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I was going to let this pass and the issue die, but then this second post came through from the tech side. Damn, it irked me once again. Many of the things you say may be right, BUT---You are at full throttle!!! Perhaps, if you have the ability to, you will be leaned out to the correct mixture, but make no doubt about it, you are at full throttle, and making only 50-55% power. Now, the above points are only details. What's bothering me here is the "mushing" being the most efficient. Also, the assertion that you're doing higher airspeed, with less power. I believe that if you're "mushing" (nose high attitude), it takes more power to stay there, and you're creating more wind resistance doing it. Can't be efficient! Certainly, if you have sufficient power to fly high, efficiently, you will make more distance, faster. But if you're fighting to stay up there, I don't believe your assertions. Larry Larry ----- Original Message ----- From: "Ed Burkhead" <[EMAIL PROTECTED]> To: "MAGIC VAC" <[EMAIL PROTECTED]>; "Coupe-Tech" <[email protected]> Sent: Wednesday, January 29, 2003 10:51 AM Subject: RE: [COUPERS-TECH] Re:"0200 conversion" > ----[Please read http://ercoupers.com/disclaimer.htm before following any advice in this forum.]---- > > > > Larry, > > The key thing you're missing is that at high altitude, you're NOT at full > throttle! > > Yes, the engine is spinning at 2400 or 2500 rpm but the air is thin and it > takes less power to spin the prop at that speed. You'll have leaned the > engine and be developing maybe 50% power using 50% or 60% of max fuel flow. > > But, since you're doing it in the high, thin air, the plane is nose high and > the wing is in the nose-high mushing attitude that give it the best > efficiency. AND you're doing this at what turns out to be a high true speed > even though the indicated airspeed is down around 75-80 mph. > > 1. The wing is in its best efficiency mode - mushing > > 2. The engine is throttled back by the leaning process so your fuel flow is > WAY low. > > 3. You're doing this at high true speed but low INDICATED airspeed because > of the thin air. > > 4. The pump into the plane during the 1-hour climb you get back at the end > with a long cruise descent at maybe 2100 or 2200 rpm - getting back maybe > 80% of the climb energy. > > 5. By the time you do the pattern, land, fuel, pay, take off, get back on > track, each fuel stop costs you at least an hour so any fuel stop you can > avoid gives you a 10-30% increase in your overall speed for the entire trip. > Because of the high altitude efficiencies and low fuel flow, you can make > long cross country trips much faster at high altitude as long as you don't > have strong headwinds. (Just don't drink much before flying a long > cross-country leg or you'll have a wet leg. :) ) > > Please don't take my word for it. Read the words of an aeronautical > engineer respected by Fred Weick. Wolfgang Langewiesche's book > _Stick_and_Rudder_ has been in print for 59 years because IT'S REALLY GOOD > and nobody has since said it as well. It's on the shelf in most decent > bookstores. Again, I suggest reading chapter 19, The Working Speeds of an > Airplane and also chapter 20, Thin Air. > > I've tested these words in my Coupe on long cross country trips and it > WORKS - it's NOT something that "Others will prove the > inefficiency of it." That can't be done because it's a well tested and > re-testable scientific and engineering fact. > > Ed Burkhead > http://edburkhead.com/ > [EMAIL PROTECTED] > > -----Original Message----- > From: MAGIC VAC [mailto:[EMAIL PROTECTED] > Sent: Wednesday, January 29, 2003 8:58 AM > To: [EMAIL PROTECTED]; Coupe-Tech > Subject: Re: [COUPERS-TECH] Re:"0200 conversion" > > I know this can be one of those points that will be proven many times over. > Some will prove the efficiency of altitude flying. Others will prove the > inefficiency of it. To each his own here. I will however say that in an > aircraft that is power challenged to begin with, and that (on a good hot > summer day) takes 30 minutes to an hour to reach high altitude, and that > once you reach that altitude you have to maintain full throttle just to stay > there for the next hour or so, high altitude flying isn't practical or > efficient unless you have that strong tail wind. > > Larry > > > ----- Original Message ----- > From: "Ed Burkhead" <[EMAIL PROTECTED]> > To: "MAGIC VAC" <[EMAIL PROTECTED]>; "Coupe-Tech" <[email protected]> > Sent: Tuesday, January 28, 2003 7:02 PM > Subject: RE: [COUPERS-TECH] Re:"0200 conversion" > > > > > > Larry, > > > > You're right in that winds are important. But high altitude IS efficient > > and MUCH more so if you can lean the engine. For cruising, please read > > chapter 19, "The Working Speeds of an Airplane" and chapter 20, "Thin Air" > > in Stick and Rudder by Wolfgang Langewiesche. This is the definitive > > information. > > > > Ed Burkhead > > http://edburkhead.com/ > > [EMAIL PROTECTED] > > > > -----Original Message----- > > From: MAGIC VAC [mailto:[EMAIL PROTECTED] > > Sent: Tuesday, January 28, 2003 12:55 PM > > To: Greg Bullough; [email protected] > > Subject: Re: [COUPERS-TECH] Re:"0200 conversion" > > > > ----[Please read http://ercoupers.com/disclaimer.htm before following any > > advice in this forum.]---- > > > > > > I've never found flying at high altitude to be efficient. Full throttle, > > but getting 55% power, and having to continually be in climb mode just to > > keep you there doesn't equate out to efficient flying. On the other hand, > a > > hell of a tail wind will offset those other problems really fast. > > > > Larry > > > > > > ----- Original Message ----- > > From: "Greg Bullough" <[EMAIL PROTECTED]> > > To: <[email protected]> > > Sent: Tuesday, January 28, 2003 5:44 AM > > Subject: Re: [COUPERS-TECH] Re:"0200 conversion" > > > > > > > ----[Please read http://ercoupers.com/disclaimer.htm before following > any > > advice in this forum.]---- > > > > > > > > > At 11:05 AM 1/27/03 -0800, Maynard Smith wrote: > > > >Cruising up high isn't about the wind, it's about efficiency. > > > > > > When winds aloft at 12000 hit 40 or 45 knots... > > > > > > ....one way or another, it's about the wind. > > > > > > :-) > > > > > > Greg > > > > > > > > > ========================================================================== == > > == > > > To leave this forum go to: http://ercoupers.com/lists.htm > > > > > > > > ========================================================================== == > > == > > To leave this forum go to: http://ercoupers.com/lists.htm > > > > > ========================================================================== == == > To leave this forum go to: http://ercoupers.com/lists.htm > ========================================================================== ==== To leave this forum go to: http://ercoupers.com/lists.htm
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