Does anyone else find it amazing that you can rear aspect lock a 450 degree prop plane with an all aspect IR missile from almost max all-aspect range, but can’t lock on the to 1000 degree Alouette past 2km even though the engine is out in the open?
Anyone have a reasonable answer to why this may happen? I’m thinking of doing a bug report or something to get this sort of thing sorted out.
IIRC Gaijin has a code that makes the IR signature of Helicopters much smaller, whether it’s natural or not. But again that’s just what I remember hearing a while back, could be false.
While you’re at it, don’t ask why a helicopter and it’s spinning rotor blades (which has a humongous radar cross section) can’t be seen or locked onto by PD radar.
Because they are mostly standing still
The blades definitely aren’t
On a radar screen the returns would look like the radio spectrum equivalent of a EDM concert
Eh, Ive found that props can be hard to lock on to even with some top tier IR AAMs.
Helis being basically unlockable over 2km is pure unregulated bullshit though.
lol… radar cannot pick up helicopter blades in this era to any of my knowledge. Feel free to prove it can though
Helicopter downwash has a significant effect on diluting the hot exhaust gasses - the engine being “out in the open” is irrelevant.
Thanks for the correction
This coupled with the fact helicopters have a few modifications that reduce the mask of the IR signature makes locking helicopters with IR missiles very tough. That said you can feel pretty confident just going in for a gun strafe especially if you turn your engine off a few KM’s before you reach your target.
For reference, in the radar handbook, “the Phenomenal APG-63” for F-15 pilots and maintainers, it also mentions that jet engines can give off significant radar returns in HPRF when the aircraft is cold aspect just due to the turbines rotation. The helicopters rotors give a similar effect, but magnified.
the issue with helis is, that they mix the exhaust etc with loads of cool air from the rotor above, which also cools the skin quit well (even if the airflow in the middle is less than on the outside)
A technique stealth planes use to lower their heat signature.
But I doubt that Gaijin has modelled the modern heat seakers of esp the stinger correctly.
Bro, you hurt my soul. It is a rotor. Helicopters have rotors, planes have propellers. And the rotor wash isn’t as effective as you would think at minimizing the heat signature. That’s why there’s HIRSS. The system employed on US helicopters gets more of its cool air through forward motion than through the rotor wash itself. And if the helicopter has to loiter and there’s not as much airflow coming through the system. That’s when the ALQ 144 Disco Ball comes into play.
https://www.sciencedirect.com/science/article/pii/S1000936114000168
yes, corrected it.
Though rotor is also a generalized word (like rotor and stator in electric engines and stuff).
I was talking from the starting point, since heli turbines are equally as hot as other turbofans, which are way better lockable, even in this game, without any specific technology to reduce the thermal signature
I was only giving you guff cuz of the whole propeller thing. The rest of my post was in response to a few other posts. But you are absolutely correct. The turbine engines on helicopters are hot as hell. I have a few scars to prove it. But in my Huey days and before the magnesium packs were added to MREs. (Yes I’m old) We would toss our MREs in the engine compartments at startup and before we launched we would take them out and you’d have a nice warm MRE to eat.
My current somewhat educated guess is that heat signature is tied to airframe speed for all aspect lock and engine thrust for rear aspect.
Mostly stationary or slow (by fixed wing standards) flying heli you have hard time getting a lock onto with lets say, Stinger past 2km, but the same Stinger can easily lock a high subsonic jet at 6km or above head on. Then heli engines are producing low three digit amount of thrust, compared to four-five digit of afterburning jet engine. To throw an example, F-5 and F-4, having similar engine temperature of ±660c, but one can decoy IR missiles easily even without turning off afterburner, while other needs help of any and all deities you like to pray to to decoy rear aspect missiles. Difference between the two is amount of thrust produced
Rotor-wash, keeps the temperature down, and diffuses it below the helicopter. Pretty much, it’s a self-cooling system, but IR SAM’ can still lock because of the seeker heads sensitivity to heat, without HIRSS it will lock in short distances.
