City Of Colorado Springs Municipal to Billings Logan International COS → BIL
454 nautical miles (522 statute miles) north on a straight line, true course 339°, about 331° magnetic at the departure end (variation 8E). At 120 knots that is 3 h 10 min at the quickest height in today's winds (30,000 ft, a 23-knot tailwind), arriving about 6:51 am MDT (12:51 UTC), after sunset at the destination. Right now COS is VFR, wind from the south (180°) at 11 knots; BIL is marginal VFR, wind from the north (350°) at 11 knots. For planning, not a briefing: the legal preflight briefing comes from Flight Service (1-800-WX-BRIEF) or the FAA's own tools. Airlines fly this pair: 2 flights in the DOT's last twelve reported months, the route's page.
The route the straight line, the warnings crossed, restrictions, pilot reports and the airports along the way · click a mark for its words
Green, blue, red and purple airport dots are the flying conditions reported there now (VFR, marginal VFR, IFR, low IFR); grey means no report. Red areas are SIGMETs, orange areas AIRMETs, hatched red areas temporary flight restrictions. Map tiles: OpenFreeMap, data © OpenStreetMap contributors.
Warnings the route crosses SIGMETs and AIRMETs whose area the line passes through or comes within 25 nm of
- AIRMET TANGO 4W: moderate turbulence above 18,000 ft (due to mountain wave) from 34,000 ft to 43,000 ft. Over the first 286 nm of the route.
- AIRMET TANGO 2W: moderate turbulence below 18,000 ft (due to mountain wave) up to 22,000 ft. Over the first 286 nm of the route.
- AIRMET TANGO 1W: low-level wind shear (due to air speed loss or gain of 20 knots or more below 2,000 ft above the ground). Over the route from 10 to 306 nm out.
- AIRMET SIERRA 1E: mountains obscured by cloud (due to mountains obscured by clouds, precipitation, mist). Over the last 296 nm of the route.
- AIRMET TANGO 5W: strong surface winds (30 knots or more) (due to sustained surface winds greater than 30 knots). Over the route from 217 to 237 nm out.
- AIRMET SIERRA 4E: low cloud or poor visibility (IFR conditions) (due to ceilings below 1,000 ft, visibility below 3 miles, precipitation, mist). Over the last 168 nm of the route.
- AIRMET ZULU 2C: moderate icing up to 23,000 ft. Over the last 138 nm of the route.
A SIGMET warns of weather hazardous to all aircraft; an AIRMET of weather that matters to small aircraft and to flying without instruments. "From 60 to 180 nm out" is measured along the route from COS.
Pilot reports along the route within 50 nm of the line, last three hours, the serious ones first
- B737 at 18,000 ft, 22 nm east, 1:24 am MDT (07:24 UTC): moderate turbulence, remarks: FL180-130. 108 nm along the route, 22 nm east of the line.
as filed, and in English
DEN UA /OV DEN330050/TM 0724/FL180/TP B737/TB MOD/RM FL180-130
- Report
- a routine report filed through DEN
- Where
- 50 nm northwest (330°) of DEN
- Time
- 07:24 UTC
- Height
- at 18,000 ft
- Aircraft
- B737
- Turbulence
- moderate
- Remarks
- FL180-130
- B38M at 37,000 ft, 42 nm west, 1:42 am MDT (07:42 UTC): light chop turbulence, remarks: mtw +/-7KT zdvwc. At the departure end, 42 nm west of the line.
as filed, and in English
PUB UA /OV PUB280055/TM 0742/FL370/TP B38M/TB LGT CHOP/RM MTW +/-7KT. ZDVWC
- Report
- a routine report filed through PUB
- Where
- 55 nm west (280°) of PUB
- Time
- 07:42 UTC
- Height
- at 37,000 ft
- Aircraft
- B38M
- Turbulence
- light chop
- Remarks
- mtw +/-7KT zdvwc
- A320 at 31,000 ft, 42 nm southwest, 12:58 am MDT (06:58 UTC): light chop turbulence, remarks: mtw a 10-knot loss of airspeed 100FT zdvwc. At the departure end, 42 nm southwest of the line.
