In the last few articles, I have outlined some of the basics of Flight Procedure and Airspace Design. In this post, I want to take a small digression and discuss Noise Abatement Procedures and THE fundamental problem with them as designed today: They are not integrated into the National Airspace System (NAS).
A vast majority of airports with noise abatement procedures (I would venture to say 98-99+%) do not mesh with existing aircraft flight procedures. Flight Procedures are very specific paths that aircraft fly. These are built by the FAA in conjunction with a number of stakeholders through a process that this blog series is shedding light on. Noise Abatement procedures are often developed by an airport or local community. These are not the same thing. (NOTE: the discussion here assumes a larger airport with business jets and/or commercial airline traffic. It does not assume small local airports solely served by General Aviation.)
Business Jets and commercial aircraft, when cleared for takeoff, are cleared on a very prescribed pattern that has been developed by the FAA in conjunction with Air Traffic Control and other stakeholders. These publications are free to the public for viewing and can be obtained here: https://www.faa.gov/air_traffic/flight_info/aeronav/digital_products/dtpp/search/
In our previous blog on “Airspace and Flight Procedure Development: Part 2 What is a Flight Procedure?” we provided insight and definition into procedures. We will not repeat that blog post here, but will simply say that Flight Procedures are how business jets and commercial aviation aircraft get to and from the ends of a runway at the airports they serve.
Noise Abatement Procedures
Communities around airports are becoming more involved in local flight activities at the airports near their homes. In an effort to mitigate impacts from increased aircraft activity at an airport, they work with local airport authorities to design their desires as to how an aircraft should fly when departing. For example: Fly heading 300 degrees until passing the industrial park, then fly on course.
Integration: Flight Procedures and Noise Abatement Procedures
Figure 1 shows an example procedure of a FAA designed flight path from a runway end. When an aircraft is cleared to depart these runways, they either fly a heading of 258 degrees or 078 degrees based on the current wind direction. What the aircraft has been given is an Air Traffic Control clearance and the pilots must comply with that clearance.
Figure 1. Departure Flight Procedure (Source: FAA)
Now, assume there is a noise abatement procedure at the airport as described above to fly a 300-degree heading until over the industrial park. The aircraft is not going to fly that procedure. They are going to fly their Air Traffic provided clearance.
The Problem & The Cure
The pilots cannot fly the noise abatement procedure as written for the following reasons: 1) Their ATC clearance mandates a 258-degree heading (assuming a west bound departure), 2) The departure procedure makes no mention of the noise abatement procedure, and 3) there is no way for the pilots to know where the industrial park is. Therefore, the fundamental problem becomes: There is no integration between the FAA developed flight procedures and the desired noise abatement procedure.
The solution is for all stakeholders to work together and develop a flight procedure that both works for Air Traffic Control and for the local community. Only then, will these two needs merge.
Airspace procedure development and the merger of noise abatement procedures is a complex task. The above provides a high-level overview of the issues. In our upcoming posts, we will continue to detail how all of this works, how procedures are designed, how aircraft navigate, and so on. At BridgeNet we work hard with local communities and the FAA to help bridge an understanding. This is accomplished through our outreach product, VOLANS (email us to see a demonstration), and our NextGen and Airspace experts.
About the Author:
Grady Boyce is a current and active Captain for a major airline flying the B-737. He has participated in, and led, airspace developments and ATC modernization efforts on all continents except Antarctica. Grady is a consultant to BridgeNet bringing flight procedure development, ATC expertise, and TERPS assistance into their current and future activities.