Federal investigators examined records and pesticide supply sources yesterday at small airports in Maryland and across the nation, because of concerns that crop-dusting aircraft could be used in a chemical or biological attack.
Attorney General John Ashcroft testified before the House Judiciary Committee that the FBI had issued a nationwide alert based on information about a possible attack using crop-dusters. But he said there was "no clear indication of the time or place of these attacks."
Officials say the discovery of a crop-dusting equipment manual and related computer information in suspected terrorist hideouts showed a possible interest in dispersing toxic agents from a plane or helicopter that is usually used in agriculture. The terrorists are believed to have the ability to produce, or get access to, toxic chemical and biological agents that could be used in an attack.
Crop-dusters were grounded along with all other civilian aircraft after the Sept. 11 terrorist attacks. Flights resumed Sept. 14, but the crop-dusters were grounded again two days later and for the past week have been barred from flying over metropolitan areas, with some exceptions.
All private planes continue to be restricted to flight plans filed with the Federal Aviation Administration, with all air traffic monitored on radar.
Crop-dusters were expected to be grounded until 12:05 a.m. today, but some owner-pilots in Maryland expressed concern that the ban might be extended.
There are about a half-dozen small crop-dusting operations in Maryland, mostly on the Eastern Shore, and about 3,500 nationwide. A large part of Maryland's pesticide-spraying business goes to out-of-state firms, including some based in California.
About 5,000 planes and helicopters work in the nation's agricultural business, dropping pesticides, fertilizer and seeds. Many are single-engine aircraft outfitted with 400- to 800-gallon tanks.
Most crop-dusters can cover up to 500 acres with a single load and can fly below FAA radar, according to pilots and industry sources.
"The FBI has talked to me, and they have done a pretty good job in finding out everything they can about my operation and the chemicals we use in our profession," Tim Curry, owner of Tim's Aerial Applications in Salisbury, said yesterday. "They are tracking chemicals we use from dealers to us, and with what happened on Sept. 11, I am all for it."
Curry, who has flown for 15 years, added: "If this ban stretches out, Maryland could have a problem with the soybean crop, which hasn't been harvested."
In southern states, officials are anxiously watching the federal ban on crop-dusting and the effect on the nation's cotton crop.
Officials at the Maryland Department of Agriculture said they have been cooperating with the FBI.
The FBI investigators "are interested in how various chemicals are regulated in the state, which flying firm is licensed to carry on aerial application operations and who receives the chemicals from source companies," said Donald Vandry, a spokesman for the state agriculture agency.
Crop-dusters use a wide variety of pesticides. Most of the pesticides, if dispersed over a population center, would make humans ill, but would not be fatal, said Dr. Charles W. Puffinberger, an assistant secretary for the state agency.
"Some could kill if used in concentrated doses, but that seems, from my vantage point, highly unlikely," he said.
Maryland requires certified commercial aerial applicators to have two licenses: One is a business license; the other is given after state-issued examinations and background checks.
"Most states have similar regulations," said Dennis Howard, a specialist with the state agriculture agency. "It is a carefully watched process with the chemicals, some of which are hotter, or more toxic, than others."
Federal, state and local law enforcement officials have been blanketing small airstrips from rural Harford County to the Eastern Shore, where much of the state's crop-dusting is done
Lt. Gary Foster, commander of the state police barracks in Centreville, said: "We're responsible for Kent and Queen Anne's counties, and we've been making contact with every airstrip. We're telling people the same thing you'd tell your kids about drugs or strangers: 'If something doesn't look right, tell somebody, speak up.'"
In Anne Arundel County, FAA restrictions have virtually shut down all three small airports - Tipton Airport near Fort Meade, Lee Airport in Edgewater and Suburban Airport in Laurel.
FBI agents examined records at Suburban Airport on Friday, airport officials said yesterday.
Similar airport closings were in effect elsewhere in Maryland.
One small Baltimore-area airport - Essex Skypark in eastern Baltimore County - did continue operations. But even there, private pilots were extremely careful.
"I flew from Martin State Airport to the Essex Skypark on Saturday, and I flew as straight a line as I could," said veteran pilot Donald Crouse. "If you wander ever so much off your flight plan, you will quickly have a U.S. F-16 behind you, and that is no fun, no way."
Sun staff writers Laura Barnhardt, Julie Bykowicz and Chris Guy contributed to this article.Copyright © 2014, Los Angeles Times