The two Atlanta police officers who died in a helicopter crash received glowing reviews from their supervisors in the years before the crash.

Meanwhile, the Hughes OH-6 that crashed Nov. 3 in a northwest Atlanta intersection was upgraded with new equipment after the engine was replaced in 2005, according to Federal Aviation Administration records obtained by The Atlanta Journal-Constitution and Channel 2 Action News.

The reason the helicopter crashed into a utility pole may remain a mystery until the National Transportation Safety Board issues its findings in about a year. Pilot Richard J. Halford and tactical flight officer Shawn A. Smiley were searching for a missing 9-year-old child when the helicopter crashed.

The records filed with the FAA show numerous technical upgrades, including installation of heat sensors for searches for fugitives and missing persons, sirens, an anti-theft system, communications equipment and a public address system and siren.

The records describe at least 17 major repairs or modifications made to the chopper in the past seven years. In 2005, the HO-6 was equipped with a new tail boom and a new Rolls-Royce engine.

Also in 2005, a batch of electronics was installed — antenna, GPS, navigation and communication radio — plus an altimeter system. If functioning properly, that would have warned the pilot of his height above the ground with time to adjust his altitude.

The aircraft also got a forward-looking infrared system that homes in on body heat for use at night or in densely wooded areas.

The AJC has requested the maintenance records for the helicopter. The Atlanta Police Department said it plans to make those documents available by Nov. 30.

The Hughes OH-6 was built in 1967 and used by the U.S. Army until it was donated to the APD in 1996 to assist with the Olympic Games.

Eleven years ago, city officials said the Vietnam War-era chopper had outlived its useful life of 25 years. But, according to city officials, the helicopter — 45 years old at the time of the crash — was completely refurbished within the past seven years.

Airworthiness records from the FAA show a variety of major repairs or alterations — a category of work that includes the helicopter’s airframe, powerplant, propeller and “appliances.”

In February 2007, a variety of equipment was installed, including a compass system, Motorola radios and a dual audio channel controller. In May of that year, exhaust equipment was installed. “The aircraft’s weight and balance were not affected,” a report noted at the time.

The two officers assigned to the helicopter Nov. 3 had been highly rated, according to personnel evaluations released Monday.

Smiley, a relative newcomer to the force, was rated effective or highly effective in a battery of evaluations in 2010 and 2011.

Though Halford’s annual performance reviews showed he rated “highly effective” or “outstanding,” he had some problems in the early days of his 26-year APD career.

In 1991, he was suspended a day for driving too fast and wrecking his motorcycle when he hit oil and a crack in the road. A few times in the early 1990s he was criticized for falling short of APD’s quotas set for each officer to make a certain number of arrests, traffic stops or DUI cases. In 1995, he was suspended for a day for leaving work without notifying his supervisor.

But by 1999 Halford’s performance review started to match his eventual reputation as a highly skilled pilot. The 1999 review said Halford performed his duties flawlessly and made decisions “with the safety of his crew in mind as well as the citizens of Atlanta.”

“As an airborne law enforcement officer, Officer Halford recognizes that there is no room for error or poor work quality. His safety record and work load is reflective of his dedication to the police department and the helicopter unit. He is an exceptional pilot and police officer,” his sergeant wrote.