Avionic Retrofit

The year 1997 brought some more mayor investment into my DUKE after the expensive replacement of both engines last year. This time it was avionics and I did not like it from the start. There you have a perfectly working KING GOLD CROWN avionic when some German beaurocrats come along and say it is not good any more. Anyway it is not their money they are spending. What happened was that ICAO was concerned that FM radio transmitters could eventually disturb airborne radio equipment. Although I have never heard Frank Sinatra in my Com ( and I bet I would never have heard him anyway ) ICAO came up with the so called Annex X ( FM Radio Immunity ) recommendation and my country, as always made it law. In simple terms that means : forget about flying your DUKE by 1.1.1998 if you don`t do something about your radios.My old panel

So, the first thing was to contact KING for a modification kit. If you think you are a valued customer if you had bought their expensive stuff 20 years ago : forget about it. KING does not even consider coming up with some sort of modification. The message is simple : Buy new avionics, since we do not support the old stuff. Thank you KING, but thank you NO. As long as I own an airplane there will be no single KING part installed anymore.

On top of that there was the next problem. In about two years we here in Germany will have to comply with 8,33 KHZ channel spacing. Another of these -no go- items in the eyes of German beaucracy.

Funny enough though when I flew from Reyjkjavik to Dundee last year I heard the driver of a German airlift transporter replying to a frequency change " Sorry we can`t change to that frequency, we have only 50 KHZ spacing ". For civil aviation 25 KHZ spacing was made law in Germany more then 10 years ago. So you see : rules apply as long as they cost other people`s money. State owned aircraft do not have to comply. Nice example of how STATE works here in Germany. But that is another story.

Back to my avionics. Keeping in mind that it is useless to install ICAO Annex X compliant avionics and throw it out again after two years I searched for something that had FM immunity and was fit to be easily modified to the new spacing requirements. In the whole process of choosing and installing I had one great help from my avionics wizz-kid Martin Wieland from Air Service Basel AG, whose deep knowledge, skills and also economic understanding made that retrofit a perfect job. I will come to that later.

The choices were not big anyway. The only thing Martin came up with that did meet my demands and also does fit the standard of a DUKE was COLLINS PROLINE II. Those things seemed to be just right but had one big disadvantage : the price. Example : one single new VOR/LOC/GS black box VIR-32 is well over 11.000 US $ ! And that does not include the control head. If I would drink I would have had a couple of large "schnapps" on that message. We than started to search for O/H units that had to be modified to meet the ICAO standard. Now one funny thing happened : All the big avionics dealers in the US had gotten word of our little European extravaganza and had come to the same conclusion as Martin : only the COLLINS units would fit the demands for a large twin. So what is happening is the prices for the O/H units went skyhigh ( and I think as the modification date gets nearer, they will even get higher ). Taking into account that one has to perform a very expensive modification on to of the purchase, the prices did not vary much from those Collins charged off avionics dealers. Fortunately for me I had a source where I could buy COLLINS avionics for net dealer price ( don`t ask me how I did that since I will not tell you. It was a one-time thing ) and so we decided to buy new black boxes, spend the extra couple of thousand and be sure to get factory guarantee and no modification messed-up units. COLLINS said they could deliver ex-stock. That made the decision even easier.

A final word to KING avionics. We did evaluate KING SILVER CROWN. That had made things much much cheaper on first sight. But apart from the fact that I don`t like that avionic particularly for the DUKE since I don`t think it "fits" it very much and apart from the fact that you never stop exchanging those displays there was another problem : KING could sell ICAO Annex X (FM Immunity) compliant units but those cannot be modified for the new channel spacing requirements. That means buy today and throw out in two years. They call it "slide-in replacement". Thank you KING but thank you NO again.

For the control heads, we choose O/H items and bought them from FieldTech Inc. in Miami. Three more things had to come in : 1. Since my panel had to be reworked anyway I wanted to install a radio altimeter, the one thing that was really missing. 2. I always had two XPDR`s, a KXP 755 and a KXP 756 and wanted to keep it that way but with only one control head. So we had to change one XPDR from KXP 755 to KXP 756 and exchange the control head. 3. We could not keep the wonderful self-made BEECH audio panel. Since the underlying black box was a KAA-445 we could couple that with a KA 119 audio panel with no big trouble.

Finally my shopping list looked as follows :

2..... Collins VHF22A......... 622-6152-011 .........VHF COMM TRANSCEIVER

5 .....Collins UMT12...........622-5212-001 .........MOUNT

2 .....Collins Conn Kit......... 634-4192-002 .........CONN KIT FOR VHF22A

2 .....Collins VIR-32........... 622-6137-201 .........VHF NAV RECEIVER

1 .....Collins CAD31 ...........622-8332-001 .........CONTR. ADAPT. FOR DME

2 .....Collins Conn Kit .........653-9014-002 .........CONN KIT FOR CAD31/CAD62

1 .....Collins Conn Kit .........634-4192-006 .........CONN KIT FOR ALT-50 A

2 .....Collins CTL-22 ..........622-6520-004 .........VHF COMM CONTR. UNIT

1 .....Collins CTL-62 ..........622-6522-008 .........ADF CONTROL

1 .....Collins CAD-62 ..........622-6590-001 .........CONTR. ADAPT. FOR ADF

1 .....KING KA 119 ...........071-1087-01 ...........AUDIO CONTROL PANEL

2 .....Sensor Systems ..........S67-2002 ..............RADIO ALT ANTENNA

2 .....Collins CTL-32 ..........622-6521-004 .........VHF NAV CONTR. UNIT

1 .....Collins DRI-55 ..........622-4160-018 ..........INDICATOR RAD ALT

1......Collins ALT-50 .........622-3201-001...........RAD. ALTIMETER

1......KING KXP 756.....................................XPDR

1......KING KFS 576.....................................XPDR CONTROL

As you can see it is quite extensive and does not even include antenna couplers, wires, bits and pieces. In fact Martin and his colleague Kathrin Haller almost had to tear the whole panel apart and rework it from scratch. An absolute "MUST" is a good documentation in form of a "WIRING" or you are lost. And : a lot of avionics shops "forget" to stamp the wires with the numbers they use in the wiring. Sure that costs a buck more, but is well spent when you thing of trouble shooting in cases something goes wrong now or in the future. Someone will pay for neglectance in that field, you or the one who owns the airplane after you. As you can imagine it is not just "a couple of wires" but literally hundreds of them.

Now have a look how the installation process went. I documented it with some pictures. You can blow them up by clicking on the link.

My old panelA start : my old GOLD CROWN Avionics

Center panel out & torn apart

While in the meantime the panel itself is vandalizedold panel removed / big hole


Some wiring is done

in the baggage compartment

in the nose behind panel

In the meantime Kathrin is busy marking wires

while the new center panel is test-fitted with the new control heads

Radar Alt. antennas being installed

New Comms New Navs

The panel is rewired

Control heads tried

Those two can be very proud of their workThank you Kathrin & Martin !

And now the result. MY NEW PANEL

Oh, I almost forgot : in the process of retrofit we decided to repaint the whole panel to match the grey of the seats. I think that was a good decision.

Another wonder happened on top of all. IT SEEMS TO BE WORKING ! With all the things I have been through with this DUKE this is the greatest miracle.

What do you think ?  send a comment to eberhard&burghalter.de (please replace & by @ ...I get soooo much automated spam)

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