Spitfire Mk. IX - Boost gauge.

[69th_Mobile_BBQ]

The Spitfire Mk. IX spec. tab indicates that nominal/unlimited setting is 7lbs. boost with 2650 rpm.  However, the red ring with the arrow that is around the boost gauge indicates that ~9.5lbs. is "Level flight manifold pressure".  Wouldn't that be the true max continuous boost setting for standard cruise, or am I missing something?   Pushing to 9.5lbs goes into "combat mode" instead of staying in continuous mode.

Was the same gauge used for a Mk. IX version that did run nominally at 9.5lbs boost and the version we have in game is not that version or is the specs tab and technical chat wrong?

 

I ask because I try to fly the planes without the technical chat enabled and it is very important to me that gauges that have settings markers - such as the green lines on the P-40 manifold gauge to indicate normal operation range, for example - be accurate. 

[unreasonable]

It is 7lbs + 2650 rpm because that is what the original Spitfire IX/XI/XVI manual gives that as the "Maximum Continuous" allowance.  In fact, this setting is described in detail under the section called Economical Flying. It is clearly an "economy cruise" setting, not perhaps what pilots might use in a fast cruise before combat over enemy territory. 

 

The same manual also gives a +12lb 2850 setting called Max Climbing, with a one hour limit: good luck trying that.

 

I think it is fair to say that the current engine limitations are not particularly sophisticated.

[-=PHX=-SuperEtendard]

You can consider the 1 hour combat mode in the Mk IX as some sort of an effective continuous mode. If I am correct you will run out of fuel in +12lb 2850 RPM before the 1 hour limit passes.

[69th_Mobile_BBQ]

I don't know why, but it struck me as odd that this model doesn't have an engine limits placard on the cockpit side panel like earlier models do.  I guess at this point of production it was pretty much assumed that pilots were going to be able to have more training time before going into active service and could be more assured of having such information committed to memory.  

 

It has gotten me interested in taking the time to read the source material manuals. 

 

My fist impression of @unreasonable's answer may be that the manuals were printed as a bulk/blanket type material for a wide range of models and used for models such as the Mk. IX because:  a.) these 'can't go wrong' settings were still valid, and b.) if "a." is true, then it's practical not to add the expense of printing a whole new manual for variations/iterations of the model when running off some extra pages to highlight model-unique features and adding it to the existing manual would be a lot cheaper.  Plus, it would save time, materiel and free printing presses to complete other war-essential projects.  

[LukeFF]

51 minutes ago, =AVG77=Mobile_BBQ said:

I don't know why, but it struck me as odd that this model doesn't have an engine limits placard on the cockpit side panel like earlier models do.  I guess at this point of production it was pretty much assumed that pilots were going to be able to have more training time before going into active service and could be more assured of having such information committed to memory.  

 

Say what? Look around the cockpit a bit more. ?

[69th_Mobile_BBQ]

11 minutes ago, LukeFF said:

 

Say what? Look around the cockpit a bit more. ?

 

Did I miss it?  I stand corrected then.    ~s~ 

[unreasonable]

2 hours ago, =AVG77=Mobile_BBQ said:

 

My fist impression of @unreasonable's answer may be that the manuals were printed as a bulk/blanket type material for a wide range of models and used for models such as the Mk. IX because:  a.) these 'can't go wrong' settings were still valid, and b.) if "a." is true, then it's practical not to add the expense of printing a whole new manual for variations/iterations of the model when running off some extra pages to highlight model-unique features and adding it to the existing manual would be a lot cheaper.  Plus, it would save time, materiel and free printing presses to complete other war-essential projects.  

 

It (AP 15651) is a 1946 version of the manual that includes details on the operations of both the early throttle type - as we have in game - and the later interconnected boost/rpm control. So I think it is fair to treat it as specific and accurate and as "general issue". You should be able to find it and download on the net.   

 

In the manual: at +12/2850 the plane uses 105 gallons/hour. Main tank capacity is 85 gallons (95 for bubble tops) so you would need drop tanks or the auxiliary rear fuselage tanks to use this for an hour as @-=PHX=-SuperEtendard says.  TBH I had forgotten that the game MkIX has an hour at this setting...confused memory of the MkV's 30 minutes at +9.

 

 

Edited September 21, 2019 by unreasonable

[Talon_]

Yeah there's no reason to fly the Spit IX at anything under +12lbs unless waiting for your wingman to catch up.

 

"Combat" power had to be extended to 1hr due to the approval of bombs for the Spitfire LF IX - the engine was no more robust than previous models but the drag of the bombs was too much for reduced power.

[[URU]Panzer-uy]

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Edited September 22, 2019 by [LAS]URU-Panzer

[gimpy117]

I'm guessing it's another "poor fuel quality" situation. they really need to add a modification for planes like the p-40, p-39 etc. which is "High quality fuel" which restores proper engine performance....especially since we can simulate these planes in western use with bodenplate 

 

Edit: i've been told that many planes have this "feature" if that's not true for this model spit please point it out 

Edited October 17, 2019 by gimpy117