Aircrafts logic/physics

[Figeac]

Do the aircrafts always follow plotted courses on maximum altitude? I have noticed that every time I manually plot a course for an aircraft (and even in some missions, like support) they always fly at maximum altitude (normally 40.000 ft). Isn't that unrealistic? Because airplanes spend a lot more energy and fuel to cruise that high. What do you think about setting some standard cruise altitude for different aircrafts/missions/loadouts? (Can be a lot of work, I know hehe [:D])

I have also noticed that, apparently, aircrafts gain speed as they dive and lose altitude, but the opposite is not true: as they climb, they always keep the same speed and throttle. I'm right or I'm missing something?

Thanks!

[jmscho]

Flying is a balancing act between gravity, drag and thrust. To get maximum range, aircraft fly quite high. Look at airliners around the world; they cruise at between 30k and 40k feet. And really, relative to the distance travelled 40k feet is not very far.

[$trummer]

It's completely goofy. Odd that this slipped through such a well-tested and detailed game. Put a little Harrier on CAP and it goes to 40,000ft. I hope they fix this.

[Dimitris]

ORIGINAL: jmscho
Flying is a balancing act between gravity, drag and thrust. To get maximum range, aircraft fly quite high. Look at airliners around the world; they cruise at between 30k and 40k feet. And really, relative to the distance travelled 40k feet is not very far.

What the main said.

AI crews seek the optimum altitude (fuel consumption wise) for their selected speed, either picked on their own (mission AI etc.) or manually dictated by the payer. If it's 40000ft, that's how high they'll go.

If you think the optimum fuel consumption happens in a different altitude for the given throttle setting, please have a word with the DB authors (Rag & Paul).

Don't bash the game because you disagree with the numbers.

[$trummer]

Come one, Sunburn, 40k is just not a remotely tactical altitude for a Sea Harrier CAP over a battle group.

[jomni]

That's correct. Since we see almost all jets cruise at 40000 that means the DB needs some more work to get the actual figure for an aircraft. I believe 40k is a placeholder.

[jomni]

Also maybe we need to put mission altitudes like in WITP.

[navwarcol]

A/C actually spend far less energy and fuel the higher they cruise. The denser air, for just one reason, lower to the ground creates more friction, while at higher altitudes there is less and less oxygen/air... and less and less friction. The trade is a tactical one, not an "energy/fuel conserving one"... higher altitude is generally more fuel efficient, while trading tactical ground as far as sensors, etc picking your aircraft up at longer ranges. Or you can fly lower, maintaining an extra few moments of surprise before the enemy sensors locate you, but also giving up a lot in the way of fuel efficiency.
Also as mentioned above, altitude gives you something to trade, for increased tactical speed if that becomes important, by dropping altitude and gaining the increase of speed from the drop.

[$trummer]

Fair enough, Jomni.

Navwarcol, I understand how altitude, energy and aerodynamics interrelate but I have to repeat, 40k is not a tactical altitude for a single-engine jet CAP, or an intercept. It makes no sense at any level. For all I know, CMANO puts A-10s at 40k and they have two engines.

[Der Zeitgeist]

The main problem in my view is that 40k feet is used as a mission altitude even in cases where it is sheer suicide tactically, like strike missions in areas with heavy SAM presence. Some planes simply don't use the capabilities they have (like NOE TFR flight) when tasked on a mission under AI control. The other problem is that they don't adjust their speed when engaged offensive in an air to ground mission, but simply fly in at a leisurely 480 knots.

Ragnar has stated that the developers intend to eventually use the flight profiles that are stored in the database for different loadouts. That might help with a lot of these problems, I think.

[Dimitris]

That is correct.


I am currently integrating Ragnar's work on altitude presets and per-waypoint orders.

[navwarcol]

Strummer.. understood. FWIW My comment was actually aimed to the original poster talking about planes using more energy and fuel to cruise at high altitude.
I should have made it more clear to whom I was referring.

