Airplane Flight Manual

How to keep the Cessna 170 flying and airworthy.

Moderators: GAHorn, Karl Towle, Bruce Fenstermacher

Post Reply
User avatar
IP076
Posts: 89
Joined: Wed Aug 21, 2019 7:37 pm

Airplane Flight Manual

Post by IP076 »

Hey all,

I have this single laminated page that's been kept in my glove box since I bought the airplane:
AFM Excerpt
AFM Excerpt
I'm curious if someone could verify its authenticity, or its source if it is part of a larger document. I've got a copy of the "owner's manual" but it is also lacking some information, like instrument markings for maximum oil temperature and pressure.

Also, I'm working with EI to get a CGR-30P set up and would like to confirm the marking numbers off this sheet. The engine is a C-145-2H.

Oil Temperature - Maximum: 225 degrees (red line)
Oil Pressure - Normal range: 30-40 psi (green range)
Oil Pressure - Maximum: 50 psi (red line)

Thanks for the help!

Here's a nice pic from Sunday at Slate Creek, ID just because:
Slate Creek
Slate Creek
User avatar
Bruce Fenstermacher
Posts: 10313
Joined: Tue Apr 23, 2002 11:24 am

Re: Airplane Flight Manual

Post by Bruce Fenstermacher »

If you look at the original AFMs here, viewtopic.php?f=31&t=9024#p80111, you will see yours is not an original. Though it may have all the same words.
CAUTION - My forum posts may be worth what you paid for them!

Bruce Fenstermacher, Past President, TIC170A
Email: brucefenster at gmail.com
User avatar
ghostflyer
Posts: 1390
Joined: Mon Apr 21, 2008 3:06 am

Re: Airplane Flight Manual

Post by ghostflyer »

That’s one very pretty aircraft ,great surrounding country and being blue it must be faster than those red ones .
User avatar
Bruce Fenstermacher
Posts: 10313
Joined: Tue Apr 23, 2002 11:24 am

Re: Airplane Flight Manual

Post by Bruce Fenstermacher »

Looking at your airplane, it appears to be a B model. The B model AFM in our library dated 1950 would be a more appropriate AFM to be carrying in the aircraft.

As for your limits marks as they came from Cessna, you can see they are not listed anyplace. Actual limits are spread thru out various documents some approved such as the engine TC E-253 and others such as the Owners Manual, not.

Looking at your numbers questioned, oil temp gauges did come with a red line at 225° though according to the latest TCM Operators Manual if using straight 50w oil max temp is 240°. Oil pressure normal range is 30-40 and I recall this to be a green range. I do not recall 50 psi being a red line on the original gauge. We've had a discussion about this with input from members perhaps you could find that. Also study any instrument pictures you can find.
CAUTION - My forum posts may be worth what you paid for them!

Bruce Fenstermacher, Past President, TIC170A
Email: brucefenster at gmail.com
User avatar
IP076
Posts: 89
Joined: Wed Aug 21, 2019 7:37 pm

Re: Airplane Flight Manual

Post by IP076 »

Thanks guys!

Bruce, I’ve noticed just that, seem to be spread out.

My current oil pressure gauge is only marked with the green range. There is no red line marked on either the pressure or temperature gauge.

When I get home from this work rotation, I think I’m going to print out the AFM at the link you sent, laminate it, and carry it with.

Thanks for the nice comments, I’m enjoying the airplane so far. It started life red, and somewhere along the line it was painted blue...someone must have been looking for some extra speed!!!!
User avatar
GAHorn
Posts: 20967
Joined: Fri Apr 12, 2002 8:45 pm

Re: Airplane Flight Manual

Post by GAHorn »

The oil pressure gauge should have one red-line.... at the minimum 5 psi.

How I remember that (since I’ve never seen a gauge-so marked: The FSDO Inspector Mr Anderson was the guest speaker whom I had invited to speak at the Benton Harbor MI convention. By pre-arrangement, I had asked him to review all the 170 on the flight-line as a courtesy-without-penalty.... and as a private joke, pretending not to know it was the Parts and Mx Advisor to the Assocn’n, personal airplane.... he confiscated MY airplanes’ Airworthiness Certificate for having no 5 psi redline on my oil pressure gauge. Everyone got a good laugh at my supposed expense.

He was supposed to return it to me privately.... but as things should happen..... Mr. Anderson forgot to return it to me! 8O

(It was located before the next flight however, stored inside the speakers podium.) Whew! :mrgreen:
'53 B-model N146YS SN:25713
50th Anniversary of Flight Model. Winner-Best Original 170B, 100th Anniversary of Flight Convention.
An originality nut (mostly) for the right reasons. ;)
User avatar
cessna170bdriver
Posts: 4059
Joined: Mon Apr 22, 2002 5:13 pm

Re: Airplane Flight Manual

Post by cessna170bdriver »

George, Rick Anderson bases his 182 on the same airport where I live. Now that I’ve gotten to know him a bit better, I think he may not have “forgotten” to return your airworthiness certificate. :lol:
Miles

“I envy no man that knows more than myself, but pity them that know less.”
— Thomas Browne
User avatar
n2582d
Posts: 2808
Joined: Mon Apr 29, 2002 4:58 am

Re: Airplane Flight Manual

Post by n2582d »

