Practice makes perfect, even when it comes to disasters. That`s why emergency personnel from around the Joplin area will converge on the Joplin Regional Airport tomorrow. A small airplane crash will be simulated Friday afternoon at 1:30. Airport manager Steve Stockam says disaster drills are usually not publicized. But in light of everything that`s happened over the past few months, he thinks its a good idea to notify the public in advance. METS, the airport fire and rescue, and the Joplin Police and fire departments will be involved in the mock incident.