In the process of removing my radios to install a 530 I discovered some corrosion. I coudn't see anything wrong from the outside, but I had to drill the arm rest nuts to remove them.

AGAC used a fire retardant on the fabric that was salt based.. This is normaly ok, unless the fabric gets wet, then it's bad news. May 10, 1995 Fletchair published SB-186 to inspect all interior parts that might come in contact with a wet interior. The most common place for corrosion are the front seat pivot points, two years ago I replaced my seats because of this.

Also both fabric holders are corroded.


The fabric holders are easy to remake, but I'm unsure how to repair the side honeycomb. It doesn't seem to be covered in my manual. My repair theories are:

  • Sand everything down to clean AL, prime and fill with epoxy. To reattach the arm rests, make a plate with three rivnuts and glue that to newly primed spot.
  • Cut one skin and honeycomb section out, sand the inside, prime and replace it with a new section of honeycomb (also with one skin) that has rivnuts installed for armrest.

    Where should I go from here?


    Abstract

    Primarily to enable Tiger N123VB to legally fly those nifty GPS approaches and secondarily enable it to receive in-flight weather updates.

    Introduction

    There is alot of talk about precision approaches with the newly enabled WAAS system. But there are no precision approaches in my NOS book. There are three years worth of non precision RNAV and overlays approaches! So adding any TSO C129a, Class A1 (en route, terminal, and approach) GPS opens more airports to Tiger N123VB today.

    The WAAS signal is broadcast on the same freq (L1) as a normal GPS satellite (SVC) so another antenna isn't required, (unlike DGPS systems) but the data rate from this geo stationary SVC and how it's applied to the fix solution requires alot more CPU (unlike DGPS and LAAS systems). This means that your GPS will at least require new software but in many cases a hole new processor.

    There are three in-flight weather systems: ARNAV has a 8km NEXRAD product using ~40 ground based 9.6kb VHF FM transmitters. King has one of their ground based 56kb VHF PCM VDL mode 2 systems running in test mode. EchoFlight uses the Orbcom SVC system (4.8kb VHF FM world wide downlink) with a 7km NEXRAD product.

    Implementation

    It would be nice to rip everything out and replace it with an entire UPS stack, but for space reasons and to maximize the existing hardware, the intercom and audio panel was replaced with a pma4000 where the old CDI was. N123VB lost Marker beacons in this process.

    The ADF and #2 nav/com was removed to make room for a gns530. The 530 should have enough cpu for WAAS when the software is available and Garmin expects their EchoFlight input box by years end. This leaves N123VB with two GPS (530 & 195), Loran map, two navs/coms each with GS. Not quite grega@pobox.com minimal panel, but it will hafta do.

    Results

    Weather last Saturday was so hazy it was hard to see the broken cloud deck around 400 feet. There was no way N123VB was going IMC after it was recently ripped apart. So we spent time checking out all the systems and cleaning the hanger. When a VFR only friend landed and told me the SVFR he got in wasn't "too" bad I decided to go.

    With one seat and no side panels in the airplane (and W&B done) we taxied out. Man the 530 looks dark.. and when I turned my head it changes colors! Might it be the polarized sunglasses? Bingo!! but wow, its bright without sunglasses. Get my special VFR and sit inline. Boy its hazy, make a mental note to wiggle the airplane to check gyros as soon as I get off the ground. ok, got clearance, final checklist and lets go.. cool, the airspeed is working.. ok and the VSI too.. good.. and the AI works too.. ok lets get more alt...

    cgf: 123vb change to cle and left turn approved for clear of clouds
         (noise abatement says climb runway heading to 1900)
    3vb: have a good one..
    3vb: cle, 3vb with you passing 1200
    
    whoa, these bases are low!! and I can't see any holes right next to
    them.. 
    
    cle: 3vb radar contact fly 180 at or below 2500
    3vb: I need to convert this to IFR, 3vb
    cle: I can work on that
    
    the clouds are too low, I gata go back and start an aggressive turn from
    south back the the airport. 
    
    3vb: cle, If unable popup for 3vb will need an immediate
         back to cgf and cancel. 
    cle: naa, I can fit you in, one sec. 
    
    oops..  there it is, inadvertent solid IMC...  you just can't see clouds
    when its super hazy..  ok stop the turn..  level the wings, cross check,
    cross check again..  yea everything is working..  I guess I'm going to
    live. 
    
    cle: 3vb, consider yourself IFR and climb 4000
    
    man, good thing I have a NASA form on me..  something I can fill out
    with my burger..  now back to 180..  yup cross check is ok...  I'm going
    to live.. dumb dumb dumb..
    
