The Proposed South Flow Departure Revision - Because “Nobody Lives There”

A proposed change to DCA South Flow departure procedures would lead to more aircraft noise in Accokeek and Fort Washington. Also: how a community in Northern Virginia got their proposal onto the table.

As we’ve previously shared, DCA has two operating patterns: North Flow and South Flow. Because of weather patterns and the FAA’s safety concerns, DCA operates in North Flow more often than it does South Flow (i.e. approximately 70% of the time). During North Flow operations, areas of Accokeek and western Fort Washington under the arrival paths have aircraft passing overhead continuously and incessantly. During South Flow operations, departing DCA air traffic veer east or west five miles south of the runway, meaning that relatively few of these flights pass over Southern Maryland, and leading to a temporary respite for residents in these communities.

Figure 1: Current DCA South Flow Departures on a typical day.

This would change if a proposal created by the FAA is enacted. To solve the noise problem for the Fort Hunt neighborhood, the proposed revision would bring departing westbound South Flow traffic further down the river to a waypoint over Piscataway Creek, where they would make the turn west. (A waypoint is a fixed coordinate with a unique identifier, used extensively on air navigation charts.)

Figure 2: The controversial FAA proposal to revise South Flow departures

While the “hypothetical revision” (dotted red line in Figure 2) is plotted mostly over the river, compare the plotted lines between waypoints and actual flight paths taken on Figure 1 , and note how many planes overfly the curve. Waypoint to waypoint navigation is controlled by the NextGen system, i.e. by flight computers using GPS; the implementation of how to fly a curve varies between different flight computer manufacturers, and so is not as uniform as direct point to point flight. The upshot of this is that residents along the river, perhaps as far south as Bryan Point Rd, would have departing flights overhead at between 5000 and 7000 feet on a regular basis on South Flow days. Note that residents of the Hatton Point neighborhood in Fort Washington would likewise be subject to the double dose of air traffic, at even lower altitudes.

It should be noted that the departing flights which would pass over portions of Accokeek and Fort Washington due to this revision would be flying higher than the current arriving flights do during North Flow operations, however the would be climbing so the noise would still be significant. It would mean that parts of the neighborhood would be subject to aircraft noise all of the time, i.e. whichever direction the airport was operating, and therefore the proposal would be of further detriment to the region.

Of less consequence to Southern Maryland communities is the “domino” proposed change to the northbound South Flow arrival route (dotted blue line in Figure 2). Most South Flow arrivals meet the final approach path from the north; however, aircraft from the south are sometimes routed over Southern Maryland, albeit at a high enough altitude to not be a serious noise nuisance. Because this existing arrival path would intersect with the new proposed departure route at a closer altitude (8500ft to 6000ft vs 8200ft to 4000ft), the FAA thought it wise to move the path east by around a mile in order to widen the altitude gap further.

Some on the MWAA working group objected to this plan on the basis that it shifted the noise burden unfairly to the Accokeek/Fort Washington area. A rejoinder from representatives from other regions, related third hand, was that “nobody lives there”.

It is certainly in the area’s interest to push back on this plan, which is still in very early planning stages. There are 37 distinct steps that a revision of this manner needs to go through in order to be approved, and its chances of succeeding are reportedly middling, at best. Nevertheless, when the FAA does start to seek public comment, concerted effort by the community to show that in fact significantly more than “nobody” actually do live here would be desirable. Please subscribe to our mailing list to be kept up to date on these developments.

The Genesis of the Plan

There’s a backstory to this proposal, and it may be instructive to our community’s efforts to enact a change to the North Flow arrival routing. We pieced this together from conversations with MWAA representatives and subsequent googling. It all began with NextGen.

Figure 3: The effect of NextGen on South Flow operations

NextGen is a modernization of air traffic routing, currently being deployed across the country by the FAA. Prior to NextGen, aircraft used ground based radar waypoints to navigate between airports. With NextGen, aircraft can instead rely on computer guidance, using GPS, to fly more directly between airports, with time and requisite fuel efficiency gains - for example, the Dulles to Los Angeles route can now be flown an hour quicker with these improved systems, since the prior “point to point” route has become a straight line. Theoretically, this is a win/win for all; the airlines would save money, passengers would save time, and the environment would have less air pollution. The reality of the implementation, however, is messier - and this is well illustrated by this situation.

