EASA SIB NM-13-20
Hawker Beechcraft Hawker 750 Aeroplanes — Communications System Wiring
Summary
Special Airworthiness Information Bulletin SAIB: NM-13-20 is an FAA informational bulletin addressing a wiring issue in Hawker Beechcraft Hawker 750 airplanes with specific serial numbers. The bulletin highlights an airworthiness concern related to under-gauge wiring in the Aircell cabin phone system. It applies to Hawker 750 aircraft with serial numbers HB-1 through HB-9, HB-11 through HB-14, HB-17 through HB-26, HB-28 through HB-32, HB-34, HB-36 through HB-40, HB-43, HB-63, HB-67 through HB-69, and HB-71.
What Changed
SAIB: NM-13-20 informs operators of the discovery that wiring fabricators used smaller gauge wire than specified for the Aircell cabin phone system, which is inadequately protected by the existing circuit breakers. The bulletin references Hawker Beechcraft Mandatory Service Bulletin SB 23-4054, which provides guidelines to replace the circuit breaker with a lower amperage unit to protect the under-gauge wiring. The FAA evaluated the risk and determined no mandatory regulatory action is required at this time.
Why It Matters
This bulletin is important for aviation professionals because under-gauge wiring can pose a risk of electrical faults or failures if not properly protected, potentially affecting aircraft safety and reliability. Operators and maintenance organizations need to be aware of the issue to ensure proper circuit protection is installed, thereby maintaining compliance with the aircraft's type design and preventing possible wiring damage or hazards. Understanding this advisory helps in prioritizing maintenance actions and avoiding unnecessary regulatory burdens.
What To Do
Owners and operators of affected Hawker 750 airplanes are recommended to follow the instructions in Hawker Beechcraft Mandatory Service Bulletin SB 23-4054 to replace the existing circuit breaker with a lower amperage breaker that adequately protects the under-gauge wiring. There is no mandatory compliance deadline, but timely action is advised to mitigate potential risks. For further technical assistance, stakeholders should contact the FAA Wichita Aircraft Certification Office or Hawker Beechcraft customer support.