[Tomcat84]

ORIGINAL: Sunburn
I am currently integrating Ragnar's work on altitude presets and per-waypoint orders.

That makes me a very happy man [:)][:)][:)]

please tell me there is not just speed and altitude but also EMCON per waypoint? Or dont cause then I might faint lol If not, all in due time

[MR_BURNS2]

FL 400 might be the best fuel-saving altitude, but it´s still totally unrealistic for some loadouts, a F-16 with bombs for example would stall at this altitude or use all its fuel in AB to get and stay there.
She doesn´t have enough lift and thrust at that altitude to carry on with such a loadout.

However i don´t see who it could be done better in CMANO, calculating the data for each and every aircraft in the DB would be very labour intensive.
Maybe an equation of weight vs lift/wing area vs thrust vs altitude vs speed? (hope this makes sense, my english is fairly bad, especially in mathematical terms).

Whatever the answer to that problem could be, it would be no small feat to implement it, and i think it´s not that important for the scope of the game.
And once we can plan altitudes for aircraft missions we can work around it and pretend it is realistic! [:)]

[starbird7]

I can't post links, but there is a document that describes the attack profiles and ranges for the av8b. Look up av8b cruise altitude and it should be the first link on google.

Its average cruise altitude is 40,000 ft with pylons and fuel tanks, and 30,000ft fully loaded in combat config. Notice the little diagrams showing the attack profiles, there are no units on them, but they show a trend of increasing altitude over the entire flight.

Your optimal altitude is based on the design coefficient of lift (CL) of the aircraft. The basic formula for CL includes airspeed, weight and altitude. As the aircraft becomes lighter through burning fuel and expending munitions you need to fly slower at the same altitude or fly higher at the same airspeed.

Overall I think 40,000ft is a good compromise. Its probably low for most fighters with a/a loadouts, especially if they have 2 engines. Its possible to compute these things if the designers really want to. How accurate that would be is difficult to say.

In air combat you want to be higher than your opponent. Its especially important when throwing long range missiles. You want your missiles to get to the guy you're shooting at before theirs hits you. You have more options in general.

[MR_BURNS2]

In air combat you want to be higher than your opponent. Its especially important when throwing long range missiles. You want your missiles to get to the guy you're shooting at before theirs hits you. You have more options in general.

I don´t think the effect of launching aircraft´s speed and altitude on the launched weapon is modeled in CMANO at the moment, or is it?

[Dimitris]

It most certainly is. The aircraft AI takes this into account. This is why you see aircraft [who don;t have alt/throttle override] going high & fast prior to launching their BVR missiles.

[MR_BURNS2]

Eeexcellent! [:)]

[Figeac]

ORIGINAL: Sunburn

That is correct.


I am currently integrating Ragnar's work on altitude presets and per-waypoint orders.

Really good news Sunburn, thank you!

The altitude presets that you have mentioned is something like we have for speed (loiter, cruise, full and flank)? That would help a lot to solve this issue, I think. If it would be minimum, low, medium, high and maximum, for example, with the numbers proportional to the altitude ceiling of each aircraft (which would depends on airframe, engines, etc), there would be easy for the AI to pick up an altitude profile based on the AC loadout/mission: if it says Hi-Low-Hi, it would just choose those presets for that specific aircraft.

But I still think they should cruise and follow plotted course bellow maximum altitude... Something like High as "standard" cruise for all AC would be very fine, in my opinion. Airplanes rarely flies on their maximum altitude. I'm not a pilot, I'm just saying this based on years and years of playing jet fighters simulators, like the Falcon and Lock on/Flaming Cliffs series, hehe... But they seem very realistic and you almost never sees planes flying at 40k. To keep a loaded airplane flying that high you usually needs to us afterburns, which is impractical for long cruises.

[jomni]

To keep a loaded airplane flying that high you usually needs to us afterburns, which is impractical for long cruises.

Are you sure about that? Didn't someone already say you need less power to fly at high altitude thus lessening the fuel burn?