51D and F4U-4

[Saxman]

Pilot's notes for Corsair I-IV (AP2351A,B,C&D)

R-2800-8 or 8W:
Combat Emergency*    2,700/60"     5min
Take-off             2,700/54"     5min
Combat               2,700/53"     5min
Climbing             2,550/49.5"   1h
Max Rich             2,550/44"     continuous
Max Weak             2,200/34"     continuous
*using water injection


Pilot's Handbook of Flight Operating Instructions (AN 01-45HA-1)
USN: F4U-1, F4U-1C, F4U-1D, F3A-1, F3A-1D, FG-1, FG-1D
FAA: Corsair I-IV

R-2800-8W:
War Emergency        2,700/59.5"    5min
Take-off             2,700/54"      5min
Military             2,700/53"      30min **
Normal               2,550/49.5"    continuous
Max Cruise           2,150/34"      continuous


edit: ** I'm dubious about this 30min, the scan isnt very clear but it does look like 30min. however, elsewhere in the manual WEP is referred to as "2700rpm (five minutes)".
later - "The rpm's and manifold pressures at a given supercharger control setting for take-off, military, and war emergency operation must never be exceeded; the five-minute time limit for each of these conditions must never be exceeded."
This is also consistent with the R-2800-21 used in P-47B/C/D/G - 2550rpm is max continuous, 2700rpm is limited to 5mins.

so ... the AH F4U-1 should look like this:
WEP             2700/53"
Military Power  2550/49.5"
Normal Power    2550/44"
Max Cruise      2150/34"

... the AH F4U-1A/C/D should look like this:
WEP             2700/60"
Military Power  2550/49.5"
Normal Power    2550/44"
Max Cruise      2150/34"

... but the current AH F4U-1/1A/C/D all look like this:
WEP             2700/57.5"
Military Power  2700/54"
Normal Power    2550/44"
Max Cruise      2150/36"


 

Like to know where you get a figure of 49.5" MP for Mil power, when the chart you referenced identifies this as CLIMBING and and gives 53-54" for MIL.... Based on your own charts, for the 1A/D/C and 4 it should be:

WEP: 2700/60"
MIL: 2700/53"
Normal: 2550/44"
Cruise: 2150/36"

If HTC is using WEP to represent water-methanol injection in the later Corsairs, then the F4U-1 should be:

MIL: 2700/53"
Normal: 2550/44"
Cruise: 2150/36"

Can post you scan these documents? Would be easier to argue request the change/fix (of either the power settings themselves OR the instrumentation) from HTC with scans of the originals.

[RTHolmes]

The Brits, US and AH all use different naming conventions for their power settings, which can be confusing. AH's Military Power setting is the highest power setting that can be used continuously, this is not the same as the Combat (Brit) / Military (US) Power referenced in the charts which is limited to 5(30?)min.

The highest setting which can be used continously in both charts is 2550/49.5", although the Brits specify a limit of 1h. since hardly any sorties in AH last over an hour, I think its reasonable to allow this as a continuous setting.

US manual
Brit manual

[RTHolmes]

... and before you ask, the same applies to the AH P-47Ds, B-17, B-24 and probably others too

[Saxman]

Let's not get into the debate on time limits at certain power settings. HTC isn't modeling operating procedures, they're modeling the documented power settings. Otherwise HTC would have to remodel ALL the power settings in the game to restrict full throttle to "highest continuous power setting" which would be even LESS realistic than the .0000000000000000000000000000 0000000000000000001% chance of your engine blowing up in your face for running too long at MIL.

MIL is MIL. If the US states MIL as 53" MAP at 2700 RPM, then that's what it should be in the game.

Thanks for the scans, tho.

[RTHolmes]

not so keen on remodelling the corsairs accurately now are we?

so if you're happy with corsairs flying around continuously in AH with power settings that were limited IRL to 5min, presumably you wont mind if we remove the WEP setting from eg. Spit XVI and allow it to use 3000/+18lb continuously as Mil?

[Saxman]

How is restricting max throttle to max continuous power--which was NOT max throttle IRL--more realistic? You're asking for an artificial limitation be imposed based on a PROCEDURAL rather than PHYSICAL limitation. Personally, I'd LOVE it if planes that used injection for WEP could run out permanently with no recharge (excluding rearms: ground techs refilling the tanks while they gas up your plane). Because that's a PHYSICAL limitation of the aircraft, not an arbitrary one based on what some technician decided "If you exceed this, your crew chief will tear you a new one while he strips down the engine to check for problems."

Incidentally, I checked the charts in the manual and WEP is altitude specific. It lists 57.3" at SL, 59" at 12,500ft, and 59.5" at 17,000ft. I tested offline and the F4U-1A does hit these marks at the indicated altitudes, so the E6B chart is a bit misleading as it doesn't account for current altitude.

[dirt911]

be careful what you ask for, you just might get it

Lol 

[RTHolmes]

yeah the manifold pressures depend on alt and blower settings, I just used the highest numbers from the charts (which are what I assume the E6B shows) to keep it as simple as possible.

