· ICAO24 c81625· last seen 10d ago

ZK-TEB is a Schleicher ASK 21. SkyMeter has tracked 122 flights totalling 52 hours of airtime via ADS-B. The most frequent segment is NZFI to NZFI. Service window in our records spans 334 days. Of those flights, 10 (8.2%) carry at least one detected incident: a go-around, unstable approach, stall warning, or runway excursion. The Schleicher ASK 21 has a maximum takeoff weight of 1,433 lb, light wake category.

About the Schleicher ASK 21

The Schleicher ASK 21 is a two-seat glider that has become the world's most widely used sailplane for training and recreational soaring since its introduction in 1979. Built by Alexander Schleicher GmbH in Poppenhausen, Germany, the ASK 21 revolutionized glider instruction with its forgiving handling characteristics, side-by-side seating, and exceptional durability, qualities that made it the standard training platform for gliding clubs across Europe and beyond. The aircraft's all-fiberglass construction and 17-meter wingspan deliver a best glide ratio of approximately 34:1, allowing student pilots to stay aloft for extended periods while learning thermal soaring techniques and cross-country navigation.

Unlike earlier training gliders with tandem seating, the ASK 21's side-by-side cockpit configuration improves instructor-student communication and makes it equally suitable for private owners seeking a rugged two-place sailplane. The type remains in production after more than four decades, with over 800 built, a testament to its enduring design. Its operating envelope spans from a minimum sink rate of about 2.1 feet per second at 46 knots to a never-exceed speed of 135 knots, with normal operations limited to 108 knots to preserve structural integrity during aerotow and thermaling flight.

SkyMeter has tracked flights across airframes and operators over routes, with the largest observed operator.

FLIGHTS
122
all time
FLOWN HOURS
52
tracked time
📍
AIRPORTS VISITED
17
unique
📡
CALLSIGNS
1
24 routes
📅
SERVICE PERIOD
9/5/2025 → 8/6/2026
first → last
INCIDENT RATE
8.2%
10 flagged

Top routes

By flight count

10
15
3
2
1
1
1
1
1
1
1

Flight numbers

Most-flown by this airframe

1

Aircraft specifications

Schleicher ASK 21

Engines
0
Vref (approach)
50 kt
MTOW
1,433 lb
Wake category
L

Recent flights

Newest 50 operations of ZK-TEB

50
8/5/2026
10m
No alerts
8/5/2026
10m
No alerts
8/5/2026
13m
No alerts
8/2/2026
13m
No alerts
7/29/2026
18m
No alerts
7/28/2026
18m
No alerts
7/25/2026
15m
No alerts
7/22/2026
1h 4m
No alerts
7/22/2026
28m
No alerts
7/22/2026
20m
No alerts
7/19/2026
12m
No alerts
7/19/2026
13m
No alerts
7/18/2026
14m
No alerts
7/18/2026
11m
No alerts
7/12/2026
48m
No alerts
7/11/2026
23m
No alerts
7/10/2026
12m
No alerts
7/10/2026
29m
No alerts
7/10/2026
5m
No alerts
7/9/2026
35m
No alerts
7/5/2026
23m
No alerts
7/4/2026
24m
△ Low approach-stability score
7/4/2026
29m
No alerts
7/4/2026
43m
No alerts
7/3/2026
24m
△ Low approach-stability score
7/2/2026
13m
No alerts
7/1/2026
16m
No alerts
6/20/2026
19m
No alerts
6/18/2026
24m
No alerts
6/12/2026
24m
No alerts
6/11/2026
8m
No alerts
6/10/2026
32m
△ Low approach-stability score
5/31/2026
1h 10m
No alerts
5/29/2026
24m
△ Low approach-stability score
5/27/2026
20m
No alerts
5/26/2026
20m
No alerts
5/24/2026
42m
No alerts
5/23/2026
28m
No alerts
5/19/2026
1h 3m
No alerts
5/19/2026
1h 16m
No alerts
5/18/2026
24m
No alerts
5/18/2026
4m
No alerts
4/30/2026
16m
No alerts
4/30/2026
14m
No alerts
3/8/2026
1h 0m
No alerts
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