Planes at Alt info

[Hard Sarge]

hi guys
I am looking for info on what planes were know to be either poor or good at different Alt levels

the Tiffy, was known to be good at low levels but poor at Med to High levels

the Spit XIV was a good high level plane

the early P-47s were poor at low level, but very good at high

early 38's were poor above 19 K

and so on

any other planes you can think of

docs or proof not needed, but would help

[HMSWarspite]

I presume that you have already accounted for LF Spits being good at Lo level, HF at High[:D]


IIRC, a Spit LF Mk IX was faster below 5000ft than a XIV

[Hard Sarge]

Well, hassle with in hassle

the game over all does not really use the Allies top speed (except in combat)

system right now, will not really let me make speed changes for Alt, but we can do other things

Mustang I was faster then the Spits at low level

there was the story of some Spit IX's seeing some Stangs down low can dropped down to play with them, pulled side by side with them and both were going full speed, and the Spit pilots were pretty happy as they seen they were keeping pace with the Stangs, but then they seen that the Stang pilots were smileing at them, then they noticed the Stangs had there flaps down, the Stang pilots waved and raised flaps and pulled away

but yes, low wing Spits should behave better at low alt then high wing Spits

right now we really only have the Low wing model for the VIII, but am looking into others

[Howard Mitchell]

Hello Sarge,

Are you thinking of something along the lines of the P-39/P-400 modifiers in War in the Pacific, or something more fine tuned which would affect most aircraft?

I can see the latter becoming a whole can of worms, but it would be good to have some altitude effects incorporated, if only for aircraft which really suffered or excelled at a particular height.

[Hard Sarge]

looking for something a little more fine tuned

with in reason, every plane with have good and bad points

[fochinell]

Performance at altitude you seem to have in hand:

Good low down, poor at high altitude:
Typhoon IB, Tempest V, Spit LF VB, Mustang I & II, A-36, P-39, P-40.

The P-38's did have problems at altitude despite being the only mainstream US Allison-engined aircraft with turbochargers; the pre--J models had problems with aerodynamic buffeting in high speed dives at altitude, as well as engine cooling issues. The J and L models were apparently better, at least in terms of the engine cooling issue, but had problems with fuel pre-detonation in the 8th AF for various reasons.

Good high, less good at low-altitude:
P-47C and early P-47D (should change with the paddle-blade and water injection in spring to mid-'44).

Now for the Spits ... the LF IX could only match (not exceed) the XIV below 5,000ft by using 150 octane fuel at +25 lbs supercharger boost instead of the normal +18 lbs limit.

[harley]

Gavin, what we are looking for is a grading system where the alt directly affects the manouverability.

Trying not to be too open about the detail at present, but lets just say there is a fair scope to change manouver from 0 feet to 45K+. Speed is fixed, so don't worry about that...

[HMSWarspite]

ORIGINAL: fochinell

Now for the Spits ... the LF IX could only match (not exceed) the XIV below 5,000ft by using 150 octane fuel at +25 lbs supercharger boost instead of the normal +18 lbs limit.

Yes, but 150grade, and +25lb was an approved rating. I thought I had seen a set of figures where IXs actually exceeded XIV, but the normal site I use agrees with you (358 vs 359mph @SL). Of course, the Griffon could use 150grade as well... However, fairly academic debate.

On to performance variation with alt: if you are going to have altitude effects modelling, how is it going to be done. You could have speed, manoevre etc tabulated against alt. (Pig to do). Or, you could come up with relationships based on typical shapes, and a few key parameters, For example, given full throttle alt for each supercharger gear ratio, the speed at that alt, and speed at SL, you can approximate speed at any alt using a curve fit. Similarly (and here I am guessing) manoevre could be a function of wing loading, speed and full speed at that alt (or something). You would then check known pairs of aircraft to check the relative performance was right at known alts... Finally, you need to do fuel consumption...

Otherwise I don't know how you can deal with altitude, and you are back to today (single ratings...)