as filed, and in English
PUB UA /OV PUB260040/TM 0658/FL310/TP A320/TB LGT CHOP/RM MTW +/-10KT 100FT. ZDVWC
- Report
- a routine report filed through PUB
- Where
- 40 nm west (260°) of PUB
- Time
- 06:58 UTC
- Height
- at 31,000 ft
- Aircraft
- A320
- Turbulence
- light chop
- Remarks
- mtw a 10-knot loss of airspeed 100FT zdvwc
- A21N at 33,000 ft, 7 nm east, 12:59 am MDT (06:59 UTC): light chop turbulence, remarks: mtw a 10-knot loss of airspeed 100FT zdvwc. At the departure end, 7 nm east of the line.
as filed, and in English
COS UA /OV BRK/TM 0659/FL330/TP A21N/TB LGT CHOP/RM MTW +/-10KT 100FT. ZDVWC
- Report
- a routine report filed through COS
- Where
- over BRK
- Time
- 06:59 UTC
- Height
- at 33,000 ft
- Aircraft
- A21N
- Turbulence
- light chop
- Remarks
- mtw a 10-knot loss of airspeed 100FT zdvwc
- B38M at 22,000 ft, 30 nm west, 2:14 am MDT (08:14 UTC): no turbulence, remarks: zdvwc. 30 nm along the route, 30 nm west of the line.
as filed, and in English
DEN UA /OV DEN216059/TM 0814/FL220/TP B38M/TB NEG/RM ZDVWC
- Report
- a routine report filed through DEN
- Where
- 59 nm southwest (216°) of DEN
- Time
- 08:14 UTC
- Height
- at 22,000 ft
- Aircraft
- B38M
- Turbulence
- none
- Remarks
- zdvwc
- B737 descending, 23 nm east, 2:10 am MDT (08:10 UTC): light chop turbulence. 59 nm along the route, 23 nm east of the line.
as filed, and in English
DEN UA /OV DEN/TM 0810/FLDURD/TP B737/TB LGT CHOP
- Report
- a routine report filed through DEN
- Where
- over DEN
- Time
- 08:10 UTC
- Height
- during the descent
- Aircraft
- B737
- Turbulence
- light chop
- B737 descending, 23 nm east, 1:10 am MDT (07:10 UTC): remarks: smooth. 59 nm along the route, 23 nm east of the line.
as filed, and in English
DEN UA /OV DEN/TM 0710/FLDURD/TP B737/RM SMOOTH
- Report
- a routine report filed through DEN
- Where
- over DEN
- Time
- 07:10 UTC
- Height
- during the descent
- Aircraft
- B737
- Remarks
- smooth
Winds aloft along the route, and the time en route the forecast for use 08:00–15:00 UTC · at 120 knots true airspeed
The westbound cruising heights for this course (VFR: even thousands plus 500 ft; above 18,000 ft the forecast levels), with the wind averaged along the line from the 4 forecast points nearest it (DEN, BFF, LND, BIL). A plus sign is a headwind, a minus sign a tailwind.
