Grumman G-1159a (G12T)
ICAO G12T Medium Jet

Grumman G-1159a

Twin Jet

The Grumman Gulfstream II-TT (G1159A) is a specialized trainer derivative of the iconic Gulfstream II business jet, purpose-built for military and commercial pilot training programs. While the baseline Gulfstream II revolutionized corporate aviation in the late 1960s as one of the first purpose-designed business jets with transcontinental range, the TT variant strips away the executive interior in favor of instructor stations, avionics bays, and mission systems that replicate fighter and transport cockpits. CAE and other training providers operate these aircraft to give military pilots realistic jet handling experience in a relatively affordable twin-engine platform, simulating everything from tanker operations to tactical approaches without the operating costs of frontline combat aircraft. Powered by two Rolls-Royce Spey turbofans producing 11,400 pounds of thrust each, the G1159A cruises at Mach 0.80 and can reach altitudes above 43,000 feet, providing a flight envelope that overlaps with many military transports and trainers. Its 73,200-pound maximum takeoff weight and durable airframe allow for repeated training sorties with high cycle counts that would age a business jet prematurely. The type's long service life in training roles (some airframes have been flying training missions for over three decades) speaks to Grumman's structural engineering and the aircraft's adaptability to evolving training requirements. SkyMeter has tracked 348 flights across 38 airframes and 3 operators, with CAE USA the largest observed operator.

ACTIVE AIRFRAMES
38
last 7 days
🏢
OPERATORS
3
unique airlines
📊
FLIGHTS
348
tracked
AVG DURATION
54m
per flight
INCIDENT RATE
16.1%
56 flagged

Safety in context

The incident rate counts flights with ANY safety event detected by SkyMeter: go-arounds (a routine response, not a failure), unstable-approach gate flags (advisory thresholds), rejected takeoffs (the system working as designed), and runway events. It is NOT an accident rate or fatality rate. For accident statistics, refer to the NTSB Aviation Accident Database (USA) or the Aviation Safety Network. See methodology for what each event type measures.

Performance

Speed envelope & approach

Vref
120 kt
Vref range
Vmo
340 kt
Mmo
0.85
Vs0 (landing)
92 kt
Vfe
200 kt
Approach category

Dimensions

Airframe geometry

Wingspan
Length
Tail height
Wheelbase
Gear width
Wake category
M

Weight & identification

Operating limits

MTOW
73,200 lb
MALW
Manufacturer model
G-1159A
FAA designator
Registered

Safety profile

Flagged flights · last 7 days

Family

Related variants

1

Recent incidents

Flagged flights of G12T

20
8/11/2026
1h 13m
△ Low approach-stability score
8/11/2026
59m
△ Low approach-stability score
8/11/2026
1h 5m
△ Low approach-stability score
8/11/2026
1h 8m
△ Low approach-stability score
8/11/2026
1h 3m
△ Low approach-stability score
8/11/2026
1h 12m
△ Low approach-stability score
8/11/2026
1h 10m
! Stall△ Low approach-stability score
8/11/2026
1h 22m
! Stall△ Low approach-stability score
8/11/2026
50m
△ Low approach-stability score
8/11/2026
1h 5m
△ Low approach-stability score

Recent flights

Real flights of G12T · airborne ≥ 20 min

30
8/11/2026
27m
No alerts
8/11/2026
1h 13m
△ Low approach-stability score
8/11/2026
59m
△ Low approach-stability score
8/11/2026
1h 5m
△ Low approach-stability score
8/11/2026
1h 6m
No alerts
8/11/2026
55m
No alerts
8/11/2026
1h 3m
No alerts
8/11/2026
1h 51m
No alerts
8/11/2026
1h 1m
No alerts
8/11/2026
58m
No alerts
8/11/2026
1h 8m
△ Low approach-stability score
8/11/2026
24m
No alerts
8/11/2026
1h 6m
No alerts
8/11/2026
1h 14m
No alerts
8/11/2026
1h 3m
No alerts
8/11/2026
1h 3m
△ Low approach-stability score
8/11/2026
1h 12m
△ Low approach-stability score
8/11/2026
1h 10m
! Stall△ Low approach-stability score
8/11/2026
1h 22m
! Stall△ Low approach-stability score
8/11/2026
50m
△ Low approach-stability score
8/11/2026
1h 14m
No alerts
8/11/2026
1h 21m
No alerts
8/11/2026
1h 14m
No alerts
8/11/2026
1h 16m
No alerts
8/11/2026
1h 3m
No alerts
8/11/2026
1h 11m
No alerts
8/11/2026
1h 11m
No alerts
8/11/2026
57m
No alerts
8/11/2026
31m
No alerts
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© SkyMeter · All flight data subject to ODbL attribution · Tracking window: 7 days (free tier)