ELECTRONIC BATTLEFIELD: Making Helicopters SAM Proof

Equipping the U.S. Army's 2,500 helicopters with defenses against shoulder fired surface-to-air missiles (like the SAM-7 or Stinger), would cost $5-7 billion and take up to a year, or more. A typical system has two components. First, there are four ultraviolet detection sensors (weighing about four pounds each) mounted on different parts of the helicopter to detect an approaching missile. These sensor are linked to an eleven pound computer that contains software for determining that the object is indeed a missile and where it is headed. The detection computer is hooked to a countermeasures system using either flares and chaff (strips of metal foil), or a laser, to confuse the missiles guidance system (that is homing in the heat of the helicopters engines.) The countermeasures component weighs 30-50 pounds, depending on type or model.

There is a debate going on inside the army over whether to equip helicopters with the army developed ATIRCM/CMWS (Advanced Threat Infrared Countermeasures/Common Missile Warning System), that uses flares and chaff, or a civilian system (DIRCM), that uses a laser to confuse the missiles guidance system. The DIRCM costs about 40 percent more than the ATIRCM/CMWS (which costs two million dollars per aircraft). The ATIRCM/CMWS uses a proven technology, which the DIRCM's laser has been successful in tests, but has not gotten much use in actual combat conditions. Because both systems use a lot of precision components, and a lot of them cannot be produced quickly. The army has equipped some of its Special Forces helicopters with DIRCM, but it would take about the same amount of time (late 2005, early 2006) to equip all army helicopters with either system. Many of the army's larger transport helicopters are equipped with an older, and less reliable, countermeasures system. So far, ten American helicopters have been hit by missiles in Iraq. If the attacks continue to bring down choppers, there will probably be a crash program to equip the most vulnerable helicopters (those operating over the few areas where most of the attacks occur) with a defensive system as soon as possible. This means 30-90 days.

I don’t know a lot about helicopters. One uncle was a helicopter pilot in the Navy and another was a helicopter mechanic in the Air Force though.

I’ve always had the impression that they’re pretty delicate, despite what you hear about them being able to withstand a variety of things. Mainly because nearly every part spins, twists, swivels or moves in some way.

The uncle that was a helo mechanic claimed that if you could get anything into the blades you could bring it down. A length of chain, piece of kindling, a brick – anything.

He worked on those banana shaped helicopters that had two sets of blades. He said they’d use a long thin fiberglass pole that had a triangular flag on it to set the pitch of the blades somehow. He said that they’d had a couple of incidents in which someone put the pole too close and it got smacked by a blade. He said he’s literally seen 18-24” pieces of blades get scattered around.

Evidently when the blade tip comes off it throws the entire thing out of balance and makes it do goofy things.

This would have been between 1957 and about 1965 though so I imagine they’ve improved stuff some.

And the upgrade to the system for attack helicopters is to determine the firing location of the missile and to place a cursor over that location on a map allowing the helicopter targeted (or another helicopter nearby) to target that location. One of the ways to stop this sort of attack is to make it costly for the attackers as well as making their missile miss its intended target.

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