What condition restricts ground operations of the T-6A?

Ground operations of the T-6A are restricted by ambient temperatures below -23 degrees Celsius. This limitation exists due to the risk of engine performance degradation and potential mechanical issues that can arise in extremely cold conditions. Operating the aircraft in such low temperatures may lead to the fluids thickening, which could affect critical systems such as lubrication and fuel flow, and may impede the functionality of the aircraft's electrical systems and avionics. Consequently, this temperature threshold is put in place to ensure the safety and reliability of operations, as well as to prevent damage to the aircraft.

While visibility less than 1 mile, wind speeds above 30 knots, and ambient temperatures above 43 degrees Celsius do impact flight operations, they do not specifically restrict ground operations in the same way that extreme cold temperatures do. Each of these conditions may lead to additional considerations for safe operation, but the critical limitation concerning ground operations related to temperature is the threshold of -23 degrees Celsius.