Country of origin
Missile launch weight
1 010 kg
Nuclear, up to 217 kT
Range of fire
Inertial navigation system
B-52, FB-111, B-1B
One of the
most iconic US nuclear munitions of the Cold War, the Boeing AGM-69
SRAM (Short-Range Attack Missile) was for some 20 years the primary
USAF strategic deterrent. This missile boasted considerable
performance, a strong yield, and some of the first stealth
technology ever applied to a guided missile, but it was a troubled
and dangerous device throughout its entire service life.
of the SRAM are rooted in a crisis the USAF experienced in the late
1950s, during which they finally began to appreciate the threat that
Soviet Surface-to-Air Missiles (SAMs) posed to the bombers of the
USAF's Strategic Air Command. The S-55 Berkut (reporting name SA-1
or Guild) had been in service for some time at that point, but the
vastly more numerous S-75 Dvina (reporting name SA-2 or Guideline)
posed a much more serious problem. As far as the USAF was concerned,
a bomber that entered a SAM umbrella was as good as dead. To that
end, development of a nuclear-tipped missile that could be launched
from bombers gained a new priority, as these would allow the
attacking aircraft to either destroy the target without coming
within range of the SAMs, or even to destroy the SAM sites
approach was the latter, with first attempt at creating such a
missile was the Northrop GAM-67 Crossbow. An anti-radiation missile
with a conventional warhead, the Crossbow was bulky, and lacked the
speed necessary to get ahead of the bomber launching it before it
ran out of fuel; the USAF deemed it a failure, and only 14 Crossbows
were built. A proposed supersonic version, the Longbow, never even
proceeded as far as its predecessor.
next tried to develop a missile that could bypass SAM umbrellas
entirely, in order to attack targets on the other side (which would
also allow bombers to attack the missile sites themselves). This
next effort was to develop an air-launched ballistic missile, the
GAM-87 Skybolt, but this weapon also proved unsuccessful. The
eventual cancellation of the Skybolt in November of 1962 triggered a
crisis in both the USAF and RAF (who had also planned to adopt this
missile), as higher authorities in the government instead instructed
the USAF to adopt the LGM-30 Minuteman intercontinental ballistic
missile instead, while the RAF's nuclear deterrent role was
eliminated altogether in favor of using Royal Navy ballistic missile
submarines only. The USAF feared the same would happen to their own
nuclear capability, so it should come as no surprise that they tried
again almost exactly a year later.
The USAF had
fortunately developed a missile intended to serve as an interim for
the Skybolt, in the form of the Boeing B-77 (later GAM-77, and
finally AGM-28) Hound Dog cruise missile, which had already been in
service since 1960. This large, airplane-like weapon could be
launched from a
B-52, flew at a speed of over Mach 2 (2 470 km/h), carried a
nuclear warhead, and boasted a range in excess of 1 200 km. However,
the Hound Dog's immense performance was offset by its immense size
and weight. The B-52 Stratofortress could only carry them
externally, and only had enough space for two of them. It was
decided that a newer, smaller missile was still needed.
On November 23rd 1963,
Strategic Air Command began a series of design studies for such a weapon, culminating
in the establishment of an official requirement in March of 1964,
designated Specific Operational Requirement 212. The Office of the Secretary
accepted of the proposal, and SecDef Robert S. McNamara officially
approved the program on March 23rd 1965. On October 31st 1966,
Headquarters Air Force contracted the Boeing Company to develop and
produce the new missile. The system was named the SRAM, and assigned
the ZAGM-69 designation number.
Though while achieving funding and endorsement for the SRAM proved
relatively easy, actually building the missile that Boeing proposed
proved a much more complicated matter. The solid fuel rocket
propulsion technology in the class required for the SRAM was still
in its infancy even in the late 1950s, and the propellant failed to
meet the USAF's requirements for safety, stability, and self life.
The schedule slipped by over two years, and the first test launch
didn't take place until July 29th 1969. The program assured Congress
that the problems with the fuel would be fixed within a few years,
but they were destined to remain mostly unresolved for decades.
Production finally began in October of 1970, but deliveries didn't
begin until March of 1972.
