Owner self-reported — never independently field-inspected
Location confidence
No coordinate anomaly detected
Terrain cross-check (USGS 3DEP)
FAA 255.5 ft MSL · USGS ground 31 ft · Δ 224 ft
Differential consistent with an elevated / rooftop pad
Structure cross-check (Overture / OSM)
Rooftop pad — the coordinate falls on a building footprint
Building height ≈ 47 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 46 ft short of the 100 ft footprint an eVTOL would need — shown to scale.
recorded pad eVTOL FATO
Recorded pad (limiting side)
54 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.
NFPA 418 adoption status not yet assessed for this jurisdiction.
FAA facility data
FAA LID
MA39
AIX ID
aix:hp:TM9P48T7
Lat / Lng
42.33639, -71.10675
Elevation
255.5 ft MSL
Pad dimensions
54 × 54 ft
Surface type
ROOF-TOP
Surface condition
GOOD
Activation date
2003/01
Last owner update
2022/10/11
FAA OEAAA airspace determinations1
Airspace clearance
On file as archived / procedural records — no standing clearance to track.
Filing activity
Most recent determination 2017-08-08
NRAARCH-DeterminedASN 2017-ANE-798-NRA2017-08-29
Form 7480 · 0 ft AGL — LAP ASN # 2017-ESA-5-LAP
Safety history (NTSB)1
Incident historyair-medical exposure
1 NTSB helicopter event within 3 nm since 2010 (1 incident); most recent 2010-12-04.
1 air-medical (EMS) event
INCIDENTEMS0.0 nm2010-12-04
EUROCOPTER DEUTSCHLAND GMBH MBB-BK 117 C-1 · Boston, MA — NTSB CAROL
NTSB helicopter accidents & incidents geocoded within 3 nm of this pad and attributed to the nearest facility — proximity, not a determination that an event occurred at this site. Source: NTSB aviation accident database.
Blueprint
The record vs. what we measured
64/100
DATA INTEGRITY
Surface elevation
The FAA record places this pad at 255.5 ft. USGS terrain plus the building put the actual rooftop at 79 ft — a -176.5 ft difference the federal record doesn’t carry.
eVTOL footprint
The 54 ft pad is 46 ft short of the 100 ft an eVTOL FATO requires (measured).
SIGNALFEDERAL RECORDMEASURED
Surface elevation255.5 ft79 ft · USGS+structure
Structurenot on recordRooftop pad
Pad dimensions54 ft side (filed)54 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.
BRIGHAM & WOMEN'S HOSPITAL, BOSTON, MA (FAA MA39). AirIndex facility record aix:hp:TM9P48T7. Verifiable at https://www.airindex.io/verify/aix:hp:TM9P48T7.