How does the angle of descent change when an aeroplane descends from FL410 to FL270, then from FL270 to FL100 at IAS achieved at FL270 assuming idle thrust?

When an aeroplane descends from a higher altitude to a lower altitude, the angle of descent is influenced by the indicated airspeed (IAS) and the rate of descent. In this scenario, the aeroplane descends first from Flight Level 410 (FL410) to Flight Level 270 (FL270) and then from FL270 to Flight Level 100 (FL100) while maintaining the indicated airspeed achieved at FL270 and with idle thrust settings.

During the descent from FL410 to FL270, the angle of descent will increase because the aircraft is starting from a higher altitude and descending to a lower altitude. The steepness of the descent increases as the aircraft descends from a greater initial altitude. The aircraft is descending at idle thrust, which means it is not generating significant lift and will have a higher rate of descent relative to its forward speed influenced by IAS.

When transitioning from FL270 to FL100, although the aircraft is still in a descent, the angle will change as well. However, the IAS remains constant during this leg, and since the altitude difference is less than during the earlier segment, the angle of descent will remain constant at this stage. Since there's less altitude to lose, the descent rate may decrease to