Seattle-Tacoma International to Perot Fld/Fort Worth Alliance Airport SEA → AFW
1,427 nautical miles (1,642 statute miles) southeast on a straight line, true course 118°, about 102° magnetic at the departure end (variation 16E). At 120 knots that is 10 h 25 min at the quickest height in today's winds (39,000 ft, a 17-knot tailwind), arriving about 9:02 am CDT (14:02 UTC). Right now SEA is VFR, wind from the north-northeast (030°) at 8 knots; AFW is VFR, wind from the south (170°) at 10 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: 492 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
- SIGMET W11W: thunderstorms (a convective SIGMET) up to 34,000 ft, moving from the southwest at 40 knots, until 9:55 pm PDT (04:55 UTC). Near the route, 938 nm along the route.
as issued
WSUS33 KKCI 120255 MKCW WST 120255 CONVECTIVE SIGMET 11W VALID UNTIL 0455Z CO NM FROM 20WNW PUB-10ENE CIM-50WNW ABQ-30NNE DVC-20WNW PUB AREA TS MOV FROM 22040KT. TOPS TO FL340.
- AIRMET TANGO 1W: moderate turbulence above 18,000 ft from 18,000 ft to 39,000 ft. Over the first 160 nm of the route.
- AIRMET ZULU 2C: moderate icing up to 20,000 ft. Over the route from 60 to 319 nm out.
- AIRMET SIERRA 1E: mountains obscured by cloud (due to mountains obscured by clouds, precipitation, mist). Over the route from 190 to 728 nm out.
- AIRMET TANGO 1W: moderate turbulence above 18,000 ft from 18,000 ft to 36,000 ft. Over the route from 279 to 419 nm out.
- AIRMET ZULU 2C: moderate icing up to 23,000 ft. Over the route from 329 to 738 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 route from 359 to 449 nm out.
- AIRMET TANGO 4W: moderate turbulence below 18,000 ft up to 18,000 ft. Over the route from 549 to 1028 nm out.
- AIRMET TANGO 4W: moderate turbulence above 18,000 ft from 18,000 ft to 36,000 ft. Over the route from 559 to 998 nm out.
- 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 599 to 908 nm out.
- AIRMET TANGO 5W: strong surface winds (30 knots or more) (due to sustained surface winds greater than 30 knots). Over the route from 639 to 708 nm out.
- AIRMET SIERRA 1E: mountains obscured by cloud (due to mountains obscured by clouds, precipitation, mist). Over the route from 848 to 868 nm out.
- AIRMET TANGO 2W: moderate turbulence above 18,000 ft from 35,000 ft to 45,000 ft. Near the route, 1008 nm along the route.
- AIRMET TANGO 3W: 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 1028 to 1108 nm out.
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 SEA.
Pilot reports along the route within 50 nm of the line, last three hours, the serious ones first
- urgent B737 at 7,600 ft, 16 nm northeast, 8:22 pm PDT (03:22 UTC): remarks: low-level wind shear 45 knots crosswind on final. 768 nm along the route, 16 nm northeast of the line.
as filed, and in English
HDN UUA /OV HDN/TM 0322/FL076/TP B737/RM LLWS 45 KTS CROSSWIND ON FINAL
- Report
- an urgent report filed through HDN
- Where
- over HDN
- Time
- 03:22 UTC
- Height
- at 7,600 ft
- Aircraft
- B737
- Remarks
- low-level wind shear 45 knots crosswind on final
- urgent B407 at 10,000 ft, 7 nm northeast, 7:13 pm PDT (02:13 UTC): moderate to severe turbulence. 918 nm along the route, 7 nm northeast of the line.
as filed, and in English
COS UUA /OV 10 W COS/TM 0213/FL100/TP B407/TB MDT-SEV
- Report
- an urgent report filed through COS
- Where
- 10 west cos
- Time
- 02:13 UTC
- Height
- at 10,000 ft
- Aircraft
- B407
- Turbulence
- mdt-sev
- E75L at 28,000 ft, 6 nm south, 6:31 pm PDT (01:31 UTC): moderate turbulence, remarks: ZDVWC-03. 788 nm along the route, 6 nm south of the line.
as filed, and in English
EEO UA /OV EKR085036/TM 0131/FL280/TP E75L/TB MOD/RM ZDVWC-03
- Report
- a routine report filed through EEO
- Where
- 36 nm east (085°) of EKR
- Time
- 01:31 UTC
- Height
- at 28,000 ft
- Aircraft
- E75L
- Turbulence
- moderate
- Remarks
- ZDVWC-03
- B738 at 23,000 ft, 49 nm northeast, 7:34 pm PDT (02:34 UTC): moderate turbulence, remarks: during the climb ZDVWC-05. 858 nm along the route, 49 nm northeast of the line.
