“Probably the most complex airborne weapon that MBDA has ever done”. That’s how the chief engineer of the SPEAR 3 described this new British air-surface missile in a presentation to the Royal Aeronautical Society in London last week. As Stephen Temple described the ongoing development, I marveled at how his team are meeting a very demanding requirement. But I found myself wondering about the concept of operations, and the cost.

SPEAR is an acronym for Selective Precision Effects At Range, one of four air-surface weapons for the Royal Air Force. The new missile offers medium range to fill a gap between the other three, which are already in service: the short-range Paveway IV bomb (SPEAR 1) and Brimstone missile (SPEAR 2), and the long-range Storm Shadow cruise missile (SPEAR 4). It is also designed to provide the flexibility and precision that is demanded by the ever-more-stringent rules of engagement that Western nations have adopted, as they attempt to avoid civilian casualties. Especially in built-up areas (see my thoughts on Urban Close Air Support in a previous article).

By the time that SPEAR 3 is ready for production, MBDA will have been working on it for about 10 years. An assessment phase lasted from around 2012 to 2016 at a cost of £150 million ($195 million), which exceeded the original estimate. In May 2016, MBDA announced the receipt of a four-year development contract worth £411 million ($534 million). That’s a lot of time and money. But as Temple described the missile’s sophistication, and the extraordinary development effort involved, it became explainable.

SPEAR 3 is powered by a small, 150lb thrust turbojet; it navigates by GPS/INS and has a datalink for mid-course updates; the terminal guidance is by semi-active laser or a small radar so that moving targets can be engaged, similar to Brimstone; and the warhead effect is adjustable depending on the type of target (and with the possibility of inflight fuzing changes). Yet it is only some six-and-a-half feet long, seven inches wide, and weighs 220 lbs. Eight of them can fit inside the small weapons bay of an F-35B, on two four-missile launchers, and alongside two of MBDA’s Meteor long-range air-to-air missiles. Temple noted: “The packaging risk was high, with very little trade space. We had to make a series of changes, including a shock-mitigation scheme.” Whereas previous MBDA missiles had a maximum 5,000 wires per cubic metre, SPEAR 3 has 12,000. Flexible harness interconnects were required.

The “intelligent” launcher calculates acceptable launch windows and initializes the missiles, amongst other functions. The missiles are carried upside-down because even when they are folded before launch, the pop-out wings needed space that was only available at the bottom of the F-35B’s weapons bay. Temple said that because of the high temperatures in that weapons bay, a complex thermal model was needed. The missiles are pneumatically ejected, so that no gas feed from the host aircraft is required. The pitch rate must be low, as the weapons rolls through 180 degrees to the wings-on-top arrangement.

There were many other requirements: a salvo-fire option; the possibility of a ground operator taking control of the missile via Link 16; a long carriage life; a long shelf life; munitions safety; disassembly for maintenance, and so on.

During the assessment, a large amount of modelling was done to avoid extensive flight test. The seeker was trialled on a Piper Navajo. To date, SPEAR 3 has flown only once, to check the release, the starting of the turbojet, and aerodynamic performance. That test in May 2016 purposely ended with the missile flying into the sea: it has not yet been flown against a ground target.

That first flight was launched from a Eurofighter Typhoon. But the development funding does not include operational qualification of the missile on the Typhoon. Instead, the whole effort is focused on the F-35B. That seems strange, since the missile’s range was set to avoid the launch aircraft having to penetrate enemy air defences. But surely, the Typhoon needs that capability far more than the supposedly stealthy Lightning II.

Temple did not specify the range. Media reports have quoted 80 miles. MBDA’s publicity says that SPEAR 3 can engage targets “far beyond the horizon”. From 10,000 feet that would be well over 120 miles. That would seem to be necessary. The range of the radar used by the Russian S-400 air defence missile system is reportedly 250 miles, and its missile engagement up to 235 miles. And SPEAR 3 is designed to attack static and mobile air defence systems.

According to Temple, the other targets include armoured vehicles, semi-hardened structures, small-to-medium fast vessels, and “asymmetric targets such as pick-up trucks.” But why the latter, which are unlikely to be operating within the cover of a sophisticated air defence system, and are therefore suited to attack by the less expensive Brimstone missile, or by Paveway bombs?

The debate about using expensive aircraft and weapons to attack such low-cost targets is ongoing. It is a difficult debate to conduct, since weapons-makers (including MBDA) and their customers are so coy about unit costs. Short-range rocket-powered missiles like Brimstone cost upwards of £75,000 ($100,000). Cruise missiles like Storm Shadow reportedly cost nearly £800,000 ($1 million). With a range that falls somewhere between these weapons, what will a production SPEAR 3 cost?


  1. This comment comes from an anonymous, but informed, senior retired RAF source that is known personally to me:
    “The perceived wisdom of using eight Spear 3 on an F-35B needs a close look, I think.
    You say that by the time it is ready for production, MBDA will be in the ante for quite a sum. For an “assessment phase from 2012 to 2016, costing £150m, and from 2016 for year years, a “development contract” for £411m.
    As a past warrior in the Plans corridors of the MOD, we all know how governments balance budgets under stress. The first play is to reduce the offtake. So let us assume we will make provisions for, say, 1,000 weapons. Therefore to amortise the assessment and development phases alone, the weapon is costing us £561,000 apiece. Then we tool up for production and who knows what that would be. Yet again we dig deep into the coffers to fulfil the companies profit.
    I have studied what the F-35B can do with its 13,300lbs of fuel. I would doubt if the aircraft will have enough fuel to release eight Spear-3s at your “trucks” (even if it has, it shouldn’t). But regardless, it seems that we propose to use a £N-squared-cost vehicle to attack with 8 x at least a three-quarter million weapon. Wow! A god job we are rich.
    By the way, do you know if the F-35B remains committed to retaining a proportion of its fuel to cool the aircraft systems? We have heard that already pilots have had to open their bomb doors inflight to cool the bays. If so, I hope wemake those little wings on the Spear 3 quite rugged.


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