Methods for altitude changes

On Apr 7, 11:00 pm, "BT" wrote:
It depends on the situation, but for your specific example, of a 4 to
6 kft climb, I would increase power to max, then pitch (and trim) for
about 90 kts. If I had the mixture leaned, I would go to full rich
first (above 75% power, full rich is required for proper engine
cooling). 90 kts is faster than Vy for my Cherokee (about 72-74 kts),
but is recommended for cruise climb since it results in a lower nose
and better forward visibility, and also better engine cooling.

For Mr Fly Cherokee.

A full rich climb at those altitudes can result in lower performance. If
your POH engine manual dictates full rich above 75% power.. then I cannot
recommend against following that procedure.

However, At 5Kft MSL, on a hot day at full throttle are you really getting
75% power? The Density Altitude.. ohh.. that bugger we live with in the
west.. could be well above 8Kft MSL. 5K Pressure Altitude, 30C, = 7779
Density Altitude

If you find that climbing through 5Kft MSL your RPMs are dropping off, then
lean to max RPM for max performance of the engine and then bump it rich just
a tad.

BT

Yes, you are quite right, density altitude is the key parameter. I
have one of those ancient Cherokees with the pamphlet-style POH.
There's not a lot in there, but they do say full rich over 75% power,
which as I recall, is about 8 kft density altitude at full throttle.

In any event, I've always been a bit conservative when it comes to
leaning, I tend to err on the too-rich side, thinking that I'm helping
the engine.

If you find that climbing through 5Kft MSL your RPMs are dropping off,
then
lean to max RPM for max performance of the engine and then bump it rich
just
a tad.

BT

Yes, you are quite right, density altitude is the key parameter. I
have one of those ancient Cherokees with the pamphlet-style POH.
There's not a lot in there, but they do say full rich over 75% power,
which as I recall, is about 8 kft density altitude at full throttle.

In any event, I've always been a bit conservative when it comes to
leaning, I tend to err on the too-rich side, thinking that I'm helping
the engine.


Mr Cherokee, I understand the problems with 1960-70s style POHs.
There have been some excellent articles in recent aviation magazines on
engine leaning, granted those procedures are best accomplished with added
engine monitoring instruments.

We fly a 1965 Piper Pawnee with 250HP (Lyc O-540) carbureted fixed pitch
configuration in glider towing operations. The airport is 2833MSL. Winter,
not many problems.. summer.. we are leaning as soon as we break ground for
max RPM. The mixture naturally gets richer as we climb after leaning due to
the climb, so we most always end up rich of peak and constantly monitor for
rpm drop with the richer mixture and then lean some more.

The mixture setting reached at altitude is left alone all the way back to
the ground.. lower power settings.. and is also used for ground idle if the
engine will idle without stumbling at that setting. Mixture is enriched for
go around or take off, until the engine gets up to speed and we are climbing
again. Oil temps are monitored, we do not have CHT or EGT gauges. Oil temp
in winter avgs about 180-190F, summer about 210F. We have two oil coolers
and change oil every 50hrs. We average about 250hrs per year on the engine
with weekend only operations.

BT

"BT" wrote in message
...
I merely wanted to speak about full rich full power climbs mentioned by Mr
Cherokee... many POH suggest leaning for max power take offs at high DA
airports... why should the DA airport make any difference than climbing at
high DA altitudes... you still want performance from the engine.. while
keeping the engine safe from overheating

---------remainder snipped-------

At the moment, I can't seem to lay hands on my meager collection of POHs,
but my recollection is that the issue of climbing at high density altitude
was covered indirectly. The aircraft for which I had/have a POH all had
fixed pitch props and, IIRC, all mentioned some density altitude above which
the engine should be leaned to peak rpm when cruising at full throttle.

Inasmuch as the rpm might decrease in a full throttle climbe at best rate of
climb airspeed, it is possible that the recommended minimum altitude for
leaning to peak rpm might be different, and this *may* have been addressed
as well. Basically, it is usually based on 75% power; but I just don't know
enough to assert that both both altitudes are really one and the same.

A call to customer support at the airframe and/or engine manufacturer might
yeild some excellent insight. Of course, if they provide references to
where the information is readily available, please post the reference--I am
sure that I am not the only reader of this NG who's research could use some
help from time to time.

Peter

"Nomen Nescio" wrote in message
...
-----BEGIN PGP SIGNED MESSAGE-----

From:

It depends on the situation, but for your specific example, of a 4 to
6 kft climb, I would increase power to max, then pitch (and trim) for
about 90 kts.

