WTPI SERVICES LLC· ICAO24 a399a9· last seen 1d ago

N331BK is a Scaled Composites SpaceShipTwo, a single-engine jet operated by WTPI SERVICES LLC. SkyMeter has tracked 110 flights totalling 54 hours of airtime via ADS-B across 2 callsigns. The most frequent segment is WS36 to KSTE. Service window in our records spans 446 days. Of those flights, 2 (1.8%) carry at least one detected incident: a go-around, unstable approach, stall warning, or runway excursion. The Scaled Composites SpaceShipTwo has a maximum takeoff weight of 19,000 lb, light wake category.

About the Scaled Composites SpaceShipTwo

SpaceShipTwo is the world's first commercial suborbital spaceplane designed to carry paying passengers to the edge of space. Built by Scaled Composites and operated by Virgin Galactic, this rocket-powered vehicle represents a fundamentally different approach to spaceflight: air-launched from a carrier aircraft at 50,000 feet, it ignites a hybrid rocket motor to climb beyond 50 miles altitude before gliding back to a runway landing. The design descends from SpaceShipOne, which in 2004 became the first private crewed vehicle to reach space and won the $10 million Ansari X Prize.

Unlike traditional spacecraft that launch vertically atop expendable rockets, SpaceShipTwo takes off horizontally beneath WhiteKnightTwo, a twin-fuselage carrier jet. After release, the spaceplane fires its single hybrid rocket motor (burning hydroxyl-terminated polybutadiene rubber fuel with nitrous oxide oxidizer) for roughly 60 seconds of powered flight. The vehicle then coasts to apogee in a ballistic arc, providing several minutes of weightlessness and views of Earth's curvature against the black of space. For reentry, the twin tail booms rotate upward into a high-drag "feathered" configuration that provides inherent stability during descent through the atmosphere, a safety innovation that eliminates the need for precise computer-controlled reentry angles.

The type has faced significant development challenges. VSS Enterprise was lost in a 2014 test flight accident that killed one pilot, leading to extensive design modifications. VSS Unity, the second SpaceShipTwo vehicle, completed its first crewed spaceflight in 2018 and began commercial operations in 2023. A third vehicle, VSS Imagine, represents an evolved design with improved manufacturability. The spaceplane's operating envelope is unlike any other civilian aircraft. It reaches Mach 3+ during rocket burn and experiences reentry heating, yet lands unpowered on a conventional runway at around 200 knots.

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

FLIGHTS
110
all time
FLOWN HOURS
54
tracked time
📍
AIRPORTS VISITED
38
unique
📡
CALLSIGNS
2
36 routes
📅
SERVICE PERIOD
06/07/2025 → 08/28/2026
first → last
INCIDENT RATE
1.8%
2 flagged

Top routes

By flight count

10
2
1
1
1
1
1
1
1
1

Flight numbers

Most-flown by this airframe

2

Aircraft specifications

Scaled Composites SpaceShipTwo

Engines
Single Jet
MTOW
19,000 lb
Wake category
L

Recent flights

Newest 50 operations of N331BK

50
08/28/2026
55m
No alerts
08/08/2026
35m
No alerts
07/14/2026
30m
No alerts
07/14/2026
2h 17m
No alerts
07/11/2026
9m
No alerts
07/11/2026
20m
No alerts
07/08/2026
50m
No alerts
07/07/2026
28m
No alerts
06/27/2026
5m
No alerts
06/27/2026
20m
No alerts
06/26/2026
17m
No alerts
06/26/2026
16m
No alerts
06/02/2026
14m
No alerts
05/24/2026
31m
△ Low approach-stability score
05/03/2026
29m
No alerts
05/03/2026
29m
No alerts
04/27/2026
38m
No alerts
04/20/2026
48m
No alerts
04/20/2026
12m
No alerts
04/20/2026
9m
No alerts
04/20/2026
37m
No alerts
04/10/2026
8m
No alerts
04/07/2026
11m
No alerts
09/18/2025
6m
No alerts
08/26/2025
8m
No alerts
08/26/2025
6m
No alerts
08/20/2025
9m
No alerts
08/20/2025
25m
No alerts
08/20/2025
22m
No alerts
08/20/2025
21m
No alerts
08/14/2025
27m
No alerts
08/14/2025
23m
No alerts
08/11/2025
23m
No alerts
08/11/2025
5m
No alerts
08/06/2025
31m
No alerts
08/06/2025
23m
No alerts
08/06/2025
1h 18m
No alerts
08/05/2025
38m
No alerts
08/02/2025
15m
No alerts
08/02/2025
54m
No alerts
08/01/2025
34m
No alerts
07/27/2025
1h 50m
No alerts
07/22/2025
23m
No alerts
07/22/2025
1h 0m
No alerts
07/15/2025
12m
No alerts
07/15/2025
5m
No alerts
07/07/2025
8m
No alerts
07/03/2025
6m
No alerts
07/03/2025
57m
No alerts
07/03/2025
6m
No alerts
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