Submitted by Dave Schiver, Airframe Tech Rep

On March 27th, the FAA issued two Notices of Proposed Rulemaking (NPRM) for Learjet 60 and Learjet 40/45. Continue reading for details.

Learjet 60

The FAA has proposed an upcoming Airworthiness Directive (AD) for Squat Switch & Anti-Skid Shielding on certain model Learjet 60 aircraft. You are encouraged to read the details of and comment about the proposed AD during the open commenting period which ends on May 13, 2013. Details of the Notice of Proposed Rulemaking can be found here.

Required Service Bulletins

This proposed AD will require the installation of the following Service Bulletins (SB): SB60-32-33 & SB60-57-7. These SBs install the metal shielding around the Main Landing Gear (MLG) Squat Switches & MLG Anti-Skid Valves to protect them in case of an accidental impact.

Terminating AD 2010-11-11

The above SBs are two of the four required SBs to terminate AD 2010-11-11. This AD is the 96-Hour Tire Pressure check, per the FAA Alternate Method Of Compliance (AMOC) Letter L115W-12-459. The other required SBs are SB60-27-6, Wheel Speed Detect Box, and SB60-78-7, Thrust Reverser (TR) Interface Box.

Another requirement called out in the AMOC is for the Temporary Flight Manual Change (TFM) 2012-03 to be inserted in the Airplane Flight Manual (AFM). Bombardier first published this information in AW32-061 on July 30, 2012.

SB60-78-7

As a side note, in order to comply with SB60-78-7, the Wheel Speed Detect Box, if previously installed, may need to be exchanged in order to be upgraded for compatibility with the TR Interface Box.

Learjet 40/45

The FAA has proposed an upcoming AD for the Baggage Door Fire Seal of certain model Learjet 40/45 aircraft. You are encouraged to read the details of and comment about the proposed AD during the open commenting period which ends on May 13, 2013. Details of the Notice of Proposed Rulemaking (NPRM) can be read here.

Required Service Bulletins

The proposed AD requires the installation of SB40-25-25, Revision 3, or SB40-25-25, Revision 3, within 300 flight hours after the effective date of the AD. These SBs call for the modification of the fire seal on the baggage door, including doing general visual inspections of the fire seal for correct contact.

Exceptions

If Revision 1 or 2 of SBs SB40-25-25 / SB45-25-35 have been complied with prior to the effective date of this proposed AD, no further action is required.

All of Duncan Aviation's full-service locations are Authorized Learjet Service Centers, and are able to provide comprehensive Learjet airframe services, inspections and technical support for all models.

Dave Schiver is an Airframe Technical Representative at Duncan Aviation’s Lincoln, Nebr. (LNK) facility. He specializes in Learjet aircraft. His aviation career began in 1981.