Jump to content

Recommended Posts

Posted
Any suggestions for improvement are welcome.

Okay........

You night want to add a line about leaning after startup at airport altitudes above 3000' msl. (because of density altitude) This would also include some leaning before takeoff, and not always going full rich for landing. A lot of POH's don't mention this, but you'll find that engine manufactures will, as well as checklist's at high elevation airports.

LA

Posted

LA,

I've never seen that on any checklist I've ever used and I did not find that in the POH or on the checklists from the POH, so I have no reference. If you have info from Cessna on this procedure and the reasons, I'll look at it.

Bill

Posted

Excerpt from X-Plane Corvalis POH, p.45:

"Mixture Settings – In cruise flight and cruise climb, care is needed to ensure that engine

instrument indications are maintained within normal operating ranges. After reaching the

desired altitude and engine temperatures stabilize (usually within five minutes), the mixture

must be adjusted. The engine driven fuel pump references deck pressure and adjusts

mixture automatically for deck pressure and altitude effects. The pilot is responsible to lean

the mixture in cruise for lower fuel flow."

Mixture leaning after startup and before takeoff, is to avoid spark plugs fouling with deposits of byproducts of rich mixture combustion. For takeoff and climb, leave the mixture at full rich and let the altitude-corrected injection do it's job. Corvalis has turbocharged engine, which puts out full power up to 18000ft, so there is no need to lean mixture under that altitude anyway, as engine doesn't get smaller amount of air, as the outside air density drops. So there is no need to restrict fuel inflow to maintain proper fuel to air ratio. Below 18000ft, the mixture lever in Corvalis is only used during cruise, just for increased fuel efficiency in LOP mode (apart from pre-takeoff leaning described above). Only above 18000ft some leaning might be required, depending on circumstances.

Posted

Yes............the fact that it's turbo-charged, hadn't entered my mind. I havn't yet seen what a checklist say's about leaning after engine startup at high altitude airports. This would of course be at idle speeds. At our airport elevation of 4603' msl., it's quite obvious when we don't lean right after startup (no turbo & carb). I also did see in a Corvalis checklist, that it's important to lean in climb, if the turbo charger isn't maintaining a predetermined value below 18000'. I'd have to look that up again, to check the numbers.

LA

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Unfortunately, your content contains terms that we do not allow. Please edit your content to remove the highlighted words below.
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...