Owner self-reported — never independently field-inspected
Location confidence
No coordinate anomaly detected
Terrain cross-check (USGS 3DEP)
FAA 175 ft MSL · USGS ground 117 ft · Δ 58 ft
Differential consistent with an elevated / rooftop pad
Structure cross-check (Overture / OSM)
Rooftop pad — the coordinate falls on a building footprint
Building height ≈ 70 ft — measured independently of the FAA record
Cross-source consensus
Corroborated — terrain and structure agree (2/2 sources)
Cross-checked against independent public data — USGS 3DEP terrain, Overture/OSM building footprints, the federal hospital registry, and measured dimensions. The State of the U.S. Heliport Record →
The recorded pad is 70 ft short of the 100 ft footprint an eVTOL would need — shown to scale.
recorded pad eVTOL FATO
Recorded pad (limiting side)
30 ft
eVTOL FATO required
100 ft
FAA EB-105 vertiport pattern — 2× a ~50 ft eVTOL controlling dimension, plus a 125 ft safety-area side.
Load-bearing FATO
100 × 100 ft must be structural
No heliport precedent — typically the binding gate for rooftop and hospital pads.
Obstruction clearance
High obstacle within 0.5 nm — conflicts with the expanded footprint and 8:1 approach
Measured against FAA pad geometry and federal FATO sizing (EB-105). A dimensional pre-screen — site-level validation required, and independent of the underwriting risk score.
FAA compliance
Q1 · FAA registrationPASS
Active FAA NASR 5010 record.
Q2 · Airspace determinationUNKNOWN
FAA OE/AAA airspace determination data integration pending.
Q3 · State enforcementMODERATE
State has partial enforcement framework.
Q4 · NFPA 418UNKNOWN
NFPA 418 adoption status not yet assessed for this jurisdiction.
FAA facility data
FAA LID
8WA9
AIX ID
aix:hp:G3D11KFZ
Lat / Lng
47.61773, -122.35040
Elevation
175 ft MSL
Pad dimensions
30 × 30 ft
Surface type
MATS
Surface condition
GOOD
Activation date
1968/08
Last owner update
2026/05/11
FAA OEAAA airspace determinations0
No FAA OEAAA determinations linked to this facility.
Blueprint
The record vs. what we measured
76/100
DATA INTEGRITY
Surface elevation
The FAA record places this pad at 175 ft. USGS terrain plus the building put the actual rooftop at 187 ft — a +12 ft difference the federal record doesn’t carry.
eVTOL footprint
The 30 ft pad is 70 ft short of the 100 ft an eVTOL FATO requires (measured).
SIGNALFEDERAL RECORDMEASURED
Surface elevation175 ft187 ft · USGS+structure
Structurenot on recordRooftop pad
Pad dimensions30 ft side (filed)30 ft side · measured
Coordinate integrityas filedterrain cross-checked
Independent inspectionowner self-reportednone on record
✓Federal record
→
✓Cross-checkedUSGS · Overture · dimensions
→
3Physically verifiedGround Truth capture
Obstructions, exact FATO geometry, surface condition, and downwash exposure require a physical Ground Truth capture — not shown above as measured. A field verification completes the record and writes the measured truth to this facility’s authority.
This page is the public data-integrity record. The full RiskIndex assessment — Q1–Q5 compliance, dimensional / FATO analysis, an underwriting-grade risk score, peer benchmark, and a sealed Site Intelligence Report — is available on request.
BROADCAST HOUSE HELISTOP, SEATTLE, WA (FAA 8WA9). AirIndex facility record aix:hp:G3D11KFZ. Verifiable at https://www.airindex.io/verify/aix:hp:G3D11KFZ.