Learjet 45
Flight Crew Air Transport Pilot (ATP); Flight Crew Flight Instructor; Flight Crew Instrument; Flight Crew Multiengine
Flight Crew Last 90 Days 140; Flight Crew Total 10000; Flight Crew Type 3500
Troubleshooting; Distraction; Situational Awareness; Training / Qualification
Aircraft Equipment Problem Critical
Aircraft Equipment Problem Dissipated; Flight Crew Took Evasive Action; Flight Crew FLC complied w / Automation / Advisory; Flight Crew Overcame Equipment Problem
Aircraft
On climb out of FL310 'Heading 1 Fail' appeared on the pilot's Primary Flight Display and Heading 2 Fail on the copilot's Primary Flight Display. We had no heading information on pilot and copilot side and lost all navigation display from the FMS and VOR. We were not able to bring up VOR NAV display on the RMU. The autopilot remained engaged in ROLL mode. We pulled and reset the AHRS 1 and 2 circuit breakers and within a few minutes regained heading and navigation display on both sides. With failure of both heading sources; we also lost all navigation display on the PFD's and MFD as well as the RMU's. Glad we were not climbing out of the mountains in IMC when this happened.
Both of a LR45's AHRS failed climbing out of FL310 but were recovered after the AHRS 1 and 2 AHRS circuit breakers were reset.