generator to alternator

[Brad Brady]

Ole Pokey,
Are you just whacking that hornet's nest? You Know as well as anyone that when you get an AP/APIA sing off it's good to go!! After all it's his butt....The FAA wants traceability, (PMA), which you will not find in an auto store......I would never use auto parts on an alt. or regulator, simply because of the type of windings and covering used on AC parts, as opposed to auto. Starter.....I don't know..... i'm sure i'll get some flack about this, but the starter is at ground level, the same as a 1950 IH tractor (?)..... are you making a log entry?.....then you need an AP and traceability....if not, you can do it your self, and down the road let the buyer beware......NOT A GOOD WAY TO DO BUSINESS.

[GAHorn]

I hold to my opinion on the conversion. If the field approval was based upon the Cessna drawings, which specified different materials in the installation, then the approval was invalidated. The only way that would not be the case would be if the installation description of the 337 specified that the installation deviated from the drawings and listed those deviations. (Perhaps that's what you meant to say in your earlier description?)

I also still have a problem with having a regulator capable of asking for more alternator output than the ship's wiring is capable of handling, regardless of the size of the C.B. That violates good procedure. The correct way to do this would be to install wire of a suitable size to the main buss, or to install a regulator that would limit alternator output to that which the existing wire was capable of handling. My opinion.

Frank, the answer to your question is: Only FAA approved parts and procedures may be utilized to repair those accessories. While the bearings/brushes in the automotive units may fit the aircraft units, they were not approved for that purpose. Also, it's doubtful the auto-electric shop had the required manuals, manufacturer's service bulletins, AD notes, etc. etc. to accomplish the repair in accordance with the rule, and it's very likely neither the workman nor the shop had the FAA repairman's/repair-station certificate necessary to accomplish the work legally.

This may or may not have anything to do with actual serviceability of the units after the repairs, but it does address the legality of them.

You could order the necessary parts (genuine aviation brushes/bearings/etc.) from an aviation supplier (such as El Reno) and your A&P could supervise you or your auto-mechanic in making those replacements and the re-installation. He could then record the work in the aircraft records and it would be legal.

Is the starter less important than the generator/alternator? After all, if you can't start it, how can it be hazardous? I used to think so, but I've since changed my mind. If that starter comes apart in flight because it was improperly torqued during reassembly, or an internal short or mal-adjustment is made by a non-qualified person that results in a problem after an attempted inflight re-start.... then it could prove problematical. Is that likely? Maybe not. Until stuff happens you'll get away with it. But I believe I'm giving you the correct answer to your question. (You ARE in the insurance bidness, right?)

[170C]

Brad & George, of course both of you are correct IMHO regarding the legality of having an auto-electric shop do work on the accessories. I am no expert on the parts, but the brushes I purchased from Sacramento Air Ranch for my starter, while no doubt PMA'd, are most likely the same as the ones I could get a the local NAPA store and again probably the same part number, but I agree they would not be legal even if identical in every way. Yea Brad, I was poking that hornet's nest with what I think was a pretty long stick, hoping the hornets would just get a bit riled up, but not sting

[GAHorn]

I'll bet they are not the same part number. Aviation parts are usually identified by special numbers. Example: When my 206 Prestolite starter gave up on a Saturday morning (that I really needed to fly) I went to the local auto-electric shop to buy brushes, and the owner instantly pointed to the "A" stamped on the worn out brush lead and told me to go elsewhere, that he would not service or sell parts for aircraft starters. He knew.

(I had to drive all the way to Austin before I found an old German who told me that as long as it "Vas und "air-boat" motoren" installation, that he'd do it.)

[N4281V]

All I will say is -

Good Luck getting anyone in a FSDO to sign off a field approval now days...

[aaronhunley]

I have come up to the same question. Rebuild generator or switch to an alternator?

I have the O-300-C in my 170 so I’m assuming I have the dampened crank, and also the previous owner told me it has the 35amp generator.

Normally I would have rebuilt the generator and gone on, but I recently got the original landing light installed so the electrical power is low during night approaches and taxing with the nav lights on. I also want to get rid of the little oil leak it has.

Is there any good alternator STC besides the Jasco? I'm not fond of the 250 hour ICA that it has. If I were to put an alternator on would I have to install a circuit breaker?
Thanks
Aaron

[GAHorn]

An alternator conversion does nothing about the oil-seal situation. The alterator will have the same propensity for oil leaks due to defective oil seal installations.

