PC-24
Flight Crew Air Transport Pilot (ATP); Flight Crew Flight Instructor; Flight Crew Multiengine; Flight Crew Instrument
Flight Crew Last 90 Days 200; Flight Crew Total 14000; Flight Crew Type 1800
Situational Awareness; Training / Qualification
ATC Issue All Types; Deviation - Altitude Undershoot; Deviation / Discrepancy - Procedural Clearance
Flight Crew Took Evasive Action
Aircraft; Procedure; Human Factors
Pilot Flying was undergoing Supervised Operating Experience 'Mentoring' on the Pilatus PC-24 for single pilot operations.After checking on the pilot in the climb at FL430 and FL440 I returned to my seat in the cabin where I had a birddog position to watch the pilot with ATC on the overhead speaker. Pilot was climbing in PIT (PITCH) mode aware of the dangers in climbing in that mode. Many pilots like to climb in Pitch mode through FL300 at it gives the passengers a smoother ride and allows the pilot to reach cruising altitude without hunting in FLC or VS.At FL443 I heard the Center controller Yell in a DEMANDING VOICE 'I need you at FL450 in 1 minute or less.'Hearing this exclamation; I ran to the flight deck to see the pilot's reaction. The Pilot Flying selected Manual Speed on the Autothrottle and dialed the speed back. (A common technique for climbing in Autothrottle FMS mode is when a controller asks you to expedite the climb you switch to Manual Speed on the Autothrottle and dial back 20-30 knots -- this will command the APFDS to pitch up exchanging airspeed for altitude); however; in this situation; the pilot didn't realize that dialing the speed back in PITCH mode would actually retard the throttles to IDLE.The Pilot [Flying] immediately corrected for the situation; however; once the aircraft lost the energy; the plane would no longer be able to reach assigned altitude. The Controller under a lot of pressure from the government shutdown clearly took his stress on the situation that required the pilot to get to FL450 in 1 minute or less out on the Pilot Flying and hit him over and over again with radio calls task saturating the pilot. The Pilot Flying did a great job on flying the aircraft; lowering the nose to break the approaching stall; and finally when he had a minute to breathe; informed the controller he needed lower.The pilot was ground schooled after the incident that he should of 'Declared an Emergency for Safety' and told the controller of the situation.The Pilot Flying now learned how to manage that type of situation and more importantly how to manage ATC in an emergency.
PC24 Check Pilot reported the pilot in training did not comply with ATC clearance.