Forum: General F-22A Raptor forum

Typhoon supercruises for 1075nm!?! ROFL, now who's posting stupidities!

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cola wrote:

wrightwing wrote:

Those weren't my feelings. I was pointing out comments from Raptor pilots FWIW. As for a Typhoon supercruising for 1.5hrs, I think you might want to put the pipe down(that'd be a supercruise range of 1386 miles) Shocked

The point is you should check basics/facts before posting such stupidities and I frankly think you just made this up, because I can't believe that even the dumbest propaganda agent could have come with such a statement, let alone actual pilot.

As for the EF, the time of 1.5h is theoretical one (let's say between two tankers) and I've calculated a generic thrust lapse, which may be (and probably is) smaller for supercruising engine like EJ200.

And again, figures aren't your friends (hence empty demagogy, I guess).
EF, doing an average M1.25 above tropopause for 1.5 hours will cover ~1075nm, which is about 150 miles short of what you "figured".

One thing that may have been overlooked in that range/time figure is some legs where afterburners(i.e. faster than supercruise speeds) were utilized. As for 1.5hrs of supercruising, not even the Mig-31 has enough fuel to fly supersonic for that amount of time, and you have the audacity to claim others are posting propaganda. Razz

wrightwing wrote:

One thing that may have been overlooked in that range/time figure is some legs where afterburners(i.e. faster than supercruise speeds) were utilized. As for 1.5hrs of supercruising, not even the Mig-31 has enough fuel to fly supersonic for that amount of time, and you have the audacity to claim others are posting propaganda. Razz

Wrightwing, there are numerous sources putting EJ200's SFC at ~ 0.7 at dry power.
Here's the first, that came out on Google:
http://findarticles.com/p/articles/mi_hb3126/is_n615_v52/ai_n28695995/
Now, do the math and you'll see that EF can maintain full dry power at SL for even MORE than half an hour, ON INTERNAL FUEL ONLY!
Add two supersonic tanks and you got 40% fuel/time increase.

EJ200's SFC is 0.74 - 0.81 kg/kg/h or 21 - 23 g/kN/s (figures from Eurojet). If we just simplify it and calculate its consumption it works out as follows.
Static dry thrust 2x6120 kg, internal fuel 4950 kg.
With a SFC of 0.74 this works out to 32.8 minutes
With a SFC of 0.81 this works out to 30 minutes

We have to take into account the fuel consumption up to lift off which means the aircraft will not fly much longer than 25 minutes (estimated). The SFC is in this case calculated with static (and uninstalled) dry thrust. Usually installed thrust is lower at SL/zero speed conditions, but thrust can increase beyond that value with the increase of speed.

The at that time Wing Commander Gav Parker of No.11 sqn stated that the fuel consumption on max dry at 40k+ ft was comparable to the idle consumption on the tarmac.

If we simplify the calculation and say 60% RPM = idle and SFC is a function of that, than it should work out as (0.74/100)*60 = 0.444. If we now calculate consumption with 2x6120 kg and 0.444 SFC (lowered SFC compensates for higher thrust) than the flight time (starting in the air) would be 54 minutes.

If we now assume an average M 1.25 with that consumption for 54 minutes it works out to 1208 km (652 nm).

Again not factoring in the speed which will have an impact on thrust output and subsequently consumption. If we factor in the increased consumption at higher mach and substract the fuel required to get there in the first place then you quickly end up with entirely different and much smaller numbers.

Let's just assume some 3000 kg of fuel are left following ramp up, taxing, take off, climb to altitude and acceleration to M 1.25, factor in a let's say 20% increase in SFC (0.444/100)*120 = 0.533 it ultimately works out as 27.6 minutes or 611 km (330 nm).

Edit:
Now let's do the same for the F-22. Assuming static dry thrust is 2x11500 kg (I've seen such a figure a few years back), let's assume an identical SFC of 0.74 with supercruise consumption high up 90% at M 1.7 (0.666) and with an internal fuel load of 9386 kg (20650 lb). Starting mid air with full fuel this works out to 36.6 minutes at M 1.7. Meaning a range of 1150 km (621 nm).

If we now assume that some 7000 kg of fuel are left following ramp up, taxing, take off, climb and acceleration then it works out to 27.42 minutes or 861 km (465 nm).

In other words both aircraft would be able to supercruise equally long, but due the much higher speed of the F-22 it would achieve a longer range (861 km vs 611 km).

What supercruise? Production EF "supercruise" is M1.1. About the same for an F-15. This entire thread is absurd. In no way shape or form is the EF in any way comparable to an F-22. I was trying to bring that out in comparisons with the F-15 until it was decided that we went "off topic". So now we are on topic and we are discussing wishful thinking and lunacy.

The correct comparison is with various updated versions of the F-15 and Super Hornet. The proposed F-15SA for Saudi Arabia is every bit as effective as EF is most instances and superior in some.

Lets not talk nonsense for the sake of being on topic. There is no comparison between the F-22 and Typhoon.

cola wrote:

wrightwing wrote:

One thing that may have been overlooked in that range/time figure is some legs where afterburners(i.e. faster than supercruise speeds) were utilized. As for 1.5hrs of supercruising, not even the Mig-31 has enough fuel to fly supersonic for that amount of time, and you have the audacity to claim others are posting propaganda. Razz

Wrightwing, there are numerous sources putting EJ200's SFC at ~ 0.7 at dry power.
Here's the first, that came out on Google:
http://findarticles.com/p/articles/mi_hb3126/is_n615_v52/ai_n28695995/
Now, do the math and you'll see that EF can maintain full dry power at SL for even MORE than half an hour, ON INTERNAL FUEL ONLY!
Add two supersonic tanks and you got 40% fuel/time increase.

