Reference only — not for real-world navigation.
4LL9
Alan B. Janssen Airport · Morrisonville
Key Facts
Essential technical summary for MSFS 2020/2024 and X-Plane.
ILS Approach StatusILS DATA NOT IN DATABASE
Field Elevation
642 ft / 196 m
Transition Altitude
18,000 ft
Primary Channel
—
Live Conversion
inHg
hPa
Runway Summary (Quick-Links)
E/W · 1,980 ft · TurfUNLITFlight Planning
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Welcome to the technical flight briefing for Alan B. Janssen Airport (4LL9), located in Morrisonville, United States. As a vital hub for Microsoft Flight Simulator 2024, MSFS 2020, and X-Plane pilots, this facility features 1 active runway with a maximum elevation of 642 ft. Please note that this field primarily supports VFR and visual approach procedures.Reference the data below for primary communication channels and detailed runway characteristics. Pilots should observe a Transition Altitude of 18,000 ft verified for this field for altimeter reset procedures.
Full Name
Alan B. Janssen Airport
ICAO / IATA
4LL9 / —
Municipality
Morrisonville
Country
Region
US-IL — Illinois
GPS Coordinates
Transition Altitude
18,000 ft
Elevation
642 ft
Pilot Toolbox
External charts, live tracking and weather reports.
Runway E / W
UNLIT
Runway Length: 1,980 ft / 604 m
Runway Width: 75 ft / 23 m
Surface Type: Turf
Heading: —° / —°
Runway Width: 75 ft / 23 m
Surface Type: Turf
Heading: —° / —°
RWY E
No ILS / Visual Only
RWY W
No ILS / Visual Only
No frequency data available.
Base Airport Data: OurAirports (Public Domain)
Instrument Approach Data: AIP 2026 Researched · Cycle: Jan 2026