Replaces Legacy Standby Instruments
Butler National Corporation and Mid-Continent Instruments and Avionics have received an FAA Supplemental Type Certificate (STC) for a replacement 2-inch standby altimeter and a separate 2-inch standby attitude indicator for Learjet models 24, 24B/D/E/F, 25, 25B/C/D/F, 28, 29, 31, 31A, 35, 35A, C21A, 36, 36A, 55, 55B, 55C and 60 airplanes. The STC authorizes replacement of either or both instruments installed in most legacy Learjets. The Butler replacement package replaces previously installed standby equipment with the Mid-Continent Instruments and Avionics MD23 2-inch Digital Counter Drum Encoding Altimeter and Attitude Indicator.