as filed, and in English
DEN UA /OV DVV270030/TM 0234/FL230/TP B738/TB MOD /RM DURC ZDVWC-05
- Report
- a routine report filed through DEN
- Where
- 30 nm west (270°) of DVV
- Time
- 02:34 UTC
- Height
- at 23,000 ft
- Aircraft
- B738
- Turbulence
- moderate
- Remarks
- during the climb ZDVWC-05
- BCS1 at 24,000 ft, 49 nm northeast, 6:30 pm PDT (01:30 UTC): moderate turbulence from 22,000 ft to 24,000 ft, remarks: during the climb ZDVWC-05. 858 nm along the route, 49 nm northeast of the line.
as filed, and in English
DEN UA /OV DVV270030/TM 0130/FL240/TP BCS1/TB MOD 220-240/RM DURC ZDVWC-05
- Report
- a routine report filed through DEN
- Where
- 30 nm west (270°) of DVV
- Time
- 01:30 UTC
- Height
- at 24,000 ft
- Aircraft
- BCS1
- Turbulence
- moderate from 22,000 ft to 24,000 ft
- Remarks
- during the climb ZDVWC-05
- GLF4 at 25,000 ft, 25 nm northeast, 7:05 pm PDT (02:05 UTC): moderate turbulence, remarks: during the climb ZDVWC-05. 868 nm along the route, 25 nm northeast of the line.
as filed, and in English
DEN UA /OV FQF250040/TM 0205/FL250/TP GLF4/TB MOD /RM DURC ZDVWC-05
- Report
- a routine report filed through DEN
- Where
- 40 nm west (250°) of FQF
- Time
- 02:05 UTC
- Height
- at 25,000 ft
- Aircraft
- GLF4
- Turbulence
- moderate
- Remarks
- during the climb ZDVWC-05
- B738 at 18,000 ft, 5 nm northeast, 7:02 pm PDT (02:02 UTC): moderate chop turbulence from 18,000 ft to 25,000 ft, remarks: during the climb ZDVWC-41. 898 nm along the route, 5 nm northeast of the line.
as filed, and in English
COS UA /OV BRK270030/TM 0202/FL180/TP B738/TB MOD CHOP 180-250/RM DURC ZDVWC-41
- Report
- a routine report filed through COS
- Where
- 30 nm west (270°) of BRK
- Time
- 02:02 UTC
- Height
- at 18,000 ft
- Aircraft
- B738
- Turbulence
- moderate chop from 18,000 ft to 25,000 ft
- Remarks
- during the climb ZDVWC-41
- BE9L at 24,500 ft, 34 nm southwest, 7:21 pm PDT (02:21 UTC): moderate turbulence, remarks: ZDVWC-41. 928 nm along the route, 34 nm southwest of the line.
as filed, and in English
PUB UA /OV PUB250040/TM 0221/FL245/TP BE9L/TB OCNL MOD/RM ZDVWC-41
- Report
- a routine report filed through PUB
- Where
- 40 nm west (250°) of PUB
- Time
- 02:21 UTC
- Height
- at 24,500 ft
- Aircraft
- BE9L
- Turbulence
- occasional moderate
- Remarks
- ZDVWC-41
- SB20 at 16,000 ft, 43 nm northeast, 6:52 pm PDT (01:52 UTC): remarks: zse. At the departure end, 43 nm northeast of the line.
as filed, and in English
PAE UA /OV PAE075045/TM 0152/FL160/TP SB20/SK TOP120/RM ZSE
- Report
- a routine report filed through PAE
- Where
- 45 nm east (075°) of PAE
- Time
- 01:52 UTC
- Height
- at 16,000 ft
- Aircraft
- SB20
- Sky
- TOP120
- Remarks
- zse
- A321 at 13,500 ft, 17 nm south, 6:54 pm PDT (01:54 UTC): remarks: zse. At the departure end, 17 nm south of the line.
as filed, and in English
SEA UA /OV SEA120045/TM 0154/FL135/TP A321/SK TOP130/RM ZSE
- Report
- a routine report filed through SEA
- Where
- 45 nm southeast (120°) of SEA
- Time
- 01:54 UTC
- Height
- at 13,500 ft
- Aircraft
- A321
- Sky
- TOP130
- Remarks
- zse
- PC12 at 13,000 ft, 17 nm south, 5:42 pm PDT (00:42 UTC): remarks: zse. At the departure end, 17 nm south of the line.
