172 N Climb Performance

[Roger Long]

Climbing at the speeds given in the Cessna POH for our 172 N are not a
particularly good idea. The nose is so high that the view of any traffic
ahead is pretty well obscured. 80 knots provides visibility sufficient to
see even some aircraft that may be climbing to your altitude. The engine
stays cooler and ground landmarks are easier to track.

Whenever I've been planning a long trip and wanted to identify top of climb
for starting the cruise legs, I've wondered what the numbers were for 80
knots in our plane and at the lower gross weight I usually make my longer
trips at. I finally decided to find out.

The results can be seen here:

http://baldeagleflyingclub.org/Climb80.pdf

This is a planning tool intended to minimize the in flight corrections to
subsequent cruise legs only. Do not rely on it for terrain clearance in the
dark.

I began leaning at 2000 feet and leaned aggressively above 3000. CHT
remained between 330 and 350 for the whole climb.

The final numbers came out fairly close to the POH table, the lighter weight
balancing the margin over optimum climb speed. The POH is close enough for
planning but this table should be easier to use.

Anyway, it was fun to get right up there and watch the VSI gradually sink
down to zero.


--
Roger Long

[Ron Natalie]

"Roger Long" m> wrote in message
...
> Climbing at the speeds given in the Cessna POH for our 172 N are not a
> particularly good idea.

Well, I'd hold the recommended speeds until I was assured of not hitting
any terrain.

Also attentitive to Vy makes a big difference when you takeoff from elevations
higher than what you find in Maine.

[Corky Scott]

On Wed, 10 Sep 2003 00:38:28 GMT, "Roger Long"
m> wrote:

>Climbing at the speeds given in the Cessna POH for our 172 N are not a
>particularly good idea. The nose is so high that the view of any traffic
>ahead is pretty well obscured. 80 knots provides visibility sufficient to
>see even some aircraft that may be climbing to your altitude. The engine
>stays cooler and ground landmarks are easier to track.
>
>Whenever I've been planning a long trip and wanted to identify top of climb
>for starting the cruise legs, I've wondered what the numbers were for 80
>knots in our plane and at the lower gross weight I usually make my longer
>trips at. I finally decided to find out.
>
>The results can be seen here:
>
>http://baldeagleflyingclub.org/Climb80.pdf

Roger, does the N model have 160 hp or 180? With or without
wheelpants?

Thanks, Corky Scott

[Roger Long]

I always hold Vx (except maybe with nervous passengers) until I'm clear of
surrounding obstacles. This also helps keep me in practice for short
fields. Then I generally transition to Vy until pattern altitude or the
fence to reduce the noise footprint and get some wiggle room if something
happens to the engine. After that, I drop the nose to 80 which I might do
sooner at an uncontrolled field with traffic.

Anything between 70 and 85 is "recommended" in the POH. There is only
performance data for 73 and slower.

--
Roger Long
Ron Natalie > wrote in message
m...
>
> "Roger Long" m> wrote
in message
> ...
> > Climbing at the speeds given in the Cessna POH for our 172 N are not a
> > particularly good idea.
>
> Well, I'd hold the recommended speeds until I was assured of not hitting
> any terrain.
>
> Also attentitive to Vy makes a big difference when you takeoff from
elevations
> higher than what you find in Maine.
>
>

[Roger Long]

160 no pants.

--
Roger Long
Corky Scott > wrote in message
...
> On Wed, 10 Sep 2003 00:38:28 GMT, "Roger Long"

[Bob Gardner]

With regard to maintaining Vx, Roger, here is a quote from the Seattle FSDO
"Plane Talk," a quarterly publication put out by the Safety Program Manager.
"Orville" is Kurt Anderson, an NTSB accident investigator with 20 years
experience in investigating accidents in the mountainous northwest:

"Dear Orville:

I read with interest 'Practical Density Altitude" in the first issue of
Plane Talk. Why would you want to hold max rate of climb airspeed to clear
an obstacle when max angle of climb will get you to a higher altitude in
less linear distance"
Don Holliday

Dear Don:
I'm really glad you asked that question. Remember the situation. You were
tasked to take off from a high density altitude airport and the challenge
was to clear a ridge four miles away. Since the ridge is four miles away,
you have room to maneuver. By climbing at best rate, you will get more feet
per minute than by climbing at best angle. This means you will attain an
altitude which permits safe crossing of the ridge sooner (fewer minutes)
than if you had climbed at best angle. As a result, even if you do S turns,
you are on your way with a minimum of Hobbs time.

Additionally, by climbing at best rate, you can see better over the nose,
you get better engine cooling, and you have a large cushion over stall than
if you used best angle. I use best angle ONLY when there is no room to
maneuver.
Orville"

Kurt has demolished a lot of old-wives tales about density altitude in
safety seminars around here. Another of his hot buttons is climbing at the
book airspeed in spite of the fact that it is affected by both weight and
density altitude. He is not in favor of pilots writing airspeeds down on a
card for easy reference unless they take those variables into account.

Just another point of view.

Bob Gardner

"Roger Long" m> wrote in
message ...
> 160 no pants.
>
> --
> Roger Long
> Corky Scott > wrote in message
> ...
> > On Wed, 10 Sep 2003 00:38:28 GMT, "Roger Long"
>
>
>

[Ron Natalie]

"Bob Gardner" > wrote in message news:hEM7b.410400$Ho3.64564@sccrnsc03...

> Kurt has demolished a lot of old-wives tales about density altitude in
> safety seminars around here. Another of his hot buttons is climbing at the
> book airspeed in spite of the fact that it is affected by both weight and
> density altitude. He is not in favor of pilots writing airspeeds down on a
> card for easy reference unless they take those variables into account.

Those of us who learned at places with density altitudes of 8000' or so don't
have so much problem with this. We also don't tend to get AGL and MSL
confused either.