Airplane under the knife again

[ryoder]

Ammeter seems a bit off reading some current when master off, fuel gauges always read high after tank reseal, transponder loose, prop being removed for Eddie Munster inspection, 80 hrs into control and gear lube interval, pitot heat not seeming to work so having that done. Good thing I am rich

[RobertGary1]

You remove the prop for the EDI?

 

-Robert

[Shadrach]

The only time I've removed my prop for an ECI is when the plane was down for something else and there was no flying it to the shop that does our NDT (poor planning on my part). Otherwise, I fly in, pull the spinner and hang out while he rubs the hub with his wand...I then give him $150 in cash, reassemble the spinner and leave. The whole thing leaves me feeling cheap and dirty.

[bonal]

Should only have to remove the spinner for the ECI

Shadrach you type too fast for my old bones

[MooneyBob]

The only time I've removed my prop for an ECI is when the plane was down for something else and there was no flying it to the shop that does our NDT (poor planning on my part). Otherwise, I fly in, pull the spinner and hang out while he rubs the hub with his wand...I then give him $150 in cash, reassemble the spinner and leave. The whole thing leaves me feeling cheap and dirty.

What's EDI, ECI, NDT? Please fill me in. How many hours is control and gear lube interval?

Thansk

[Yetti]

Eddy Current Inspection = ECI   Non Destructive Testing = NDT   100 hours or a year

[Yetti]

Ammeter seems a bit off reading some current when master off.     It's just resting.  The master kills all power through a solenoid by the battery.

[Shadrach]

What's EDI, ECI, NDT? Please fill me in. How many hours is control and gear lube interval?

Thansk

I think EDI was a typo ( in my non aviation professional world it means Electronic Data Interchange)

ECI = Eddy Current Inspection (AD mandated every 100 hrs on the compact Hartzell hubs)

NDT = Non Destructive Testing - any number of analysis or tests used to evaluate a material without damaging it; to include but not limited to ECI.

At a minimum I lube my gear and controls at every annual. I think it's a 100 hour item but I'll look it up later. Check the MX manual for specs on lubricants application.

[RobertGary1]

Eddy Current Inspection = ECI   Non Destructive Testing = NDT   100 hours or a year

Now it's just 100 hours. No more 1 year. I'd like to think I helped with that. I wrote a letter to he faa inspector noted on the AD and explained that even Harzell's own SB only called for 100 hours.

The annual was a pain. I had to get a ferry permit after annual each year to do it. Signed off "annual except discrepancy" each year.

I usually pay $350 for the ECI. Although last time I sent the prop in to have all the metal shavings thrown by the engine cleaned out. Once the hub is open they only charged me $90.

-Robert

[FloridaMan]

Is it the old 6-pack cluster gauge? If so, I am not sure how the current meter works, but I know that I had a high oil temp reading that made me uncomfortable. I noticed that the needle didn't go all the way to zero with the master off. Pressing firmly on the instrument with my thumb "fixed" the issue. I'm assuming it was a bad ground. A couple months later I bought an EDM-900 as that incident reduced my confidence in the old factory instruments. 

[ryoder]

My prop is old and the guy didn't want to come out to ZPH to do the testing so he told me to bring it in and he would do a prop inspection for me. I work right near the prop shop so we can look at it together. He will do the inspection and let me know if it needs an overhaul. He prop has hundreds of hours since overhaul but that was in 1984. He isn't charging much for the inspection I think it was 100 bucks and my mechanic is charging me a half hour to pull it and a half hour to reinstall it. I might end up with a reseal, overhaul, or clean bill of health. I don't see a new hub going in there to cancel the ad as that costs 3500 I think.

Yes this is the six pack cluster. I like the idea of an engine monitor but can't afford it right now. I want all the old instruments working correctly so if I have to scrounge for a used replacement or send it for repair I'll do that.

[carusoam]

How the old ammeter works...

The ammeter is really a simple volt meter.

It reads the voltage drop across a known resistor (shunt) and reports the value as the current needed to generate that voltage drop.

For this to work,

- All the current being used in the plane must flow through the shunt. (Verify with your ship's POH)

- the resistance of the shunt must be very low or the heat generation would be very large.

- the voltage meter is very sensitive because the voltage drop is very small.

Because of the high sensitivity, even a small oxidation challenge on the electrical ground will cause funky readings.

When the master is off, no electrons can flow through the shunt.

Other things to know...

The location of the shunt (in line with the battery solenoid) is depicted in the electrical diagram that is in your POH (yes, that POH...probably not the AFM)

The POH electrical diagram is interesting. Simplified drawings of the starter, alternator, battery and the ammeter are included. Not just standard symbols... CAD drawings hadn't been invented yet...

Check it out,

[RobertGary1]

Another option is to go with the wet hub. It cancels the ad since any crack would result in a visible oil leak. The prop shop pushed me in this direction during by tear down but I opted to keep the ad.

-Robert

[ryoder]

My mechanic sent the six pack cluster and transponder to an avionics repair guy. The transponder has a plastic tab that locks it in place with the set screw and this tab was worn so it was loose. The fuel level indicators were funny and he had to push on them to get them to move from full. The ammeter was dead. I asked him to do the 100hr lubrication because that was coming up too. These 100 hr things are better to have done at the same time imho.