Blackbird Sims / Milviz Forum Archive

Another observation I would like to hear your point of view upon.
I’m a bit surprised that with summer temperatures slightly above ISA and at SL, the ITT already reaches red line way before 65 psi torque. ITT 790 C should becoming a limiting factor for max cont. torque only at high altitudes, according my information on the PT6A. Maybe possible to lower actual ITT calculation a bit so that the 65 psi can be used for take-off at ISA+5 or ISA+10.
Thank you for considering!
Alexander

ITT values are correct.

Torque and ITT limits for take off apply for props at 2200 RPM.

Torque limit is top green zone (58.7) and ITT 790.

Torque limit is no longer sustentable above ISA+4 at SL (~19 ºC) without exceeding ITT; equivalencies following with altitude.

Max 64.5 torque is for props at 2000 RPM, and MAX Continuous, limited to 3 minutes.

Torque limit at ISA conditions can be maintained up to ~ 4000 ft. without exceeding ITT.

Tomas

Thanks for pointing me to check and in the POH I missed reading footnote 1) in the limitations table.
All good then!
Alexander