St Mary's traffic pattern

Pattern altitude at St Mary's (KSM · PASM) is 1,300 ft MSL (≈1,000 AGL) by the standard convention — none is published for this field, and every runway end is standard left traffic. · Open on the map

All of St Mary's — runways, frequencies, charts and live weather

Pattern diagram

Drawn to scale from the FAA NASR runway alignments and the per end right traffic flags — pick a runway to see its pattern. Live wind picks the favored runway when PASM reports it.

RWY 17LEFT traffic

Heading: 175° mag · 182° true
Dimensions: 6,000 × 150 ft
TPA: 1,300 ft MSL (≈1,000 AGL) · standard
Surface: GRAVEL
Lights: 4-light PAPI (left) (3°)
ILS: LOC/DME · CAT I · LOC 109.1 (SMA)
CTAF: 122.3

Enter the left downwind (heading 355°) on the 45° at 1,300 ft MSL (≈1,000 AGL).

More details — RWY 17

Threshold elev: 291 ft
Markings: none
Threshold crossing height: 51 ft
TDZ elevation: 306 ft
End lights: REIL

Condition: Good. Edge lights: High.

Pattern side: FAA NASR · TPA standard 1,000 ft AGL (not charted) · layout: FAA runway-end coordinates

Pattern direction by runway

Runway	Pattern	Heading	Pattern altitude
17	Left traffic	175° mag	1,300 ft MSL (≈1,000 AGL)
35	Left traffic	355° mag	1,300 ft MSL (≈1,000 AGL)
07	Left traffic	070° mag	1,300 ft MSL (≈1,000 AGL)
25	Left traffic	250° mag	1,300 ft MSL (≈1,000 AGL)

No pattern altitude is published for PASM; the figure above is the AC 90-66B 1,000 ft AGL convention for propeller aircraft, rounded to the field. Turbine aircraft normally fly 1,500 ft AGL. Headings are the runway alignment; downwind is the reciprocal.

Flying the pattern at PASM

St Mary's is non towered, so the pattern is self announced on CTAF 122.3. AC 90-66B asks for a report on entry and on each leg, and for the standard 45° entry to downwind at pattern altitude.

All ends are left traffic, which is the FAR 91.126 default — turns to the left unless the field charts otherwise. The full entry procedure is here →

Frequently asked

What is the traffic pattern altitude at PASM?

St Mary's has no traffic pattern altitude published in the FAA NASR data. The AC 90-66B convention for propeller aircraft is 1,000 ft AGL, which works out to roughly 1,300 ft MSL (≈1,000 AGL) here — but confirm it against the Chart Supplement before you fly, since a field can have a non standard pattern altitude that NASR does not carry.

Does PASM have right traffic?

No. All 4 runway ends at St Mary's use standard left traffic, so no right pattern is charted here.

What frequency is the pattern on at PASM?

St Mary's is non towered, so pattern position reports go on the CTAF, 122.3. AC 90-66B asks for self announcing on entry and on each leg.

More about PASM

Pattern direction and alignment are drawn from the FAA NASR (28-day cycle); the diagram is generated, not an FAA chart. Pattern altitude is shown as published where NASR carries one, otherwise as the AC 90-66B 1,000 ft AGL convention. For planning and education only; always verify against the Chart Supplement.

Something here wrong or out of date? Report a data problem.