Fuel Guage

[Bozdog]

I recently purchased the A2A spitfire, and rushed into the air with it. However after a couple of hours I ran out of fuel.
There must be perhaps some mechanical reasoning behind it, but why does the fuel gauge require a button push to show the fuel level. Otherwise it always shows empty?

Why would a pilot not just tape the button into the depressed position? Done a search around Google but not found an answer yet.
Thanks to anyone who can enlighten/ educate me.


Cheers
Steve

[Oracle427]

While I haven't got a clue as to why it was built this way I'm going to go out on a limb and say that it was done to protect the instrument from damage while the needle bounces around while fuel sloshes around in the tanks. I've never flown in a warbird but the older fuel gauges in aircraft tend to oscillate rapidly.

[Alan_A]

Interesting theory. I was wondering if it had some sort of power-saving rationale... or maybe if it was just another example of strange 1930's ergonomics. Amazing to see how much progress was made in a short time if you follow the thread from the P-40 and the early Spits through the P-47 and up to the Mustang. A continuously readable fuel gauge seems like a necessity for us but might not have to a designer c. 1936.

But maybe there's another explanation I'm missing.

[Lewis - A2A]

I think to place the aircraft in the context a fuel gauge wasn't all that important, get up to altitude quickly take out bombers and home in time for tea, there wasn't any patrolling or anything ever planned when the initial design was thought out. It was all about the pure interceptor role to combat the bomber terror of the 1920-30's what was then the idea that a few massed bomber raids could flatten and wipe cities from the map, a taste of which had started by wars end in 1918 and was slowly being backed up given the events in smaller wars, the classic example being Guernica in Spain, an event Picasso would later use for his Guernica Piece.

thanks,
Lewis

[Piper_EEWL]

I was wondering about that too since I got the Spitfire this summer.

I think to place the aircraft in the context a fuel gauge wasn't all that important, get up to altitude quickly take out bombers and home in time for tea, there wasn't any patrolling or anything ever planned when the initial design was thought out. ...

Interesting theory Lewis but yet it was still important enough for the designer to include a fuel gauge. So why make it more complicated in design and harder to operate for the pilot (who I can only imagine already had his hands full flying and fighting in this machine) by making him press a button to read the gauge?! That doesn't make a lot of sense to me. Sorry

I'm leaning more to a technical explanation as Alan or Oracle have suggested.

I was thinking it was some sort of power saving technique too since the Spitfire doesn't have a battery master switch??

Interesting theory. I was wondering if it had some sort of power-saving rationale...

But the explanation that Oracle presented makes sense too. Especially when looking at the Mustangs fuel gauges during a turn or high G-Force maneuver.

While I haven't got a clue as to why it was built this way I'm going to go out on a limb and say that it was done to protect the instrument from damage while the needle bounces around while fuel sloshes around in the tanks. I've never flown in a warbird but the older fuel gauges in aircraft tend to oscillate rapidly.

I don't have a better explanation so maybe someone else can chime in?

I have one more question which I've been wondering about. Do you guys know why the MkI Spitfire has two fuel gauges on for the upper and one for the lower tank and the MkII Spit only has one fuel gauge for the lower tank? It looks like there's plenty of space left in the panel to incorporate the second gauge. Just doesn't add up for me.

Take care,

[Lewis - A2A]

Yes that's what I mean, though technical its very reasoning would be in the lack of importance in such a gauge, so why power or have systems to power something that needs glancing at briefly and not used again, at least not under what the designer thought would have been normal operation. This is also why the Gear indicator and a few other things is the way it is btw in the early MkI Spitfire

[Tomas Linnet]

this is the level of geekiness I really enjoy

[Piper_EEWL]

Ok I can see your point of view

But why does the MkII only have one fuel gauge and no flap indicator other than the one(s) on the wing(s)? Because as I've said before there would be enough space on the panel to incorporate those in my opinion. Or was that plainly to reduce cost and or weight?
I could understand the lack of the flap indicator in the panel because the flap lever itself is pretty much an indicator and additionally you would have the two little indicator flaps on the wings standing up.
But the fuel gauge? I mean you only know if the top tank is empty once the bottom tank fuel gauge starts showing that fuel is taken from the bottom tank. But at this point you already went through half of your fuel / endurance. And I think that was pretty important in war times too!?

[Bozdog]

Thanks for all your input, I also wondered if it was a power saving reason, but thought "could it really make that much difference?" However in a life or death situation I guess every little bit helps.
I saw a documentary recently on the battle of Britain where one pilot was explaining his ground crew used to keep the plane spotless and would polish it affter every flight, justs to squeeze an extra mile an hour or so out of it.
Glad I am not the only one who didnt know the answer.

