Clark Airport

23IS · Plymouth, IL · Print kneeboard

Elevation

570 ft MSL

Longest runway

1,600 ft E/W

Runway

Nearby now

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Weather

METAR observed

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TAF forecast

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Sun & FAA night2026-08-04 · night begins 08:45 PM

Event	Local (CDT)	UTC
Morning civil twilight Loggable night ends	05:33 AM	10:33Z
Sunrise	06:03 AM	11:03Z
Sunset	08:15 PM	01:15Z
Evening civil twilight Loggable night begins	08:45 PM	01:45Z

Loggable night (§1.1)

08:45 PM → 05:33 AM

Night currency (§61.57)

09:15 PM → 05:03 AM

Plan a flight from 23IS

Destination

TAS (kt)Burn (gph)Reserve (hr)Cruise (ft)Max alt (ft)Wind from (°)Wind (kt)

Winds aloft NOAA forecast · 3,000 to 53,000 ft

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Advisories

NOTAMs

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Pilot reports

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Airspace hazards

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Runways

RWY ELEFT traffic

Heading: 000° true
Dimensions: 1,600 × 70 ft
TPA: 1,600 ft MSL (≈1,000 AGL) · standard
Surface: TURF

Enter the left downwind (heading 180°) on the 45° at 1,600 ft MSL (≈1,000 AGL).

Pattern side: FAA NASR · TPA standard 1,000 ft AGL (not charted) · layout: schematic (headings + lengths)

Headings shown are true (magnetic variation unavailable).

Will it fit? Your aircraft's required runway length (from the POH) — checked against every runway here

ft · ≥1.5× comfortable, under 1.25× tight · saved across airports

Runway	Length	Your margin
E/W	1,600 ft

Prefer one flat page? Full runway details for 23IS → · New to pattern entries? The 45° entry, explained → · Teaching here? Print the 23IS kneeboard →

Comms & NavAids

Nearby navigation aids

BRL 115.55 · UIN 113.60

NavAid	Type	Freq · ch	Range	Radial / Dist magnetic
BRL · Burlington	VOR/DME	115.55 · 102Y	Low	r164° / 24.3 NM
UIN · Quincy	TACAN	113.60 · 83X	—	r031° / 35.4 NM

Charts & procedures

No published instrument procedures or Chart Supplement for 23IS — open it on the VFR sectional →

Airport info

Airport information

FAA LID: 23IS
Coordinates: 40.3257, -90.8276
Elevation: 570 ft MSL

Detailed FAA facility data isn't available for this airport.

No published services or facility detail for 23IS.

Nearby airports

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Also nearby: 5IS9 Mc Pherson Airport (private) (10 NM) · LL27 Smith Airport (12 NM) · IS56 Herren Airport (private) (15 NM) · IL52 Williams Airport (private) (16 NM) · 5K4 Schuy-Rush Airport (17 NM)

About 23IS

Clark Airport (23IS) is an airport in Plymouth, IL, at 570 ft MSL. It has 1 runway, the longest 1,600 ft. This page shows live METAR/TAF weather, runway crosswinds, frequencies, navaids, and FAA charts for 23IS, refreshed from the Aviation Weather Center and FAA NASR.

What is the longest runway at 23IS?

Clark Airport has 1 runway; the longest is 1,600 ft. See the Runways section for headings, surface, and lighting.

Where is 23IS?

Clark Airport is in Plymouth, IL, at an elevation of 570 ft MSL. Coordinates: 40.3257, -90.8276.

Fly out of 23IS often?

Save 23IS as your home base in the SkyReady app for a one-tap Go/No-Go readiness brief, weather alerts, and automatic FAA currency — free to log.

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Weather is live from the Aviation Weather Center; airport facility data is from the FAA NASR (28-day cycle). For planning and education only; always verify against official sources. Open 23IS in a full tool: METAR/TAF decoder, crosswind calculator, sun & night times, or the density altitude calculator. Planning from here? Find the nearest airport with fuel or an approach, or check whether an IFR alternate is required.