The capacity of the generator, in-flight, will keep up with any otherwise-approved electrical load, but it is certainly likely that during low-idle prolonged taxy operations the battery will largely have to provide most support for electrical loads. Since this is generally of short-duration, it doesn't likely pose an overwhelming or absolute need for an alternator (in my personal opinion, of course.) Batteries are very capable of keeping things going for the taxi out for takeoff. (And I should know, as my taxi lights are dual and pull about 120 watts. I have only a 35 amp gen.)

Therefore, I would weigh-in ...in favor of keeping the generator, which can be rebuilt for less than $200 while an alternator conversion will cost between $800 - $1000 or more. I can taxy a long time for that kind of money.

[Brad Brady]

I have come up to the same question. Rebuild generator or switch to an alternator?

I have the O-300-C in my 170 so I’m assuming I have the dampened crank, and also the previous owner told me it has the 35amp generator.

Normally I would have rebuilt the generator and gone on, but I recently got the original landing light installed so the electrical power is low during night approaches and taxing with the nav lights on. I also want to get rid of the little oil leak it has.

Is there any good alternator STC besides the Jasco? I'm not fond of the 250 hour ICA that it has. If I were to put an alternator on would I have to install a circuit breaker?
Thanks
Aaron

Arron,
I don't know of any other Alt's but Jasco, that have an stc for our engines....as for the 250 ICA I don't think that is a problem....If I remember right, that's just an Ap sing off....We run Jasco's on all the piston Ag, aircraft we have.....I have had problems with the Alt's....But Jasco was there in less than a day to fix the problem... And , Yes you need to rewire to, at least the new circuit breaker you need for the new instillation..Brad

[GAHorn]

You would have to comply with the installation instructions contained in the STC. If that requires a new circuit breaker.... then it requires a new circuit breaker. (And if it does....then it also likely requires new wiring.)

[blueldr]

Doesn't the TIC170A headquarters have data for instalation of the Cessna (Ford) alternator? I have acquired them from he salvage yards

[GAHorn]

Doesn't the TIC170A headquarters have data for instalation of the Cessna (Ford) alternator? I have acquired them from he salvage yards

See the Members Issues thread on SK172-22.

[15A]

When my generator needed repair, I chose to replace it along with a solid state voltage regulator. I'm very satisfied with that choice. My minor oil leak was eliminated, radio noise disappeared, and I've flown at night with everything on without any issues. All for less money than a conversion. Your decision should be based on the type of flying you do.

[blueldr]

A local fellow here in town runs an automotive electrical shop where he also overhauls starters, generators, and alternators. I asked him if he could do my Cessna (Ford) alternator. He said he would be delighted to do the job, but he cannot buy the diode sets. They will not sell him the aeronautical diode sets, which are heavier duty than automotive, without an FAA repair station authorization.

[johneeb]

Something new has come over the Horizon. According to EAA Sport Aviation magazine (March page 24) Plane-Power has received STC/PMA approval for it's new Gear Driven Generator to Alternator Conversion Kit. Plane-Power's literature says they have approval for all three models of 170 and makes no reference to dampened or non-dampened cranks. Pricey compared to overhauling the original generator ($712.00 at Spruce) however the kit includes a regulator, alternator out light, and some wiring.
http://www.plane-power.com/Fit_Guide.htm


As an interesting aside Plane-Powers installation instructions http://www.plane-power.com/images/11-1001A_REV-A.pdf

12. If original output circuit breaker is rated at less than 50-amps and you wish to be able to utilize the increased capacity of
the alternator, remove the breaker and replace with suitable breaker up to 50-amp maximum size (Refer to AC43.13-1B,
Chapter 11, Section 4, Paragraphs 11-47 through 11-52 for additional information). Ensure wire size from alternator
output terminal to output circuit breaker and from output circuit breaker to bus is rated for more than the size of
breaker installed (Refer to AC43.13-1B, Chapter 11, Section 5, Table 11-9 for additional information). Note: If
aircraft has been equipped with an Amp Meter, ensure that it is of adequate size to handle the increased output
capability before increasing the output wire and breaker.

do not require a cercuit breaker that matches the rated output of the alternator.