What value is associated with the starter becoming a generator?

• A. Speed of High Pressure Spool
• B. 7 bearings
• C. Pax emergency exit door
• D. 61.5%

Answer: (D)

The question is testing when the starter, which also serves as a generator, switches from cranking the engine to supplying electrical power. That take-over point is tied to engine speed, specifically the percentage of the high‑pressure spool (N2). When the engine reaches about 61.5% of its normal N2 speed, the starter transitions from acting as a motor to acting as a generator, beginning to produce electrical power for the aircraft systems. The other options don’t relate to this transition—the speed of a specific spool is not given as a fixed take-over value, and bearings or a Pax exit door have no bearing on the starter’s electrical mode.