Is this practical, or am I smoking dope?

[langley]

The Hawker Tempest mk5 was good at medium and low altitude anything over 20,000 feet and performance started to fall away! It was however able to out run the fw 190A still at higher altitude and match a Fw 190A in a turn. The Me109G could match the Tempest at higher alitude for speed but not out turn the Tempest.

MJT

[Denniss]

ORIGINAL: langley

The Hawker Tempest mk5 was good at medium and low altitude anything over 20,000 feet and performance started to fall away! It was however able to out run the fw 190A still at higher altitude and match a Fw 190A in a turn. The Me109G could match the Tempest at higher alitude for speed but not out turn the Tempest.

MJT

Please specify the Bf 109G variant (for spped), I suppose you mean older versions without MW-50 boost.

[langley]

ORIGINAL: Denniss

ORIGINAL: langley

The Hawker Tempest mk5 was good at medium and low altitude anything over 20,000 feet and performance started to fall away! It was however able to out run the fw 190A still at higher altitude and match a Fw 190A in a turn. The Me109G could match the Tempest at higher alitude for speed but not out turn the Tempest.

MJT

Please specify the Bf 109G variant (for spped), I suppose you mean older versions without MW-50 boost.

Sorry to say that my source book only lists this as a Bf 109G and does not say which sub variant this was.
Information taken from The Typhoon and Tempest Story by Chris Thomas and Christopher Shores.

MJT

[fochinell]

ORIGINAL: harley
Gavin, what we are looking for is a grading system where the alt directly affects the manouverability.

Trying not to be too open about the detail at present, but lets just say there is a fair scope to change manouver from 0 feet to 45K+. Speed is fixed, so don't worry about that...

That's gonna be hard: what do you want as a yardstick for approximation? Or do you want to model the actual engine output/altitude graphs? That would be a bit mind-boggling.

Assuming a Merlin 60-series yardstick, I think it might be worth treating it on an engine basis, with the Tempest V/Typhoon sharing the Sabre, the Mustang I/II, P-40M and N and P-39 all sharing the Allison, the P-38H the turbo-Allison with power and aerodynamic limitations and the J and L with those limitations removed. The odd one out being the Spit LF VB (if that exists) on a Merlin 45M or equivalent.

In any case, that cuts the variables you need to model down to five, rather than by type. On the other hand, the Typhoon was proportionately worse than the Tempest at altitude due to aerodynamic differences. But the engine output was the critical factor.

So it all depends upon how insane you are (don't answer that question), and how much detail you want as a consequence. It's got to be easier using some approximations to do the modelling to my mind...

[HMSWarspite]

ORIGINAL: harley

Gavin, what we are looking for is a grading system where the alt directly affects the manouverability.

Trying not to be too open about the detail at present, but lets just say there is a fair scope to change manouver from 0 feet to 45K+. Speed is fixed, so don't worry about that...

OK - but first are we happy what manouvre actually is (as it affects the game - i.e. what parameter or group of parameters produces the right effect in the combat calcs?) Sustained turn rate? Instantaneous? Both in some sort of way? SEP (related to STR)...

If mostly ITR, you are looking at a local pressure term (i.e. pressure lapse rate with alt). If STR, it is a combination of pressure, and engine power (i.e. supercharger rating etc).

Any clues?

[harley]

remember that combat is not a 3d BnZ fest, or luffberry or 1v1 dogfight. It's an abstraction of 2 enemy aircraft coming together, working out an attacker, working out who has the better pilot rating, who has the better aircraft, who has the best position then who will be the victor (if there is one).

The same 2 pilots can meet the following day in different circumstances and get a different result. There are a lot of factors at play, and MVR was just one.

Take MVR to mean "The ability to make the aircraft do what the pilot wants when the pilot wants" so a slow roll or easy stall or slow accell is a negative, and a quick roll, or great turn rate and fast accell is all positive.

It's abstract, but it is detailed...

