SWA3521 is operated by SOUTHWEST AIRLINES CO between Chicago Midway International Airport (KMDW) and Seattle Tacoma International Airport (KSEA). The flight is most often flown by a BOEING Boeing 737-700. Typical block time is 1h 54m. SkyMeter has observed 94 legs of this flight number via ADS-B.

✈
FLIGHTS
94
last 90 days
⏱
AVG DURATION
1h 54m
tracked time
📅
SERVICE PERIOD
5/29/2025 → 8/11/2026
first → last seen
🗺
ROUTES / TYPES
17 / 3
city pairs · airframes
⚠
INCIDENT RATE
1.1%
1 flagged

Routes flown

By count · last 90 days

10
KMDW → KSEA
21
avg 3h 56m · Chicago Midway → Seattle Tacoma
KLAX → KPHX
15
avg 1h 17m · Los Angeles → Phoenix Sky Harbor
KSMF → KLAX
15
avg 1h 21m · Sacramento → Los Angeles
KMDW → KBOS
8
avg 1h 59m · Chicago Midway → General Edward Lawrence Logan
KTPA → KATL
7
avg 1h 20m · Tampa → Hartsfield Jackson Atlanta
KATL → KHOU
7
avg 1h 43m · Hartsfield Jackson Atlanta → William P Hobby
KSRQ → KMCO
3
avg 35m · Sarasota Bradenton → Orlando
KLAS → KONT
2
avg 1h 4m · McCarran → Ontario
KSEA → KLAS
2
avg 1h 57m · Seattle Tacoma → McCarran
US-1410 → KPHX
1
avg 1h 16m · Sheraton Gateway Los Angeles Hotel Helipad → Phoenix Sky Harbor

Aircraft types

Equipment used on this number

3
B737 BOEING Boeing 737-700
54
B38M BOEING Boeing 737 MAX 8
30
B738 BOEING Boeing 737-800
10

Safety profile

Flagged flights · last 90 days

Go-arounds
0
Unstable approach
1
Rejected TO
0
Stall warnings
0
Overspeeds
0
Runway excursion
0
Counts represent flights with at least one occurrence of each flag, not the total event count. See /incidents for individual events.

Recent flights

Newest 30 operations of SWA3521

30
N8846QBOEING Boeing 737 MAX 8
→
8/11/2026
37m
No alerts
Replay Analysis
N7742BBOEING Boeing 737-700
→
8/10/2026
1h 23m
△ Low approach-stability score
Replay Analysis
N467WNBOEING Boeing 737-700
→
8/7/2026
2h 9m
No alerts
Replay Analysis
N481WNBOEING Boeing 737-700
→
8/6/2026
1h 28m
No alerts
Replay Analysis
N481WNBOEING Boeing 737-700
→
8/6/2026
6m
No alerts
Replay Analysis
N569WNBOEING Boeing 737-700
→
8/5/2026
34m
No alerts
Replay Analysis
N8746QBOEING Boeing 737 MAX 8
→
8/4/2026
35m
No alerts
Replay Analysis
N8544ZBOEING Boeing 737-800
→
8/3/2026
2h 10m
No alerts
Replay Analysis
N7868KBOEING Boeing 737-700
→
8/1/2026
30m
No alerts
Replay Analysis
N203WNBOEING Boeing 737-700
→
7/29/2026
1h 30m
No alerts
Replay Analysis
N203WNBOEING Boeing 737-700
→
7/29/2026
1h 16m
No alerts
Replay Analysis
N246LVBOEING Boeing 737-700
→
7/28/2026
1h 25m
No alerts
Replay Analysis
N246LVBOEING Boeing 737-700
→
7/28/2026
1h 24m
No alerts
Replay Analysis
N8795LBOEING Boeing 737 MAX 8
→
7/27/2026
1h 55m
No alerts
Replay Analysis
N456WNBOEING Boeing 737-700
→
7/25/2026
1h 32m
No alerts
Replay Analysis
N456WNBOEING Boeing 737-700
→
7/25/2026
1h 49m
No alerts
Replay Analysis
N295WNBOEING Boeing 737-700
→
7/22/2026
1h 51m
No alerts
Replay Analysis
N295WNBOEING Boeing 737-700
→
7/22/2026
1h 18m
No alerts
Replay Analysis
N969WNBOEING Boeing 737-700
→
7/21/2026
1h 11m
No alerts
Replay Analysis
N969WNBOEING Boeing 737-700
→
7/21/2026
1h 28m
No alerts
Replay Analysis
N9004HBOEING Boeing 737 MAX 8
→
7/20/2026
1h 52m
No alerts
Replay Analysis
N460WNBOEING Boeing 737-700
→
7/18/2026
1h 47m
No alerts
Replay Analysis
N460WNBOEING Boeing 737-700
→
7/18/2026
1h 14m
No alerts
Replay Analysis
N216WRBOEING Boeing 737-700
→
7/15/2026
1h 0m
No alerts
Replay Analysis
N216WRBOEING Boeing 737-700
→
7/15/2026
1h 44m
No alerts
Replay Analysis
N200WNBOEING Boeing 737-700
→
7/14/2026
1h 21m
No alerts
Replay Analysis
N200WNBOEING Boeing 737-700
→
7/14/2026
1h 19m
No alerts
Replay Analysis
N8629ABOEING Boeing 737-800
→
7/13/2026
1h 58m
No alerts
Replay Analysis
N203WNBOEING Boeing 737-700
→
7/11/2026
1h 40m
No alerts
Replay Analysis
N203WNBOEING Boeing 737-700
→
7/11/2026
1h 20m
No alerts
Replay Analysis
© SkyMeter · All flight data subject to ODbL attribution · Tracked: 90-day window