0-300-B engine

[jwlynnav]

I’m looking at a 56 C170B with the Continental 0-300-B engine. What all do I need to see in paperwork/logbooks for it to be legal?

[n2582d]

The conservative answer is it should either have the engine installation approved by a field approval or STC SA01837SE available from our Association. The O-300B is basically the same engine as its predecessor, the C-145-2H, which is an approved engine on the TCDS. As you can see in this Table of Cessna Production Aircraft there were C-170A and C-170B aircraft that left the factory with the C-145-2H engines.

Click to enlarge

I ended up buying the STC for my O-300B powered C-170B but wouldn't have too much heartburn annualling such a plane without the STC.

[Bruce Fenstermacher]

FYI, we have strong evidence that Cessna installed 0-300B models in '55 and then perhaps '56 without ever having it approved on the TCDS. They likely considered the C-145-2H and the 0-300B one in the same. So it would not surprise me in the least if you told me this 0-300B was the original engine on the aircraft.

Fast forward to todays world, that 0-300B is not legal without as Gary pointed out, an approved 337 which you likely won't find or the Associations STC which a TIC170A member can purchase for $75 ($150 for non-members)

[jwlynnav]

Thanks to both of you for the reply. So if I purchase this 170 I will purchase the STC before hand. Again thanks for the information.

[jwlynnav]

The plane I’m considering is 56 model with the 0-300-B engine. He says it’s the original engine. So my understanding per this post is I will still need the STC. Is that all or will there need to be 337 or mechanic sign off?
Thanks

[GAHorn]

It’s a shame that Cessna can’t be easily contacted for written approval…but if the logs are complete…and the same engine is in it that left the factory… I’d have ZERO problem with that issue. (But I’d contact my FSDO and ask them to look into it and give me written ruling on it.)

Then come back and give the Assoc’n a copy.

[n2582d]

Does he have the original equipment list showing that the original engine serial number matches what is on the aircraft? If it matches, there is no need for an STC.

Here's a screenshot of the equipment list I got from Cessna.

Click to enlarge

[jwlynnav]

Thank you both for answering. I’ll keep you posted. I’m waiting to hear back from seller.
Again thank you

[jwlynnav]

It’s the original engine and what he has sent me is a pic of engine logbook showing this 0-300B engine and matching serial number installed when it left factory. So it should be good?? Right??

[Bruce Fenstermacher]

Given the evidence you have should you buy this plane, I'd certainly not consider it an issue at all. I doubt you would find any anyone but a stubborn Fed which nothing else to do who thinks different. However, it is also nice to know that should you buy this plane, and the world comes down on you, it can be fixed very easily and cheaply. This is not the case with many other discovered modifications documented or otherwise, discovered from the past.

If I was to buy this plane, I'd be just as stubborn and run around telling everyone who would listen how special my airplane was cause Cessna installed an illegal engine.

Should you pursue the STC, like all STCs a 337 must be executed and this must be signed by an A&P IA. In the case of the Associations engine STCs the IA would be attesting the engine was installed per the STC instructions which is nothing more than Cessna instructions.

[voorheesh]

I agree with Bruce that, given the engine is properly documented as original, this is a total non issue. There is no reason to get the FAA involved and it is highly unlikely that a FSDO would bless this engine in writing. Why? Because it is already justified based on valid aircraft records. Why look for a problem when there is no problem? IMO, pilots and mechanics spend way too much time worrying about what the FAA might think or do. For the most part, FAA delegates questions like this to maintenance personnel with inspection authorization. I suggest the time to get the FAA involved would be when a disagreement comes up with an IA and you are sure your position is the correct one. Otherwise, enjoy the airplane!
(Disclaimer: I used to work for the FAA and know they can be difficult. That is why I recommend avoiding inquiries unless absolutely necessary)

[jwlynnav]

Again thank you both. I’ve owned other planes and been in other groups but the 170 organization (you guys) are definitely the best.
Again thanks
JW

[n2582d]

JW,
Out of curiosity, what propeller did that 170 originally have? It should have been a Koppers Aeromatic F200-H/00-74E or a McCauley two-position prop.

[Bruce Fenstermacher]

JW, I just looked closely at the equipment list and note that Cessna called it a C-145-2. I assume you have seen the data plate with the serial number written on the equipment list and the plate says it is a 0-300-B.

This being the case there are two interesting (to me) points. 1. Cessna obviously considered the C-145 and the 0-300 one in the same. If the FAA took their lead, things would be SO MUCH simpler. 2. Cessna got it wrong twice. The equipment list should have had C-145-2H, the 0-300- B equivalent.

Should you buy this plane, it would be really great if you would document this with better pictures of the equipment list and the data plate and send them to the Association for our archives.

[jwlynnav]

I haven’t been to the aircraft yet, trying to go this coming week. The picture that was sent is the engine logbook. On the engine description page.
Continental 0-300-B serial number 11027-B-r-B (serial number is blurry so not sure if numbers/letters are correct.145HP 2700RPM. I was told matches engine data plate.

Propeller McCauley, no blade design number or blade serial number, 53 pitch 76 diameter, hub design 1A170.