as filed, and in English
YKM UA /OV YKM270050/TM 0042/FL130/TP PC12/SK TOP130/RM -ZSE
- Report
- a routine report filed through YKM
- Where
- 50 nm west (270°) of YKM
- Time
- 00:42 UTC
- Height
- at 13,000 ft
- Aircraft
- PC12
- Sky
- TOP130
- Remarks
- zse
- PC12 at 15,000 ft, 17 nm south, 5:42 pm PDT (00:42 UTC): remarks: zse. At the departure end, 17 nm south of the line.
as filed, and in English
YKM UA /OV YKM270050/TM 0042/FL150/TP PC12/SK TOP130/RM -ZSE
- Report
- a routine report filed through YKM
- Where
- 50 nm west (270°) of YKM
- Time
- 00:42 UTC
- Height
- at 15,000 ft
- Aircraft
- PC12
- Sky
- TOP130
- Remarks
- zse
- C337 at 12,000 ft, 26 nm south, 6:18 pm PDT (01:18 UTC): light rime icing, -12 °C, remarks: zse. 100 nm along the route, 26 nm south of the line.
as filed, and in English
YKM UA /OV YKM155020/TM 0118/FL120/TP C337/TA M12/IC LGT RIME/RM ZSE
- Report
- a routine report filed through YKM
- Where
- 20 nm southeast (155°) of YKM
- Time
- 01:18 UTC
- Height
- at 12,000 ft
- Aircraft
- C337
- Temperature
- −12 °C
- Icing
- light rime
- Remarks
- zse
- PC12 at 13,500 ft, 27 nm northeast, 6:08 pm PDT (01:08 UTC): no turbulence, a trace of icing, overcast from 9,000 ft to 13,500 ft, -10 °C. 140 nm along the route, 27 nm northeast of the line.
as filed, and in English
PSC UA /OV PSC360025/TM 0108/FL135/TP PC12/SK OVC090-TOP135/TA M10/TB NEG /IC TRACE RM 135-090
- Report
- a routine report filed through PSC
- Where
- 25 nm north (360°) of PSC
- Time
- 01:08 UTC
- Height
- at 13,500 ft
- Aircraft
- PC12
- Sky
- overcast from 9,000 ft, tops 13,500 ft
- Temperature
- −10 °C
- Turbulence
- none
- Icing
- trace remarks from 13,500 ft to 9,000 ft
11 more routine reports are on the map.
Winds aloft along the route, and the time en route the forecast for use 02:00–09:00 UTC · at 120 knots true airspeed
The eastbound cruising heights for this course (VFR: odd thousands plus 500 ft; above 18,000 ft the forecast levels), with the wind averaged along the line from the 14 forecast points nearest it (SEA, YKM, LWS, BOI, PIH, RKS, GJT, DEN, PUB, GCK, AMA, GAG, SPS, DAL). A plus sign is a headwind, a minus sign a tailwind.
| Height | Average wind | Head- or tailwind | Temperature | Ground speed | Time en route | Arrival |
|---|---|---|---|---|---|---|
| 5,500 ft | 210° at 10 kt | +3 kt | 11 °C | 117 kt | 12 h 12 min | 10:49 am CDT (15:49 UTC) |
| 7,500 ft | 220° at 16 kt | 0 | 7 °C | 120 kt | 11 h 54 min | 10:31 am CDT (15:31 UTC) |
| 9,500 ft | 230° at 16 kt | −2 kt | 4 °C | 122 kt | 11 h 42 min | 10:19 am CDT (15:19 UTC) |
| 11,500 ft | 240° at 18 kt | −4 kt | 1 °C | 124 kt | 11 h 30 min | 10:07 am CDT (15:07 UTC) |
| 13,500 ft | 230° at 20 kt | −3 kt | -3 °C | 123 kt | 11 h 36 min | 10:13 am CDT (15:13 UTC) |
| 15,500 ft | 220° at 23 kt | −2 kt | -7 °C | 122 kt | 11 h 42 min | 10:19 am CDT (15:19 UTC) |
| 17,500 ft | 220° at 26 kt | 0 | -11 °C | 120 kt | 11 h 54 min | 10:31 am CDT (15:31 UTC) |
| 18,000 ft FL180 | 220° at 26 kt | +1 kt | -12 °C | 119 kt | 11 h 59 min | 10:36 am CDT (15:36 UTC) |
| 24,000 ft FL240 | 220° at 32 kt | 0 | -23 °C | 120 kt | 11 h 54 min | 10:31 am CDT (15:31 UTC) |
| 30,000 ft FL300 | 240° at 44 kt | −12 kt | -30 °C | 132 kt | 10 h 49 min | 9:26 am CDT (14:26 UTC) |
| 34,000 ft FL340 | 240° at 44 kt | −16 kt | -36 °C | 136 kt | 10 h 30 min | 9:07 am CDT (14:07 UTC) |
| 39,000 ft FL390 | 240° at 41 kt | −17 kt | -44 °C | 137 kt | 10 h 25 min | 9:02 am CDT (14:02 UTC) |
