Final answer:
Engine start-up during aircraft pushback may be prohibited due to safety considerations, regulations, proximity to ground personnel or equipment, refueling operations, flammable hazards, aircraft maintenance issues, environmental concerns, or noise restrictions. The pilot-in-command, following airline and airport policies, decides when and where it is safe to start the engines.
Step-by-step explanation:
Starting an aircraft engine during pushback would be prohibited in situations where it may compromise safety or when regulations or procedures set by the airport or the airline dictate it.
For instance, engine start-up could be unsafe due to the proximity of ground personnel or equipment, refueling operations, or the presence of flammable hazards. Additionally, specific aircraft maintenance issues that require attention before the engine can be safely started may prohibit engine starting during pushback. Each airport and airline may have its own set of procedures that must be followed, and failure to comply with these could violate safety protocols and regulations.
Furthermore, environmental concerns and noise restrictions might mandate engine start only in designated areas further away from the terminal or in-flight paths. The pilot-in-command, complying with airline and airport policies, will typically be the one to decide when and where it is safe to start the engines.