SMYRNA, Tenn. (AP) _ The Boeing 707 that crashed in the Azores Islands, killing all 144 people aboard, had recorded no serious mechanical problems and relatively few flight hours for a 20-year-old jet, officials said.

The craft, one of two Boeing 707s owned by Independent Air Corp., had logged 12,500 cycles, or takeoffs and landings, and less than 50,000 hours in the air.

''If properly maintained, there should not be a problem because of hours or number of cycles,'' said Jack Barker, a Federal Aviation Administration spokesman in Atlanta. ''Other aircraft involved in the news have had as much as 50,000 cycles, a great many more.''

The Caribbean-bound charter jet, carrying 137 vacationers from Italy and a seven-member American crew, crashed into a fog-shrouded mountain Wednesday as it approached an airport in the Portuguese archipelago for refueling.

A.L. Pittman, president of Independent Air, headquartered in this town 25 miles southeast of Nashville, told reporters that for employees of the air charter service ''it's like losing a member of your family.''

''Generally everybody knows everybody else in a company this size,'' Pittman said. ''There have been some tears here today in shock.''

The crew members were: Leon Daugherty, 41, of Nashville, the captain; Sammy Adcock, 36, Nashville, 1st officer; Jorge Gonzalez, 34, Rex, Ga., the flight engineer; and flight attendants Yvette Murray, 26, of Marietta, Ga., Angela Urban, 24, West Palm Beach, Fla.; and Helen Ziegler, 45, Warner Robins, Ga., and Sabrina Cromarty of Atlanta.

Ms. Murray and the captain were planning to be married May 20, according to her father, Tom Murray of Atlanta.

The plane had seven service difficulty reports during the past six years, according to records at the FAA's aeronautical center in Oklahoma City, spokeswoman Bobbie Mardis said.

A report filed in January 1983 said the plane's No. 2 engine was shut down due to turbine failure. Another that month said a switch in the main landing gear failed and was replaced. Further details on the incidents were not immediately available, Ms. Mardis said.

Two reports filed July 1987 showed problems with the plane's altimeter and air speed monitors. In the latter case, the plane returned to Atlanta for repairs.

The latest report, filed in December, indicated that during inspection a mechanic noticed a crack in an engine fan duct. The duct was replaced and the plane was returned to service.

Barker said Wednesday night that he had not seen the reports and did not know their contents, but he said any faults with the plane would not be considered a problem, ''not if they've been repaired.''

He added that the FAA had fined Independent Air $18,000 in 1984, but he did not know why.

Pittman said one of the company's two jetliners lost oil pressure Jan. 21 as it flew into Denver and was repaired for eight to 10 hours before it resumed flying. He did not know if the jet was the one that crashed Wednesday.

''I'm not aware (of the service difficulty reports) so I'd have to say they are fairly minor,'' said Orien Dickerson, the company's vice president and co- founder. ''We have the same stringent monitoring program as Delta, American and all the major airlines.''

Independent Air is 15 years old and flies 400-500 charters per year, mostly in the Caribbean and Europe.