On the Cusp of the Century Series

Having read my Continental Air Defense series, you’re now familiar with the Century Series of fighters, starting with the F-100 Super Sabre.

But what was the F-99?

Before the Tri-Service designation system came into being in 1962, the Air Force went through several iterations of naming conventions for missile designations. One of the weirder ones was to number some missiles in the same line as fighter aircraft. In the Air Force eyes, a guided missile was just an unmanned fighter. That lead to the Falcon missile bearing the designation (for a very short time) of F-98. And the only surface to air missile the Air Force operated became the F-99, though it was far more commonly referred to as the BOMARC.


Beginning in 1949, the Air Force sought a long range anti-aircraft guided missile for continental air defense. The contractor, Boeing, partnered with the Michigan Aerospace Research Center (hence BOMARC) to develop a long range, high altitude ramjet powered missile. Development was lengthy, but by 1957 the missile system was ready for production, and entered service in 1959 with the designation IM-99 (intercept missile). After the Tri-Service designation system was put in place, the BOMARC was redesignated the CIM-10.

The BOMARC was launched and boosted to supersonic speeds by a booster rocket, then powered in flight by gasoline fueled ramjet engines. Ramjets were a popular choice for early missiles for the range they gave. Solid rocket fuels were not advanced enough to provide sufficient range. Ramjets had most of the advantages of liquid fueled rockets, without the disadvantage of having to carry oxidizer. But ramjets only work at supersonic speeds. Hence the booster rocket. The “A” model BOMARCs used a liquid fuel booster. The missile was raised from its coffin like shelter to the vertical position, and the booster would then be fueled. That added about 2 minutes to the firing time. Advances in rocketry meant the BOMARC B used a solid fuel booster.  Cruise speed under ramjet power was approximately Mach 2.8 at an altitude of around 60,000 feet.

The BOMARC A had either a 1000 pound conventional warhead, or a 10 kiloton nuclear warhead.  All BOMARC B missiles were armed with the nuclear warhead.

The BOMARC was a long range missile. Very long range. The A model had a range of about 250 miles. The B model had a whopping 400 mile range.

Because of this long range, the BOMARC had an unusual guidance system. The missile would be launched toward a predetermined intercept point, and proceed under auto-pilot. Mid-course guidance was by steering commands directly from the Semi-Automatic Ground Environment. Finally, as the missile closed within 10 miles of the target, it used its own onboard active radar seeker to complete the intercept.


At the height of its deployment, there were 14 US BOMARC sites. Canada, tightly interwoven with the US in the continental air defense mission, also operated the BOMARC at  two sites. The Canadian decision to deploy BOMARC was a political one, more than a military one. Craig mentioned the reliable Avro Canada CF-100 Canuck a while back. It’s replacement was intended to be the superb CF-105 Mach 2 interceptor. But rising costs lead to Canada cancelling the project just as it was coming to fruition. In its place, the BOMARC was purchased instead.

Technologically, the BOMARC system was an impressive achievement. The missile flew as advertised, the guidance system was relatively effective and reliable, and 10 kilotons will kill just about any intruding bomber.

The problem was, operationally, the system was something of a flop. Long range guided missiles lack the flexibility of manned interceptors. Most “airspace intrusions” in those days were international airline flights either arriving ahead of or behind schedule.  A manned interceptor such as an F-102 could launch, intercept the bogey, determine if it really was the leading elements of the Red hordes, and attack. A BOMARC, however, couldn’t do that. And blowing up airliners in those days was frowned upon.  Further, BOMARC was useless against the ballistic missiles that were coming to dominate the strategic scene just as it became operational. It soldiered on through the 1960s mostly because it was there, but by 1972, all US and Canadian BOMARC sites had been deactivated.

Over 700 missiles were built. And even though they were not a great success as an air defense asset, they still had life in them. Many were converted to high speed aerial targets, ironically dying at the hands of other anti-aircraft missiles.

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2 responses to “On the Cusp of the Century Series

  1. Esli

    I thought I was reading a post on all of those missing numbers in the gaps between actual production models of various aircraft. Pretty interesting note about the F99 designation but what about all those other numbers?

    • A few of them are also “missiles” but the majority are redesignations. For example the F-86D was originally the YF-95. Then common sense took over and the Air Force just appended a letter to the base designation.