ICAO: A5ADF1
Owner: UNITEDAIRLINES
Flt: UAL521 N465UA A320 ATL-IAH-BOS
Time: 2026-04-01 23:43:27 EDT
Min Alt: 8725 ft
Min Dist: 1.1 nm (45deg NE)
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ICAO: A12755
Owner: UNITEDAIRLINES
Flt: UAL521 N17346 B38M ATL-IAH-BOS
Time: 2026-03-25 23:27:31 EDT
Min Alt: 8050 ft
Min Dist: 0.98 nm (19deg NNE)
Squawk: 7266
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ICAO: A2B12E
Owner: UNITEDAIRLINES
Flt: UAL521 N27261 B38M ATL-IAH-BOS
Time: 2026-03-22 23:26:36 EDT
Min Alt: 9425 ft
Min Dist: 1 nm (26deg NNE)
Squawk: 2522
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ICAO: AAA593
Owner: UNITEDAIRLINES
Flt: UAL521 N78509 B738 ATL-IAH-BOS
Time: 2026-03-21 23:11:49 EDT
Min Alt: 8675 ft
Min Dist: 0.8 nm (49deg NE)
Squawk: 7474
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ICAO: A1272D
Owner: UNITEDAIRLINES
Flt: UAL521 N17331 B38M ATL-IAH-BOS
Time: 2026-03-19 23:30:13 EDT
Min Alt: 8150 ft
Min Dist: 0.99 nm (19deg NNE)
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ICAO: A123BF
Owner: UNITEDAIRLINES
Flt: UAL521 N17254 B38M IAH-BOS
Time: 2026-03-05 23:22:42 EST
Min Alt: 9325 ft
Min Dist: 1 nm (15deg NNE)
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ICAO: A10E23
Owner: UNITEDAIRLINES
Flt: UAL521 N16703 B737 BOS-EWR
Time: 2026-02-09 18:26:22 EST
Min Alt: 4775 ft
Min Dist: 0.32 mi (162deg SSE)
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ICAO: A10E29
Owner: UNITEDAIRLINES
Flt: UAL521 N16709 B737 BOS-EWR
Time: 2026-02-08 18:41:57 EST
Min Alt: 5000 ft
Min Dist: 0.36 mi (145deg SE)
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ICAO: A0E751
Owner: UNITEDAIRLINES
Flt: UAL521 N15751 B737 BOS-EWR
Time: 2026-02-04 18:39:04 EST
Min Alt: 4675 ft
Min Dist: 0.4 mi (-139deg SW)
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ICAO: A47809
Owner: UNITED AIRLINES
Flt: UAL521 N38727 B737 BOS-EWR
Time: 2026-02-02 18:27:12 EST
Min Alt: 4400 ft
Min Dist: 0.9 mi (107° ESE)
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ICAO: A24C99
Owner: UNITED AIRLINES
Flt: UAL521 N24715 B737 BOS-EWR
Time: 2026-02-01 18:59:24 EST
Min Alt: 4525 ft
Min Dist: 0.5 mi (130° SE)
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ICAO: A10E8B
Owner: UNITED AIRLINES
Flt: UAL521 N16732 B737 BOS-EWR
Time: 2026-01-30 18:34:31 EST
Min Alt: 4625 ft
Min Dist: 0.3 mi (114° ESE)
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ICAO: A2B157
Owner: UNITED AIRLINES
Flt: UAL521 N27277 B38M BOS-EWR
Time: 2026-01-29 18:39:26 EST
Min Alt: 4925 ft
Min Dist: 0.4 mi (-130° SW)
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ICAO: A44214
Owner: UNITED AIRLINES
Flt: UAL521 N37354 B38M BOS-EWR
Time: 2026-01-28 19:22:17 EST
Min Alt: 4675 ft
Min Dist: 0.4 mi (119° ESE)
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ICAO: A10E8B
Owner: UNITED AIRLINES
Flt: UAL521 N16732 B737 EWR-FLL
Time: 2026-01-23 18:35:29 EST
Min Alt: 5000 ft
Min Dist: 0.78 mi (107° ESE)
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ICAO: A13608
Owner: UNITED AIRLINES
Flt: UAL521 N17730 B737 EWR-FLL
Time: 2026-01-22 18:41:47 EST
Min Alt: 4700 ft
Min Dist: 0.4 mi (116° ESE)
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ICAO: A5CF66
Owner: UNITED AIRLINES
Flt: UAL521 N47357 B38M BOS-EWR
Time: 2026-01-20 18:45:42 EST
Min Alt: 4775 ft
Min Dist: 0.3 mi (126° SE)
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Map of the St. Louis area showing the position and track of the aircraft described in the post.