| Height | Average wind | Head- or tailwind | Temperature | Ground speed | Time en route | Arrival |
|---|---|---|---|---|---|---|
| 8,500 ft | 260° at 19 kt | +5 kt | 7 °C | 115 kt | 3 h 57 min | 7:38 am MDT (13:38 UTC) |
| 10,500 ft | 250° at 21 kt | +2 kt | 4 °C | 118 kt | 3 h 51 min | 7:32 am MDT (13:32 UTC) |
| 12,500 ft | 240° at 25 kt | −3 kt | 1 °C | 123 kt | 3 h 41 min | 7:22 am MDT (13:22 UTC) |
| 14,500 ft | 230° at 30 kt | −8 kt | -4 °C | 128 kt | 3 h 33 min | 7:14 am MDT (13:14 UTC) |
| 16,500 ft | 230° at 36 kt | −13 kt | -8 °C | 133 kt | 3 h 25 min | 7:06 am MDT (13:06 UTC) |
| 18,000 ft FL180 | 220° at 40 kt | −17 kt | -11 °C | 137 kt | 3 h 19 min | 7:00 am MDT (13:00 UTC) |
| 24,000 ft FL240 | 220° at 49 kt | −21 kt | -22 °C | 141 kt | 3 h 13 min | 6:54 am MDT (12:54 UTC) |
| 30,000 ft FL300 | 220° at 58 kt | −23 kt | -32 °C | 143 kt | 3 h 10 min | 6:51 am MDT (12:51 UTC) |
| 34,000 ft FL340 | 230° at 63 kt | −21 kt | -37 °C | 141 kt | 3 h 13 min | 6:54 am MDT (12:54 UTC) |
| 39,000 ft FL390 | 230° at 65 kt | −21 kt | -46 °C | 141 kt | 3 h 13 min | 6:54 am MDT (12:54 UTC) |
Based on data from the 12th at 06:00 UTC; valid on the 12th at 12:00 UTC for use 08:00 to 15:00 UTC; temperatures above 24,000 ft are below zero. Heights are above sea level; a height is left out when the forecast has no wind for it over most of the line (the ground is higher). Ground speed is the airspeed less the headwind; the time en route is for the straight line and ignores climb, descent and routing around weather.
The forecast points as issued
| Point | From | 3,000 | 6,000 | 9,000 | 12,000 | 18,000 | 24,000 | 30,000 | 34,000 | 39,000 |
|---|---|---|---|---|---|---|---|---|---|---|
| DEN | used from 0 nm out; 42 nm from the line | 270/24 11° | 230/13 5° | 230/48 -8° | 230/46 -20° | 230/63 -30° | 240/78 -36° | 240/78 -48° | ||
| BFF | used from 148 nm out; 113 nm from the line | 280/28 | 260/39 11° | 240/34 5° | 210/38 -11° | 210/52 -22° | 230/61 -31° | 230/61 -36° | 240/56 -45° | |
| LND | used from 197 nm out; 105 nm from the line | 240/10 3° | 240/30 0° | 220/42 -13° | 230/52 -23° | 220/54 -33° | 220/52 -36° | 220/53 -44° | ||
| BIL | used from 345 nm out; 84 nm from the line | 300/14 | 270/19 -2° | 260/26 -2° | 220/28 -13° | 210/51 -25° | 220/56 -33° | 220/61 -39° | 220/72 -45° |
The weather now: both ends and the airports along the way public airports with a weather report within 25 nm of the line, one for each stretch
| Airport | Where | Conditions | Wind | Visibility | Ceiling | Elevation | Reported |
|---|---|---|---|---|---|---|---|
| COS Colorado Springs, CO | departure | VFR Sky: scattered clouds at 20,000 feet | from the south (180°) at 11 knots | 10+ mi | none | 6,187 ft | 2:54 am MDT (08:54 UTC) |
| BJC Denver, CO | 69 nm out, 6 nm east of the line, tower | VFR | from the south (180°) at 7 knots | 10+ mi | none | 5,673 ft | 09:35 UTC |
| FNL Fort Collins/Loveland, CO | 99 nm out, 22 nm east of the line, tower | VFR | from the southeast (140°) at 3 knots | 10+ mi | none | 5,020 ft | 08:56 UTC |
| LAR Laramie, WY | 158 nm out, 13 nm east of the line | VFR | from the west-southwest (240°) at 18 knots, gusting to 24 | 10+ mi | none | 7,283 ft | 08:53 UTC |
| CPR Casper, WY | 256 nm out, 15 nm northeast of the line, tower | VFR Sky: scattered clouds at 6,500 feet, a broken layer at 10,000 feet | from the southwest (230°) at 22 knots, gusting to 28 | 10+ mi | 10,000 ft | 5,344 ft | 08:53 UTC |
| WRL Worland, WY | 345 nm out, 21 nm southwest of the line | marginal VFR Sky: overcast at 1,000 feet | from the north-northwest (340°) at 8 knots | 10+ mi | 1,000 ft | 4,251 ft | 08:53 UTC |
| GEY Greybull, WY | 375 nm out, 13 nm southwest of the line | marginal VFR Sky: a few clouds at 1,000 feet, overcast at 2,800 feet Weather: mist | from the northwest (310°) at 9 knots | 6 mi | 2,800 ft | 3,941 ft | 09:28 UTC |
| BIL Billings, MT | destination | marginal VFR Sky: overcast at 1,800 feet Weather: light rain, light snow, mist | from the north (350°) at 11 knots | 4 mi | 1,800 ft | 3,662 ft | 2:53 am MDT (08:53 UTC) |
The highest airport on this list sits at 7,283 ft; the ground between airports is higher still. Check the sectional chart for the terrain and the minimum safe heights along the line.
