jliltd
Well Known Member
We have a G3X Touch system in an RV-8. It uses a GTX 45R and a Gap 26 AOA/Pitot tube.
My best friend took the aircraft to a local repair station to have a Transponder Certification done. They had no idea how to put the remote 45R transponder in Ground Test mode. They had no experience with nor did they realize the airplane had an AOA probe pitot tube. Their test set didn't have proper adapter pads to connect the static test line to the flat side of the fuselage *rivet" style static ports.
The technician attached their test set pitot tube line to the GAP 26 AOA/pitot tube by slipping a vinyl tube over the entire length of the tube. Since they didn't have provisions to connect to the fuselage static ports they just left them off. Once the aircraft systems were fired up they could not get a transponder beacon code of any kind since they didn't realize or know that the 45R had to be placed into Ground Test mode before it would transmit any beacon like it does in the air. They also couldn't get any airspeed readings on the GDU 465 EFIS.
So that's when the owner called me for advice. I told my friend that the repair station should review the manuals for the G3X Touch and GTX 45R before doing any more testing. I looked up the G3X Touch manual and it said that the AOA and static ports on the aircraft needed to be both attached to the static line of the test set while the pitot tube be attached to the pitot line of the test set. There are grave warnings about damaging sensors if pitot and static ports are not all connected properly to the test set.
I advised my buddy to abandon the cert test until we could find out more information.
So some questions for those in the know:
1. Where are the AOA ports on the GAP 26? Would slipping a test set pitot line down the entire length of the pitot tube cover the AOA ports?
2. What kind of adapter would pick up the AOA pressure ports so they could be interconnected with the fuselage static ports and the test set?
3. Why was the GDU not showing any response to test set pressure applied to the pitot with the system powered up on the ground? Meanwhile I know how to set the remote transponder into Ground Test mode (unlike the repair station guy).
4. Should we take the airplane around the patch to see if the pitot/static/AOA sensors in the GSU 25 have been compromised?
Thanks in advance,
Jim
My best friend took the aircraft to a local repair station to have a Transponder Certification done. They had no idea how to put the remote 45R transponder in Ground Test mode. They had no experience with nor did they realize the airplane had an AOA probe pitot tube. Their test set didn't have proper adapter pads to connect the static test line to the flat side of the fuselage *rivet" style static ports.
The technician attached their test set pitot tube line to the GAP 26 AOA/pitot tube by slipping a vinyl tube over the entire length of the tube. Since they didn't have provisions to connect to the fuselage static ports they just left them off. Once the aircraft systems were fired up they could not get a transponder beacon code of any kind since they didn't realize or know that the 45R had to be placed into Ground Test mode before it would transmit any beacon like it does in the air. They also couldn't get any airspeed readings on the GDU 465 EFIS.
So that's when the owner called me for advice. I told my friend that the repair station should review the manuals for the G3X Touch and GTX 45R before doing any more testing. I looked up the G3X Touch manual and it said that the AOA and static ports on the aircraft needed to be both attached to the static line of the test set while the pitot tube be attached to the pitot line of the test set. There are grave warnings about damaging sensors if pitot and static ports are not all connected properly to the test set.
I advised my buddy to abandon the cert test until we could find out more information.
So some questions for those in the know:
1. Where are the AOA ports on the GAP 26? Would slipping a test set pitot line down the entire length of the pitot tube cover the AOA ports?
2. What kind of adapter would pick up the AOA pressure ports so they could be interconnected with the fuselage static ports and the test set?
3. Why was the GDU not showing any response to test set pressure applied to the pitot with the system powered up on the ground? Meanwhile I know how to set the remote transponder into Ground Test mode (unlike the repair station guy).
4. Should we take the airplane around the patch to see if the pitot/static/AOA sensors in the GSU 25 have been compromised?
Thanks in advance,
Jim