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R4D-DC3 mixture control question.

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This has always been a "problem" area for me. How does a pilot know he has his mixture set correctly? Before I purchased the MAAM-SIM R4D-DC3 I used Tim's panel in the (highly modified) FS9 default DC3. I had a fuel flow gauge that would help with the setting of the mixture. Now that I'm flying the MAAM AC, which has no fuel flow gauge, what does a pilot look at, as far as instruments, to determine if his mixture is set correctly? This has been an ongoing question for me with all piston aircraft...what tells the pilot that his mixture is set correctly? On various AC's I've used EGT gauges, Cylinder head temp. etc., never really knowing what I was doing. What would a REAL pilot look at on a DC3/R4D? Also, with the MAAM AC, if I set the Realism setting to "Automixture", should I expect to see the mixture handles move as I climb? Thanks for any info on this subject, gang. Vic


Victor Buck

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It is not unreasonable to use the FS Automixture check facility to control mixture, although it is not very accurate. More fun to do it manually, though.Dave Bitzer and I developed an automixture gauge for the MAAM-SIM DC-3 that you can find at the major sites. This simulates the autorich and autolean detents on the real aircraft's mixture quadrant. We'd like to think that the settings are much closer to the real world aircraft's specification.Before using this, I used to tune my mixture by ear! You can hear when it's right .... note, though, that my "IFR" panel for the MAAM-SIM package includes a 'hidden' fuel flow gauge if you prefer things that way.Mark "Dark Moment" Beaumonthttp://www.swiremariners.com/newlogo.jpg


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Mark "Dark Moment" Beaumont

VP Fleet, DC-3 Airways

Team Member, MAAM-SIM

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OK, Mark...but if using the "automixture" setting...will I see the Mixture levers move? I like to see verification that something is working. I have always been impressed with the way the FSDZigns Lockheed L049a "Connie" behaved...if "automixture" is checked, you can see the mixture levers move as you climb. I also liked the fact that it had "tooltips", which would tell you where a lever, switch, etc. was set when you "moused over" it. That's something I wish the MAAM had. I, also, have used the "ear" method, and seem to do allright with it. What is the name of this "automixture gauge" you and Dave made?? I'd love to check it out.In review: With "realism" "automixture" set "on"...will my mixture levers (in the MAAM AC) move (to verify that my mixtures are, in fact, being adjusted)? I still don't know what a pilot would look at, as far as instruments, to determine his mixture setting. There must be some parameters that he would look at to determine this? I can do it by "sound"...but that seems questionable? Anywho...thanks!! Vic


Victor Buck

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All our work is showcased at www.swiremariners.com/dc3FS9.html , Vic.As for your further questions about what a pilot would look at ... read the checklists, manual and performance specs!Mark "Dark Moment" Beaumonthttp://www.swiremariners.com/newlogo.jpg


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Mark "Dark Moment" Beaumont

VP Fleet, DC-3 Airways

Team Member, MAAM-SIM

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Vic, As I'm sure you're aware the reason for "setting" mixture on piston engine aircraft is because the air density changes with altitude - therefore altering the ratio of fuel/air, (resulting in a less efficient engine)The idea is to adjust the mixture in order that you obtain maximum power from the engine(s) as you climb/descend. By monitoring the engine revs. and maniford pressure whilst altering the mixture you will be able to ensure power efficiency. Rule of thumb (in the simplified sense) you would "lean" out the mixture as you climb so obtaining max revs/power, then take it back (enrichen the mix) slightly. (prevent overheating etc) The opposite, clearly would be true if descending.Hope this helps. (Not actually sure how much of this is modelled in the MAAM aircraft :-) )Regards, Blue.

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>(Not actually sure how much of this is>modelled in the MAAM aircraft :-) )>Yessir, very much so. Hours and hours of feverish, beer-driven beta testing caused Rob Young to lose plenty of virtual hair over flight dynamics and performance as modelled in this package!Mark "Dark Moment" Beaumonthttp://www.swiremariners.com/newlogo.jpg


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Mark "Dark Moment" Beaumont

VP Fleet, DC-3 Airways

Team Member, MAAM-SIM

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Hi Vic,The C-47 Dash-1 has a set of performance charts for various aircraft weights, fuel flow rates, ranges, and either one or two engines operating. The mixture setting is one of the variables, and there are Auto Rich and Auto Lean settings for all altitudes. In other words, some long range settings incorporate Auto Lean mixture at sea level, and some high-speed settings use Auto Rich at 15,000 feet. So the short answer is to follow the charts. Unless you have a copy of the Dash-1, you don't have the charts, but it appears that at normal cruise settings of about 30 inches and 2050 rpm, you would switch to Auto Lean once established in cruise, regardless of altitude. Follow the checklists provided with the sim for takeoff, descent, and landing.In general, the FAA doesn't say much in regards to mixture control. The "Pilot's Handbook of Aeronautical Knowledge" just says to follow the manufacturer's guidelines. The "Flight Training Handbook" says the same, but it goes on to recommend leaning until the engine starts to run rough, then enrich until it's smooth. It also says that the common policy of not leaning below 5,000 feet isn't necessarily correct... that a more reasonable policy is to avoid leaning if the engine is operating above 75 percent power (as in climbs).Rod Machado goes further in his "Private Pilot's Handbook", providing recommendations for use of Fuel Flow Gauges and EGT Gauges. By the time I had gotten to his manual, I had to leave for work. But if you're still interested, I'd be happy to summarize his recommendations.Best,Ken