DAMMIT!!
Just when it was starting to look like everyone had wised up and
wouldn't waste time on giving the idiot, simmer, arrogant loser,
douchebag, an answer. You just gotta show up and post this.
I guess Mxsmoron will be here for another month.

DAMN YOU!
WHY?
WHY?
WHY?


I think everyone has wised up a good bit. At least those with any brains.
What we might be seeing here is either sock puppet time, or just MX talking
to himself. There sure seems to be no shortage of gmail accounts in there.

Probably would hurt if more of us, me included, watched more closely for
MX's attempts to cross post his trolls over to .student and .sim and alike
to draw in non pilots for seasoning and sock puppeting.

Just a suggestion to the 95% of the people here I have come to seriously
respect. But I would be happy to hear anyone's thoughts, either here or on
direct.

"Dave" wrote in message
...
Well stated!

Of all the above, 2 knew the answer and posted proper replies....

Others could not wait to trumpet their attitude... (sigh)

..a lot of noise on this NG, and it is not from MX...

Dave


I'd have to disagree. ANY student pilot that didn't know the answer to that
question needs to be looking for a new flight instructor. No one was posting
answers, because they didn't want to feed the troll.

"BT" wrote in message
...
I merely wanted to speak about full rich full power climbs mentioned by Mr
Cherokee... many POH suggest leaning for max power take offs at high DA
airports... why should the DA airport make any difference than climbing at
high DA altitudes... you still want performance from the engine.. while
keeping the engine safe from overheating

I did not intend to answer MX


No problem. Just reframe your question and start a new post.

I have a memory of taking off from Grand Canyon Airport in a Mooney
201 in the summer and the density altitude had to be 9000 feet. I had
to lean at full throttle to get reasonable power in that circumstance.
I was getting pulled around the sky by an IO 360.

I don't remember the POH instructions for those conditions but sure
know how read RPMs and CHTs and treat engines with TLC.





On Apr 8, 7:23 pm, "Maxwell" wrote:
"BT" wrote in message

...

I merely wanted to speak about full rich full power climbs mentioned by Mr
Cherokee... many POH suggest leaning for max power take offs at high DA
airports... why should the DA airport make any difference than climbing at
high DA altitudes... you still want performance from the engine.. while
keeping the engine safe from overheating

I did not intend to answer MX

No problem. Just reframe your question and start a new post.

Maxwell wrote:

I think everyone has wised up a good bit. At least those with any
brains. What we might be seeing here is either sock puppet time, or
just MX talking to himself. There sure seems to be no shortage of
gmail accounts in there.
Probably would hurt if more of us, me included, watched more closely
for MX's attempts to cross post his trolls over to .student and .sim
and alike to draw in non pilots for seasoning and sock puppeting.

Just a suggestion to the 95% of the people here I have come to
seriously respect. But I would be happy to hear anyone's thoughts,
either here or on direct.

Not sure WHY, but it does seem the troll seems to attract the same "serious"
respondents a majority of the time - which only "innocently" starts the fire
that turns into a out of control blaze. Just an observation...

Maxwell wrote:

Just a suggestion to the 95% of the people here I have come to
seriously respect. But I would be happy to hear anyone's thoughts,
either here or on direct.

My thoughts are simply this - stop reading the guy if he bothers you that
much.

Seems like the loudest complainers are the ones anxiously awaiting his next
post in hopes that there will be some minor glitch they can jump on and
point out. Then the ridiculous back and forth ensues where something like
the definition of the word "is" is debated ad nauseum.

Why is that any worse than reading a week's worth of "tower induced go
around" arguments?

BDS

"BDS" wrote in message
...
Maxwell wrote:

Just a suggestion to the 95% of the people here I have come to
seriously respect. But I would be happy to hear anyone's thoughts,
either here or on direct.

My thoughts are simply this - stop reading the guy if he bothers you that
much.

Seems like the loudest complainers are the ones anxiously awaiting his
next
post in hopes that there will be some minor glitch they can jump on and
point out. Then the ridiculous back and forth ensues where something like
the definition of the word "is" is debated ad nauseum.

Why is that any worse than reading a week's worth of "tower induced go
around" arguments?

BDS



The difference in a topic you might not be personally interested in - and a
jackass dedicated to nothing more than discouraging valuable and experienced
contributors, while ****ing out potentally fatal advice to those who may
actually not know the difference.