Installation of a gravel runway operations kit.

Installation of VHF communication antenna.

Installation of mach trim system.

Installation of an Optical side window and a window plug.

New installation of a Precise Flight Pulsating Recognition and Landing Lights System.

Install tail logo lights.

Installation of a drag reduction system (contoured flap)

Removal of 24-inch wide executive door and installation of 36-inch wide cargo door per AVCON Drawing List 36000 stamped “FAA Approved” with a date of May 8, 1979, July 3, 1980, November 15, 2010, or later approved revision for Learjet Models 25, 25A, 25B, 25C, 25D, 25F, 28, 29, 31, 31A, 35, 35A, 36, and 36A.

Installation of an aft fuselage stowage locker.

Replace engine inlet nose skins.