Flight Crew Instrument; Flight Crew Multiengine; Flight Crew Air Transport Pilot (ATP)
Communication Breakdown; Situational Awareness
Ground Event / Encounter Ground Strike - Aircraft
Aircraft Aircraft Damaged
Environment - Non Weather Related; Human Factors
During normal G650 Completion test flight engine checks; Individual engine Idle-Rated-Idle thrust sweeps; at approved engine run pad; Cessna 172 [taxied] behind the aircraft exhaust direction. The Cessna experienced an 'upset event' where aircraft suddenly tipped to the right and nose down; resulting in the right wing contacting the ground and damaging the wing tip and also resulting in the propeller striking the pavement and being bent at the tips. Ground made no radio calls advising us to cease our engine run operations or that there was conflicting traffic exiting the runway behind us. We were not aware at the time nor any other time subsequently that day of any potential involvement between our engine checks and the Cessna event.Production/Completion test card requirements for preflight engine power sweeps/high power operations to be pointed into the wind +/- 10 deg should be reexamined for relevance and importance for protecting against potential engine damage.
G650 Captain reported during an engine test run a C172 behind the aircraft was affected by the jet blast.