Handley is a character who makes a one-time appearance in the Season 2 episode titled "HX-1".
Handley is one of three mercenaries working for Dunkirk, together with Decker and Joe Ganns. At the beginning of the episode, Handley goes in with Dunkirk and the others, mounting a raid to steal the HX-1 helicopter, intending to sell it to foreign buyers.
When Archangel asks Hawke to find the HX-1, Hawke suspects it to be the work of mercenaries. He goes to a weapons range to look up some of them and meets Joe Ganns and Handley. He tells Ganns that the raid looks very much like the kind of operation Mace Taggert and his brother Saint John Hawke used to pull off in Vietnam. He has a real feeling some of them are still alive.
After Hawke leaves, Handley tells Ganns they have trouble--Hawke is getting too close to the truth.
When Hawke next looks up Dunkirk at a bar, Handley joins the rest of Dunkirk's men to beat Hawke up. But Hawke is not deterred. He tracks them to a warehouse where HX-1 is being hidden.
Later Handley is with the rest of Dunkirk's men at Red Rock Flats to demonstrate ground weapons to Dunkirk's potential customers. He is shown firing a M72 LAW at a car to an appreciative audience. He is probably killed when HX-1 was shot down by Airwolf and crashes into the weapons display area.
Note: the credits in the episode bills his name as "Allen Graf".