The Critical Importance of Weight in Aviation
In aviation, weight is a crucial factor that significantly impacts the safety and performance of flights. One of the critical scenarios where weight becomes a focal point is during an overweight landing.
What is an overweight landing?
An overweight landing is defined as a landing made at a gross weight exceeding the maximum design (i.e., structural) landing weight for a particular aircraft model.
Description: There are situations, such as an engine failure, that may necessitate an airplane to land shortly after takeoff. In such cases, the pilot faces two primary options:
- Land at a weight considerably above the maximum design landing weight: This option reduces the time spent in the air but may cause further damage to the aircraft and increase the risk of a runway excursion.
- Reduce the weight before landing:
This can be achieved in two ways -
Execute a holding pattern to burn fuel: This method is closer to normal operations but requires the aircraft to remain airborne longer.
Dump (jettison) fuel: This allows for a quicker landing within operational limits but may impact other aircraft or people on the ground.
Things pilots need to consider before an overweight landing
Regulatory: Generally, the maximum landing weight is an operational limitation that must be adhered to. However, deviations are permissible in the interest of safety, such as:
- A malfunction rendering the aircraft unairworthy.
- A situation where an expeditious landing reduces exposure to a hazard.
- A scenario requiring immediate medical attention.
Safety: Reducing the aircraft's weight requires additional time, increasing the risk of further deterioration of the situation. Conversely, an overweight landing reduces performance margins.
Ecological: Dumping fuel is generally undesirable below 5000-6000 feet, as the fuel may not evaporate before reaching the ground.
Airplane Structural Capability: While the maximum landing weight is an operational limitation, aircraft components, especially the landing gear, are designed to withstand much higher loads than those encountered during typical landings.
Airplane Performance Capability: The Aircraft Flight Manual (AFM) typically provides landing performance data at weights significantly above the maximum design landing weight. Pilots must balance maximum braking application with the available landing runway to avoid exceeding brake energy limits.
Automatic Landings: While automatic approaches can be attempted, it is generally recommended that landings be performed manually.
Inspection Requirements: A special inspection is usually required after an overweight landing, regardless of how smooth it was. Additional maintenance or repair actions may also be necessary.
While all three procedures (burn fuel, dump fuel, land overweight) are considered safe, it is the pilot's responsibility to assess the factors and choose the optimal solution for the specific situation.
Additive Manufacturing and Weight Reduction:
At BMT Aerospace, we are involved in projects that help set the standard for additive manufacturing (AM) in the future. AM has shown its ability to reduce the weight of manufactured parts significantly, which could be a huge benefit for the aerospace industry.
By leveraging AM technologies, we can produce lighter components without compromising on strength and durability. This weight reduction is essential for improving fuel efficiency, enhancing aircraft performance, and ensuring safer flights. Our commitment to innovation and advanced manufacturing techniques positions us at the forefront of the aerospace industry, driving progress and setting new benchmarks for the future.