Your source claims a TARGETED SFC and there's nothing to say it ever reached that target either.
Either way the whole "Typhoon can do 1075nm supercruising" that you claim is just silly and rivals some of the tripe i've overheard coming from dumb chavs that were watching it fly at airshows.

@Scorpion, two points.
First, you've deducted 2 tons of fuel for both F22 and EF.
Well, that doesn't work since a pair of F119s and EF200s can't begin to compare in terms of overall fuel consumption and F22 most certainly can't do as much with 2 tons of fuel as can EF.
The consequence of that is increased cruising time for EF, or shorter for F22, than you've calculated.
Second, SFC for F119 is almost certainly higher than EJ200's, widening the gap even further.
This is the reason I went with "M1.5 for 41 mins", as it gives an empirical, ballpark figure for F22's SFC during SC.

All of this leads us closer to the point of my previous posts and it's very likely that an EF even without tanks can SC longer than F22.
The actual range covered is questionable, due the difference in speed, though.

Forum Veteran Joined: Apr 16, 2005 - 03:16 PM Posts: 800

Wouldn't their ability to supercruise depend on the amount of fuel they have? At full internal fuel the F-22 will probably supercruise easily while the typhoon may be enable to supercruise at all.

Also the F-22 flies higher where there's less drag, it seems to me that you should take that into account too.

As insisted this comparison is largely simplified and neither meant to be accurate, nor the end of all figures. Refinements are certainly possible. What it shows however is that the figures mentioned before aren't realistic by a long shot. And what it also shows is that the F-22's range isn't so much longer than that of the Typhoon.

We have to take into account that:
1.) The F-22 is 79% heavier than the Typhoon
2.) The F-22 has 89% more fuel
3.) It's engines are at least 88%/73% (dry/rh) more powerful

This shows that the F-22's fuel fraction is ~32.27%. In case of the Typhoon it's 31%. With all that in mind how can the F-22 reach a much greater range as insisted my many here?

Thumper3181 wrote:

What supercruise? Production EF "supercruise" is M1.1. About the same for an F-15.

In your dreams Thumper.

Scorpion82 wrote:

As insisted this comparison is largely simplified and neither meant to be accurate, nor the end of all figures. Refinements are certainly possible.

Don't get me wrong. A great effort on your part, which puts things into perspective.
All I pointed out was a couple of things to make an emphasis.

Quote:

What it shows however is that the figures mentioned before aren't realistic by a long shot.

I'm not sure what figures, do you mean?
As I said, I've used a general rule of thrust lapse for a turbofan engine.
Check this F15/F100's undisclosed SFC table and you'll see what I mean.
Whether, the EF in full dry power at tropopause produces 1/3 or 1/2 of SL thrust is something I don't know.

I meant the 1000+ nm range figures for a supercruising Typhoon. Could it be that km was not down converted to nm? Haven't done the math...

Thanks for the chart btw. If you compare the SFC values for M 0.2 at SL with M 1.6 at 40k ft in the mil chart it looks not to dissimilar to my assumption of 90% the SL SFC for the F119 at M 1.7 that high up.
Even if it is a different engine.

As for the SFC, if you take a closer look, you'll see that F100 consumes more than three times more fuel at M1 at SL, than at 40k ft, in full dry power.
That's the rule I was referring to...
EJ200 might have rather different thrust lapse though...

Scorpion82 wrote:

Thumper3181 wrote:

What supercruise? Production EF "supercruise" is M1.1. About the same for an F-15.

In your dreams Thumper.

Show me a single reliable source that states that a production EF can supercruise at more than 1.1 with a useful payload and fuel fraction.

There is a reason why all those wild M1.5 claims have been withdrawn.

Thumper3181 wrote:

Show me a single reliable source that states that a production EF can supercruise at more than 1.1 with a useful payload and fuel fraction.

There is a reason why all those wild M1.5 claims have been withdrawn.

The Luftwaffe stated M 1.2 in combat configuration and a few years ago someone wrote an email to Eurofighter about the configuration for the M 1.2 @36k ft figure and it was confirmed as 6 AAMs and a belly drop tank. Anecdotal hints indicate at speeds between M 1.2 - 1.3 depending on altitude and configuration.

Wrt the M 1.5 claim it was somewhere stated for an aircraft with 50% internal fuel, 4 AAMs on the semi recessed weldings at ~45k ft. Whether true or not, that figure is at least mentioned (without details) at the Eurofighter website.

That performance is the result of high thrust output AND aerodynamics. The latter is particularly important for aircraft with less powerful engines. That's why a Gripen NG an fly at M >1.2 (albeit clean as it seems) with a comparably weak engine.

I'm not aware of an teen fighter being able to touch that speed even clean, let alone with missiles and possibly tanks.

I'll at least look for that email confirmation the Luftwaffe's figure was not from the internet.

Forum: General F-22A Raptor forum

F-22 versus Eurofighter Typhoon