconds to drink the first one.

[mikoriad]

This is actually how it should work ;) Fuel consumption up there is low, even in AB.

 

Yes, of course it's lower up at high altitude. It still just doesn't seem correct, or even close to correct. Anyone know about what the fuel flow of an f-15 at 40K, in AB should be?

[Force_Feedback]

Guys, I'm goint to try doing the stretch in a mig-29S under 25 minutes (and come to a complete halt before that time). Wish me luck. :megalol:

[golfsierra2]

First attempt

 

Aircraft - Mig-29A

Take off - 12:00:00

Max Speed - 2,507 Km/h

Full Stop - 12:25:26

 

 

Gosh, you found a shortcut !!!

[MiGMadness]

Gosh, you found a shortcut !!!

 

Yup. ;)

 

2nd Attempt

 

Aircraft - Mig-29A

Take off - 12:00:00

Max Speed - 2,541 Km/h

Full Stop - 12:24:09

 

[Force_Feedback]

Yup. ;)

 

2nd Attempt

 

Aircraft - Mig-29A

Take off - 12:00:00

Max Speed - 2,541 Km/h

Full Stop - 12:24:09

 

 

Fuel state?

[golfsierra2]

Yes, of course it's lower up at high altitude. It still just doesn't seem correct, or even close to correct. Anyone know about what the fuel flow of an f-15 at 40K, in AB should be?

 

To roughly answer that question, a bit of calculation has to be done:

 

Only found this reference so far:

http://en.wikipedia.org/wiki/Pratt_&_Whitney_F100

 

"Thrust:

 

17,800 lbf (79.1 kN) military thrust

29,160 lbf (129.6 kN) with afterburner

 

Specific fuel consumption:

 

Military thrust: 0.76 lb/(lbf·h) (77.5 kg/(kN·h))

Full afterburner: 1.94 lb/(lbf·h) (197.8 kg/(kN·h))"

 

"The common unit of measure is lb/(hp·h) - that is, pounds of fuel consumed for every horsepower generated during one hour of operation (or kg/(kW·h) in metric units). Therefore a lower number indicates better efficiency."

 

So that would be

197.8 kg for every kN of thrust in a/b mode during 1 hour of operation.

 

197.8 x 129.6 = 25634.88 kg in one hour, that equals

 

427.248 kg per minute or

 

7.1208 kg per second. And that is for one engine, so for two it would be

 

14.2416 kg per second or 854.496 kg per minute.

 

Given a total fuel of 20 000 lbs equals 9 060 kg, the engines would flame out after 10 minutes 40 sec with full a/b .... eh ..... ????

 

So, there must be something wrong here, any math specialists here ?

[GGTharos]

Did you take into account reduced fuel flow for a non-static engine at high altitude?

[britgliderpilot]

To roughly answer that question, a bit of calculation has to be done:

 

Only found this reference so far:

http://en.wikipedia.org/wiki/Pratt_&_Whitney_F100

 

"Thrust:

 

17,800 lbf (79.1 kN) military thrust

29,160 lbf (129.6 kN) with afterburner

 

Specific fuel consumption:

 

Military thrust: 0.76 lb/(lbf·h) (77.5 kg/(kN·h))

Full afterburner: 1.94 lb/(lbf·h) (197.8 kg/(kN·h))"

 

"The common unit of measure is lb/(hp·h) - that is, pounds of fuel consumed for every horsepower generated during one hour of operation (or kg/(kW·h) in metric units). Therefore a lower number indicates better efficiency."

 

So that would be

197.8 kg for every kN of thrust in a/b mode during 1 hour of operation.

 

197.8 x 129.6 = 25634.88 kg in one hour, that equals

 

427.248 kg per minute or

 

7.1208 kg per second. And that is for one engine, so for two it would be

 

14.2416 kg per second or 854.496 kg per minute.

 

Given a total fuel of 20 000 lbs equals 9 060 kg, the engines would flame out after 10 minutes 40 sec with full a/b .... eh ..... ????

 

So, there must be something wrong here, any math specialists here ?

 

You don't need a maths specialist, you need an F100 designer . . . .

 

 

SFC values are generally only valid for one flight condition. Without specifying what that flight condition is . . . . we can't really draw much from it.

 

Someone had an F-15A flight manual lying around - that might give some more useful info :)

[peterj]

Listen, you need to go about 1000kph faster than that frog can fly at to catch up with me ;)

You mean like this :) ,

 

Su-27

 

12:00:15

12:21:46

 

Cruise altitude: 15000m

VMax: Mach 2.5

 

Fuel left: 0 (touched the burner on short appr.)

[GGTharos]

Yep :)

[golfsierra2]

Did you take into account reduced fuel flow for a non-static engine at high altitude?

 

No. I noticed that something must be wrong with this calculation, and I guess this calculation then is only good for an engine static running at ground level, which would explain why the fuel consumption is that high. It must be lower at higher levels, I fully agree.