8 EN-ROUTE CLIMB PERFORMANCE
8.1 Multi-engined aeroplanes engaged in charter operations under the Instrument
Flight Rules or aerial work operations under the Instrument Flight Rules must
have the ability to climb with a critical engine inoperative at a gradient of 1%
at all heights up to 5 000 feet in the standard atmosphere in the following
configuration:
(a) propeller of inoperative engine stopped;
(b) undercarriage (if retractable) and flaps retracted;
(c) remaining engine(s) operating at maximum continuous power;
(d) airspeed not less than 1.2 VS.8
What /Temp/Pressure Height situation do they mean by standard atmosphere