When aircraft depart an airport, they fly between waypoints to get out of the region’s airspace, before setting their course to the destination. Prior to NextGen, when getting between these waypoints was done by radar, the pilots had more room for “interpretation”; now that the precision of tracking the aircraft’s location has been improved and computers are guiding the navigation, the area of land over which the planes fly when travelling between waypoints is concentrated. This is obvious in Figure 3, above: when planes previously made the westbound turn, they’d be flying over anywhere between Belle Haven and Fort Hunt. Post NextGen, the vast majority of westbound South Flow departures now pass over one neighborhood north of Fort Hunt known as Villamay. While residents elsewhere in the area experienced a relief because of this change, residents in the relatively small area under the tightened path went from planes passing over intermittently to continuous and incessant overhead flights during South Flow operations. To the FAA this is a “successful outcome”: fewer people are troubled by (and complaining about) noise -- and therefore they’ve lessened the noise impact, so job well done. Too bad for the individuals under the concentrated flight path whose quality of life was severely reduced.

Of note to this situation, the law known as Title 14 Part 150 has a clause which may be applicable, and which reads as follows (emphasis ours):

(f)(1) Title 49, section 47506 provides that no person who acquires property or an interest therein after the date of enactment of the Act in an area surrounding an airport with respect to which a noise exposure map has been submitted under section 47503 of the Act shall be entitled to recover damages with respect to the noise attributable to such airport if such person had actual or constructive knowledge of the existence of such noise exposure map unless, in addition to any other elements for recovery of damages, such person can show that

(i) A significant change in the type or frequency of aircraft operations at the airport; or

(ii) A significant change in the airport layout; or

(iii) A significant change in the flight patterns; or

(iv) A significant increase in nighttime operations;

occurred after the date of the acquisition of such property or interest therein and that the damages for which recovery is sought have resulted from any such change or increase.”

Based on the change evidenced in Figure 3, it would seem quite reasonable for residents in the Villamay area to attempt to claim damages based on clause iii (“significant change in flight patterns”) of this law. Indeed, similar legal challenges have been made to the FAA by other communities affected by NextGen.

The Villamay Community Association began fighting back, quickly getting their concerns heard via their representative on the MWAA Noise Working Group.

Don Minnis: Ft. Hunt homeowners are very discontented from being bombarded by South Flow departures.

Can FAA extend South Flow departures along the Potomac River, currently turning southwest at 5 miles over VA, to turn southeast at 10 miles over an uninhabited MD park (Piscataway Park)?

Mike Jeck:/MWAA Noise Office: Accokeek, MD is located ~10 south of DCA. MWAA currently receives a lot of noise complaints from that area.

They kept up the drumbeat, gathering 493 signatures on a petition.

The Villamay Community Association is beginning a door-to-door signature drive for a “Statement of Concern” regarding the unacceptable level of air traffic noise generated by South Flow flights to and from Reagan National Airport. Villamay and surrounding neighborhoods south of Old Town Alexandria have experienced an increase in air traffic noise since the implementation of the Federal Aviation Administration’s NextGen air traffic control system. The new nationwide system of flight routing was implemented without community comment.

The FAA reacted rapidly with the proposed revision discussed above, and the MWAA working group then issued a formal recommendation, which endorsed the idea of modifying the southern flight route.

The Working Group endorses the concept of the FAA modifying flight paths south of DCA to keep aircraft more centered over the Potomac River on departures, as well as modifying waypoints to move departing aircraft farther down the Potomac River before turning east or west. A vote on a firm recommendation for the FAA to pursue such changes is pending consultation with Working Group members representing communities that would be impacted by these adjustments, as well as consultations with the airlines serving DCA.

The residents pressed on, convincing their congressman Don Beyer to join the congressional Quiet Skies Caucus.