Based on data from the 12th at 00:00 UTC; valid on the 12th at 06:00 UTC for use 02:00 to 09:00 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 |
|---|---|---|---|---|---|---|---|---|---|---|
| SEA | used from 0 nm out; 25 nm from the line | 050/7 | 050/11 1° | 050/12 -5° | 030/31 -7° | 010/61 -15° | 010/69 -26° | 360/73 -40° | 360/62 -47° | 330/21 -43° |
| YKM | used from 50 nm out; 18 nm from the line | 070/10 | 040/15 -1° | 020/27 -8° | 030/25 -13° | 020/48 -20° | 010/83 -27° | 010/77 -37° | 010/49 -40° | 350/14 -41° |
| LWS | used from 150 nm out; 71 nm from the line | 070/10 | 080/12 -2° | 030/12 -6° | 080/7 -10° | 170/34 -21° | 160/46 -32° | 200/33 -35° | 220/22 -35° | 230/18 -38° |
| BOI | used from 299 nm out; 72 nm from the line | 300/7 2° | 280/5 -4° | 210/16 -9° | 210/60 -20° | 210/75 -29° | 210/63 -32° | 220/64 -32° | 220/54 -39° | |
| PIH | used from 399 nm out; 70 nm from the line | L/V | 240/13 1° | 240/15 -3° | 210/42 -15° | 200/70 -25° | 220/74 -29° | 220/71 -36° | 220/62 -43° | |
| RKS | used from 599 nm out; 45 nm from the line | 200/41 | 220/44 1° | 220/35 -11° | 220/46 -24° | 210/53 -27° | 220/62 -35° | 230/61 -44° | ||
| GJT | used from 748 nm out; 86 nm from the line | 210/43 7° | 230/45 1° | 220/49 -12° | 220/62 -22° | 220/59 -28° | 230/60 -33° | 220/55 -45° | ||
| DEN | used from 798 nm out; 88 nm from the line | 240/21 14° | 250/44 6° | 220/49 -8° | 220/49 -21° | 230/54 -30° | 240/57 -35° | 240/49 -45° | ||
| PUB | used from 898 nm out; 31 nm from the line | 230/25 13° | 230/32 6° | 220/44 -8° | 230/49 -21° | 240/70 -28° | 240/67 -34° | 240/58 -46° | ||
| GCK | used from 1048 nm out; 102 nm from the line | 220/48 21° | 230/37 14° | 250/30 8° | 230/37 -6° | 240/37 -20° | 240/69 -28° | 250/67 -37° | 260/58 -48° | |
| AMA | used from 1098 nm out; 76 nm from the line | 210/38 | 230/29 14° | 240/29 7° | 220/27 -5° | 240/37 -18° | 240/66 -28° | 250/59 -37° | 260/47 -49° | |
| GAG | used from 1197 nm out; 61 nm from the line | 220/40 19° | 230/28 14° | 240/23 8° | 230/21 -6° | 240/31 -19° | 250/66 -29° | 260/58 -38° | 260/47 -49° | |
| SPS | used from 1247 nm out; 71 nm from the line | 200/39 | 220/28 17° | 230/27 12° | 240/15 9° | 250/15 -4° | 250/24 -15° | 260/45 -28° | 270/43 -39° | 280/45 -51° |
| DAL | used from 1397 nm out; 39 nm from the line | 190/29 | 220/23 17° | 220/17 13° | 250/18 8° | 230/18 -5° | 240/18 -15° | 270/34 -29° | 280/33 -39° | 300/36 -51° |
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 |
|---|---|---|---|---|---|---|---|
| SEA Seattle, WA | departure | VFR Sky: a few clouds at 3,000 feet | from the north-northeast (030°) at 8 knots | 10+ mi | none | 432 ft | 7:53 pm PDT (02:53 UTC) |
| YKM Yakima, WA | 90 nm out, 11 nm southwest of the line, tower | VFR Sky: overcast at 8,500 feet | calm | 10+ mi | 8,500 ft | 1,098 ft | 02:53 UTC |
| PSC Pasco, WA | 150 nm out, 3 nm north of the line, tower | VFR Sky: a broken layer at 10,000 feet, overcast at 11,000 feet | from the north-northwest (340°) at 8 knots | 10+ mi | 10,000 ft | 410 ft | 02:53 UTC |
| MYL Mc Call, ID | 299 nm out, 1 nm southeast of the line | VFR Sky: overcast at 3,300 feet | from the west-northwest (290°) at 4 knots | 10+ mi | 3,300 ft | 5,024 ft | 02:51 UTC |
| PIH Pocatello, ID | 489 nm out, 14 nm south of the line, tower | marginal VFR Sky: a few clouds at 800 feet, a broken layer at 1,200 feet, overcast at 2,100 feet | from the south-southwest (210°) at 11 knots | 10+ mi | 1,200 ft | 4,451 ft | 02:53 UTC |