The figures arent arbitrary, they all come from official documents, and are the safe, tested and certified limits "by the book".

I'd just like to see all the AH aircraft treated the same. As it is, some aircraft (eg. Spit IX) are limited to using the RL official power settings, whereas others (eg. F4U-1A) can fly for hours using settings which IRL were limited to 5mins. does that seem right to you?

[SgtPappy]

I'm not sure if I'm reading wrong, but it seems as though both sources posted at the top of this page contradict each other.

Therefore, neither of you are wrong and neither of you are correct (yet). I assume there still needs to be more speculation on both sources before we can figure out what's the 'truth'.

[Saxman]

No, they don't contradict each other. RTHolmes is arguing that the Corsair should be restricted to Climbing Power (2550 RPM at 49.5" MP) at max throttle because the book says not to use Military Power for longer than 5mins continuous. Even though this was a procedure and not a physical limitation of the engine and airframe (whereas the 5min limit on WEP is because the Corsair only carried 5mins of injection water). He's trying to argue that the Spitfires have their WEP limited to 5mins even though they used Boost, so the Corsair shouldn't be able to fly for an hour at MIL. However the Corsair and Spit are NOT being treated any differently: Both can fly at MIL for as long as they want, and both have their power settings ABOVE MIL (as given by the SOP's--including the Merlin, which at least in the P-51 book I believe gives separate MIL and Boost settings) regulated with the same 5min timer.

I chose to extract myself from this discussion because it's heading RIGHT into the same sort of "But the BOOK says" circular argument of people trying to get HTC to arbitrarily enforce the SOP's power restrictions via engine overheats and failures.

[Karnak]

The 5 minute limit on Merlin engined fighters is also a procedure and not a physical limitation.  That is his point.  If the F4U isn't limited by procedural restrictions, then why are the P-51s, Spitfires, Hurricanes or Mosquito? I don't think the Merlin should be able to ignore that.

[SgtPappy]

Maybe the question here is "Why do the Brits have different limitations vs the USN?"

Or maybe that 'blur' of 30 mins is actually 5 mins 

At any rate, how bad of a hit would the F4U take in combat rating performance even IF these lower figures are the correct ones?

[Saxman]

Karnak,

Reread the pertinent parts of the thread:

R-2800-8W:
War Emergency        2,700/59.5"    5min
Take-off             2,700/54"      5min
Military             2,700/53"      5min
Normal               2,550/49.5"    continuous
Max Cruise           2,150/34"      continuous

... the AH F4U-1A/C/D should look like this:
WEP             2700/60"
Military Power  2550/49.5"
Normal Power    2550/44"
Max Cruise      2150/34"

(I've corrected the time limit in the SOP chart).

Like to know where you get a figure of 49.5" MP for Mil power....

The highest setting which can be used continously in both charts is 2550/49.5", although the Brits specify a limit of 1h. since hardly any sorties in AH last over an hour, I think its reasonable to allow this as a continuous setting.

Holmes is treating it like the F4U getting to run at MIL non-stop means it's not being treated in the same was as the Spitfire. Which is NOT the case. The Spit can run MIL non-stop, too, despite SOP restrictions (I'm not even getting INTO boost!). The reasoning he's giving is that, since the Spit's Boost is limited to 5mins because that's the procedure, the F4U's MIL time should be restricted as well, and that HTC should force the Corsair to max out on Normal Power and skip MIL entirely when engaging WEP.

He's not even TALKING about limiting WEP in the Corsairs (which already IS limited).  He's saying "Spit doesn't have unlimited BOOST, so Corsair shouldn't get unlimited MIL." Even though BOTH AIRCRAFT get unlimited MIL in the game.

[Karnak]

Saxman,

Based on the British chart, and AH mechanics, I'd say the unlimited setting would be 2,550/49.5" and the 5 minute WEP would be 2,700/59.5" and just ignore the 2,700/53" setting.

EDIT:

I am not an F4U expert and I don't know if the British charts are junk or not.  I am just saying that if I was going off of that data and nothing else, that is how I would do it.

[Saxman]

Karnak,

Take a closer look at the US vs. British charts. They're largely identical, only labeled slightly differently. Climbing Power for the UK is equivalent to Normal Power under the US. The 44" setting is NOT normal power for the British, they just note it as Max Rich. The US book doesn't note Max Rich or Lean, just Cruise, Normal, Mil and WEP.

And if you're going to remove MIL for the Corsair, then you sure as hell BETTER do it for ALL aircraft. Because that's EXACTLY what happens if you remove the 2700/53 setting from the Corsairs (this was MIL under US, combat under the British charts. NOT WEP). The SOP's of EVERY SHIP IN THE GAME would have "safety" notes restricting the use of MIL power.

Spit XVI? Restricted to 2650 at +7 Boost.
109G-6? 2300 at 1.15 ATA
La7? 2500RP at 35"

Restricting one plane to Normal Power at max throttle because of SOPs while leaving the rest of the plane set alone is FAR more unbalanced than the current HTC setup of allowing all planes to use MIL indiscriminately with limited WEP.