The SRAM promised to drastically improve the standoff nuclear attack
capabilities of Strategic Air Command's bombers. The AGM-28 Hound Dog cruise missile
it replaced had been a huge and ponderous weapon that was very
conspicuous (and thus easily detected and shot-down). A B-52
Stratofortress could only carry two Hound Dogs, both of which had to
be mounted externally under the wings, which also created tremendous
drag. By contrast, the SRAM was several-times smaller and lighter,
and enormously faster, enabling a B-52 to carry 8 of them internally
and attack from a greater distance. The B-52 could also carry an
additional 6 SRAMs (for a total of 12) in a pair of 3-missile
clusters under its wings, at a substantially lower penalty in
weight and drag compared to a pair of Hound Dogs.
FB-111A Aardvark and
B-1B Lancer were also able to carry SRAM.
The FB-111A carried less (2 internally and 4 externally, for a total
of 6), while the B-1B carried more (three rotary launch racks with
an 8-round capacity, for a total of 24). The arrival of the SRAM was
even more critical for these aircraft, as they were unable to carry
ordnance as large as the Hound Dog.
The AGM-69 SRAM has a simple appearance, with a long cylindrical
fuselage, a nosecone that tapers down to a fine point, and a boat
tail at the aft end. Three small rectangular fins are located aft,
in a triangular pattern. A narrow strip along the topside of the
fuselage holds both the lifting eyes used to mount the SRAM on a
pylon, and wiring pathways. The rocket motor sports a single small
Little information has been published on the composition of the
SRAM, though a 1975 USAF report on the missile reveals that its rocket
motor is made of steel.
The SRAM is also notable for being one of the first missiles ever
constructed with radar-defeating features, though it isn't as
stealthy as many subsequent tactical missiles. Almost the entire
fuselage if coated by a 20 mm thick rubber-based compound, while the
fin assembly was made of phenolic material, all of which are
substantially absorbent of radio waves. Combined with the SRAM's
blistering speed and minimal radio emissions, this significantly
reduced its chances of being detected and tracked, let alone
Propulsion for the SRAM is provided by a Lockheed-Martin Lockheed
SR75-LP-1 solid-fuel rocket motor. The fuel in the aft cell of the
combustion chamber effectively forms the boost stage, which
accelerates the missile to its full speed in a matter of seconds,
and is totally expended in the process. The forward cell contains a
slower-burning fuel that forms the sustainer stage, and propels the
SRAM throughout most of the remainder of its flight
The performance of the SRAM is staggering, even by 21st century
standards. It flew at a speed of up to Mach 3 (3 700 km/h), and out to ranges of
56 km to 169 km, depending on the programmed flight profile. This
allowed a bomber to attack from far outside the effective range of
nearly all Cold War-era air defense systems, and left the enemy very
little time to react, and a fiendishly difficult target to hit (not
even considering the SRAM's stealth features) even if they could
fire upon it in time.
The guidance system of the SRAM is the General Precision/Kearfott
KT-76 inertial measurement unit, a type of inertial navigation
system. While such guidance systems are notoriously
imprecise, they carry two very strong advantages for a missile like
the SRAM; The guidance system is completely passive, with no detectable emissions,
and effectively impossible to jam or misdirect. However, the SRAM
does emit radio waves, as a Stewart-Warner radar altimeter is used
to gauge its altitude. It is probable that the radar altimeter
could be jammed, though unless the SRAM was flying through steep and
complex vertical terrain (e.g., a mountain range), this would have
little effect on the missile's accuracy. These systems are
collectively controlled by a Delco 2 000-word computer (after
modernizations, the Delco computer had a 8 000-word capability).
The accuracy of the SRAM is rather poor compared to most
conventionally-armed air-to-ground missiles, with a circular error (CEP) of 430m.
Though granted, CEP only determines the grouping of half of a given
set of projectiles fired (the other half are omitted from the
figure), and has no bearing on where the intended target is located,
but it matters little in the case of a weapon with a yield of up to
210 kT; as the old saying goes, "Close only counts in horseshoes and
Perhaps the most interesting aspect of the SRAM's guidance is that
it can be programmed to perform a single, very sharp turn shortly
after launch. This can even be a 180-degree "U-turn", allowing a
bomber to attack a target behind it. This gives the launch aircraft
an element of surprise, as it can attack a target off its course,
or even launch a missile against an enemy as it withdraws (a
high-technology "Parthian Shot"). In short, aircraft carrying the
SRAM can attack anything around them in any direction, without
changing course, which presents many tactical advantages.
