All-Star first baseman Mo Vaughn of the Boston Red Sox, who was scheduled to conduct a baseball clinic Thursday evening in Bangor, canceled his appearance only hours before the event.

Vaughn was to talk baseball with the children of employees of local Pepsi-Cola distributors during a three-hour session at Mansfield Complex. He was reportedly unable to make the trip because of a medical appointment, according to Richard Russell, the market development representative at Pepsi-Cola in Brewer.

More than 160 youngsters ages 6-14 had planned to attend the event, one of several Vaughn agreed to do for corporately owned Pepsi facilities in New England, Russell said.

“We have a lot of disappointed kids,” said Russell, whose oldest sons, ages 9 and 5, were among those planning to attend.

Russell explained that Vaughn will, eventually, return to Bangor for the clinic.

“It has absolutely got to be done,” Russell said. “It’s a commitment we made as a company. It’s just a matter of when.”

Matt Shaw, representing the Boston public relations firm of Agnew, Carter and McCarthy, said Thursday afternoon he did not know why Vaughn canceled.

However, Russell said Vaughn is reported to be afraid of flying on small airplanes, and there is no commercial jet service into Bangor International Airport.

Russell explained that Thursday marked the third time this year that Vaughn had canceled a trip to Bangor. The difference was, this time, Vaughn pulled out at the last minute, causing a panic at Pepsi’s Brewer office.

“We all pitched in,” Russell said of having to telephone the people who were planning to attend the clinic. “We didn’t officially get notified until 2:30, but we got about 80 percent of the people who were invited. Everybody was understanding.”

Russell explained that Vaughn has a friend who works for Pepsi in Massachusetts, which is where the relationship developed. Vaughn, who was to be paid handsomely for his appearance, according to Russell, has expressed interest in buying a string of Kentucky Fried Chicken restaurants, which sell Pepsi products.