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FORT WORTH, TX. June 28, 2008 – HTA Aviation, LP, a privately held woman owned small business entity provides trouble-shooting and recovery of an Astra SPX with a starter/generator problem and discovers an uncompleted Service Bulletin 100-54-252 as the root cause for the conditions.

The crew reported that the left generator was dropping off line during takeoff and could not be brought back on line. HTA Aviation was asked to provide AOG support.

The left starter/generator was replaced and the system tested. However, intermittent left generator and inverter problems continued. HTA contacted the operators to determine if Service Bulletin (SB) 100-54-252 had been accomplished. This SB is for the pylon firewall feed through inspection of starter generator cables and replacement of cable support. The operators reported the subject SB had been accomplished in 2002.


The complete system and related components were inspected. A short was present with the starter/generator cables. The left pylon lower panels were removed and the area inspected. A short was discovered at the pylon feed through cable support as shown in the photo to the left.

Upon this discovery, the right pylon area was inspected with no short visible as shown in the photo to the right. After reviewing all of the findings, it was evident that some of the steps required in Part B/C of the SB had not been accomplished. The new cable supports were installed; however, the new protective sleeve P/N 6653957 “EXPENDO” black material did not pass through the new cable support as required by the SB. In addition, the installation had not been injected with DAPCOCAST 18-4 sealant between starter generator cables and the cable support. A correct accomplishment is shown in the photo below right.

The damaged left cable support was replaced and new cables having the black “expend” protective sleeve installed were passed through the cable support. DAPCOCAST 18-4 sealant was injected between starter generator cables and the cable support. After operational checks were performed and passed, the aircraft was returned to service.


HTA Aviation, LLC, a privately held company, providing superior CLS and COMBS services for our government and support for the world's most technologically advanced business jet aircraft. HTA also offers Service Engineering (DER & PMA), Technical Publications, and Consulting Services for the business aviation industry.