Boeing Kc-135 Stratotanker (K35R)
i
ICAO K35R Heavy

Boeing Kc-135 Stratotanker

Quad Jet· 4 globally registered

The Boeing KC-135R Stratotanker is the backbone of American aerial refueling, a Cold War-era tanker that has kept U.S. and allied combat aircraft aloft for more than six decades. Derived from the Boeing 367-80 prototype that also spawned the 707 airliner, the KC-135 entered service in 1957 as the world's first jet-powered tanker, replacing piston-engine KB-29s and KB-50s. The R-model designation marks the most significant upgrade in the type's history: between 1984 and 2002, the Air Force re-engined 415 airframes with CFM International CFM56 turbofans, replacing the original Pratt & Whitney J57 turbojets. The new engines delivered 24 percent more thrust, cut fuel consumption by 25 percent, and dramatically reduced noise, transforming a 1950s design into an aircraft expected to serve into the 2040s. The KC-135R can offload roughly 200,000 pounds of fuel on a typical mission, operating from a service ceiling above 50,000 feet with a range exceeding 1,500 nautical miles when fully loaded. Its flying boom system transfers fuel at up to 1,000 gallons per minute, far faster than the probe-and-drogue rigs used by most other tankers. The Stratotanker has supported every major U.S. military operation since Vietnam, from Desert Storm to enduring campaigns in Afghanistan and the Middle East, often flying 20-hour sorties with multiple receiver aircraft. Beyond the U.S. Air Force, France, Singapore, Turkey, and Chile operate KC-135 variants, and a small number have entered civilian hands for cargo and specialized transport roles. SkyMeter has tracked 43 flights across 27 airframes and 2 operators, with WILMINGTON TRUST CO TRUSTEE the largest observed operator.

ACTIVE AIRFRAMES
27
last 7 days
🏢
OPERATORS
2
unique airlines
📊
FLIGHTS
43
tracked
AVG DURATION
3h 10m
per flight
INCIDENT RATE
4.7%
2 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
135 kt
Vref range
Vmo
425 kt
Mmo
0.90
Vs0 (landing)
115 kt
Vfe
230 kt
Approach category
C

Dimensions

Airframe geometry

Wingspan
131 ft
Length
136 ft
Tail height
42 ft
Wheelbase
47 ft
Gear width
29 ft
Wake category
Heavy

Weight & identification

Operating limits

MTOW
322,500 lb
MALW
119,231 lb
Manufacturer model
Boeing KC-135 Stratotanker
FAA designator
K35R
Registered
4

Top operators

By fleet size · last 7 days

1

Safety profile

Flagged flights · last 7 days

Family

Related variants

0

No related variants.

Recent incidents

Flagged flights of K35R

20
08/21/2026
5h 36m
△ Low approach-stability score
08/19/2026
1h 32m
↻ Go-around
08/14/2026
3h 59m
↻ Go-around
08/13/2026
3h 12m
↻ Go-around
08/13/2026
34m
↻ Go-around
08/10/2026
1h 26m
↻ Go-around
08/10/2026
1h 30m
△ Low approach-stability score
08/07/2026
23m
△ Low approach-stability score
08/06/2026
3h 6m
↻ Go-around
08/04/2026
3h 5m
↻ Go-around

Recent flights

Real flights of K35R · airborne ≥ 20 min

30
08/23/2026
6h 33m
No alerts
08/23/2026
21m
No alerts
08/23/2026
6h 24m
No alerts
08/23/2026
5h 9m
No alerts
08/22/2026
7h 49m
No alerts
08/22/2026
50m
No alerts
08/22/2026
1h 55m
No alerts
08/21/2026
2h 12m
No alerts
08/21/2026
5h 5m
No alerts
08/21/2026
5h 36m
△ Low approach-stability score
08/21/2026
7h 26m
No alerts
08/20/2026
3h 35m
No alerts
08/20/2026
5h 18m
No alerts
08/19/2026
57m
No alerts
08/19/2026
59m
No alerts
08/19/2026
1h 32m
↻ Go-around
08/19/2026
2h 15m
No alerts
08/19/2026
4h 5m
No alerts
08/19/2026
1h 52m
No alerts
08/19/2026
5h 52m
No alerts
08/19/2026
42m
No alerts
08/19/2026
2h 40m
No alerts
08/18/2026
2h 5m
No alerts
08/18/2026
5h 45m
No alerts
08/18/2026
2h 57m
No alerts
08/18/2026
3h 43m
No alerts
08/18/2026
1h 16m
No alerts
08/18/2026
7h 58m
No alerts
08/18/2026
1h 9m
No alerts
08/18/2026
4h 11m
No alerts
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© SkyMeter · All flight data subject to ODbL attribution · Tracking window: 7 days (free tier)