Pre-buy inspection C-180

[Scandinaviansky]

We are looking to buy a C-180 to operate it as a floatplane on straight floats.
Any tips and advises what to check for in particular in a pre-buy inspection? It´s our first airplane purchase, so maybe there is somebody out there with some experience to share, especially with 180`s.

Obviously, remaining time on engine and prop is essential as well as a float kit and factory corrosion proof.

There is many different versions of the O-470 (and 520 conversion) with hp ranging from 230-300 ( P-Ponk etc.). Is there any engine version/combination which is known for beeing prone to extra maintenance or failure?

Thanks!

Daniel

e-mail: daniel@scandinavianskies.net

[Big Pistons Forever]

Do you have a particular airplane in mind ? If so then what year is the C 180 and what make/model floats does it have ?

[Scandinaviansky]

There is no particular plane yet, but several different offers out there. We are looking for a plane below 100K USD, it´s gonna be most probably a plane from the 50´s, but not necessarily. As far as the floats are concerned I have good experience with the EDO 2870, in my opinion the better choice for the 180 than the 2960.

[Big Pistons Forever]

Salt or freshwater ?

[Scandinaviansky]

Mostly freshwater

[CamAero]

Have a thorough inspection of the main gearboxes, tailwheel saddle attachment, aft bulkhead & fin rear spar, stab trim-jacks and the hockey sticks.

Pay careful attention under the floor. Make sure the control cables are not rubbing on the fuel lines and that battery cables are not chafing anything.

Check the float V brace for weird repairs, cracks or damage.

Check the flap rollers for excessive wear.

Check the fuselage, wings& horizontal stab for odd wrinkles and oil canning. Outwardly visible anomalies warrant thorough internal investigation.

Make sure that the float kit, including engine mount, V-Brace and main spar rivet pitch mods were carried out IAW the Cessna SB for float installation.

Inspect the carb air box for loose rivets, particularly just below the flange where it bolts to the carb. Check the carb heat flapper door shaft for slop (bad bearings and or stepped wear in the shaft)

Try to snug the bolts on the carb that hold the bowl on. They are often loose, in spite of having lock-tab washers.

Check the engine lord mounts for cracks & deterioration.

Inspect cowl gills for form, fit and function. They are very usually sloppy, cracked, worn out and out of adjustment. Same with engine baffling.

Get under the dash and confirm that the primmer lines are not routed where they are going to chafe, leak and/or short out on electrical items and burn you to death.

Have the AME or AMO who will be carrying out your annual inspections also do your pre-purchase.

Take caution with the old McCauley C66 propeller if it is nearing the 10 yr calendar O/H. Overhaul shops are having a tough time getting usable blade ferules.

Stay away from "J" engines. K model and subsequent are all good, with the U & S O-470s being the ultimate. P-Ponk 520s are now generally pretty good. They suffered teething problems in early years but those have been resolved. They gobble quite a bit of extra gas but improve cruise speed as an offsetting factor. I do not know much about the Norland conversion to the IO-470 but you will be relegated to avgas only with that mod.

2960s are not terrible floats. They are more demanding of good technique to get off the water though. The rigging and small transoms are more aerodynamic than straight, (pre-"A-Model"), 2870s. 2960 rigging is also superior in strength.

Have fun. They're great airplanes.


CA

[Big Pistons Forever]

What Camero said with the following additional points

- The 1950's 180 are the lightest and make the best float planes IMO. The in 1964 Cessna standardized the C 180 and C 185 models. The problem with that is the 180 got the extra beef up for the 185 which adds 100 lbs to the empty weight and is not required on lighter lower powered 180.

- The original factory float kit did not include internal corrosion proofing ( ie treating all the inside skins with zinc cromate) which makes corrosion a real issue on early 180's particularly ones operated off salt water.

- Prior to the 1962 180 E only the small 55-60 gal fuel tanks were only available. If you want the long range tanks you have to go with a later one or spend big bucks for aux tanks. In either case the Cessna bladder tanks are a poor design. They are prone to leaking and are expensive and a PITA to replace. If the job is poorly done wrinkles in the bottom can trap water.

- The cowl on the early models has a million screws and is time consuming and frustrating to get on and off.

- The best prop is an 88 inch 2 blade seaplane prop. The stock 2 blader is too short and causes a noticeable loss in takeoff performance. The 3 blade props look nice but are expensive, heavy, and have even worse performance than the short 2 blader

- Do not buy an airplane with the J engine. It is now virtually unsupprtable. The K is supportable but does not have a great rep. The L is better and the last version, the R is the best. In any case while the O 470 is a good engine its major weakness is the fact that the cylinders will not tolerate high CHT's. Good baffles and a properly fitting cowling with correctly rigged cowl flaps is an absolute must to keep the engine temps down. The AME doing the prebuy should be especially looking for signs the engine was overheated.

- My 1957 180 had 2870's. I thought it was a good combination. I do not think 2960's give you any advantage on the early light 180's and are heavier. I don't like CAP 3000's very much. They are great for into wind operations in heavy chop but are terrible on glassy water and very demanding in a cross wind.

- Be wary of carb ice. The engine will develop carb ice very rapidly in the worst case conditions.

