Sb-208B

[Tommy]

Hi everyone!

Taking my plane 1981 M20J in for SB-208B as part of annual, I have about a week to do it and will really appreciate any advice! Specifically

1) tips and tricks in getting off the interior and put them back on

2) good insulation material to use? I live in Australia with average temp ranges from 18-36C.

3) worth while put run a couple of RG400 for ADS-B installation? What about GPS antenna, I have a very old one Garmin 100 (!) and am thinking about going to GTN, is it too ambitious?

4) best rust prevention treatment to the tubular structure?

5) is this SB an annual thing? Or once every so many years?

Thanks every one!

 

Kind regards

Tom

 

[Mooneymite]

For a C model:   TIME OF COM PLI ANCE: Part A At the next an nual or 100 Hr. In spec tion, which ever comes first, and only an nu ally there af ter. Part B For Part B effec tivity aircraft in ex cess of 18 months from date of manuonly fac ture and annually thereafter.

However, these are recommendations and I suspect that your A & P would agree that where the aircraft is stored and how it is stored has a lot to do with the interval.  If you are in a dry climate, in a hangar your interval can be longer than for a Mooney stored outside in a humid, salt air environment.  If in doubt, take a look!

 

 

[Tommy]

That's what I think as well. It is not a trivia undertaking and to think that I have to do it every year....

[Yetti]

Your plane tube frame was painted at the factory.  The SB was mostly for the pre 1975 planes that were rusting from window leaks onto unpainted tubing and water staying in the fiberglass insulation.

[Mooneymite]

I talked to a guy with a '91 Mooney.  He had corrosion in the tubing in several places.  

[Shadrach]

I used a two part zinc chromate epoxy on the tubes after cleaning them with a wire brush and polishing with 00 steel wool. Corrosion X sprayed into the inner tube. We utilized .5" closed cell foam (super sound proofing) as insulation. Plane is only slightly quieter, but the cabin temp is much more consistent. The steel cage should now well outlast the average citizenries right/ability to operate GA aircraft in this country.

[bradp]

I just did everything you are planning to do with my IA last annual. 

As you go through the process of the SB, we'll all be here to answer questions along the way. 

Quick tips:

1. Pulling the interior and putting it back in is a lot of work.  Take pictures and store your hardware in plastic bags with labels.  I ended up replacing most of the hardware with new stainless.  McMaster Carr has the best selection of standard stainless hardware. 

2. Anticipate replacing all the old insulation - there are different options for replacement.  LanceCasper used the foil wrapped stuff from spruce, I used the Super Sound Proofing stuff from Wicks.  The flammability standards of the stuff you put back in differ between car-3 and far 23 standards but best bet is to use the stuff that passes flammability testing and comes with a cert.

3. Wing root seals are overlooked and super important.  If you have 45 year old sealant and a thin layer of duct tape keeping water away from your steel tubular cage and wing roots, now's the time to inspect and/or reseal.  To inspect run a hose while you are looking for moisture along seams.  Same thing with the windows - run a hose and look for any moisture from areas of old or missing sealant. 

4. If you have thought about side window replacement or plastic panel replacement/refurb, now's the time.  It's like with the avionics upgrades - while we're in there we might as well... Look at Bruce Yaeger's Spatial Interior if you want new panels.  Seems to be the most value with his upgrade - replacement panels from plane plastics are just as expensive if you do more than a few and you don't get any design improvements. 

5. Good job thinking ahead about wiring runs.  I removed old ADF wiring and Loran wiring and reorganized some orphan wiring runs that I didn't like when the interior was out.  If the wiring runs are in anticipation of an ADS-B install, have some idea of what kind of equipment you will need.  I needed one RG-400 run for the new GPS antenna that will be installed, another to replace an old wire that was running my COM1 radio, and a third for a GPS install for GPS transponder.  Wiring on the last was minimal in terms of weight, so I went ahead and did it.  If I don't use that RG-400 for transponder, it's available for COM2.  I also pre-wired for an Flight Stream 210 that I'm going to put in when I do the WAAS upgrade. 

6. Make sure that you do all items on 208-B carefully.  Don't skip the magnets.  Inspect the wing spar covers below the seats.   Clean and protect everything that you need to.  Remove all the old duct tape (which collects water when it's old), and replace with new foil tape. 

7.  Have fun getting to know the guts of your plane. 

 

[Tommy]

Thanks for the great advice, Brad!