According to the Lightning Operating Data Manual acceleration from Mach 1 to Mach 2 took 90 nautical miles. So that is accurate.
Isnt the lightning suppose to be able to hit Mach 1 in a vertical climb? or is that just one of those myths? Because in game you cant
I don’t believe it could actually do that, but the climb performance is much better than the game appears to demonstrate. https://www.youtube.com/watch?v=VC8CsVpg64o here you can see an unrestricted climb to 9km in 102 seconds.
Just tested following the exact flight profile of the video in tandem. It appears to behave very similarly until I begin the climb (on minimum fuel!!!) at which point in the video the aircraft is accelerating, and I am decelerating in game.
In other words - the time to altitude is the same or remarkably similar, but what it appears to be is the in-game lightning accelerates faster down low, before struggling in the climb.
With further testing, I can exceed mach 2 (barely!!) at ~52000 (the in game “flight ceiling”) but cannot sustain my speed “in excess of 60000” as all publications stated.
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Here is a photo of the Lightning during that record setting climb. You may notice the lack of a whopping big fuel tank under the fuselage:
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And yet it carried fuel for 10 minutes of flight, which is above the six I am carrying. The presence of the fuel tank isn’t particularly relevant if it’s not loaded with that fuel.
Ever heard of drag?
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I cannot prove whether it would have had that large of an effect or not - but then it comes to performance in level flight. How come the aircraft that can fly at altitudes “in excess of FL600” cannot effectively maintain level flight at FL600 (let alone above it)?
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If it’s losing speed in a climb, whereas in reality it accelerates in a climb, then the issue is most likely thrust. If it were drag then it would be accelerating slower/maintaining constant speed in a climb, because it would have enough excess specific energy to meet the max velocity.
disclaimer: I have no idea if the claim about it accelerating in climbs is accurate or not.
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Intake ramps help with a speed range. If that range is exceeded either too slow or too fast, they can become less efficient.
As shown in your post, the speed range for Mig-29 is 700 - 980MPH.
Speed range for F-14B is somewhere between 400 & 800MPH.
F-16A, somewhere between 500 & 900MPH.
Tornado F3 600 - 910MPH.
FGR2 700 - 907.
Mig-23 800 - 920.
F-4S probably around 700 - 835.
As you can see, different aircraft have different start points where their intake systems become most efficient for thrust generation. Some start FAR later than others such as Mig-23 & Mig-29, some start far earlier than others such as F-16 & F-14.
The proof you have to supply then is how the variable air intakes can account for a larger range of speeds; and prove they can in exceeding certain speeds.
Yes, however intake ramps are designed to function at supersonic speeds on most of these aircraft - on the Tornado for example they should be most effective between Mach 1.2-2 (this is consistent for most aircraft). Don’t forget that the primary purpose of intake ramps is to break the shockwave and compress+decelerate the air before it reaches the engine - they would serve no functional purpose below Mach 1.
It makes no logical sense in any regard for the engines to suddenly lose effectiveness as the aircraft passes Mach 1, before Mach 1.2-1.3 where they actually begin to deploy intake ramps on most aircraft.
The purpose of intake ramps is to retain (and in most cases increase) the power of the engines at high speed and/or allow the engines to function at high speed by compressing the air optimally for the engine’s function. They do not have an “optimal” speed, but they do have a minimum (where they are not deployed) and a maximum (which is often far beyond the limitations of the aircraft, and will simply result in a compressor stall due to the engine ingesting supersonic air)
If you would like, I have some excellent information on both Concorde and the F-14A (early variants) which both use variable intake ramps. I can demonstrate my point.
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I took a second look at this image and realised that the aircraft used for the record climb is actually a trainer variant, which, while it may be missing the fuel tank underneath, is still similarly draggy due to the side by side cockpit seating. Not entirely sure why they chose such a variant for a record but I suppose it’s for the sake of the video?