[tblersch]

Define "good" and "bad"? Speed, maneuverability, available power, maintenance (one of the big problems with the early -38 is that in European air the damned turbochargers kept freezing up and exploding - which doesn't exactly make for a maintenance friendly plane). Or general mission capability?

Some planes, too, "good" or "bad" depended somewhat on a combination of flight paramaters - the -109K, for instance, was a very good (if twitchy) plane at all altitudes, but if your speed got too high at too high an altitude, it could get very squirrely (start giving stall warnings, controls got mushy and unresponsive). Ditto the Do-335, which would snake and porpise all over the sky at high speed.

Not that I'm telling anyone here anything they don't already know. Just making the point that "good" or "bad" is a pretty broad question. I suppose I could ask in game terms: what numbers, or set of numbers (speed and maneuverability vs. altitude, for example) are you trying to qualify?

[harley]

ORIGINAL: tblersch
Just making the point that "good" or "bad" is a pretty broad question. I suppose I could ask in game terms: what numbers, or set of numbers (speed and maneuverability vs. altitude, for example) are you trying to qualify?

It's not a good v bad calulation. There will be an attacker rating, and a defender rating, and if they aren't the same then one will be higher than the other, that's just math.

just use my guidelines as posted. "Take MVR to mean "The ability to make the aircraft do what the pilot wants when the pilot wants" so a slow roll or easy stall or slow accell is a negative, and a quick roll, or great turn rate and fast accell is all positive."

if this figure changes from 15K to 30K then give us a different figure, we have a high degree of adjustment at various altitudes we can make.

So mushy controls at 40000 feet == big negative...

If a pilot can make a bird sing then he's going to have a good chance of a counter attack or evasion. If he's at a bad alt for the plane, then he's got less chance... Experience is already taken care of, so no need to factor that in, but this has got some wheels turning in my mind now.

Like I said it's all abstracted. What we need is what feels right for a given plane. This isn't a precision task, there's no way it could be, but we have effectively added 3.725e+33 new variables to combat. There used to be 10, and they only affected one aircraft.

[HMSWarspite]

In which case, it is very difficult to be systematic. You are after soemthing that is a combination of SEP ('spare power at the dogfight alt and speed', which is available to turn into accel, offset draggy manoevres like tight turns, climb etc). But also you are in to far less systematic things like controls heaviness, harmonisation (of controls not guns), etc. You are also in to intangables, like P51 is a real pig if you spin it more than a couple of turns, and so maybe this inhibits less experienced pilots from usinh the plane to the full. I guess you could call it 'niceness to fly!'. I do not know any way to deal with the latter 2 other than read flight test accounts, etc.

The former would correlate with max speed to some extent (assuming reasonably constant combat speeds with alt), but with prop planes, even that is compromised by prop efficiency at various speeds etc.

Don't really know how to drive this forward.

A totally pragmatic way is some sort of 'forced pairs' type comparison... You might have a comparison with say the 190A8 with a Spit IX at all alts, and can set those 2 relative to eachother. You then use them as a datum, and space the other aircraft around them (using what info you have, and then subjective feel). you then have to test as many reasonable combinations in 'set up' combats (if you can) and test the realtve loss rates in fair fights at varous alts against history if possible, or gut feel if not. You would probably need a hacked out combat routine that you could force these combats in(wouldn't want to do it in game!). Heck of a job though!

Sorry if I am teaching the obvious!

[Hard Sarge]

- the -109K, for instance, was a very good (if twitchy) plane at all altitudes

?
say who ?
the flight simmers ? (I have not seen a flight sim that does not make the 109 K the best model of the bunch)
I have not read one GE pilot who even liked the 109 K, it had speed and it had firepower, other then that, it is what was called in pilot slang, a lead sled

it could go fast, forward, it could climb, it could go forward, other then that, it was too heavy for the airframe, the controls surfaces were too small for the power that had been added to the plane, most pilots who flew them, thought it was the worse model of the whole bunch

(the G2 being the best, and then the later G-10 model)

oh, did I tell you I added in the 109 K6 also