Re: leaning below 5000

Jose wrote:
There was a discussion in my club about leaning the engine (of our cherokees) below 5000 feet in cruise. This was prompted by the observation in the manual that the engine should be leaned above 5000 feet at all times in cruise, and below 5000 feet at the pilot's discrescion. So, how should the pilot discrede? The old timers seemed to agree that:

1: at low power (say 65% or less) you can't hurt the engine by leaning to peak EGT, but...

2: at high power (above that, including the 75% many like to fly at to go fast) one should only lean if it's cold enough, and that the best thing to do is run full rich if you're in doubt.

This runs counter to my understanding and practice. I lean (50 degrees ROP) in cruise at all altitudes, including the ones where I can pick the leaves off the trees, and I run 70-75% power. Running full rich is just dumping a third of the fuel out the tailpipe.

Either the Warrior II POH or my instructor said to lean above 3000. But I couldn't find it after a quick look at an ARROW POH. Nonetheless, I would follow the manual and if it didn't mention a specific procedure, I wouldn't do it.
.

Relevant Pages

  • Re: (Mini-500)I want to build the most EVIL plane EVER !!!
    ... It had to be re-jetted to produce that much power, and had a horrible TBO and mean time between failures. ... Did you know that by running the engine at one RPM and varying the power setting was better than varying the RPM and power settings? ... They were declared pilot error, but it might be said that no pilot could have saved them in similar situations. ... Already 150 feet high over the witness, ...
    (rec.aviation.homebuilt)
  • leaning below 5000
    ... There was a discussion in my club about leaning the engine below 5000 feet in cruise. ... This was prompted by the observation in the manual that the engine should be leaned above 5000 feet at all times in cruise, and below 5000 feet at the pilot's discrescion. ...
    (rec.aviation.piloting)
  • Re: leaning below 5000
    ... > cherokees) below 5000 feet in cruise. ... > observation in the manual that the engine should be leaned above 5000 ... I don't bother leaning if I'm staying at 2500 feet or lower. ...
    (rec.aviation.piloting)
  • Re: optimal altitude calculations?
    ... If by optimal you mean highest available cruise speed, ... RECOMMENDED continuous power, it's the highest altitude ... at which the engine can develop maximum recommended continuous power. ...
    (rec.aviation.piloting)
  • 2000 Civic EX Cruise Control Issue
    ... small but reputable car lot in the town where I live. ... The engine purred. ... little items, power sliding roof, power door locks, windows, AC, heat, ... test...the cruise control. ...
    (rec.autos.makers.honda)
Loading