The SRAM is often mistaken for a cruise missile, given its range,
but its trajectory is actually that of a ballistic missile (much
like the ill-fated Skybolt). Upon launch, the missile either flies
into a steep arc and plunges down onto the target from high above,
or when programmed to fly straight ahead, it will do so briefly on
thrust and inertia before beginning its descent.
The only warhead used in the SRAM was the W69, a nuclear warhead
with a variable yield. The aircrew launching the missile could
remotely program the W69 during a mission and prior to launch, with
the lowest setting at 17 kT, and the highest at 217 kT. The W69 is
essentially a hydrogen bomb, whose higher yield settings are
produced by creating nuclear fusion in the fissile core during
detonation. The lower-yield settings are achieved by disabling the
mechanisms that create nuclear fusion, resulting in a fission
reaction instead. As such, these types of munitions are often
referred-to as "fission-fusion" warheads.
The AGM-69 SRAM ultimately served two decades in the USAF, during
which it was the primary nuclear weapon in Strategic Air Command's corner of the
Pentagon's "Nuclear Triad". However, despite the SRAM's importance,
its long-standing problems that had been "swept under the rug"
continued to plague the missile throughout its career.
The first test launch of an operational SRAM didn't occur on August
20th 1974, and it ended in failure. While no subsequent test
launches of the SRAM, the final launch of an operational SRAM took
place on July 26th 1983; meaning, no SRAMs were test-launched during
almost the entire latter half of their service life.
A special variant of the SRAM for the B-1A Excalibur bomber was
planned throughout the 1970s as well, but this missile (the AGM-69B)
was canceled along with the B-1A bomber. The AGM-86A ALCM was initially
intended to succeed the canceled AGM-69B, but this too was canceled
soon after the B-1A, and the larger
AGM-86B variant replaced it in
development. The later B-1B Lancer was briefly compatible with the
SRAM, though the latter was retired soon after, and none of the
other ALCMs were integrated into the B-1B either.
Possibly the worst moment in the history of the SRAM occurred on
September 15th 1980, when the right wing of a B-52H parked on the
alert apron at Grand Forks air force base caught fire. The fire was contained
on the wing and extinguished, but had the crosswind not been
blowing away from the fuselage, experts contended, it would likely
have entered the bomb bay --- which contained live SRAMs. A nuclear
detonation would not have occurred, but the volatile nature of the
solid rocket motor propellant was another matter.
The W69 warhead itself was also found to be vulnerable to fire. If
exposed to open flame, it was possible for the conventional
explosives inside to combust or even spontaneously detonate,
depending on the circumstances. Officially, a cooked-off W69 would
not successfully produce a nuclear chain reaction (fortunately, the USAF never had to find out the hard way), though the resulting plume
of pulverized plutonium still represented a serious radiation
hazard. Moreover, the toxicity of plutonium is far more dangerous
than even its radioactivity.
The end of the SRAM's operational service was also decidedly
ignominious. Mounting concerns of the weapon's safety margins
accumulated throughout the 1980s, beginning with the aforementioned
September 1980 ground fire, and Boeing's now two-decade-long failure
to make good on their promise for improved reliability and safety.
As a result, SecDef Richard "Dick" Cheney ordered the entire SRAM
inventory grounded in June of 1990, pending the completion of an
investigation into the missile's problems. The outcome showed that
the SRAM's problems were not only dire, but also unfixable, and
worsening every year. This led to the termination of the entire SRAM
inventory in 1993.
Production of the
SRAM lasted only 5 years, but during that time a total of 1 541
SRAMs were produced, including 41 developmental missiles (which
were, for all intents and purposes, prototypes). The tooling, jigs,
and other equipment needed to produce more was retained at USAF
Plant #77 in the event that further orders were placed, and an
option for another 45 missiles was initially offered, but no further
operational SRAMs were produced. According to Forecast
International, each had a unit cost of over $740 000 in 1975 US
have been produced since the 1970s, and the support and spare parts
infrastructure for them was terminated in 1991, along with all the
factory tooling and documentation required to produce more.
Furthermore, in accordance with arms reduction protocols, every SRAM
in the US inventory was either destroyed or rendered inoperable for
display purposes. The W69 warheads removed from the SRAMs were put
into storage, and some of these were later installed in B-66
free-fall nuclear bombs.
