Leaning at the hold

[modelman]

Operating from a busy airport with charter operators,I often spend a fair bit of time on the ground holding and have got into the habit of leaning the mixture and using the carb heat occasionally.I'll also give another quick power/mag check when lined up.Full rich/carb cold for t/o of course.
Am I paranoid/is this ok for the engine(or not)?

MM

[Chilli Monster]

Standard practice in the U.S.

Density altitude (one of the reasons why we lean) changes from day to day anyway, so the engine is set up to run slightly rich taking in account all possible scenarios. Leaning on the ground therefore makes sense to take into account ambient conditions.

Also helps prevent plug fouling. So - rather than being bad for the engine, it's actually the reverse.

[Dave Gittins]

Absolutely agree. Mid west USA at 6,800 AMSL, leaning is esential as soon as the donk fires. Have another fiddle about at the hold for the power checks to get best smoothest running and than continue to fiddle to get best running in the climb and cruise ... give it a touich of rich in the descent to make sure it still runs OK at circuit height..

Was quite a bit leaned at (ahem) 11,999 feet.

DGG

[172driver]

modelman, absolutely correct procedure :ok:

[Cusco]

Essential if you're in the queue for departure on a summer's Duxford Airshow day............

Safe flying

Cusco;)

[SkyHawk-N]

As has been said above, leaning aggressively for taxying and holding prevents the plugs from fowling. I've been doing it regularly and my plugs never have a build up of deposits on them.

BTW Lycoming recommend that leaning is carried out on their engines for take off when the density altitude is at or above 5,000ft. Turbo charged aircraft must always take off with mixture set to rich.