IAS on the HUD?

[EtherealN]

I've been spending some time doing all that stupid stuff that's oh so fun, like landing inside hangars (damn that's tight...), hammerheads/wingovers, loopings and so on. I've found the wingovers particularly difficult to time though, and while I can do reasonably acceptable ones I would love to have IAS on the HUD to help out. If I keep the ascent angle at like 70 degrees instead of a 90 degree pitchup I'll still get groundspeed on the HUD and that helps, but that's not a true wingover...

 

Is there any way to get IAS on the HUD?

[ZaltysZ]

Is there any way to get IAS on the HUD?

 

I don't think this is possible, however you may use Shkval TV, it shows IAS at top left corner.

[EtherealN]

Yeah, it's just my InsanityMk1 maneuvers tend to gank the generators and the Shkval will be powered off. >.< (Then again, I have also managed to get the HUD offlined through that by being a bit too violent. :P )

 

The reason I want it on the HUD tho as compared to using the analog or just Mk1 eyeball on the horizon is that (at least so far) I need to really micromanage on the ascent to maintain that straight up trajectory.

 

But ah well, practice makes perfect and in the end I'll just have to get the "feel" for it.

[iRocco]

show us some videos or tracks please...

[EtherealN]

I am in the planning stages of a video going through the maneuvers. Can't promise an ETA but I'm working on it. :P

[BTTW-DratsaB]

What about turning on the internal batteries?

[amalahama]

You can use usual IAS gauge, at the left glareshield.

 

Ey, Su-29 hasn't any HUD and can do spectacular maneouvers!

 

Regards!!

[EtherealN]

Thrust direction is quite different on an aircraft compared to a chopper and this is mainly a training aid. Hammerheads/wingovers in gliders is no problem at all, but it's a whole different kind of aircraft with whole different rudder authorities and behaviours.

 

I am not sure I understand your meaning of left glareshield for "usual IAS gauge", though. I can use the IAS indicator on the left side of the control panel, but that does not work in conjunction with my need for finetuning the 90 degree climb. This does however not change the fact that the HUD displays ground speed, not IAS, and that it cannot display ground speed when in a 90 degree nose-up attitude.

 

BTTW-DratsaB, I have my batteries on.

[ericinexile]

The HUD is for killing people and breaking things...not for flying. For aerobatics, you look out whichever window is providing the best view of the horizon and make quick glances at the ASI, accelerometer and altimeter as needed. 25 years of combat sims and the fixed HUD view have raised a generation of virtual pilots who think that's where they are supposed to look.

 

Smokin' Hole

[EtherealN]

As mentioned already: I can do these maneuvers in other aircraft, and have performed them in real aircraft, and I know how to do them in real aircraft.

 

In a simulated aircraft I can not feel it's behaviour. Therefore, while practicing, having a good idea of the airspeed to couple that to visual inputs and behaviours is very helpful because I cannot feel theese inputs as I can in a real aircraft.

 

Compare with driving a rally car and playing Colin McRae. When you drive the real thing you actually feel everything that's happening and have a very clear idea of what sounds mean what. In a computer simulation, no matter how well done, you don't have the same stimuli.

 

25 years of combat sims on ever more capable computers has created a generation of virtual pilots who think that their high-fidelity simulation somehow approximates the sensations you get from flying the real thing. You can simulate the behaviour of an aircraft however much you want, but you're not simulating the physical sensations of flying.

 

You cannot fly by the seat of your pants if your pants are seated on an office chair.

[EtherealN]

In fact eric, I'll make the point even more obvious: at which speed do you need to give rudder input to do a clean wingover while in a 90 degree nose-up attitude in a Ka-50?

 

If you cannot answer that question, then I reserve the right to have inquired on the possibility of ascertaining that speed through displaying it on the hud. Especially since the analog IAS indicator on the Ka-50 is very very imprecise in low velocities.

 

If you have another method of ascertaining this beyond pure repetition (guess what I'm already doing) and that does not include you making wild assumptions about where I think I am supposed to have my eyes as a pilot and being generally condescending in tone - please elaborate on it. ;)

[Safari Ken]

Zing! :P

[RvETito]

You just answer your own request- why the HUD doesn't show IAS, especially in low speeds. There is no such an airdata system in the world that can accurately measure dynamic pressure of an airflow slower than 50-70 km/h.

 

One more thing- IAS is by no means function of the pitch angle. You can fly both 90 degrees up or down and have IAS indication on the gauge provided the IAS is more than 60-70 km/h. It's the direction and magnitude of the aircraft's velocity vector (ram airflow) that matters.

[EtherealN]

AirTito, that the limits were such that IAS is impossible at those low speeds is news to me (I have a stall speed of 70-80km/h anyhow IRL so displaying anything lower was never really relevant to me before. :P ), that explains the inaccuracy nicely. Thanks.

 

And I'm not saying that it's a function of pitch angle. What I'm saying is that in a 90 degree pitch up the ground speed indicator appears to lose track of the ground and is therefore incapable of displaying speed on the screen. That is the reason why I was interested in having airspeed displayed instead (beyond that it is the one speed that has anything to do with the medium the aircraft actually moves in. :D ).

