sierrakilo99
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- Apr 20, 2011
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I've got a customer in the shop for annual, right after he had a GFC500 a/p installed by a 'reputable' Garmin dealer / shop in the area. Not one that I recommended, but...
This is the first GFC500 a/p install I've seen, and I'm referencing the Garmin ICA document for the GFC500 to verify the a/p system is functional per the STC and as part of the annual I'm checking cable tensions, especially given the fact that a complete new a/p system has been installed and this setup is the big enchilada... roll, pitch, auto trim, yaw damper, so all the rigging has been touched.
What I've found is the tensions on aileron and stabilizer cables are significantly out of tolerance, on the low side, on the order of 10-20lbs depending on the cable, and corrected for the 90-degree temps here in Central FL right now. I would have expected the installation of the servos would have necessarily required the installation tech to check the rig of the controls that were affected by the installation, since all the control cables have been affected by the installation.
The problem is, the avionics install shop is giving the customer the runaround when I challenged the cable specs per the Garmin documentation. The shop even told the customer "We are not to adjust any existing cable tensions, Only the bridle cable" and they reference note 19 on the drawings, which actually state otherwise:
19. SET THE ROLL/PITCH/YAW SERVO CABLE TENSION TO 15 +3 -0 LBS AT 70°F. TENSION THE PITCH TRIM CABLE PER THE PIPER
SERVICE MANUAL. CORRECT THE CABLE TENSION FOR TEMPERATURE USING SERVO CABLE TENSION CHART ON SHEET 2.
I can adjust the cable tensions, but I don't want the install shop to point fingers back at me if there's anything wrong with the installation and they say 'we didn't touch it, you did' and then void this guy's warranty.
Looking for information from the folks who have installed these new systems?
sk
This is the first GFC500 a/p install I've seen, and I'm referencing the Garmin ICA document for the GFC500 to verify the a/p system is functional per the STC and as part of the annual I'm checking cable tensions, especially given the fact that a complete new a/p system has been installed and this setup is the big enchilada... roll, pitch, auto trim, yaw damper, so all the rigging has been touched.
What I've found is the tensions on aileron and stabilizer cables are significantly out of tolerance, on the low side, on the order of 10-20lbs depending on the cable, and corrected for the 90-degree temps here in Central FL right now. I would have expected the installation of the servos would have necessarily required the installation tech to check the rig of the controls that were affected by the installation, since all the control cables have been affected by the installation.
The problem is, the avionics install shop is giving the customer the runaround when I challenged the cable specs per the Garmin documentation. The shop even told the customer "We are not to adjust any existing cable tensions, Only the bridle cable" and they reference note 19 on the drawings, which actually state otherwise:
19. SET THE ROLL/PITCH/YAW SERVO CABLE TENSION TO 15 +3 -0 LBS AT 70°F. TENSION THE PITCH TRIM CABLE PER THE PIPER
SERVICE MANUAL. CORRECT THE CABLE TENSION FOR TEMPERATURE USING SERVO CABLE TENSION CHART ON SHEET 2.
I can adjust the cable tensions, but I don't want the install shop to point fingers back at me if there's anything wrong with the installation and they say 'we didn't touch it, you did' and then void this guy's warranty.
Looking for information from the folks who have installed these new systems?
sk
