Leaning for taxi

james rosinski wrote:

Jay Honeck wrote:

What do folks think of this procedure? Can it harm the engine? It's a
Lycoming O320-D2G in a Skyhawk. Thanks in advance.

Can you get the autogas STC for that engine?

No, the D2G engine is higher compression and requires 100 octane. The
upside is you get 10 more horses (160 vs 150).

Petersen has an STC for the Skyhawk with the O-320-D2G.
http://www.autofuelstc.com/autofuels...nAviation.html

George Patterson
If you want to know God's opinion of money, just look at the people
he gives it to.

G.R. Patterson III wrote:

Petersen has an STC for the Skyhawk with the O-320-D2G.
http://www.autofuelstc.com/autofuels...nAviation.html

So they do! Thanks for the pointer. Interesting reading--no ethanol
blends are allowed, and the STC for the D2G engine requires a minimum 91
octane rating. Reading the descriptions of airframes/engines that failed
certification tests due to "failed the vapor lock test" causes some
concern, particularly for the high altitudes I must often fly at.

Since self-serve 100LL is only $2.45 at my home base, the cost savings
of using premium mogas in a Skyhawk would be minimal. But it's nice to
know a simple STC is available in case the unthinkable happens--sources
of 100 octane avgas drying up.

N.B. there are LOTS of engine/airframe combinations mentioned on the web
site.

Jim Rosinski
N3825Q

I lean for taxi, but I did learn one lesson. On one occasion soon after I
started the practice, the engine quit when I applied power to get the wheels
rolling. The passenger wasn't impressed. Now I lean a little less.

-- David Brooks

Despite your passenger's opinion, this is actually best practice since
it prevents you from taking off if you forget to enrich for the
takeoff. I know, I know, that's what checklists are for, but who
among us has never skipped an item on a checklist?

What do folks think of this procedure? Can it harm the engine? It's a
Lycoming O320-D2G in a Skyhawk. Thanks in advance.


We're running an O-360 with an Ellison throttle-body injector... after start
we just pull the mixture nearly all the way out and taxi around like that
(the engine really doesn't like full rich on the ground). It stays there
till runup, and then after landing I usually lean out even before I clear
the runway. The RPM gain is significant when I do this; a full-rich idle
will sit somewhere between 500 and 600, and after leaning it will go to
around 900. With the mixture full out, you can get up to about 1300 RPM
before it starts to sag--this is good for clearing the plugs at the end of a
flight just before shutdown.

Hi,

I have learned from my intructor to lean for taxi, and I regularly do so. I
do so while waiting for take-off as well. One trick that I use (also learned
from my instructor) while waiting, is to place my checklist between throttle
and mixture, that way I don't forget to enrich. And also use my hand to push
everything forward at the same time (throttle, mixture, and with little
finger carb heat).
Usually fly Piper Cherokee 140MOD with 160HP Lycoming engine.

Regards,
Shkumbin, EFHF
PPL(A)-SEP,
Delete DELTA from email to reply.

P.S. Regarding skipping items from checklist: I have done it so in several
occasions, but once I got a bit scared during take-off roll. I skipped the
TRIM to Neutral item, and while on a take-off roll I got some "strange"
behaviour...the nose trim was at quite heavy Nose Up position. It took me
few seconds to realize that. For the moment I thought that the elevator got
somehow jammed. Since than I check the Trim three times at least...and never
skip an item from checklist. But I am still a novice, barely 100hours, so my
discipline will fade with time I guess...

"PaulH" wrote in message
om...

I lean for taxi, but I did learn one lesson. On one occasion soon after
I
started the practice, the engine quit when I applied power to get the
wheels
rolling. The passenger wasn't impressed. Now I lean a little less.

-- David Brooks

Despite your passenger's opinion, this is actually best practice since
it prevents you from taking off if you forget to enrich for the
takeoff. I know, I know, that's what checklists are for, but who
among us has never skipped an item on a checklist?

"PaulH" wrote in message
om...

I lean for taxi, but I did learn one lesson. On one occasion soon after
I
started the practice, the engine quit when I applied power to get the
wheels
rolling. The passenger wasn't impressed. Now I lean a little less.

-- David Brooks

Despite your passenger's opinion, this is actually best practice since
it prevents you from taking off if you forget to enrich for the
takeoff. I know, I know, that's what checklists are for, but who
among us has never skipped an item on a checklist?

Well, sure, it prevents you from taking off because you can only taxi 2 or 3
feet from the parking space, and never get to runup. You then have the wear
on the battery and started all over again.

But I take your point.

-- David Brooks

David,

Well, sure, it prevents you from taking off because you can only taxi 2 or 3
feet from the parking space, and never get to runup.


How? it's real easy to lean to a point where you can taxi without problems but
not advance power to full. if you need full power for taxi, you have a
different set of problems...

--
Thomas Borchert (EDDH)

"Thomas Borchert" wrote in message
...
David,

Well, sure, it prevents you from taking off because you can only taxi 2
or 3
feet from the parking space, and never get to runup.


How? it's real easy to lean to a point where you can taxi without problems
but
not advance power to full. if you need full power for taxi, you have a
different set of problems...

Yes, but my point was it's also real easy to lean to past that point. That
was the scenario - I had leaned too well after startup and the engine
stopped after we had moved a few feet. Of course I can lean enough to allow
taxi, but I don't know of a way of getting the right setting for taxi while
I'm standing still. You have to use the TLAR (That Looks About Right)
method, which takes experience.

-- David Brooks

David,

Well, i found it pretty easy to catch a stumbling engine by ust being
prepared and advancing the mixture a little.

--
Thomas Borchert (EDDH)