From the Flight Deck features insights from the core of our aviation family – our pilots! This issue, learn more about maximum take off weight with Mike Kopp, Jet Linx Director of Operations and longtime pilot.
Preflight preparations require a significant amount of planning. One factor in planning is to determine the Maximum Allowable Take-Off Weight. The Maximum Allowable Takeoff Weight (MATOW) represents the most conservative weight and is determined based on several calculations.
The first and most obvious limit is the maximum structural takeoff weight. Aircraft manufacturers publish these weights for aircraft, and they are mandatory maximums. The weights published in the Airplane Flight Manual (AFM) can be further broken down to Maximum Ramp Weight, Maximum Zero Fuel weight (MZFW) and the Maximum Landing Weight (MLW). Baggage compartments and closets also have their own published limitations. The loading of the aircraft must take all of these published weights into consideration and ensure none of the limitations are exceeded. There are also center of gravity limits which affect the forward and aft balance of the aircraft and may affect where in the aircraft the passengers and baggage can be placed.
While the structural limits of the aircraft are critically important, they don’t give the pilot any indication of the performance specific to any given flight. A pilot of a transport category airplane must ensure that the aircraft is at a weight appropriate for the airport and runway to be used. Every takeoff requires a Take-Off Field Length Computation to ensure the aircraft can takeoff after engine failure or accelerate to take off speed and then stop again on the runway. The length of the runway, elevation, temperature, barometric pressure and condition (wet, dry, snow etc.) all play a role in determining the maximum weight that will allow either of these scenarios. Once the runway limit is determined, the airman must also determine the obstacle limit. Obstacles in the intended flight path must be cleared in the event of an engine failure or malfunctions. High elevations and rising terrain often require the aircrafts weight be reduced to ensure a safe departure.
For each departure the Pilot in Command is required by law to prepare a Load Manifest that documents the actual weights and the MATOW along with the limitations on center of gravity to ensure a safe and successful flight.