Bruce Fenstermacher wrote:As for your limits marks as they came from Cessna, you can see they are not listed anyplace. Actual limits are spread thru out various documents some approved such as the engine TC E-253 and others such as the Owners Manual, not.
GAHorn wrote:The oil pressure gauge should have one red-line.... at the minimum 5 psi.
The oil pressure gauge in the 170/170A/170B, according to the IPC's is p/n 0411016-2. I'm quite certain this corresponds to Rochester p/n 2525-5-168. As you can see the original markings had two red lines, one at 5 psi and one at 50 psi. These numbers match the AFM.
Rochester p/n 2525-5-168
Rochester p/n 2525-5-168
But Bruce is correct in that one can find a wide variety of limits sorting through various Cessna, FAA, and Continental publishings. The '69-'76 C-172 Service Manual lists the following for the O-300D engine:
Screen Shot 2021-04-14 at 9.26.44 PM.png
Here are some other places that list C-145/O-300 oil pressures:
Click to Enlarge
Click to Enlarge
Gary
User avatar
GAHorn
Posts: 20967
Joined: Fri Apr 12, 2002 8:45 pm

Re: Airplane Flight Manual

Post by GAHorn »

My oil pressure at 200 hours TSOH ran at 55 psi. I first confirmed the accuracy of my gauge, then I contacted TCM and talked to their Field Rep in CO, a Mr. Thompson, who informed me the C-145/O-300 early lifters were risky above 45-50 therefore the early limitation, but that all engines built/ovhl’d since 1960 used lifters with upper limits of 55 therefor my indications were no problem. After 1000 hours TSOH fully warmed up my pressure runs at 50 psi hot, cruise RPM and 35 at hot idle RPM. (Here in hot, Texas summers, my oil temp commonly runs around 185-210 at cruise.)

We’ve seen this on the upper oil temp as well, with the Aircraft TCDS and gauges stipulating 225F, but the Engine Type Cert allowing 240F using straight SAE 50 wt oil as already mentioned. (Keep in-mind that early-on this engine was recommended to be operated on SAE 30 or SAE40.) The engine overhaul manual X30013, pg 35, specifies the Test Run Operating Limits oil pressure at 35-50 psi with normal oil temps 175-185F, and the min oil press 5 psi oil temps at 140-150F.
So.... the early limitations issued by Cessna do not match what the engine mfr’r specify, nor do the Cessna specified instrument markings.... inspectors need to see the Aircraft TCDS and AFM compliance on Inst. Markings.... but pilot knowledge of the allowable limit-differences should be applied to our operations. In every case, having calibrated instruments are important. Lot’s of unnecessary concerns, work, and expenses are avoided that way.
'53 B-model N146YS SN:25713
50th Anniversary of Flight Model. Winner-Best Original 170B, 100th Anniversary of Flight Convention.
An originality nut (mostly) for the right reasons. ;)
User avatar
dstates
Posts: 472
Joined: Sun Jun 30, 2019 5:50 pm

Re: Airplane Flight Manual

Post by dstates »

Although faded, you can see my oil pressure gage had red lines at 5 and 50 psi. Now they are a light pink.
DAD88256-C594-496E-A0A0-C06017D9BC4F.jpeg
N1235D - 1951 170A - SN: 20118
User avatar
IP076
Posts: 89
Joined: Wed Aug 21, 2019 7:37 pm

Re: Airplane Flight Manual

Post by IP076 »

Thanks for the continued discussion, all good points.

I think as George mentioned, probably best to plan instrument markings per the manufacturer of the airplane, and then have a knowledge of the the engine manufacturer limits also.
User avatar
cessna170bdriver
Posts: 4059
Joined: Mon Apr 22, 2002 5:13 pm

Re: Airplane Flight Manual

Post by cessna170bdriver »

dstates wrote:Although faded, you can see my oil pressure gage had red lines at 5 and 50 psi. Now they are a light pink.
Doug, mine looks about like yours, and has since I bought the airplane in 1982. When I overhauled the engine in 2006, with a new spring for the oil pressure relief valve and new bearings, the pressure indicated 55psi in cruise, and till does at oil reps below 190 or so. I was a bit concerned with that being over the marked redline, but was assured that is what Continental intended with the current issue spring.
Miles

“I envy no man that knows more than myself, but pity them that know less.”
— Thomas Browne
User avatar
lowNslow
Posts: 1530
Joined: Mon Apr 22, 2002 4:20 pm

Re: Airplane Flight Manual

Post by lowNslow »

cessna170bdriver wrote:
dstates wrote:Although faded, you can see my oil pressure gage had red lines at 5 and 50 psi. Now they are a light pink.
Doug, mine looks about like yours, and has since I bought the airplane in 1982. When I overhauled the engine in 2006, with a new spring for the oil pressure relief valve and new bearings, the pressure indicated 55psi in cruise, and till does at oil reps below 190 or so. I was a bit concerned with that being over the marked redline, but was assured that is what Continental intended with the current issue spring.
Miles, same here. After overhaul I indicated 55psi, I was advised by the overhaul shop that the 55psi pressure relief spring was the only one available for these engines from Continental.
Karl
'53 170B N3158B SN:25400
ASW-20BL
Post Reply