Intake ramps will be impacted by indicated air speed tho.
Going mach 2 by at IAS 800 is similar to the engine intake as going IAS 800 at mach 1.01.
And yes, the engine of Tornado IDS is indeed most effective between mach 1.2 & 2, when the indicated airspeed is in that 600 - 910MPH range.
I am not saying that IAS is the only factor, as that’d be ignorance.
On top of that, the variable intake can only attempt to get the air at the engine inlet as close to the speed as possible. There is only so much variation you can have.
I don’t know more about IAS impact on variable air intake & engine performance to speak further on this issue.
I’ve stated the limits of my knowledge.
You have to prove the variation is larger than it currently is. & for now, Tornados maintain their maximum speed of 2400KPH, mach 2.3, with relative ease.
That is simply not how variable intake ramps work. Air is air, and as long as you go faster the engine will be getting more air and therefore be able to produce more thrust. The purpose of intake ramps is to adjust for the effects of MACH, the IAS is irrelevant.
The amount of air the engine will receive is of course affected by IAS, but the purpose of intake ramps is to allow the thrust to continue increasing past Mach by keeping the air below Mach while you are flying supersonic. They do not react to IAS. There should be no reduction in thrust when crossing Mach for this reason.
If you can prove that, for whatever reason and directly to the contrary of any of my sources and basic aerodynamics, that the engines will receive less air while at higher speed I will consider your point but I simply do not see the logic here.
Here is an image demonstrating my point (apologies for the blue lighting)
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You said it, above mach the intakes have to slow the air down.
Slowing the air down too much would lead to lower engine performance.
Aircraft airspeed =/= the speed of air entering the engine after being slowed down by the intake system.
If at certain aircraft speeds the variable intake system slows the air down too much then the engines bring in less air.
There’s also channel losses at different speeds as well.
I’m not disagreeing with the sources you provide at all, nor am I disagreeing with aerodynamics.
Incorrect because the amount of air entering the engine is not a factor of its velocity. The deceleration of incoming air causes compression - this is how Concorde could achieve a supercruise at Mach 2 - a compression ratio of approximately 85:1.
The intakes cannot delete air (sounds obvious, but gotta say it). at higher speeds, more air will enter the engine and the intake decelerating it just means that the air entering the engine will be at a higher pressure.
Thrust is relative to the velocity of exhaust air, which is a factor of two things. Exhaust nozzle design, and the velocity of the exhaust air. The velocity of the exhaust air is DIRECTLY related to how much fuel the engine burns, which is limited by the intake air. More air into engine = more fuel burned = higher combustion chamber pressure = faster exhaust air = more thrust.
Don’t forget that the engine’s first stage is a COMPRESSOR, which slows down the air to compress it for combustion anyways! If velocity was important it would not need this!
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This has some great animations and explanations for intake ramps , though doesnt touch on the effects so much
That’s a flawed assumption. The Lightning T.5 apparently performed very similarly (some sources even say it had superior performance) to the fighter variants of the Lightning, due to the larger cockpit acting as a form of area ruling, meaning it actually reduced drag (welcome to the counter-intuitive world of aerodynamics).
The T.5 does however have a different wing to the F.6 (T.5 has the straight wing and F.6 has the kinked wing), so that further illustrates that you cannot compare that video to the Lightning we have in game.
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What is going on here is that Gaijin know the top speed the F.3 (and other aircraft) can sustain in level flight at all altitudes, according to the manual. They then adjust the thrust curve of the engines to make the aircraft match it’s claimed real world performance. If the aircraft is capable of accelerating past the speed it should be able to achieve them Gaijin tweak the thrust at those speeds to stop it from happening.
That is how they do it for pretty much all aircraft.
Level Flight Envelope
I hope this could be help to you guys
This will be most simillar flight characteristic to GR.1
Italian IDS varient with MK 101 engine
note: not classified documents, its over 30 years and previously Gaijin have been accept the data from this document