At BIL when you get there the forecast at the estimated arrival, 6:51 am MDT (12:51 UTC)
Wind from the north-northwest at 10 knots, visibility 5 miles, light rain snow ice pellets, mist, a few clouds at 300 feet, overcast at 1,000 feet marginal VFR
The whole forecast for BIL
- From Mon 12:00 am MDT (06:00 UTC): wind from the north-northwest at 10 knots, visibility 5 miles, light rain snow ice pellets, mist, a few clouds at 300 feet, overcast at 1,000 feet
- At times between Mon 12:00 am MDT (06:00 UTC) and 4:00 am MDT (10:00 UTC): visibility 2 miles, light rain snow ice pellets, mist, a broken layer at 300 feet, overcast at 800 feet
- From Mon 7:00 am MDT (13:00 UTC): wind light and variable, visibility more than 6 miles, showers nearby, a few clouds at 300 feet, overcast at 800 feet
- From Mon 12:00 pm MDT (18:00 UTC): wind light and variable, visibility more than 6 miles, scattered clouds at 800 feet, a broken layer at 2,000 feet
- From Mon 8:00 pm MDT (02:00 UTC): wind from the east at 8 knots, visibility 5 miles, mist, a few clouds at 300 feet, overcast at 1,500 feet
The forecast for COS, the departure
- From Mon 12:00 am MDT (06:00 UTC): wind from the south at 12 knots, visibility more than 6 miles, scattered clouds at 6,000 feet, a broken layer at 20,000 feet
- From Mon 6:00 am MDT (12:00 UTC): wind from the north-northeast at 8 knots, visibility more than 6 miles, clear skies
- From Mon 11:00 am MDT (17:00 UTC): wind from the south at 15 knots, gusting to 25, visibility more than 6 miles, scattered clouds at 12,000 feet
- From Mon 1:00 pm MDT (19:00 UTC): wind from the south-southwest at 20 knots, gusting to 30, visibility more than 6 miles, scattered clouds at 12,000 feet
- From Mon 7:00 pm MDT (01:00 UTC): wind from the south-southwest at 12 knots, visibility more than 6 miles, clear skies
Temporary flight restrictions on the line or within 25 nm of it
- 6/8784 LAKE GEORGE, CO, Sunday, October 11, 2026 through Tuesday, October 13, 2026 UTC 25 nm from the route, 20 nm along the route · a hazard on the ground (fire-fighting, a chemical spill, rescue work) · until 13 October · ZDV
Daylight
Sunset at COS 6:23 pm MDT (00:23 UTC), at BIL 6:32 pm MDT (00:32 UTC) (civil twilight ends 7:02 pm MDT (01:02 UTC)). At 120 knots the arrival at BIL is before sunrise there (7:26 am MDT (13:26 UTC)).
Each restriction opens the FAA's own page with the exact area, heights and times. Ordinary notices to air missions (closed runways, lights out) are not shown: the FAA's notice search is not open to sites like this one at this time.
Radar and forecast charts for the regions crossed government pictures, the latest each time the page loads
Sources: the Aviation Weather Center's data service (SIGMETs, AIRMETs, graphical AIRMETs, pilot reports, winds and temperatures aloft, observations and terminal forecasts), the National Weather Service radar, the Weather Prediction Center's charts, the FAA's temporary flight restriction list and shapes, and the FAA's airport file for the positions, elevations and magnetic variation. Fetched when the page is viewed and kept a few minutes. Each leg is the straight line between its two airports; airways, terrain and airspace are not considered. The airports in detail: City Of Colorado Springs Municipal, Billings Logan International.