When flaps are extended more than 60%, the aircraft’s structural and flap-system limits require a lower maximum indicated airspeed to keep the wing and flaps within safe loads. In this configuration, the published maximum KCAS is 220. Exceeding that speed risks flap overspeed, excessive loads on the flap hinges, and possible control issues, so you must stay at or below 220 KCAS with flaps over 60%. The other speeds listed aren’t the established limit for this flap setting, making 220 KCAS the correct value here.

The main idea is that the T-38’s flight-control hydraulic system is designed to operate within a defined normal pressure band, specifically 2850 to 3200 psi. This range provides enough force to move control surfaces reliably under typical loads and speeds, while keeping all hydraulic components within their safe operating limits. If pressure drops toward the lower end, actuator output weakens and control feel becomes sluggish; if pressure climbs toward the upper end, components can be stressed and protections may engage. That’s why describing normal hydraulic pressure as 2850 to 3200 psi is the best choice. The other statements don’t match how the system is specified. A minimum of 1500 psi implies a much lower, and not normally available, operating pressure. Describing 3200 psi as the maximum suggests a hard ceiling at that value, which isn’t how the normal range is defined. And stating a normal range of 1500 to 3200 psi includes values outside the intended operating band, which isn’t correct for normal operation.

The main idea here is that each power setting in the operating limits has a defined endurance. Military steady-state means holding Military power in a steady, non-transient condition. It’s a high-thrust setting, but not the maximum, and it’s limited in time to protect engine and turbine windings from overheating and excessive wear. For the T-38C, that sustained MIL power duration is 30 minutes. So you can operate at Military power for up to half an hour before you’d need to step down or reassess power to stay within limits. The other time options don’t match the published endurance for Military steady-state operation.

Hydraulic system limits are set to protect the systems that move the flight controls. In the T-38C, hydraulic power drives the actuators that move the elevators, rudder, and ailerons, so staying within specified pressure and temperature ranges keeps those components from damage and keeps control surfaces responsive and reliable. If pressure is too high, actuators, hoses, and seals can be overstressed, leading to leaks, ruptures, or binding. If hydraulic fluid gets too hot, seals can degrade, viscosity can drop and stray or erratic motion can occur, plus components wear faster. Too cold, and fluid becomes overly viscous, making control inputs sluggish or unresponsive. All of this can compromise control authority, which is why the limits matter. Other choices miss the point because hydraulic limits aren’t primarily about protecting landing gear, monitoring electrical power, or safeguarding oxygen systems—those are different systems with their own limits and protections.