HUNTSVILLE, Ala. - Your average Black Hawk helicopter costs about $16 million. One rotor blade carries a price tag of $220,000. Obviously, if you can repair a damaged blade rather than replace it, you can save big money. That's where shot peening comes in.
First used on automobiles back in the 1940s to increase the strength of valve springs, it's actually pretty simple. The surface of a metal part is hammered, or impacted to compress the surface layer. It makes the surface tougher, and less likely to crack.
"It's a little counterintuitive, because you think you're actually damaging the material by creating dents, but you are creating a stronger surface that's actually resistant to cracks," says Kelly McClurg of Huntsville's Avion Solutions. The company has developed equipment to ultrasonically shot peen damaged rotor cuffs on Black Hawk helicopters. The peening takes place as small beads of material are literally bounced against the parts surface. What was smooth is made rough, much tougher.
Longtime helicopter repairman Glen Soule says 20 years ago, the parts that are now repaired using shot peening, would have had a different fate. "Oh we would have had to replace the rotor blade. Of course that costs a lot of money, and we'd have just had to get a new one, buy a new one," says Soule. Once again, the equipment and process developed by Avion Solutions means quick repairs, and so far some $60 million in savings.
"I mean it's obviously a good news story for our company, but being able to save that kind of money for the Army, and knowing that money goes back into other things to support the war fighter, it's just fantastic," says Avion's Jeff Blackmon.
Once again, shot peening is a technique that essentially hammers the surface of a metal part. The hammered portion is covered with small dents, but those dents make it a tougher surface. Using it on Black Hawk helicopters has saved tens of millions of taxpayer dollars.
Avion makes repairs on rotor blade cuffs at the Meridianville Airport in Madison County. The Army has two of the shot peening machines at the Corpus Christi Army Depot. The company's goal is to eventually deploy the equipment to forward areas, for on-the-spot repair.