Gulfstream GIV Window Heat Malfunction

  • Tue, January 24, 2012 9:02 AM
    Message # 806150

    - This tip is by Joe Venturo

     The aircraft I maintain is a Gulfstream GIV. Back in June we had a side window in the cockpit that lost its window heat. We diagnosed the window by checking resistance as per the manual and it failed.  We changed the window and it worked fine.  Now, six months later the pilots again reported that the window was not heating properly.  I was concerned that we had just changed the window so our first action was to swap the window heat controllers.  The pilots took the aircraft for another flight and reported no change or improvement.  I checked the resistance in the window as per the maintenance manual and it was well within the specified limits.  I checked the wiring to the window for a short or an open wire. The wiring checked out fine. There is a relay in each window heat system. I swapped the relays from left to right, that did not work either. I had called Gulfstream Technical Operations with what I had found so far. There was nothing in the manuals or wiring diagrams left to check but this is what I had learned.  Originaly when the aircraft was built in 1988, the windows that were used were developed for the GIII aircraft as well as the window controller.  The equipment on the aircraft was original.  Since then the window design has improved. Dimensionally, the window for the GIII, GIV,GV has remained the same yet the materials and internal design has improved.  The current window in production is for a GV/550 and G-450 aircraft. The current window is an 1159SCB5100-11 and is used in aircraft ranging from GIII to G550 and is compatible with window heat controllers for those aircraft.  The heat controllers for GIII and GIV is pn 574-3 when the GV went into production the new style controller p/n 1042-1 was used.  The manual says that the current window is compatable with either controller.  When I spoke with Tech Ops they said that they had heard that the old p/n controllers were not working well with the new windows and it is advisable to use the new p/n  controller. 

    Since this is not published I felt that we as mechanics need a forum to exchange information that will help others save time. I hope this helps.

    Last modified: Tue, January 24, 2012 9:09 AM | Dunn
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