The chairman of the Civil Aeronautics Board yesterday accused the trucking industry of lying about the impact of airline deregulation in an attempt to build opposition to deregulation of trucking.

The truckers, CAB chief Marvin S. Cohen complained, "are trying to use scare tactics to give the impression that small communities have lost air service," as a result of deregulation.

"That's just not true," said the CAB chairman, who called in reporters yesterday to denounce an antideregulation advertisement published last week in The Washington Post and The Wall Street Journal.

"Deregulation has shot down more planes than The Red Baron," proclaimed the ad run by Kysor Industrial Corp., a Cadillac, Mich., conglomerate involved in the trucking business. The ad, also carrying the imprint of the American Trucking Associations Foundation, listed 25 cities which it said had lost "certified" air service since federal airline regulations were lifted in October of 1978.

Cohen said he hadn't checked the service record of the World War I flying ace, but CAB files show the ad is "grossly misleading" and in some cases flatly wrong.

"The impression they gave in this ad is that those communities lost all air service," complained Cohen "That's just false."

Going down the list of 25 cities, Cohen said:

Five of the 25 still are served by CAB-certified major airlines, although the lines have announced plans to end service sometime in the future.

Thirteen of the 25 lost CAB-certified service before airline deregulation went into effect but are still served by commuter airlines.

Twenty-four of the 25 still have scheduled airline service. The one that doesn't, Winona, Minn., specifically asked the CAB to end its service and switch flights to the nearby La Crosse, Wisc., airport.

Since deregulation, Cohen claimed, there is little difference between CAB-certified and non-certified air service.

"The consumer is not concerned about whether a carrier holds a certificate, but is concerned about the overall quality of service," the CAB chief said. "Small communities are receiving increased service since the passage" of airline deregulation.

Cohen outlined his argument with the trucking deregulation foes in letters to the chairmen of the House and Senate committees handling trucking legislation.

Spokesmen for the American Trucking Associations and Kysor Industries said they could not comment on Cohen's criticism until they have had time to review his letter. Officials of ATA and Kysor declined to say who prepared the ad. It was paid for by Kysor whose businesses include a truck line and companies that make parts for heavy trucks.

Cohen said he has frequently "endorsed the principle" of deregulating trucking, but is not supporting any specific legislation in the field.

The CAB chief insisted that switching from major airlines to commuter carriers has not hurt air service to small cities and in many cases has improved it.

Among the cities cited in the truckers' ad was Danville, Va. Cohen said Danville had 28 flights a week with a total of 1,600 seats when it was served by a major carrier and now has 87 flights a week with 2,000 seats on commuter flights.