Learjet 35
Flight Crew Multiengine; Flight Crew Air Transport Pilot (ATP); Flight Crew Flight Instructor
Flight Crew Last 90 Days 100; Flight Crew Total 16000; Flight Crew Type 300
Situational Awareness
Aircraft Equipment Problem Less Severe; Deviation - Altitude Crossing Restriction Not Met; Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Published Material / Policy; Deviation / Discrepancy - Procedural Clearance
Air Traffic Control Issued New Clearance; Flight Crew Overcame Equipment Problem; Flight Crew Became Reoriented
Aircraft; Human Factors
Navigating JAIKE3 to TEB. At JAIKE the FMS lost programming and began navigating back to JAIKE. Advised ATC that we lost 'our box' and needed a vector towards WACKI while we re-program it. ATC instructed a five degree left turn rejoin the arrival. The First Officer's first attempt to re-program the FMS failed and I instructed him to '99 it' and start over - which he did. During the process we had no way of knowing our position and I knew that we needed to cross WACKI at 11000 feet; so after a minute I began an early descent from 13000 to 11000 feet. ATC noticed that we had begun our descent prior to ILENE and instructed us to level at 12000 feet and 250 kts. The crossing restriction at ILENE is 13000 feet. By that time the FO (First Officer) has successfully reprogramed the FMS and we continued the arrival as per the STAR.JAIKE is depicted in bold lettering on the Jeppesen chart and WACKI has an enhanced altitude box with the altitude in it. ILENE was not noticed during the distraction of re-programming the FMS. Also ILENE is a redundant fix identical to JAIKE with a crossing altitude of 13000 feet. When briefing the STAR; JAIKE at 13000 feet was noted and the arrival scanned ahead for the next crossing restriction which was WACKI at 11000 feet. Most arrivals do not have duplicate crossing fixes which led to missing the second fix.Perhaps depicting the route segment of the STAR differently would help in better situational awareness; such as depicting the 'segment' as an absolute value of 13000 feet; instead of duplication of two waypoints on either end of the segment.
LR-55 Captain reported deviating from cleared track and altitude on arrival to TEB when their FMS lost programming.