Quote:
Originally Posted by Blackdog_kt
Actually i think they are wondering if the mixture lever operated "backwards". In most planes lever forward=rich. However, i've seen a freeware FSX tiger moth add-on and it too had it backwards (lever back=full rich, while in most cases the full back position is the fuel cut-off). Even more so, if you pulled the throttle back in the Moth it would pull the mixture lever back along with it.
....
However, i have absolutely no idea how they did it back then in planes with constant speed props (that don't exhibit enough of an RPM difference to indicate the proper leaning point) but no EGT gauges. It's ok doing it in a civilian aircraft, but when people are shooting at you i guess it's a bit harmful keeping your head inside the cockpit for long periods of time, looking to catch a glimpse of a tiny jump of the RPM needle before it stabilizes again due to the pitch governor. I guess it's one of the reasons that mixture was automated to a large extent early on in many designs, either completely in the German ones, or partially like in the US designs (cut off, full rich, plus two automatic settings, one for auto lean for economy during cruise and one for auto rich to keep temps a bit cooler during climb out and combat).
Maybe it was also done "by ear", listening for changes in the engine's sound? Would be interesting to know.
As for running full rich without taking altitude into account, it won't kill the engine (in fact engines run cooler with richer mixture) but it's generally not advisable if you want to develop any kind of serious power. Restored warbirds run richer than specified in the manuals to preserve their old engines, but back in the day they were more concerned with delivering peak power during combat.
I doubt they would ever go to full rich over 8000 feet or so, unless the engine was starved of fuel/stalling due to battle damage and they tried to keep it running no matter what, at the cost of optimum power.
...
|
I found a copy of the MKII Spitfire pilots notes on Zeno's war birds (close as I could find to a MK I)
There is very little said about adjusting mixture except for the pre-start (Mixture Control -RICH), engine test(test cruse power (WEAK mixture) followed by maximum boost (RICH)), and pre-takeoff (Mixture Control - RICH) checklist. Then two paragraphs use WEAK mixture for maximum range and endurance.
The description of the control is as follows
--------------
14 .
Throttle and mixture controls - The throttle and mixture
levers (10 and 11) are fitted in a quadrant on the port
side of the cockpit . A gate is provided for the throttle
lever in the take- off position and
an interlocking device
between the levers prevents the engine from being run on
an unsuitable mixture . Friction adjusters ( 8 ) for the
control s are provided on t he side o f the quadrant.
----------------
I guess the pilots had enough on their plates as it was.
I was never quite happy with the mixture in IL-2 which was basically wait for the brown smoke to start coming out and then drop the mixture one step.
Cheers!