From an SEC filing by American Mobile Satellite Corporation dated 14 August 1996:

"In connection with testing of the Communications Ground Segment ('CGS') in May 1995, a transmission was sent to AMSC-1 which caused certain components of the communications payload to overheat, damaging one of the eight hybrid matrix amplifier output ports that serve the spotbeams covering the eastern and central United States. Beginning in December 1995, AMSC-1 experienced an intermittent degradation of power in the eastern spotbeam. Although the Company attempted to make adjustments ... to compensate and correct for this power loss, it was unable to eliminate recurrences of this power degradation. ... Based on its analyses to date, the Company believes that AMSC-1's channel capacity will not be reduced by more than 15%. ...

"In occurrences not directly related to testing and deployment of the CGS, AMSC-1 has experienced on separate occasions the failure of two solid state power amplifiers ('SSPA') serving the Mountain, West, Alaska/Hawaii and Caribbean spotbeams. These spotbeams were designed to be served by eight SSPAs with two spares. The Company is currently operating these spotbeams in a seven SSPA configuration and preserving one spare SSPA. AMSC-1 has also experienced the failure of an L-band receiver supporting the Alaska/Hawaii spotbeam. While the Company and its contractors were not able to identify the specific cause of the failure, it is believed that it may be attributable to a defective receiver and not a problem inherent in the design of AMSC-1. The Company is using a spare back-up L-band receiver on AMSC-1 to service the Alaska/Hawaii spotbeam. As a result of reconfiguring AMSC-1 to operate with five spotbeams, there is one other back-up L-band receiver on AMSC-1."

MSAT is the first dedicated system in North America for mobile telephone, radio, facsimile, paging, position location, and data communications. Each satellite uses four L-band spot beams to cover North America and 300 kilometers of coastal waters. Another beam serves Alaska and Hawaii.

Last updated: 27 May 2010