| EMM Kemmerer, WY | 609 nm out, 14 nm southwest of the line | VFR Sky: scattered clouds at 4,800 feet, scattered clouds at 6,000 feet, scattered clouds at 7,000 feet | from the west-northwest (290°) at 12 knots | 10+ mi | none | 7,288 ft | 03:15 UTC |
| EGE Eagle, CO | 818 nm out, 15 nm southwest of the line, tower | VFR | from the west (280°) at 5 knots | 10+ mi | none | 6,547 ft | 02:56 UTC |
| PUB Pueblo, CO | 958 nm out, 6 nm west of the line, tower | VFR | from the west-northwest (290°) at 7 knots | 10+ mi | none | 4,729 ft | 02:53 UTC |
| GUY Guymon, OK | 1127 nm out, 18 nm northeast of the line | VFR | from the south (180°) at 15 knots, gusting to 22 | 10+ mi | none | 3,125 ft | 02:53 UTC |
| PPA Pampa, TX | 1187 nm out, 13 nm southwest of the line | VFR | from the south (180°) at 18 knots, gusting to 22 | 10+ mi | none | 3,245 ft | 03:10 UTC |
| SPS Wichita Falls, TX | 1347 nm out, 4 nm northwest of the line, tower | VFR | from the south-southeast (160°) at 10 knots | 10+ mi | none | 1,019 ft | 02:52 UTC |
| AFW Fort Worth, TX | destination | VFR | from the south (170°) at 10 knots | 10+ mi | none | 723 ft | 9:53 pm CDT (02:53 UTC) |
The highest airport on this list sits at 7,288 ft; the ground between airports is higher still. Check the sectional chart for the terrain and the minimum safe heights along the line.
At AFW when you get there the forecast at the estimated arrival, 9:02 am CDT (14:02 UTC)
Wind from the south at 13 knots, gusting to 23, visibility more than 6 miles, a few clouds at 23,000 feet VFR
The whole forecast for AFW
- From Sun 10:00 pm CDT (03:00 UTC): wind from the south at 10 knots, visibility more than 6 miles, clear skies
- From Mon 9:00 am CDT (14:00 UTC): wind from the south at 13 knots, gusting to 23, visibility more than 6 miles, a few clouds at 23,000 feet
The forecast for SEA, the departure
- From Sun 8:00 pm PDT (03:00 UTC): wind from the north at 6 knots, visibility more than 6 miles, clear skies
- From Mon 3:00 am PDT (10:00 UTC): wind from the southeast at 4 knots, visibility more than 6 miles, patches of fog, clear skies
- From Mon 9:00 am PDT (16:00 UTC): wind from the south-southeast at 4 knots, visibility more than 6 miles, clear skies
- From Mon 11:00 am PDT (18:00 UTC): wind from the west at 6 knots, visibility more than 6 miles, clear skies
- From Mon 8:00 pm PDT (03:00 UTC): wind from the northwest at 5 knots, visibility more than 6 miles, scattered clouds at 25,000 feet
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 0 nm from the route, 898 nm along the route · a hazard on the ground (fire-fighting, a chemical spill, rescue work) · until 13 October · ZDV
- 6/8770 COLORADO SPRINGS, CO, Saturday, October 10, 2026 through Monday, October 12, 2026 UTC 11 nm from the route, 908 nm along the route · a hazard on the ground (fire-fighting, a chemical spill, rescue work) · until 12 October · ZDV
- 6/8646 Arlington, TX, Thursday, October 15, 2026 through Friday, October 16, 2026 UTC 18 nm from the route, at the destination end · drones kept away from a public gathering · starts Thursday 15 October · ZFW
Daylight
Sunset at SEA 6:27 pm PDT (01:27 UTC), at AFW 6:59 pm CDT (23:59 UTC) (civil twilight ends 7:24 pm CDT (00:24 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: Seattle-Tacoma International, Perot Fld/Fort Worth Alliance Airport.
