What airspeed range is recommended for airstarts from 15,001 to 20,000 feet msl?

The recommended airspeed range for airstarts from 15,001 to 20,000 feet mean sea level (MSL) is important for ensuring the proper aerodynamic characteristics needed for engine restart. The range of 135-200 KIAS takes into account the optimization of control authority and aircraft handling characteristics during an airstart.

At too low of an airspeed, the aircraft may not have sufficient airflow over the control surfaces, which can make it difficult to manage the aircraft effectively during the critical phases of the airstart process. Conversely, excessively high airspeeds might increase the difficulty of bringing the engine online, as well as the risk of stalling or losing control.

Therefore, the selected range of 135-200 KIAS provides a balanced approach, ensuring that the aircraft maintains sufficient airspeed to successfully execute the airstart while also preserving the necessary control and stability throughout the maneuver.