[RvETito]

At pitch angle over 30 degrees the GS data is all but accurate. The Doppler ground speed and drift angle measuring device DISS-32 is installed in the tail boom (two circle antennas on the bottom) and it scans straight down the helicopter. You realize when you're at 90 degrees pitch up for instance the DISS will measure infinity ;) Same as when you turn her upside down. In high attitude angle flight you shouldn't be using the HUD for speed reference at all- look at the Shkval screen or at the IAS gauge. And try be more gentle with the collective to avoid rotor RPM drop and generators switch off. You might wanna know that this is considered an emergency IRL. Having generators automaticallly off (rotor RPM below 80%) with both engines running means that you gotta go back to flight school :P

[ericinexile]

If you want to execute an extreme maneuver then the important time to note speed, altitude, attitude, acceleration is at the BEGINNING of the maneuver not in the middle of it. Once you start you just must have the experience, practice and SA to execute and complete the maneuver without constant reference to instrumentation. A pilot flying on the edge is NEVER staring at his HUD...Never! The HUD is a device for pointing weapons. There is a reason that Eurocopters, Sokois, Extras, and all other civilian aerobatic and airshow demonstrators lack HUDs--because they provide useless information...much akin to having a GPS display on a NASCAR racer.

[ericinexile]

In fact eric, I'll make the point even more obvious: at which speed do you need to give rudder input to do a clean wingover while in a 90 degree nose-up attitude in a Ka-50?

 

If you cannot answer that question, then I reserve the right to have inquired on the possibility of ascertaining that speed through displaying it on the hud. Especially since the analog IAS indicator on the Ka-50 is very very imprecise in low velocities.

 

If you have another method of ascertaining this beyond pure repetition (guess what I'm already doing) and that does not include you making wild assumptions about where I think I am supposed to have my eyes as a pilot and being generally condescending in tone - please elaborate on it. ;)

 

I don't base my rudder input on speed. I base it on achieving 90 ANU pitch. If by clean you mean zero speed and a perfect turn-about-the-rotor-hub to a 90 degree nose-down pitch attitude then I am completely unable to do it. But, in my instance, no HUD info will make me perform any better.

 

And btw, ALL airspeed indicators are inaccurate at low speeds--it is just a fact of life. The two speeds available on the HUD are equally useless to you: One is just a repeater of your ASI--the other is based on a dopplar reflection bounced off ground or water below. Don't worry about it--just fly!

[EtherealN]

Yeah, on the inaccuracy of all IAS indicators I had not realized that before AirTito's post. As mentioned anything even close to 50km/h is something I in real life only achieve during stall proceedure practices so it never occured to me to check where the lower level of accuracy was on them. That point is taken.

 

As for checking velocities and so on before a maneuver, of course I do. That's how I verify that it is safe to enter the maneuver, and it works well for loopings since, well, they're easy. :P The wingover is more difficult though since it's a two step maneuver (or three, depending on how you look at it) with vastly different parameters in the various steps. But yeah, if the IAS is by definition incapable of giving data at such low velocities then quite obviously it wouldn't help to move the IAS info to the HUD even if I could.

 

And yeah, AirTito, I know how the ground speed indicator works and that I really shouldn't let the maneuvers get such that generators start dropping. But after all it is a game and the easiest way to find the limits is to cross them and then reload the game after impact. :D

 

It's also pretty fun, in a way. Like landing inside a hangar - absolutely nothing one would do in the real thing but it is very amusing to do in the game. Sort of like landing on a moving train. :D

 

And that's really the point. A real aerobatics pilot wouldn't do any of this shit the way I'm doing it, but he would also have about 10 times the flying hours I have in the thing (not to forget that he'd have those hours in the REAL thing and have had the advantage of a proper training regime) and he's doing all of it with his life on the line. The only thing with it's life on the line when doing things like this at home might be the cat with it's habit of crawling around my feet when I'm using pedals. :P

Edited March 23, 2009 by EtherealN

[DarkWanderer]

The Doppler ground speed and drift angle measuring device DISS-32 is installed in the tail boom (two circle antennas on the bottom) and it scans straight down the helicopter. You realize when you're at 90 degrees pitch up for instance the DISS will measure infinity

There're several (4 IIRC) beams tracking in 30 degrees from vertical angle actually. You can't measure two components of speed with one beam ;) They're also limited (by Chizh's words) to 4-300m range, though specifications state 2-3500. (proof)

Edited March 23, 2009 by DarkWanderer

[EtherealN]

Does any part of that system know that it's at a high pitch angle and therefore stop giving results? Like, if I were to find a very tall sheer cliff somewhere and pitch up along it, would it give an altitude reading due to then looking into the cliff wall or would it know that I'm doing silly shit and not tell me anything?

[Washer UK]

I recon you would hit the cliff and then it wont tell you anything :P

[EtherealN]

Nah, I only crash when I decide to land inside the hangar again. :D

[Washer UK]

From memory you only crashed after I crashed in the entrance to the hanger!!

[RvETito]

I said there are two antennas, not beams ;)

 

The DISS-32 is not so reliable as it is in BS. Similar to the radiolatimeter it's operation highly depends on the surface the helicopter is flying over. The older versions of Ka-32 have exactly the same DISS-32 like Ka-50 (though the indication is difirent) and I've seen it many times going inoperative in flight usualy when flying over water surface or steep terrain. It only serves navigation and autopilot, it is never used as a speed reference for maneuvering.

[EtherealN]

Yeah, but if I fly towards a sheer cliff (like, the coast of england or something) and then pitch up to 90 degree up attitude, will it measure my distance to that cliff in the last few seconds it has to live before my helicopter crashes? :D

 

Basically, does it always attempt to measure distances in the same line relative to the aircraft, no matter the pitch angle of the aircraft? Or does it have some method of adjusting itself to point straight down to the ground as you maneuver? I mean, if it does, even very gentle maneuvers would cause pretty big errors.