You do not necessarily need an STC for FAA Approval of the system.
You can go to a FAA Designated Engineering Representative (DER) who can approve the upgrade as a Major Alteration on a FAA Form 8110-3 provided you have all the supporting data for the modification like the EO, Test Plans etc.
If your particular PMI/oversight insists on STC approval, you can go to Honeywell (I believe they have an STC on the 747-400) and purchase a Rights-to-Use for the STC. Then go to a DER or Engineering company, and have the installation approved as a minor deviation to the STC.
I can recommed some DERs if you need..
Perhaps we should leave the recommendations to email ? - JT
Last edited by Limer; 14th June 2008 at 22:27.