The Federal Aviation Administration (FAA) has granted Butler National a supplemental type certificate for installing Mid-Continent Instruments and Avionics' new standby altimeter and attitude indicator in Learjet Models 23 through 60. This approval enables the replacement of existing two-inch standby altimeters or attitude indicators in most Learjets with digital versions.
Mid-Continent highlighted that their Digital Attitude Indicator and Counter Drum Encoding Altimeter, equipped with liquid-crystal displays, offer enhanced reliability compared to traditional mechanical instruments. Van Winter, Mid-Continent's vice president of marketing and aftermarket sales, stated, "Customers can cost-effectively install our two-inch digital attitude indicator and counter drum encoding altimeter in their aircraft. In most installations, there’s no need to cut the panel and minimal bus or wiring changes are required." He added that this upgrade provides "smooth, high-resolution graphics and advanced functionality."
Butler National's president and CEO Chris Reedy pointed out the challenges faced by avionics technicians with current RVSM standby altimeters during airworthiness checks. He remarked, "The replacement standby altimeter is a quality and cost-effective replacement solution that provides the RVSM standby functionality. Similarly, the MD23 two-inch digital attitude indicator provides a great-looking LCD-display replacement for the aging mechanical standby attitude indicator."