PlaneTrack / aircraft / N421EF

N421EF - Alexander Schleicher Gmbh & Co ASK 21

N421EF is a Alexander Schleicher Gmbh & Co ASK 21 operated by Soaring Society Of Boulder, Mode-S hex code A4FFC0. Track it live, browse its recent flights, or download its full position history.

Alexander Schleicher Gmbh & Co ASK 21 (representative image)

Representative image of a Alexander Schleicher Gmbh & Co ASK 21. No photo of N421EF yet.

Photo © Steve Homewood / Planespotters

RegistrationN421EF

Mode-S hexA4FFC0

ManufacturerAlexander Schleicher Gmbh & Co

ModelASK 21

OperatorSoaring Society Of Boulder

Last seen2026-08-22 18:06 UTC

Last callsignN421EF

Recently active. Last received 10 hours ago, possibly beyond receiver coverage or landed.

Open the live map Buy full history (CSV) API access

Flight history 48 flights since Mar 2026

Date	Callsign	From	To	Dep
2026-08-16 (partial)	N421EF	KBDU	?	09:05 MDT
Route flown, from our receiver network. Green = start, red = end.
2026-08-15 (partial)	N421EF	KBDU	?	09:22 MDT
Route flown, from our receiver network. Green = start, red = end.
2026-08-13 (partial)	N421EF	KBDU	?	10:17 MDT
Route flown, from our receiver network. Green = start, red = end.

