faster 182?

"Kingfish" wrote:

On Feb 12, 11:38 am, "Dan Luke" wrote:
Got a demo flight in a new Skylane Saturday morning. Very nice airplane.
The G1000 stuff was a bit bewildering at first but otherwise it flew just
like any good 182...

I got a demo ride in the SR22 and Columbia 400 last year. Like you, I
was behind the curve a bit with the Avidyne & G1000 panels (and I fly
an EFIS equipped Pilatus) The capabilities are pretty amazing, once
you read through the (lengthy?) ops manual

The bad news is that we were burning 15.5 GPH to get that speed.

What pwr & mixture setting? EGTs?

23" & 2300 rpm, IIRC. The mixture was 25 deg. ROP. Didn't check the EGTs.
I wish I'd looked at the CHTs.

Dan Luke wrote:

The bad news is that we were burning 15.5 GPH to get that speed.
What pwr & mixture setting? EGTs?

23" & 2300 rpm, IIRC. The mixture was 25 deg. ROP. Didn't check the EGTs.
I wish I'd looked at the CHTs.



Then something is wrong. At 23 squared that is 65% for me(IO-520) and
book flow is 13 gph.

On Feb 12, 2:53 pm, "Dan Luke" wrote:

What pwr & mixture setting? EGTs?

23" & 2300 rpm, IIRC. The mixture was 25 deg. ROP. Didn't check the EGTs.
I wish I'd looked at the CHTs.

Dan, that EGT value looks quite close to the "red box" value that John
Deakin teaches in his engine management course. Here's a link to his
latest article, which covers (or reviews, actually) the EGT/CHT
relationship. Good stuff here..

http://www.avweb.com/news/pelican/194452-1.html

Will wrote:
On Feb 12, 2:53 pm, "Dan Luke" wrote:
What pwr & mixture setting? EGTs?
23" & 2300 rpm, IIRC. The mixture was 25 deg. ROP. Didn't check the EGTs.
I wish I'd looked at the CHTs.

Dan, that EGT value looks quite close to the "red box" value that John
Deakin teaches in his engine management course. Here's a link to his
latest article, which covers (or reviews, actually) the EGT/CHT
relationship. Good stuff here..




I believe he said the 23 squared was 65%. If so he is in the red box.
You want to be richer then 100 ROP or leaner than peak EGT.

"Newps" wrote: Will wrote:
On Feb 12, 2:53 pm, "Dan Luke" wrote:
What pwr & mixture setting? EGTs?
23" & 2300 rpm, IIRC. The mixture was 25 deg. ROP. Didn't check the
EGTs.
I wish I'd looked at the CHTs.

Dan, that EGT value looks quite close to the "red box" value that John
Deakin teaches in his engine management course. Here's a link to his
latest article, which covers (or reviews, actually) the EGT/CHT
relationship. Good stuff here..




I believe he said the 23 squared was 65%. If so he is in the red box. You
want to be richer then 100 ROP or leaner than peak EGT.

According to the boss of the flight school who was giving me the test flight,
that is the setting achieved by using the Garmin G1000's "lean assist"
feature. Also according to him, that's Cessna's SOP for the airplane.


--
Dan
C-172RG at BFM

"Dan Luke" wrote in message


...it trued 147 knots! Non-turbo at 5,500 feet,
10 deg. C OAT, 135 KIAS. ... The bad news is
that we were burning 15.5 GPH to get that speed.

The '67 182K I fly typically trues a good bit slower (~120), but I get much
better fuel burn. I'm typically burning about 12.5 gph at that altitude.

Lessee... 422nm trip @ 147 knots and 15.5 gph = 2.9 hours and $200 (no wind
and 100LL @ $4.50/gal). Same trip @ 120 kt & 12.5 gph = 3.5 hr and $197.

Three dollars to buy 30 minutes? Tempting deal.

My real question is: What power setting were you guys using? I'm usually in
the 65-70% range during cruise.

--
John T
http://sage1solutions.com/blogs/TknoFlyer
Reduce spam. Use Sender Policy Framework: http://openspf.org
____________________

John T wrote:

Three dollars to buy 30 minutes? Tempting deal.

How much does thirty extra minutes on your tach cost you?

If you make those sorts of trips often it adds up to more
maintenance dollars for ADs, more hours on the airframe when
you sell, parts weraing out quicker and getting closer to TBO.

"ktbr" wrote:

Three dollars to buy 30 minutes? Tempting deal.

How much does thirty extra minutes on your tach cost you?


Good point.

In a typical year, I fly 120 hours. Let's say I average 125 kts, that's
15,000 nm. and $5670 of gas @ $4.50/gal.

In a new Skylane, let's say I average 137 kts. That's 15,000 nm. in 109.5
hours. Times gas @ $4.50/gal * 15.5 gph (probably a high number) = $7638. So
I would spend $2K more for gas, but put 10.5 fewer hours on the airplane,
saving eight hundred bucks or so. Net $1200 more to fly the Skylane vs. the
Cutlass RG. Not a bad deal to get the comfort of a 182.

--
Dan
C-172RG at BFM

ktbr wrote:
How much does thirty extra minutes on your tach cost you?

I see your point (adding another $47.50 to my cost above). There's also the
question of "how much is 30 minutes worth to you?"

I'm really wondering if the airframe is the root of the speed difference or
power settings. I haven't parked next to a glass Skylane, so I don't konw
what airframe differences there are. If a different style wheel pant and
cowl would buy me 27 knots, I'm all over it.

On the other hand, if most of this comes from running at a significantly
higher power setting, it doesn't look as appealing. There may also be a
significant difference in powerplant since I'm running a carbureted 230hp
engine and I'd bet he's running an IO-540 (260hp?).

--
John T
http://sage1solutions.com/blogs/TknoFlyer
Reduce spam. Use Sender Policy Framework: http://spf.pobox.com
____________________

"John T" wrote:


...it trued 147 knots! Non-turbo at 5,500 feet,
10 deg. C OAT, 135 KIAS. ... The bad news is
that we were burning 15.5 GPH to get that speed.

The '67 182K I fly typically trues a good bit slower (~120), but I get much
better fuel burn. I'm typically burning about 12.5 gph at that altitude.

Lessee... 422nm trip @ 147 knots and 15.5 gph = 2.9 hours and $200 (no
wind and 100LL @ $4.50/gal). Same trip @ 120 kt & 12.5 gph = 3.5 hr and
$197.

Three dollars to buy 30 minutes? Tempting deal.

That's about the same mileage as Mobile to Houston, a frequent trip of mine.

In my airplane, that's 422nm/135KTAS = 3hrs 7 min. * 10.5gph * $4.50/g=
$148.00.

Hmm...$52 more to save 13 minutes. Not very exciting, but then the Skylane
is a much roomier ride than mine. Comfort counts.


My real question is: What power setting were you guys using? I'm usually in
the 65-70% range during cruise.


I believe it was 75% power, 23 X 2300, 25 deg. ROP.

--
Dan
C-172RG at BFM