🇺🇸 N497UA - Airbus A320 232 - United Airlines UAL521/UA521, St Louis Lambert (STL) to George Bush Intcntl/Houston (IAH) - 3.2 mi away @ 9050 ft, heading SSW at 315 mph. Spotted 37x before. [06:09:10 PM CST] #A62BDC #N497UA #A320 #UNITED #UAL521 #UA521 #TakingOff #Departure #ADSB #ADSBbot
Planefence ICAO: A13608
Flt: UAL521 UNITEDAIRLINES JFK - SFO
First seen: 2026-01-16 18:39:03 EST
Min Alt: 4300 ft MSL
Min Dist: 0.23 mi
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Planefence ICAO: A31216
Flt: UAL521 UNITEDAIRLINES JFK - SFO
First seen: 2026-01-11 18:48:48 EST
Min Alt: 4800 ft MSL
Min Dist: 1.19 mi
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Map of the St. Louis area showing the position and track of the aircraft described in the post.
🇺🇸 N458UA - Airbus A320 232 - United Airlines UAL521/UA521, St Louis Lambert (STL) to George Bush Intcntl/Houston (IAH) - 3.7 mi away @ 10050 ft, heading SSW at 319 mph. Spotted 25x before. [04:54:24 PM CST] #A59197 #N458UA #A320 #UNITED #UAL521 #UA521 #TakingOff #Departure #ADSB #ADSBbot
Planefence ICAO: A10E29
Flt: UAL521 UNITEDAIRLINES JFK - SFO
First seen: 2026-01-08 18:40:37 EST
Min Alt: 4825 ft MSL
Min Dist: 1.83 nm
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Planefence ICAO: A10E29
Flt: UAL521 UNITEDAIRLINES JFK - SFO
First seen: 2026-01-08 18:40:04 EST
Min Alt: 3275 ft MSL
Min Dist: 0.42 mi
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Planefence ICAO: A8D46A
Flt: UAL521 UNITEDAIRLINES JFK - SFO
First seen: 2026-01-07 18:35:01 EST
Min Alt: 4975 ft MSL
Min Dist: 1.97 nm
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Planefence ICAO: A8D46A
Flt: UAL521 UNITEDAIRLINES JFK - SFO
First seen: 2026-01-07 18:34:25 EST
Min Alt: 3500 ft MSL
Min Dist: 0.3 mi
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Planefence ICAO: A44257
Flt: UAL521 UNITEDAIRLINES JFK - SFO
First seen: 2025-12-15 19:21:18 EST
Min Alt: 3700 ft MSL
Min Dist: 0.23 mi
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Planefence ICAO: A44257
Flt: UAL521 UNITEDAIRLINES JFK - SFO
First seen: 2025-12-15 19:21:55 EST
Min Alt: 4950 ft MSL
Min Dist: 1.92 nm
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Planefence ICAO: A5CF82
Flt: UAL521 UNITEDAIRLINES JFK - SFO
First seen: 2025-12-12 19:26:29 EST
Min Alt: 3900 ft MSL
Min Dist: 0.51 mi
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Planefence ICAO: A12777
Flt: UAL521 UNITEDAIRLINES JFK - SFO
First seen: 2025-12-11 20:08:38 EST
Min Alt: 3900 ft MSL
Min Dist: 0.07 mi
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