In August 2016, after more internal discussion, the MWAA working group issued a second recommendation:

The Working Group will continue its dialog with the FAA, the airlines and the Airports Authority on flight paths and other pertinent operating characteristics related to aircraft noise. The Working Group further recommends relocating the turning point for aircraft heading west off the river farther south along the Potomac River to minimize flight over residential areas and at a location where aircraft have reached the highest practical altitudes, consistent with the FAA’s study of operational considerations.

The Working Group further recommends that the FAA engage in outreach to communities that could be impacted by modifications in flight paths or procedures resulting from this recommendation.

For the record, Southern Maryland Fair Skies Coalition sought to set up a meeting with FAA contacts in November 2016, and were rebuffed:

We are committed to working with airport noise roundtables or working groups like the one at DCA because it’s the best use of our limited resources and it has all communities represented and sitting around the table - with FAA, the airport authority, and industry - hearing the same information and involved in the same discussion. To do otherwise inevitably leads some communities to believe “deals” are being cut with others at their expense. Viable solutions to address noise concerns in heavily populated areas around an airport are never easy to attain and will generally involve a give and take with communities, industry, the airport authority, and FAA. For example, the DCA Noise Working Group recently recommended FAA look at the departures to the south of DCA to try and adjust them more over the river – a longstanding goal for both arrivals and departures at DCA. That work has just begun but before any decision is made on a final path, we will hold FAA sponsored public workshops to provide information and get comments and feedback.

-- FAA Official, via email

As of October 21st, the progress on the proposal was described as follows:

The MWAA WG community reps met on October 19 to get consensus on a comprehensive plan to present to MWAA and the FAA at the Nov 3 meeting. The reason for the comprehensive plan is that the reps have been focused only on what affects their community, which is not unexpected. As a result the collective focus was lost and the WG forgot that they are dealing with a system problem not just a noise issue over DC, Montgomery County, Prince George’s County, Alexandria and Fairfax County. There are many community working groups across the US dealing with the same issue and some airport authorities use these groups to demonstrate to the public that they care. Privately that may not be the case. We are fortunate that we have a WG that is making progress even though it is slow. BWI is dealing with similar noise issues, and the MAA and FAA are just starting to consider meeting with community reps.

Political pressure has some impact, but in the end, unless there is something substantial to recommend other than get the FAA to move more quickly, the politicians will get their face time with the FAA. Then, the FAA will tell them they are working on it and reference all the support and activity they are doing with a WG. Everyone walks away; blocks are checked, and everyone is satisfied except for us.

As you may know, Prince George’s County does not support the conceptual revised flight procedure for south flow, and, last week I gave a presentation to the Mount Vernon Citizens Association (not MVCCA) explaining the process and the conceptual south flow departure procedure. They were not very supportive and were highly concerned that they will inherit more noise, which may mean they are not likely to support any changes to south flow. Another challenge that hopefully can be overcome.

- Source withheld due to email addresses embedded within.

The minutes of the Nov 3rd MWAA meeting have not been publicly posted as of the date of this posting. We'll post an update once they are available.

While the proposed revision is currently passing through bureaucratic process and is far from being a slam dunk, it was a huge success for the Villamay community to clear the first hurdle to get the proposal on to the table, and to get the working group’s backing.

Given the long and established history of community activism in the Accokeek area, it’s not a leap to suggest that we can replicate this model. The community made their case, demonstrated widespread community support via a petition, and then worked with their representative on the MWAA working group to get the process moving.

In our discussion with the MWAA, they asserted that North Flow arrivals haven’t been impacted by the NextGen rollout, and that therefore we have less of a case than Villamay to lobby for revisions. The counter argument can be made that our situation is actually worse than Villamay’s: we have a concentrated flight path over our neighborhood which carries 100% of arriving traffic 70% of the time (as opposed to the 60% of departing traffic going over Villamay 30% of the time), and at significantly lower altitudes to boot. Have flight patterns “significantly changed” over our neighborhood since the last Part 150 noise contour study was undertaken in 2004? Anecdata says yes. We’re actively working on gathering hard data to prove the point. With this, we hope to be able to make the case so that the MWAA working group can enact a similar recommendation, and the FAA can propose an alternate North Flow arrival route which is more equitable to the Southern Maryland area. Please sign up to our mailing list if you’d like to help with these efforts.