STC's and Specific Models

[Dave Underwood]

What has been the general experience with STC's that do not include your specific aircraft model on the STC paperwork? Does the STC holder add your model or does the FAA say close enough, and grant a go ahead. The specific example is JPI does list a P337H, but does not list my aircraft which is an 1977 FT337GP. We all know it is virtually the same plane. When looking at several STC, the T337GP's seem to be missing - any reason?

Regards - Dave Underwood

[GMAs]

Yes they STC does not cover your plane... it only covers the ones that they got acceptance on... which is a good thing in your case.. why because you don't have to buy the STC... instead you can take the accessory (all things added to planes are accessories)... and go down to the FAA and say... hey I want to put this in mine... which is the same series aircraft... TC A6CE.... here is the manufacturs SIMILAR data... for others of this series... but, here is the 337FORM for my model... and they will sign it off... providing it meets the following....

1. that the accessory does not interfer with any of the other aircaft systems... yep just because you have one STC for a item... doesn't mean it will be OK to put it on your plane if another accessory has been added that could cause problems... (something that most don't think about even if you have the STC)

2. After installation it meets or exceeds the manufacturs specs...

Here we had a bunch of GPSs' that failed to meet the IFR requirement.. why because they interfeared with the com radios... KX 155's and the old IImorrow nav management systems... seems that the gps and event he transponder got into a mess... on certan frequencies... and even KIng has a problem with antenna placement for the DME and transponder that they make... so they even have to let you know that their system may not work... togeather... and have a fix it for it... if you put the two in...


In the case of the GPS and com radios.. check out the 134 freqs... on your radio.. and the GPS... if the antenna is too close or the radio to noisy.. you can be following your on tail around the sky... and guess what both were TSO'd... with the FAA/FCC blessing... so long as they were used alone and not with each other... so compatabliity is a big thing in installing any accessory... and the major stopping point... from the FAA's point of view...

HOpe this helps GMAs.