What is the limitation for minimum runway length for takeoff at maximum weight?

The limitation for minimum runway length for takeoff at maximum weight for the ERJ 170/175 is specified as 5,000 feet. This value reflects the necessary distance required to ensure a safe and effective takeoff under maximum weight conditions, accounting for factors such as aircraft performance, environmental conditions, and safety margins.

When flying at maximum weight, the aircraft's engines must generate sufficient thrust, and other performance considerations—such as takeoff distance, obstacle clearance, and engine-out scenarios—are critical. A minimum runway length of 5,000 feet allows for these factors to be adequately addressed, ensuring pilots have a safe operational limit during takeoff.

In contrast, other options like 4,000, 6,000, and 7,000 feet may not align with the designed performance specifications of the aircraft for safe takeoff at maximum weight, either being too short to handle the necessary distance or exceeding typical runway requirements for this aircraft type, potentially leading to inefficiencies in operational planning.