The International Cessna 170 Association

Please excuse my lack of knowledge on this subject , but why do you want to remove your fuel pump? What happens in extreme turbulence and low levels of fuel in the tank . I have 2 fuel pumps , one mechanical and a electrical back up .
Once the GO juice stops flowing it can get very quite and scary. I have read your inquires very carefully and you want to put 170a or b series fuel lines in but 170a/b have a mechanical fuel pump to,feed the engine .I am sure Mr Cessna has thought long and hard about fuel flow in his aircraft .

Not required in the A and B models and I'm routing my fuels as such. Nothing will happen turbulence

I was typing from my iPhone in a cab coming from the airport, sorry about the short answer, let me add.....and there are a number of discussion topics on the matter on this forum that can provide light on your question. The original 170 was the only model 170 with a mechanical fuel, the A and B's don't have fuel pumps, nor is there a requirement to have one on the A and B. The original 170 (1948) fuel lines ran forward from the main tank to the forward doorpost then down to the selector the A and B ran back along the wing root and down the aft door posts, providing a full gravity system. In the day, (1948) although there has been no substantiation from Cessna, they incorporated a fuel pump in the event of a fuel flow interruption, I.E. high angle of attack climb that might result in starvation.....lol high AOA in a 170.....really? Anyway,in my case the fuel pump and associated hardware was removed in the 70's and in order to comply to the type certificate I would need to reinstall all of the associated parts. Since my wings are coming off next week I thought I would reroute the fuel system identical to the A and B. Since it has been done by others on this site...FAA approved, 337 forum. I thought I would pursue this with Transport Canada, TC have approved me to do so and therefore eliminating the requirement to install the original pump, manifold, two fuels, and a fuel pressure gauge. That's the story....I will need to submit the appropriate paperwork but the main thing is they are good with it.

ghostflyer wrote:Please excuse my lack of knowledge on this subject , but why do you want to remove your fuel pump? What happens in extreme turbulence and low levels of fuel in the tank . I have 2 fuel pumps , one mechanical and a electrical back up .
Once the GO juice stops flowing it can get very quite and scary. I have read your inquires very carefully and you want to put 170a or b series fuel lines in but 170a/b have a mechanical fuel pump to,feed the engine .I am sure Mr Cessna has thought long and hard about fuel flow in his aircraft .

Don't believe I have ever seen an "A" or "B", with C-145 or O-300, with a mechanical fuel pump. You have?????

Fuel pumps are for the '48 170s and snobs with big engines.

At least the 0-360 has a pump required, don't know about the I0-360 but I suspect it does.

Oh...body blow... Well.. we actually have two pumps that you other guys don't have

Bruce Fenstermacher wrote:Fuel pumps are for the '48 170s and snobs with big engines.

At least the 0-360 has a pump required, don't know about the I0-360 but I suspect it does.

I kind of figured he had a double pumper based on his response......lol.....

Sorry gents, yes I have a four banger up front with 2 fuel pumps . But not a snob. I talk to ‘anybody ‘

ghostflyer wrote: But not a snob. I talk to ‘anybody ‘

Don't worry, we took note who you hung around with at convention.

Bruce Fenstermacher wrote:

ghostflyer wrote: But not a snob. I talk to ‘anybody ‘

Don't worry, we took note who you hung around with at convention.

GOOD ONE BRUCE!

48RagwingPilot wrote:'48 C170 Owners,

I have received from the FAA via field approval permission to remove the engine-driven fuel pump, check valve and fuel pressure gauge from my '48 C170 and to reroute the fuel lines aft from the main wing tanks down the rear door posts as designed for the A and B models. Thanks to those members who assisted with photos and other information.

I hope to start the project within the next week or so, though it will be tedious and will take several more weeks to complete.

Once the Form 337 is signed and filed with the FAA, I will be glad to donate copies of the paperwork (Form 337, AFM Supplement, placard for Owner's Manual, etc.) to the Association.