[mmartin1872]

Look for corrosion at the rear seat belt middle attach bracket under the floor.. There is a piece of steel riveted to aluminum there that corrodes.
Where the rear float fittings bolt to the airframe look at the fuselage frame. Hard landings and they are cracked. Not a hard form block to make and bang out a repair but it is a spot that seems to get beat up.
Where the tail stinger sits in the bulkhead seems to corrode really bad there.
Look at yhe elevator and rudder torque tubes (up inside the elevator and rudder) look for corrosion.
I've seen the gear leg fittings cracked and massively corroded.
Look at the flap closeout skins. They are always smoking and the only real way to fix them is to replace them. People try to resqueeze those rivets and they upsise them but the p problem always Comess back. You replace the 2 skins and the aluminum stiffener that is in between the 2 skins.

If the flaps have been let out over the flap extension speed you'll find cracked brackets that attach the flap well skins to the flap tracks.

Look at the trim Jack screws. See if the boot is torn, galling on the threads etc.

I've found a lot of float planes that the tail surfaces were out of rig so that the elevator and rudder could actually hit each other. I have a feeling that it may get done to give more rudder knowing that you would probably be never giving full rudder and full elevator deflection whole on floats (but i don't know if that is true it just seems likea logical reason to me.)

I really suggest making sure you geta 180 expert in your area to check out the plane. I've seen the wrong wings installed wrong horizontal stabilizers. Etc.

[CamAero]

This page is great resource for changes through the model years:

http://www.skywagons.com/modelchgsweb.html

[Scandinaviansky]

BPF/CamAero, thanks a lot for all this great and useful info!

Just to confirm, TBO for the O-470 is 2000 hrs? Is there any calendar time limit for private operations?

Concerning the prop ( Mc Cauley 88in) the calender time limit is 10 years?
What about the flight time limit/TBO? 1800 hrs?

If the airplane has no factory corrosion proof, but was operated on fresh water and is free of corrosion, would you take the risk to buy and operate it as a seaplane in Alaska?
Or would you say that a corrosion proofing is mandatory for a seaplane in any case?

Would you recommend to do a cylinder compression test? Or is this a standard check item in any pre-buy inspection?

I have seen very nice cockpit front panels for the early 1950 models cockpit design ( see link below). Do you have any clue where to get one of these to replace a worn out old black one?

http://www.barnstormers.com/listing_ima ... 507d3f8ec2

[CamAero]

BPF/CamAero, thanks a lot for all this great and useful info!

Just to confirm, TBO for the O-470 is 2000 hrs? Is there any calendar time limit for private operations?

Here is the link to TCM's TBOs. There is variation between models of O-470. None are as high as 2000 hours. http://www.tcmlink.com/pdf2/sil98-9c.pdf

TCM has a Service Bulletin which requires O/H at 12 years calendar time.

However, that said; in Canada, there is no hard time for piston engines on privately operated aircraft. See CAR 625 Appendix C, 7(d) {note} https://www.tc.gc.ca/eng/civilaviation/ ... c-2460.htm

Concerning the prop ( Mc Cauley 88in) the calender time limit is 10 years?
What about the flight time limit/TBO? 1800 hrs?

All constant speed propellers operating in Canada must be overhauled every ten years calendar time or at the air-time interval recommended by the manufacturer. See CAR 625 Appendix C 5 (a) https://www.tc.gc.ca/eng/civilaviation/ ... c-2460.htm

If the airplane has no factory corrosion proof, but was operated on fresh water and is free of corrosion, would you take the risk to buy and operate it as a seaplane in Alaska?
Or would you say that a corrosion proofing is mandatory for a seaplane in any case?

In the above case, go through the airplane and clean and vacuum everywhere possible, (under the floor, behind wall panels and insulation and in behind the aft bulkhead, back to the tail-cone). Soak all possible internals with ACF 50 and remove and re-install all of the float hardware with Mastinox applied. You shouldn't suffer any major problems, particularly if you take the normal precautions of rinsing with fresh water whenever possible, installing float zincs, etc.

Would you recommend to do a cylinder compression test? Or is this a standard check item in any pre-buy inspection?

You would never buy an airplane without doing a cylinder differential compression test. Also, your pre-purchase might as well also be an Annual Inspection. The cyl compressions are required there anyhow.

I have seen very nice cockpit front panels for the early 1950 models cockpit design ( see link below). Do you have any clue where to get one of these to replace a worn out old black one?

[url]http://www.barnstormers.com/listing_ima ... 507d3f8ec2

I am pretty sure that the panel pictured is just a stock old metal panel from about pre-'57 when they switched to plastic. It's just been stripped and repainted. I agree. It looks super-sharp.

[Scandinaviansky]

Great! Thanks!

Daniel

[Big Pistons Forever]

Would you recommend to do a cylinder compression test? Or is this a standard check item in any pre-buy inspection?

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If I found an aircraft I was serious about I would have the following engine checks performed.

1) compression test
2) oil filter cut open and examined or if not fitted with an oil filter have the oil screen pulled and checked
3) have the inside of the cylinders examined with a boro scope looking for corrosion pitting and the exhaust valves examined for heat distress.

Depending on how steps 1 to 3 went I would also consider having at least 1 lifter and cam lobe visually inspected.

however before paying for any inspection find an AME familiar with 180's and have the seller scan and e-mail the last 5 years worth of tech log entries to that AME. Pay him to have a good look at what is there .

[Scandinaviansky]

Thats really great advices! Seems like we have a good checklist what to do. Thanks!