How real is real?

[159th_Falcon]

WOW

Sure didnt suspect so many replies to this post. Interesting enough none of the questions have been answered yet. (lot of people have said "i think or i believe" and "you wont notice the power loss")

But the question was not if you would notice the difference, but if it is modeled or not and in fact changes the aircraft's behavior.

 

About the generators i would like to say the following. Although, as stated by some, the total amount of power required by the systems stays indeed the same, the load on the generator increases.

This would indeed not increase the workload on the ENGINES (not engines so both of them).

But in an one engine on scenario, the load on the remaining engines increases cause it has to supply all the power to turn the generators instead of just half.

 

As for the fact if you would notice it, depends on the conditions.

In the case of me flying back over the top of an hill, it might make the difference in either clearing the hill or flying into it.

I know from work that there was an fery flight from Italy to The Netherlands in an Agusta AW 139 helicopter. They had to clear an mountain pass and at 1st they could not clear it. The air was to thin and the helicopter to heavy.

They flew around for something like 5 minutes to burn fuel and tried again, this time they made it over the ill top......

 

Just comes to show even an apparently insignificant amount of weight can make the difference your looking for.

 

So anyone that can answer my questions whit an definitive yes or no?

(instead of if you would or would not notice the difference?)

 

Shutting down electrical systems (laser/Hud/Abris/lights) causes the generator to generate less power thus the engine has more power available for driving the rotors.

 

Flares have weight, dropping all your flares makes you lighter thus you need less power to fly.

 

Cannon rounds have weight, expending all your (gun) ammo makes you lighter thus you need less power to fly.

 

Is there an difference in power requirement from the engines when performing turns? for example an left hand turn needs more power then a right hand one???

 

I guess thats it for now, curious if this is modelled in the shark and to what extend.

 

 

And last but not least.

 

Thanx for giving your opinions, might not have sounded like it in the above post but it's greatly appreciated.:thumbup:

 

***EDIT*** Thanx for the reply Etherealn, sure answers some of the questions.

Edited November 23, 2009 by 159th_Falcon

[Yskonyn]

So anyone that can answer my questions whit an definitive yes or no?

(instead of if you would or would not notice the difference?)

 

Shutting down electrical systems (laser/Hud/Abris/lights) causes the generator to generate less power thus the engine has more power available for driving the rotors.

- NO

 

Flares have weight, dropping all your flares makes you lighter thus you need less power to fly.

-NO

 

Cannon rounds have weight, expending all your (gun) ammo makes you lighter thus you need less power to fly.

- YES

 

Is there an difference in power requirement from the engines when performing turns? for example an left hand turn needs more power then a right hand one???

- NO

 

So there you have it. Abbreviated by request. :thumbup: Although most of these WERE actually answered if you would read a little in between the lines.

[159th_Falcon]

Thanx a lot, thought i wasn't sure whether some people where giving opinions or facts in regards to the simulator.

Anyway we know now, thanx a lot everyone.

[Frederf]

With an inverter, they can.

 

I thought the Ka-50 only had DC->AC conversion but I have re-read and see the POS-500B does DC->AC conversion. My mistake. Only a few emergency systems seem to be on the AC inverter bus.

 

One generator supplying 1000W and two generators supplying 500W each will not take exactly the same engine power, but close. Generators have an efficiency curve that depends on load. I am trying to tell if the L and R generators are connected to the engines directly or if they are independent. Can you run the L & R generators from only one engine or does the R engine drive the R gen and the same with the L gen / L engine. I don't know.

Edited November 23, 2009 by Frederf

[159th_Falcon]

the generators are mounted on the same gearbox that drives the rotors.

So the #1 (left hand) engine can drive the gearbox and thus both of the generators

The #2 (right hand) engine can drive the gearbox and thus both of the generators

Or option number 3;

both engines ( 1 and 2) are driving the main gearbox and thus there both driving generators numbers 1 and 2 at the same time.

Maybe this schematic helps a bit

http://www.digitalcombatsimulator.com/index.php?lang=en&end_pos=1630

[sobek]

Only a few emergency systems seem to be on the AC inverter bus.

 

Everything is on the inverter (or one of the two) except the right common AC bus. Things like gyros need AC IIRC. The only obvious consumer hanging on said bus is the shkval TV screen (i'm sure there are others, but i don't know which).

Edited November 23, 2009 by sobek

[Frederf]

Thanks for the info.

 

According to the FM13-20,21:

The POS-500B inverter supplies the following consumers connected to the emergency

bus:

 Radar altimeter

 Power plant‟s oil pressure switches

 Fuel quantity indicator, G-load accelerometer, engines RPM and EGT indicators,

and vibrations monitoring system

 IFF equipment

 Warning and indications systems

 Audio tones for rotor RPM drop

 Emergency instrument panels illumination

The diagram on the same FM13-20 seems to suggest that the POS-500B seems to only power the left and right AC reserve buses, not the commons.

 

To answer an earlier question the POS-500B has a 500W rating while the L and R AC generators have a 80kW combined rating.

 

Here's another question I never really fully understood. The POS-500B cockpit switch has three positions, OFF, MANUAL and, AUTO. If the AC/DC inverter is in the MANUAL position... how do you control it? Is MANUAL forced on?

 

And to answer the question I was just about to ask, the UV-6B rectifiers provide DC power from the AC side (a sort of reverse inverter). Are there any controls for the UV-6Bs?

[sobek]

The diagram on the same FM13-20 seems to suggest that the POS-500B seems to only power the left and right AC reserve buses, not the commons.

 

Yes you are correct, i overlooked the fact that the left AC commons is not powered by the inverter.

[AlphaOneSix]

Here's another question I never really fully understood. The POS-500B cockpit switch has three positions, OFF, MANUAL and, AUTO. If the AC/DC inverter is in the MANUAL position... how do you control it? Is MANUAL forced on?

 

The MANUAL position turns the inverter ON, regardless of whether or not the main generators are online. When the generators are online, they provide all of the aircraft's AC power needs, so there is no need to have the inverter on. In the AUTO position, the inverter is only on if the AC generators are offline. That is, during normal flight, the inverter will be off, but if your generators fail or drop offline for some reason (low rotor speed), it will kick on automatically. In the OFF position, the inverter just stays off no matter what.

[Frederf]

Ok, I suspected as much but couldn't really tell. OFF-ON-AUTO would be more sensible labeling of the switch positions I think. Yeah I realize that POS-500B is an emergency backup device in case the primary AC source generators fail.

 

It's probably not "by the book" to do this but is turning the POS-500B on during startup to get yourself some AC power before the rotors get up to speed a plausible option?

[AlphaOneSix]

It's probably not "by the book" to do this but is turning the POS-500B on during startup to get yourself some AC power before the rotors get up to speed a plausible option?

 

Might as well just hook up ground AC power. But yes, I fly in Mi-17s all the time, and during startup we turn the AC inverters to manual so the cockpit gauges work, then switch to auto once the generators are online.

[Frederf]

Cool. Sometimes ground AC power isn't available ya know.

 

I often get caught unawares by switching from ground AC power to internal AC power and I always forget to bring the RPM up to throttles-auto first! Doh!

[kiss4luna]

the very real is real ;)