Earlier flights (45) - back to 2026-03-28

Date	Callsign	From	To	Dep	Arr
2026-07-23 (partial)	N421EF	KBDU	?	09:42 MDT
Route flown, from our receiver network. Green = start, red = end.
2026-07-22 (partial)	N421EF	KBDU	?	10:14 MDT
Route flown, from our receiver network. Green = start, red = end.
2026-07-16 (partial)	N421EF	KBDU	?	10:14 MDT
Route flown, from our receiver network. Green = start, red = end.
2026-07-15 (partial)	N421EF	KBDU	?	09:26 MDT
Route flown, from our receiver network. Green = start, red = end.
2026-07-13 (partial)	N421EF	KBKF	?	10:09 MDT
Route flown, from our receiver network. Green = start, red = end.
2026-07-10	N421EF	KDEN	KBKF	10:54 MDT	12:04 MDT
Route flown, from our receiver network. Green = start, red = end.
2026-07-09 (partial)	N421EF	KBKF	?	09:56 MDT
Route flown, from our receiver network. Green = start, red = end.
2026-07-06	N421EF	KDEN	KBKF	10:15 MDT	13:48 MDT
Route flown, from our receiver network. Green = start, red = end.
2026-07-05	N421EF	KDEN	KBKF	12:15 MDT	14:02 MDT
Route flown, from our receiver network. Green = start, red = end.
2026-07-04 (partial)	N421EF	KBKF	?	11:03 MDT
Route flown, from our receiver network. Green = start, red = end.
2026-07-01 (partial)	N421EF	KBKF	?	09:32 MDT
Route flown, from our receiver network. Green = start, red = end.
2026-06-30 (partial)	N421EF	KBKF	?	15:22 MDT
Route flown, from our receiver network. Green = start, red = end.
2026-06-26 (partial)	N421EF	KBKF	?	12:42 MDT
Route flown, from our receiver network. Green = start, red = end.
2026-06-20 (partial)	N421EF	KBKF	?	11:32 MDT
Route flown, from our receiver network. Green = start, red = end.
2026-06-17 (partial)	N421EF	KBKF	?	10:40 MDT
Route flown, from our receiver network. Green = start, red = end.
2026-06-16 (partial)	N421EF	KBKF	?	09:46 MDT
Route flown, from our receiver network. Green = start, red = end.
2026-06-15 (partial)	N421EF	KBKF	?	13:03 MDT
Route flown, from our receiver network. Green = start, red = end.
2026-06-12 (partial)	N421EF	KBKF	?	09:11 MDT
Route flown, from our receiver network. Green = start, red = end.
2026-05-29	N421EF	KDEN	KBKF	11:01 MDT	12:26 MDT
Route flown, from our receiver network. Green = start, red = end.
2026-05-27 (partial)	N421EF	KBKF	?	11:10 MDT
Route flown, from our receiver network. Green = start, red = end.
2026-05-26	N421EF	KDEN	KBKF	10:26 MDT	12:06 MDT
Route flown, from our receiver network. Green = start, red = end.
2026-05-24	N421EF	KBKF	KDEN	10:09 MDT	10:56 MDT
Route flown, from our receiver network. Green = start, red = end.
2026-05-23 (partial)	N421EF	KBKF	?	10:21 MDT
Route flown, from our receiver network. Green = start, red = end.
2026-05-22 (partial)	N421EF	KBDU	?	09:56 MDT
Route flown, from our receiver network. Green = start, red = end.
2026-05-21	N421EF	KDEN	KBKF	11:08 MDT	12:34 MDT
Route flown, from our receiver network. Green = start, red = end.
2026-05-19 (partial)	N421EF	KBKF	?	02:31 MDT
Route flown, from our receiver network. Green = start, red = end.
2026-05-12 (partial)	N421EF	KBKF	?	09:35 MDT
Route flown, from our receiver network. Green = start, red = end.
2026-05-10 (partial)	N421EF	KBKF	?	09:49 MDT
Route flown, from our receiver network. Green = start, red = end.
2026-05-09	N421EF	KDEN	KBKF	09:19 MDT	12:58 MDT
Route flown, from our receiver network. Green = start, red = end.
2026-05-08 (partial)	N421EF	KBKF	?	09:30 MDT
Route flown, from our receiver network. Green = start, red = end.
2026-05-04 (partial)	N421EF	KBKF	?	11:56 MDT
Route flown, from our receiver network. Green = start, red = end.
2026-05-01	N421EF	KBKF	KBDU	09:43 MDT	10:00 MDT
Route flown, from our receiver network. Green = start, red = end.
2026-04-29 (partial)	N421EF	KBKF	?	09:40 MDT
Route flown, from our receiver network. Green = start, red = end.
2026-04-28 (partial)	N421EF	KBKF	?	12:12 MDT
Route flown, from our receiver network. Green = start, red = end.
2026-04-25 (partial)	N421EF	KBKF	?	10:23 MDT
Route flown, from our receiver network. Green = start, red = end.
2026-04-24 (partial)	N421EF	KBDU	?	09:53 MDT
Route flown, from our receiver network. Green = start, red = end.
2026-04-22 (partial)	N421EF	KBDU	?	10:04 MDT
Route flown, from our receiver network. Green = start, red = end.
2026-04-21 (partial)	N421EF	KBDU	?	15:44 MDT
Route flown, from our receiver network. Green = start, red = end.
2026-04-19 (partial)	N421EF	KBDU	?	09:25 MDT
Route flown, from our receiver network. Green = start, red = end.
2026-04-12 (partial)	N421EF	KBDU	?	13:36 MDT
Route flown, from our receiver network. Green = start, red = end.
2026-04-11 (partial)	N421EF	KBDU	?	09:33 MDT
Route flown, from our receiver network. Green = start, red = end.
2026-04-05 (partial)	N421EF	KBDU	?	14:00 MDT
Route flown, from our receiver network. Green = start, red = end.
2026-04-04 (partial)	N421EF	KBDU	?	09:57 MDT
Route flown, from our receiver network. Green = start, red = end.
2026-03-29 (partial)	N421EF	KBDU	?	09:21 MDT
Route flown, from our receiver network. Green = start, red = end.
2026-03-28 (partial)	N421EF	KBDU	?	09:53 MDT
Route flown, from our receiver network. Green = start, red = end.

Times are local to each airport. Hover for UTC. Tap Map to see the route flown. Partial records have a confirmed departure but no reliable arrival fix.

Data access

Live position and 365-day history for this aircraft are available through the PlaneTrack API (commercial use from $29/month) and as one-off CSV extracts from our own receiver network archive.