As such, the
AGM-69 SRAM is effectively an extinct weapon system --- an
altogether surprising fate, considering that the B-1 and B-52
bombers meant to carry it are both still operational.
Designation of the initial design; following testing, no production
AGM-69s were forthcoming.
SRAM: The basic production model, as described above.
SRAM: This was an improved AGM-69A with a new guidance system,
motor, and warhead, which was intended for use in the B-1A Excalibur
bomber. When President Jimmy Carter terminated the B-1A in 1978, the
AGM-69B program was terminated with it, and none of these missiles
were ever delivered. The B-1 program later produced the
B-1B Lancer in later years, but this bomber used standard
AGM-69As, and no later models of this missile were forthcoming.
II: More of a new design than an actual derivative, the AGM-131 SRAM
II was proposed as the successor to the SRAM. Due to
rapidly-shifting defense politics and budgetary priorities at the
end of the Cold War, this program was terminated in 1991 by
President George Bush, and no AGM-131 SRAM IIs were ever
proposed extended-range version of the AGM-69 design with
radically-increased electronic counter-countermeasure capability,
the SRAM-L was offered by Boeing to the USAF in the early 1980s. It
was rejected by the USAF, as it was found to conflict with their
already ongoing ASALM (Advanced Strategic Air-Launched Missile)
ASAT: The most
unusual SRAM variant, the LTV ASAT missile was partially derived
from the AGM-69 SRAM. This air-launched missile was designed to be
launched from a fighter, and shoot-down satellites. Though
ultimately, this missile was never accepted into service either.
This was a proposed air-launched anti-ballistic missile, based on
the SRAM (LEAP is short for "Low-Exo-Atmospheric Projectile"). The
program was terminated before any could be built.
conventionally-armed version of the SRAM was proposed as well (which
apparently never received an official designation), but due to the
poor accuracy of the nuclear version, no conventional SRAMs were
This British tactical missile was the spiritual predecessor of the
AGM-69 SRAM. Everything about this missile was shocking; it weighed
over 3 100 kg, carried a 680 kg thermonuclear warhead with a
multi-megaton yield, was carried in pairs and launched from the
famed V-Bombers, boasted a range of 925 km, and covered that
distance at 2 840 km/h (Mach 2.3) (a decidedly much more impressive
feat than 80 km at 4 320 km/h (Mach 3.5)). The existence of an
operational missile like this one would create quite a panic even in
the 21st century, but the Blue Steel entered service way back in the
1950s. Due to rapidly shifting strategic priorities in the UK
government, the Blue Steel was retired without replacement after
only a decade of service.
Skybolt: The Skybolt was a technological marvel, with three times
the speed and ten times the range of the SRAM --- when it worked.
Poor reliability, cost and schedule overruns, and disagreements
between the US and UK governments over this missile ultimately led
to its cancellation.
1B: Though not technically an air-launched ballistic missile, the
USAF demonstrated that the Minuteman ICBM could be dropped from a
C-5 Galaxy and launched in mid-air during its descent. However,
it proved a significant technical challenge, and coupled with the
then-upcoming SALT negotiations, further development was not
ASMP: The French
counterpart of the SRAM, the Aérospatiale ASMP (Air-Sol Moyenne
Portée) boasts a comparable speed and yield to the SRAM, but with
two critical differences. It has three times the range, and is a
cruise missile rather than a ballistic missile. The ASMP is used
only by France.
Developed in response to the SRAM, the Raduga Kh-15 (code-named
AS-16 or Kickback by the West) could be said to be the missile that
achieved everything that slipped away from the SRAM. Another
air-launched ballistic missile, the Kh-15 is launched from a much
wider range of aircraft, it's almost twice as fast, the range is
claimed to be three times as long, and it has conventionally-armed
versions as well as nuclear versions. This missile is also still in
service as of mid-2018, and is used only by Russia.
Kh-47M2 Kinzhal: The newest air-launched ballistic missile, the
Kinzhal ("Dagger") is claimed to have a Mach 10 speed (around
12 000 km/h), a range of over 2 000 km, a nuclear payload, and
quasi-ballistic maneuvering capabilities on descent. However Western
observers have expressed skepticism toward its capabilities. This
missile is used operationally since 2018 on MiG-31K long-range
multi-role fighters. NATO currently has no codename for this
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