Flight path research

Six departure procedures, one community, one question: which routing causes least harm?

This page presents a theoretical noise model comparing six proposed altitude-based departure restrictions for westbound flights from BWI Runway 15R — the procedure that concentrates aircraft over Severn, Maryland residential communities. The model draws on calibrated TrueNoise field measurements, 94 AirNoise complaint records, and three ADS-B approach tracks to ground the geometry in empirical data.

The Maryland Aviation Authority has submitted a proposal to the FAA to remove the WARYN waypoint and replace it with an altitude-based turn restriction. The FAA is conducting a feasibility study. This analysis models the MAA's proposed range (800–1,200 ft) alongside a community-proposed alternative: a new waypoint designated BRGHT at the Brightview Drive/Route 97 overpass, with a turn altitude of 3,000–5,000 ft.

800–1,200 ft turns

MAA proposed altitude range. All five turn within 1.26 nm of the runway — near-identical geometry to the current WARYN waypoint. Toggle each on/off to compare.

3,000 ft BRGHT

Community-proposed alternative. A new geographic waypoint at Brightview Dr/Route 97, 3.74 nm from the runway. All aircraft converge on this point — no performance-based dispersion.

Solid vs dashed lines

Each altitude shows 4 tracks — solid lines are light/fast-climbing aircraft, dashed are heavy/slow. The spread between them is the geographic dispersion band without a waypoint.

Markers

Yellow = Ashbrook observer (TrueNoise measurement location). Green = BRGHT proposed waypoint. Red = WARYN current waypoint. Click any marker for details.

How to use this map

Toggle altitude tracks on and off using the checkboxes in the map panel
Click any flight track for altitude, estimated noise level, and community impact
Click any marker (WARYN, BRGHT, Ashbrook, etc.) for detailed information
Zoom and pan freely — the map uses OpenStreetMap for accurate geography
Solid lines show light/fast aircraft; dashed lines show heavy/slow aircraft at the same altitude

Important: This is a theoretical model for research and public education. Peak noise estimates are computed from each procedure's closest-approach slant range to a receptor and anchored to TrueNoise field measurements (2,561 calibrated samples across 136 flights, 18–22 July 2026; external microphone on an IEC 61672 Class 2 traceable chain; mid-weight jet ≈ 69.7 dBA at 0.6 mi slant range). Each estimate is given as a range bracketing textbook inverse-square propagation against the steeper falloff measured at this site. Aircraft-class differences reflect measured source-level variation. Fuel estimates use published aircraft performance data. This is not a certified FAA AEDT noise analysis and should not be cited as one; precise receptor-by-receptor levels depend on turn radius, groundspeed, thrust schedule, and atmospheric conditions that only formal modeling resolves. Its purpose is to demonstrate that the BRGHT alternative warrants formal independent modeling by the FAA as part of its feasibility study — modeling this multi-track proposal has not yet received. See full methodology for the calibration chain and its limitations.

Turn altitude — toggle tracks

800 ft over homes

900 ft over homes

1,000 ft (≈ WARYN) over homes

1,100 ft over homes

1,200 ft over homes

3,000 ft (BRGHT) over parkland

            Label = where the concentrated departure burden falls. Click any track for the
            measured-anchored peak estimate at Ashbrook (one receptor; low turns move the
            burden to whichever community sits under that turn).
          

Dispersion (per altitude)

Light/fast climber (solid)

Heavy/slow climber (dashed)

4 tracks per altitude show the spread between lightest and heaviest aircraft. Without a geographic waypoint, this band determines which communities are overflown. BRGHT eliminates dispersion — all aircraft converge on the same point.

Key findings

800–1,200 ft: All turn within ~1.3 nm — near the current WARYN geometry. These options relocate the low-altitude overflight among residential neighborhoods; they do not remove it. Aircraft remain low and close to homes.

BRGHT 3,000 ft: Turn at 3.74 nm — the arc sweeps over the uninhabited Severn Run Nature Area, holding aircraft high until past the homes. This is the distributional case: the concentrated departure burden moves off residences onto parkland. Modeled peak at Ashbrook falls into the low-to-mid 60s dBA, from low 70s under the low-altitude turns.

Fuel delta: ~4 gallons per flight at 3,000 ft — 0.1% of total fuel load. Commercially immaterial.

How levels are estimated. Each track's closest-approach slant range to a receptor is computed from the turn geometry, then converted to a peak level anchored to TrueNoise field measurements (2,561 calibrated samples, 136 flights, IEC 61672 Class 2 chain; mid-weight jet ≈ 69.7 dBA at 0.6 mi). Ranges bracket textbook inverse-square against the site's measured falloff. These are estimates to show the proposal merits formal AEDT modeling — which it has not yet received — not a substitute for it.

Six departure procedures, one community, one question: which routing causes least harm?

Explore the BRGHT altitude tradeoff interactively