Grindstone Air Harbor Airport
29C · Port Austin, MI · 640 ft elevation · var 7W · Non-towered
Airport information
- FAA LID
- 29C
- Coordinates
- 44.0478, -82.9142
- Elevation
- 640 ft MSL
- Magnetic variation
- 7W
- Sectional chart
- LAKE HURON
- Airport use
- Public
- Control tower
- No
- ARTCC
- MINNEAPOLIS (ZMP)
- Flight service (FSS)
- LANSING · 1-800-WX-BRIEF
- NOTAM facility
- LAN
- Attendance
- UNATNDD
- Segmented circle
- No
- Wind indicator
- yes
- Activated
- 1996/11
- Distance from city
- 4 E
Weather
METAR observed
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TAF forecast
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Sun & FAA night 2026-06-22
| Event | Local (EDT) | UTC |
|---|---|---|
| Morning civil twilight Loggable night ends | 05:12 AM | 09:12Z |
| Sunrise | 05:49 AM | 09:49Z |
| Sunset | 09:18 PM | 01:18Z |
| Evening civil twilight Loggable night begins | 09:55 PM | 01:55Z |
Plan a flight from 29C
Night operations
- Pilot-controlled lighting
- Usually keyed on CTAF 122.9 — confirm the click sequence in the Chart Supplement
FAA night windows (civil twilight, loggable night §1.1, currency §61.57) are in the live weather panel above.
Traffic pattern
- Landing
- Rwy 18 · 185°
- Pattern
- left (turns left)
- TPA
- 1,600 ft MSL (≈1,000 AGL)
- CTAF
- 122.9
Enter the left downwind for Rwy 18 at 1,600 ft MSL (≈1,000 AGL) on a 45°. TPA estimated at 1,000 ft AGL (not charted for this field).
Runway 18/36
1,800 ft × 85 ft · Turf (Fair)- Heading
- 185° mag · 178° true
- Threshold elev
- 611 ft
- Traffic pattern
- Left
- Approach obstacle
- Trees, 18 ft, 0 ft from threshold, 65 ft R of centerline
- Heading
- 005° mag · 358° true
- Threshold elev
- 626 ft
- Traffic pattern
- Left
- Approach obstacle
- Trees, 30 ft, 0 ft from threshold, 65 ft L of centerline
| Runway | Length | Your margin |
|---|---|---|
| 18/36 | 1,800 ft |
Communication frequencies
Tower & ground
| CTAF | 122.9 |
Source: FAA NASR (current 28-day cycle).
Nearby navigation aids
| NavAid | Type | Freq | Radial / Dist magnetic |
|---|---|---|---|
| BAX · Bad Axe | VOR-DME | 108.20 | r016° / 16.2 NM |
| ASP · Au Sable | VOR-DME | 116.10 | r146° / 31.7 NM |
VFR sectional
No published instrument procedures or Chart Supplement for 29C. VFR sectional link above.
Ownership & management
Remarks FAA
- MAN-MADE OR NATURAL OBJECTS EXIST WI THE ASP NEEDED TO ENSURE SAFETY IN THE TKOF/LDG OF ACFT.
- FOR CD CTC MINNEAPOLIS ARTCC AT 651-463-5588.
- DEER & LRG BIRDS ON & INVOF ARPT.
- 3 FT YELLOW CONES.
- 3 FT YELLOW CONES.
- CTLG OBSTN EXCEEDS A 45 DEG SLP. APCH RATIO 16:1 TO THR OVR +76 FT TREE, 1244 FT DIST, 42 FT L. APCH RATIO 20:1 OVR 27 FT PLINE, 570 FT DIST, 125 FT L/R.
- CTLG OBSTN EXCEEDS A 45 DEG SLP. APCH RATIO 20:1 OVR 25 FT PLINE, 720 FT DIST, 125 FT L/R.
Nearby airports
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 29C 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.
About 29C
Grindstone Air Harbor Airport (29C) is an airport in Port Austin, MI, at 640 ft MSL. It has 1 runway, the longest 1,800 ft, with no control tower (pilot-controlled). This page shows live METAR/TAF weather, runway crosswinds, frequencies, navaids, and FAA charts for 29C, refreshed from the Aviation Weather Center and FAA NASR.
Does 29C have a control tower?
No. Grindstone Air Harbor Airport is a non-towered (pilot-controlled) airport; use the published CTAF/UNICOM on the Comms & NavAids tab.
What is the longest runway at 29C?
Grindstone Air Harbor Airport has 1 runway; the longest is 1,800 ft. See the Runways tab for headings, surface, and lighting.
Where is 29C?
Grindstone Air Harbor Airport is in Port Austin, MI, at an elevation of 640 ft MSL. Coordinates: 44.0478, -82.9142.
Fly out of 29C often?
Save 29C 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.