Inverted Flight

[Paladin3]

Someone once said to me that the fuel pumps on WWII fighters were much like allot of civilian aircraft today - they won't feed fuel when inverted for long periods of time... Does anyone know the truth about such things? If not, that would be an interesting thing to model into the game seems like...

[ImADot]

Well, I know that the engine in the Hurri Mk1 will die if flown inverted for more than a couple of seconds - unless I'm pulling positive G's like in a corkscrew or barrel roll.  Not sure about the fuel-injected planes, but the coad is there if indeed the other planes had similar issues.

But I believe your question begs this question:  Why would you be flying inverted long enough for your engine to starve?  Practicing for the Oshkosh air show?

[Paladin3]

Not knowing how long it takes for an engine to starve, it made me wonder about all the negative g pulling I seem to notice in game for defensive purposes, as well as when folks roll inverted before making a BnZ pass through a fight. I am not sure if it would have any affect at all, just wondering about it and I know there are folks here with allot more knowledge than I have about the subject so I thought I would ask.

[rvflyer]

Well, I know that the engine in the Hurri Mk1 will die if flown inverted for more than a couple of seconds - unless I'm pulling positive G's like in a corkscrew or barrel roll.  Not sure about the fuel-injected planes, but the coad is there if indeed the other planes had similar issues.

But I believe your question begs this question:  Why would you be flying inverted long enough for your engine to starve?  Practicing for the Oshkosh air show?

  Fuel injected engines don't care if they are upside down or not and will run fine if they have an inverted oil system and fuel pickups.

[BaldEagl]

Well, I know that the engine in the Hurri Mk1 will die if flown inverted for more than a couple of seconds - unless I'm pulling positive G's like in a corkscrew or barrel roll.  Not sure about the fuel-injected planes, but the coad is there if indeed the other planes had similar issues.

But I believe your question begs this question:  Why would you be flying inverted long enough for your engine to starve?  Practicing for the Oshkosh air show?

The Spit I is the same.  Both will kill if inverted and not under positive G's or if under negative G's.

Fuel injected engines don't care if they are upside down or not and will run fine if they have an inverted oil system and fuel pickups.

They don't even have to be fuel injected.  The Spitfire/Hurricane problem was solved with the advent of Miss Shilling's Orifice and later with pressurized carborators.  They still used carborated engines but no longer stalled under negative G.

[Paladin3]

Gotchya, so it is not something that we see in the MA anyway, with older planes being equipped with other devices that would allow inverted flight. Thanks gang.

[pipz]

With some planes as I recall it was a problem of oil starvation.

[Tigger29]

Gotchya, so it is not something that we see in the MA anyway, with older planes being equipped with other devices that would allow inverted flight. Thanks gang.

Well most of the planes we fly in the MA (Especially Late War) would run inverted anyhow, but a few planes will not, and those are accurately modeled.

[WWhiskey]

With some planes as I recall it was a problem of oil starvation.

the Allison engines /p-38/p-40/early 51's,  could only run inverted for about 30 seconds if i remember right, it had a dry sump oil system but no way to pick enough oil up from the valve covers to sustain pressure,
 the main pickup was in the pan, there was also a line from the back of each valve cover about 1 inch I.D.  , nose down inverted zero or negative G was a big no no!
 the lines in the back of the valve covers were there to drain off access oil during nose up flight but could also help feed the pump for a short time in inverted flight as long as you kept the oil at the back end of the motor!

[Infidelz]

Flying inverted is a way to scope what is going on below. Those below can't really see that you are watching them. Seems like it should be modeled as time limited if that is the case.

Infidelz.

[doright]

I haven't research this extensively but the problem of prolonged inverted flight is 3 fold.
First is a plane with a float carburator will cut out because the float is floating the wrong way under neg G. Pressure Carb's and fuel injection do away with that problem, and note there is a difference between the two.
Second as noted the engine oil supply under neg g would be time limited.
Third the fuel supply under neg g would be time limited.
The oil and fuel under neg g could be supplied by a hopper that trapped fuel at the pickup. Inversion time could be limited to the contents of the hopper.

[ink]

I haven't research this extensively but the problem of prolonged inverted flight is 3 fold.
First is a plane with a float carburator will cut out because the float is floating the wrong way under neg G. Pressure Carb's and fuel injection do away with that problem, and note there is a difference between the two.
Second as noted the engine oil supply under neg g would be time limited.
Third the fuel supply under neg g would be time limited.
The oil and fuel under neg g could be supplied by a hopper that trapped fuel at the pickup. Inversion time could be limited to the contents of the hopper.

I have no problem flying inverted....didn't you read? the ones that could not, are modeled properly, the ones that can, are also modeled properly.

[SIK1]

I have no problem flying inverted....didn't you read? the ones that could not, are modeled properly, the ones that can, are also modeled properly.

Not entirely true. The corsair has a 10 second inverted flight limitation, due to the loss of oil pressure in inverted flight.
Where there is no restriction in AH as to how long you can keep the F4U inverted.

[guncrasher]

I have no problem flying inverted....didn't you read? the ones that could not, are modeled properly, the ones that can, are also modeled properly.

wrong, I have flown nearly all airplanes upside down just to see how long i can sustained it, and there was never any limit, and that includes the buffs, who would never go upside down, on purpose i should say.

semp

[BaldEagl]

wrong, I have flown nearly all airplanes upside down just to see how long i can sustained it, and there was never any limit, and that includes the buffs, who would never go upside down, on purpose i should say.

semp

The Spit I and Hurri I won't fly inverted forever.  Go try them.  Well, they will fly but not with the engine running.