    3vb: leaving 1300 for 4000 heading 180 assigned, thanks!, 3vb
    cle: 3vb, pick up the MFD 89 radial, track inbound then direct.
    3vb: MFD 89, direct, direct, 3vb
    
    

    I know that controller... gata get his name to thank him sometime.. anyway, the MFD 89 is way south but I can cut 15 or so right.. what's the darn freq for MFD? Hay, I have this cool 530! zip to nrst, and then vor... rats!! its too far away.. oops, fly the plane.. hmm, plugging it into the gps isn't going to help me find a radial.. fly the plane.. oh and spin up the AP while I'm at it.. ok.. MFD freq.. plates.. it would be on the NOS approach plate... fly the plane.. where is the book, now the copilot seat is gone? flight bag.. in the back.. fly the plane.. ok got it... engage heading hold, check it.. retirm for climb... looks good... yea, AP works... find the page.. 108.80 and put it into the 530... now what? its still navigating via GPS!.. man, forget these fancy toys, put it into the kx165 and move the CDI, phew its acting about right, better check the indent just in case, yup.. ok.. cut alittle more right to grab a 45 into MFD's 89... so much for fancy toys.. ahhhh, the tops!! phew.. but man its hazy, and way bright.. where are those sunglasses? I need them more than the 530..

    anyway, you get the idea. I didn't know it, but a Cherokee Six killed 4 people around this time. And I now know how to find radials of airports and intersections with the 530 so I'm sure I will worm up to it. The biggest suppress is the 4000. Its active squelch isn't perfect but it works remarkably well. The wiring problem discovered with the old AltAlert is nice to have fixed too.. and in-flight tunes are way cool!

    Retrospect

    If I had a chance to do it all over again I might not do the 530. The 195 and 295 will map all approaches, unlike the 530 which will only show approaches with overlays. The new hand held EchoFlight map will offer more weather products sooner as its VFR only while the 530's box will need to be certified. So a cheaper M3, GX60, or 420 with a VFR map and weather would offer the same or greater capability while leaving more money in the sf260 fund. But I'll get over the buyers remorse.

    Terms

    LAAS            http://gps.faa.gov/Programs/LAAS/laas.htm
    WAAS            http://wwws.raytheontands.com/waas/
    DGPS            http://www.navcen.uscg.mil/dgps/
    UPS             http://www.upsat.com/
    C129a           TSO C129a, Class A1 (en route, terminal, and approach)
    SVC             Satellite ftp://ftp.navcen.uscg.mil/gps/Status.txt
    NOS Plates      http://www.americanflyers.net/ap/newq.asp
    ARNAV           http://www.arnav.com/network.htm
    NEXRAD          http://www.osf.noaa.gov/news.htm
    Orbcom          http://www.orbcomm.com/
    EchoFlight      http://www.echoflight.com/press/00_7_23.html
    VHF             around 170Mhz
    AM              Ampludude Modulated
    FM              Frequency Modulated
    PCM             Pulse Coded Modulated
    VDL mode2       http://www.faa.gov/nexcom/
    N123VB          http://rob.com/rob/images/flycle.jpg
    Old pannel      http://rob.com/rob/images/mypanel.jpg
    New pannel      http://rob.com/rob/530/mypanel2.jpg
    intercom        http://www.sigtronics.com/air/spa400fr.html
    audio pannel    http://www.seaerospace.com/king/kma24.htm 
    pma4000         http://www.ps-engineering.com/pma4000.shtml
    nav/com         http://www.seaerospace.com/king/kx155.htm 
    ADF             http://www.seaerospace.com/king/kr87.htm
    ki227           http://www.seaerospace.com/king/ki227.htm
    ka44b           http://www.seaerospace.com/king/ka44b.htm
    530             http://www.garmin.com/products/gns530/
    CDI             http://www.seaerospace.com/king/ki204.htm
    HSI             http://www.seaerospace.com/king/ki525a.htm
    195             http://www.garmin.com/products/gpsmap195/
    295             http://www.garmin.com/products/gpsmap295/
    GS              Glide Slope used with LOC (single radial VOR)
    VOR             Old navagation system
    Loss            http://www.avweb.com/newswire/news0036a.html
    IMC             In the clouds
    420             http://www.garmin.com/products/gnc420/
    M3              http://www.northstarcmc.com/m3.htm
    GX60            http://www.upsat.com/gx60des.html
    sf260           http://www.geocities.com/~sf260w/
    NASA form	Aviation Safety Reporting System