[Lewis - A2A]

Ok I can see your point of view

But why does the MkII only have one fuel gauge and no flap indicator other than the one(s) on the wing(s)? Because as I've said before there would be enough space on the panel to incorporate those in my opinion. Or was that plainly to reduce cost and or weight?
I could understand the lack of the flap indicator in the panel because the flap lever itself is pretty much an indicator and additionally you would have the two little indicator flaps on the wings standing up.
But the fuel gauge? I mean you only know if the top tank is empty once the bottom tank fuel gauge starts showing that fuel is taken from the bottom tank. But at this point you already went through half of your fuel / endurance. And I think that was pretty important in war times too!?

Remember the MkII is still essentially a big pre-war design to overcome some limitations and updates since MkI, so still that thoroughbred interceptor role that in the end wasn't really needed as it more just the standard fighter that was needed to take down bombers as good as any real bomber destroyer. Also at a time when time was really limited and all of a sudden the only Allied nation was the island of UK. So again for the MKII your talking about the context of the Air Ministry actually testing Tiger Moths fitted with slicing devices in order to fly through paratroop drops to slice chutes in the air in an act of utter desperation in the face of invasion.

By the time things had moved on I guess things are somewhat set in stone with the design, so maybe looking at a wartime Mark V or above or even better a true wartime design like the Typhoon would be a better to look at as a comparison.

cheers,
Lewis

[Piper_EEWL]

Ok ok I got it Considering the timeline in which those planes went from a sketch to their maiden-flight I guess stuff like flap indicators and fuel gauges were not that important. Still doesn't make a whole lot for sense for me though that you have to push a button to get a reading on a fuel gauge

Thanks for the explanation and I'll stop nagging now

[Paughco]

The seat heater in my Spitfire is not working. How do I fix that?



Seeya
ATB (wonder if they had seat heaters in those 109s?)

[MadRobbie1]

There were a lot of new design ideas and kit introduced into the Spitfire and Hurricane MkI's that had never been seen before in RAF fighters up to that point in time (mid 1930's).

It's easy to say "why wasn't that used..?" when you have an additional 80 years of hindsight in your favour!

Remember that the Air Ministry that governed the commission and supply of equipment to the RAF was not a flawless organisation (they gave the Boulton-Paul Defiant the go-ahead for production and squadron service for example) - it had to bow to pressures from government influences at times, and like everything else had to adhere to budget constraints.
The fact that you have to push a button to get a reading of a fuel tank contents may seem odd today, but it was the 'norm' back then. HOTAS and cockpit ergonomics didn't exist. Pilots pulled levers and pushed buttons. It was in the small print of their contract. It was the technology of the day.

They also had spare light bulbs to put in to the reflector gunsight if the current light bulb failed. Imagine having to deal with that in the middle of a dogfight so you can have a chance of shooting accurately again. Suddenly a fuel tank reading push button isn't such a big deal!

These were interceptors, short range defence aircraft. Standing patrols for hours on end weren't their intended business. They carried mere seconds worth of gun ammunition, so combat persistence wasn't in their design 'CV'. Short, quick missions with quick turn-arounds and back in the air was their forte. Plus, because of their range and how the RAF fighter defence network was set up around the coast of England, generally you were never that far from a military airfield of some kind (RAF, Navy, fighter, bomber, training or otherwise).
Some of their contemparies in other air forces elsewhere in the world had to put up with fuel gauges that consisted of a wrist watch worn by the pilot.

The original MkI's when delivered had WWI vintage ring and bead gunsights. They also had 2-blade fixed pitch props. The landing gear had to be pumped as it wasn't electric driven. Within 3 years all this had changed because technology had moved on and was readily available.
Most of the RAF pilots flying the early MkI's had never flown an aircraft with retractable flaps or undercarriage before - the indicators in the wings helped as a visual reminder (but sometimes failed as the pilots went in 'biplane mode' - i.e. thinking the wheels were always down!).

The original Spit's and Hurri's went through an incredible amount of mods and upgrades in their relatively short service life. New kit and upgrades were continuously introduced at a factory/manufacturing level, and eventually these enhancements would filter down to be added at an individual RAF squadron level. Some were introduced with ease and after only a few hours maintenance on the ground, while others had to wait till specific servicing schedules allowed due to the complexity of the work.
As a result, it was not unheard of to (for example) line up 6 aircraft for a formation training flight at the start of the day, and each aircraft would have differences in the instrument panel and cockpit controls to each other. There was no 'service standard'. All of this would be documented in the aircraft log (Form 700 Series) so the pilot signing for any aircraft would be aware of it's current state and equipment prior to climbing aboard though.

Its all part of the character and charm of these old warbirds!

Cheers!
Rob

[TomMarius]

Great post - thanks Rob.

[Bozdog]

Yes great informative post , thanks Rob. I am really enjoying this plane