Honeywell Service Bulletin MST67A-34-56 addresses a software issue related to EASA Airworthiness Directive No. 2008-0159. This European AD identifies a problem in the MST-67A. The transponder datalink does not communicate all of the surveillance parameters correctly with the Mode S Secondary Surveillance Radar (SSR). Therefore, the affected MST-67A does not fully support Mode S enhanced surveillance.

MST-67A P/N 066-01143-2001 units with serial numbers MST67A-F1450 and below are affected. MST-67A P/N 066-01143-2101 units with serial numbers MST67A-G2850 and below are affected.

Honeywell Service Bulletin MST67A-34-56 incorporates a software modification to address the enhanced data communication issues. This SB involves replacing to intergrated circuits on the IOP/DLP COM board and appropriate labeling.

Since safety and quality are of the utmost importance, Southeast Aerospace is pleased to inform its customers and prospective clients that we will incorporating the Honeywell Service Bulletin into all MST-67A P/N 066-01143-2001 and 2101 that are serviced and processed in our FAA/EASA approved repair facility. If you have an MST-67A that is affected by this Airworthiness Directive, please contact our Service Center at shop@seaerospace.com for more details on a quick, responsive solution.