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Sorry for the late reply, Ken. Is the C-47 Dash-1 an addon? If you get the time I'd love a summary of RM's recommendations. Although the MAAM-SIM R4D/DC3 has neither a fuel flow or EGT indication the info would certainly be useful in other AC's. I have used these 2 guages before, when provided, to set an aircraft's mixture...but who knows if I'm doing it right!?. Thanks Ken. Vic


Victor Buck

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Since we would rather you save that twenty bucks to put toward the TBM package...The original R4D CD, circa FS98 to 2000, incuded three WWII era manuals. One of these, the Pilot's Training Manual you will already have, as it was included on the curret R4D / DC-3 CD.But it just so happens that one of the others was the very "Dash 1" of which you speak. I have just uploaded the PDF format version of the PFOI, and followed it up with the third manual, the RAF Pilot's Notes for Dakota IV.This is meant to be another service to our customers, rather than a stick in the eye of purveyors of old government-produced, public domain documents. ;-)You may download both manuals through our FREE STUFF page at http://www.maam.org/flightsim/enhance/enhance.htmHappy Tax Day :-madBill Rambow MAAM-SIM - Rambow, Visser, Banting, Young, Womack, Sodja & Beaumonthttp://www.fssupport.com/maam/maamsim_neon.gif


Bill Rambow

MAAM-SIM

www.maam.org

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Guest kennethg

For my 5 cents (and at the risk of a LONG post): what I know about engine leaning from being both a private pilot and a aircraft mechanic is basically you pull the mixture back to lean until the engine runs rough, then push it forward just a bit to get the engine to smooth out. The roughness is caused by one of the cylinders leaning past the optimum mixture and is caused by losses inside the intake manifold, common in carburetor-equipped engines; the longer the manifold pipe is the leaner the mixture will be when it reaching the intake valve. Fuel injection (like in the Cessna 172SP) solves this problem because only air is carried in the intake manifold and the fuel is added right above the intake valve. I just flew a injected engine and the difference is quite noticable, there was a lot less roughness as the mixture reached peak.Gauges like an Exhaust Gas Temperature (EGT) and engine analysers allow you to better monitor what the cylinders are doing by monitoring their operating temperatures (and sometimes other parameters), but the leaning procedure is the same, you're just getting better feedback as to what the engine is doing and you lean until you get peak EGT reading. EGT's never are marked with numbers, all you care about is the peak tempurature, whatever that may be.I've found that leaning is generally not well modeled in FS2004, mainly because there isn't any modeling for the sounds and vibration of a rough running engine. FS2004 is a better flight simulator than it is a engine sim. Also, this is usually a pretty good topic to bring up at a real-world flight club. You'll usually find that the number of different opinions about proper leaning is equal to the number of pilots talking about it.

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Wow...thanks Bill.Just another reason that the MAAM-SIM R4D/DC3 is the most enjoyable payware addon I've ever bought. Rather than "beat around the bush" when there is a problem, or, in this case, remain silent about info...you guys come right out with the stuff we need. It's an amazing breath of fresh air in my payware experience.I have a select group of freeware and payware developers that I will ALWAYS get new stuff from, without worries. I am glad to add another one to that list...MAAM-SIM. It's a VERY short list, gang, believe you me. Thanks. VicPS. I'm going to need a new sig banner, this keeps up! LOL!


Victor Buck

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Guest kennethg

Let me second Vic's statement: so far MAAM is #1 on my (very) shortlist of trustworthy payware developers.>I have a select group of freeware and payware developers that>I will ALWAYS get new stuff from, without worries. I am glad>to add another one to that list...MAAM-SIM. It's a VERY short>list, gang, believe you me.>> Thanks.>> Vic>>PS. I'm going to need a new sig banner, this keeps up! LOL!

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Hi Vic,Machado's recommendations are summarized as follows:1. Fixed-pitch prop, with a conventional carburetor, and without fuel flow or EGT gauges: lean for peak RPM. If the engine runs rough, enrich slightly until the engine smooths out.2. "With a fuel flow gauge you can set the manufacturer's recommended fuel flow rate for a given power condition... Unfortunately, fuel flow gauges are often not accurate enough for precise leaning."3. With an EGT gauge, lean until you get peak EGT. Then, either lean more until EGT cools 50 degrees F from peak for best economy (only if the Pilot's Operating Handbook allows it... most don't), or enrich until EGT cools 125 degrees F from peak for best power.Rod implies that using an EGT gauge is far and away the best method. He also seems to concur with the FAA's position that I mentioned in the post above, i.e., lean when operating at or below 75 percent power.KenP.S., I was most happy to see that Bill Rambow has posted the Dash-1 so that you can download it.

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