I will also have for sale an engine-driven fuel pump, check valve, fuel pressure gauge and associated fuel lines for anyone who would rather restore than alter.

Dave

Greetings folks, new member here and would like to ask if this has been completed and is the paperwork now available? Helping to return a 48 C170 back to flight and this is a modification we would like to do. Can anyone here point me in the right direction?

Thank you for any help and input. Great forum by the way.
Craig Q

We have a Member, Les Partridge, who has converted his ‘48 to the A-model fuel system routing with a DER approval basis. He has written his preliminary article and posted it and the follow-up article is forthcoming.

(See pg 10 of the 3rd Qtr The 170 News)
https://cessna170.org/download/24/170-n ... r-2021.pdf\

The method involved re-routing the fuel lines down the aft doorpost. This ‘48 model is pre-Serial 18573 (with the fuel selector valve on the flap-handle-tunnel….later SNs, post 18574 had the valve located on the firewall operated by a universal-joint-shaft.

Thank you Sir for the reply. The work would be inline with Mr. Partridges as the one we are working is S/N 18100. The interior is out so now would be the best time to do this mod, which to me makes sense in several ways. Also thank you also for the newsletter link, I printed of the article for the conversion. Will join the 170A in appreciation of the help.

Best regards
CraigQ (A&P/IA )

I’ve made a request to another Member who once did this under a Field Approval, asking for a copy of the paperwork to post in the MX Library. (The MX Library is only open to Members of TIC170A…so joining is not only appreciated…it is also beneficial to you to have access to a Huge resource-library on this airplane and also to some others.)

Mr. Partridges’ modification was done via the approval of a DER….and his paperwork will probably only be specific to his serial number….but at least it’s approved data and therefore useful support info. I do know the DER who approved it and am soliciting him to donate his work to the Assoc’n. Don’t hold your breath…as that’s how DERs make their money…. more on this in a follow-up article.)

Previously in this thread, a Member noted plans to install an electric pump instead of the mechanical pump. (He discovered the cam installed did not have a fuel pump lobe. I’m only speculating, but I’d say it should be obvious that engine does not meet the requirements of the certificated engine intended and approved for that airplane.)
It has been convincingly said that only One airplane has had the electric pump approved…(Duane Shockey's airplane)…and that FAA has stated no others will receive that approval. No explanation as to why…but Duane is who passed that info along so he should know.

However, I did once rec’d a call from one of three partners in a ‘48 that had an electric pump installed…seeking info and approval-paperwork from us on that mod. The story had a humorous outcome. When he stated they were based at OKC, I mentioned how lucky they were that a knowledgeable FAA Inspector had not noticed they were flying the airplane illegally.
The bottom line of that inquiry was…. the partner AND BOTH his partners in that airplane were FAA Inspectors based in OKC and had been flying the airplane for years without a basis of approval. They were trying to “fill-in-the-blanks” on their paperwork.
After we explained the situation to them….they attempted to get approval themselves for the electric pump…(they certainly thought they had an avenue of relief)….but gave up. They did the less-expensive thing to do…they bought a pump from Spruce and a check valve from Univair and returned the airplane to original, type-certificated condition. (The pump is not expensive as far as airplane parts go…. the major issue is usually locating a check-valve, but suitable substitutes are out there and have been discussed in these Forums.)

The best solution, IMO, is to return the airplane to original status OR convert the system-routing to the later aft-doorpost standard with approval.

Thanks for the input, that is some 'poetic justice' that the FAA inspectors tried to play the system and got turned down!

An electric pump never made it into discussion when we first started looking into the possibility of eleminating the fuel pump. Just made sense from a safety standpoint, removing a potential fuel leak from close proximity of a hot cylinder. The rerouting of the lines makes sense and does not look to be that tedious. When I ran a search for such a mod the thread here popped up and got my attention. Having a copy of the 337 for reference data would go along way for the approval. Again, thanks for the input and help.

Best
CraigQ

Take a look at 076-2 here.