The Boeing
KC-135 Stratotanker is a military aerial refueling aircraft. It and
the Boeing 707 airliner were developed from the Boeing 367-80
prototype. It is the predominant variant of the C-135 Stratolifter
family of transport aircraft. The KC-135 was the US Air Force's
first jet-powered refueling tanker and replaced the KC-97
Stratofreighter. The KC-135 was initially tasked with refueling
strategic bombers, but was used extensively in the Vietnam War and
later conflicts such as Operation Desert Storm to extend the range
and endurance of US tactical fighters and bombers.
The KC-135 made its first flight on August 31, 1956 and entered
service with the United States Air Force in 1957; it is one of six
military fixed-wing aircraft with over 50 years of continuous
service with its original operator. The KC-135 is supplemented by
the larger KC-10. Studies have concluded that many of the aircraft
could be flown until 2040, although maintenance costs have greatly
increased. The aircraft will eventually be replaced by the Boeing
KC-46 Pegasus.
The KC-135R has four turbofan engines, mounted under 35-degree swept
wings, which power it to takeoffs at gross weights up to 322,500
pounds. Nearly all internal fuel can be pumped through the tanker's
flying boom, the KC-135's primary fuel transfer method. A special
shuttlecock-shaped drogue, attached to and trailing behind the
flying boom, may be used to refuel aircraft fitted with probes. This
apparatus is significantly more unforgiving of pilot error in the
receiving aircraft than conventional trailing hose arrangements; an
aircraft so fitted is also incapable of refueling by the normal
flying boom method until the attachment is removed. A boom operator
stationed in the rear of the aircraft controls the boom while lying
prone. A cargo deck above the refueling system can hold a mixed load
of passengers and cargo. Depending on fuel storage configuration,
the KC-135 can carry up to 83,000 pounds of cargo.
When it was
first delivered to the United States Air Force, the KC-135 fleet was
powered by four Pratt & Whitney J57 turbojet engines. Each
engine delivered approximately 12,000 pounds of thrust and a fully
loaded KC-135 needed a 12,000 foot runway to safely get off the
ground. Water injection was sometimes needed to gain
additional thrust in some situations. These aircraft were
designated KC-135A and served until the 1980s, when two programs
were initiated to re-engine the aircraft. Approximately 138
aircraft were re-engined with Pratt & Whitney JT-3D engines taken
from surplus retired 707s to become the KC-135E while about 500
aircraft were re-engined with CFM International turbofan engines and
designated the KC-135R. The new CFM engines reduced the noise
footprint, increased fuel efficiency, and increased the amount of
fuel the KC-135 can offload to receivers.
As the aircraft has been in service since the late 1950s, the USAF
decided to replace the KC-135 fleet. However, the KC-135 fleet is
large and will need to be replaced gradually. Initially the first
batch of replacement planes was to be an air tanker version of the
Boeing 767, leased from Boeing. In 2003, this was changed to
contract where the Air Force would purchase eighty KC-767 aircraft
and lease 20 more. In December 2003, the Pentagon froze the contract
and in January 2006, the KC-767 contract was canceled. This followed
public revelations of corruption in how the contract was awarded, as
well as controversy regarding the original leasing rather than
outright purchase agreement. Then Secretary of Defense Rumsfeld
stated that this move will in no way impair the Air Force's ability
to deliver the mission of the KC-767, which will be accomplished by
continuing upgrades to the KC-135 and KC-10 Extender fleet.
In January 2007, the U.S. Air Force formally launched the KC-X
program with a request for proposal. KC-X is first phase of three
acquisition programs to replace the KC-135 fleet. On 29 February
2008, the US Defense Department announced that it had selected the
EADS/Northrop Grumman "KC-30" (to be designated the KC-45A) over the
Boeing KC-767. Boeing protested the award on 11 March 2008, citing
irregularities in the competition and bid evaluation. On 18 June
2008, the US Government Accountability Office sustained Boeing's
protest of the selection of the Northrop Grumman/EADS's tanker. In
February 2010, the US Air Force restarted the KC-X competition with
the release of a revised request for proposal. After evaluating
bids, the USAF selected Boeing's 767-based tanker design, with the
military designation of KC-46, as a replacement in February 2011.
In addition to
the United States Air Force, the KC-135 is used by the Air Forces of
Chile, France, Singapore, and Turkey.
USAF KC-135R Stratotanker Bases |
Unit |
Squadron |
Active Duty/Reserve/Guard |
Base |
Callsign |
97th AMW |
54th ARS |
Training |
Altus AFB, OK |
BART, JUST, OILER |
97th AMW |
55th ARS |
Training |
Altus AFB, OK |
412th TW |
412th FTS |
Active Duty, Test and
Evaluation |
Edwards AFB, CA |
ARRIS, TROUT |
412th TW |
412th FTS |
Active Duty, Test and
Evaluation |
Edwards AFB, CA |
6th AMW |
91st ARS |
Active Duty |
MacDill AFB, FL |
BOLT, PIRATE |
6th AMW |
99th ARS |
Active Duty |
MacDill AFB, FL |
927th ARW |
63rd ARS |
Reserve |
MacDill AFB, FL |
22nd ARW |
344th ARS |
Active Duty |
McConnell AFB, KS |
KANZA, TOTAL, TURBO |
22nd ARW |
349th ARS |
Active Duty |
McConnell AFB, KS |
22nd ARW |
350th ARS |
Active Duty |
McConnell AFB, KS |
22nd ARW |
384th ARS |
Active Duty |
McConnell AFB, KS |
931st ARG |
18th ARS |
Reserve |
McConnell AFB, KS |
92nd ARW |
92nd ARS |
Active Duty |
Fairchild AFB, WA |
BEAK, EXPO, ZAGS |
92nd ARW |
93rd ARS |
Active Duty |
Fairchild AFB, WA |
15th WG |
96th ARS |
Active Duty |
Hickam AFB, HI |
PRO |
18th WG |
909th ARS |
Active Duty |
Kadena AB, Japan |
START |
100th ARW |
351st ARS |
Active Duty |
RAF Mildenhall,
England |
QUID |
434th ARW |
72nd ARS |
Reserve |
Grissom AFB, IN |
INDY, MASH |
434th ARW |
74th ARS |
Reserve |
Grissom AFB, IN |
452nd ARW |
336th ARS |
Reserve |
March ARB, CA |
BAJA, GRIZZLY, RATS |
459th ARW |
756th ARS |
Reserve |
Joint Base Andrews,
MD |
DEECEE |
507th ARW |
465th ARS |
Reserve |
Tinker AFB, OK |
OKIE |
507th ARW |
730th AMTS |
Reserve |
Tinker AFB, OK |
OKIE |
914th ARW |
328th ARS |
Reserve |
Niagara Falls, NY |
BISON |
916th ARW |
77th ARS |
Reserve |
Seymour-Johnson AFB,
NC |
BACKY, REGAL |
940th ARW |
314th ARS |
Reserve |
Beale AFB, CA |
STOUT |
101st ARW |
132nd ARS |
Guard |
Bangor, ME |
MAINE |
108th WG |
141st ARS |
Guard |
Joint Base
McGuire-Dix-Lakehurst, NJ |
HOSER, ROCCO,
TIGER,
TOPCAT,
WALDO |
108th WG |
150th ARS |
Guard |
Joint Base
McGuire-Dix-Lakehurst, NJ |
117th ARW |
106th ARS |
Guard |
Birmingham, AL |
BAMA,
DIXIE |
121st ARW |
166th ARS |
Guard |
Rickenbacker ANGB, OH |
COHO, EDDIE |
126th ARW |
108th ARS |
Guard |
Scott AFB, IL |
CODER, HAPPY |
127th WG |
171st ARS |
Guard |
Selfridge ANGB, MI |
JEEP, MOTOWN |
128th ARW |
126th ARS |
Guard |
Milwaukee, WI |
UPSET |
134th ARW |
151st ARS |
Guard |
Knoxville, TN |
SODA |
151st ARW |
191st ARS |
Guard |
Salt Lake City, UT |
UTAH |
154th WG |
203rd ARS |
Guard |
Hickam, HI |
HOKU |
155th ARW |
173rd ARS |
Guard |
Lincoln, NE |
HUSKER |
157th ARW |
133rd ARS |
Guard |
Pease ANGB, NH |
PACK |
161st ARW |
197th ARS |
Guard |
Phoenix, AZ |
COPPER |
168th ARW |
168th ARS |
Guard |
Eielson AFB, AK |
ARCTIC, COON, MOOSE, TARBABY |
171st ARW |
146th ARS |
Guard |
Pittsburgh, PA |
STEEL |
171st ARW |
147th ARS |
Guard |
Pittsburgh, PA |
185th ARW |
174th ARS |
Guard |
Sioux City, IA |
BAT |
186th ARW |
153rd ARS |
Guard |
Meridian, MS |
JAKE, KEYS |
190th ARW |
117th ARS |
Guard |
Topeka, KS |
WYLIE |
Photos in the slideshow were
taken between March 2016 and April 2018. Apologies for the
large copyrights in each photo - this is necessary in this day and
age where photos are widely stolen and passed along as if they are
one's own. |