NYPD Grounds Two Copters, Reconfigures Another
After grounding one air-sea rescue craft because of the suspected mechanical failure of another, the New York City Police Department has reconfigured one of its seven police helicopters for air-sea rescue missions.
These precautionary actions by the NYPD were taken two weeks in advance of the Air Service Bulletin issued by Pratt & Whitney of Canada indicating, “It is possible that the output drive gearshaft assembly can fracture, resulting in loss of power,” in certain models, including the most recent airsea rescue helicopters purchased by the NYPD.
On September 22, NYPD air-sea rescue helicopter No. 12, a Bell 412, experienced an apparent mechanical failure causing its emergency landing in Jamaica Bay not far from the Department’s Aviation headquarters at Floyd Bennett Field. None of the six members of the service on board was seriously injured. They had been performing a security sweep that afternoon ahead of President Obama’s arrival for the United Nations General Assembly.
The NYPD took delivery of No. 12, along with a second, identical Bell 412 – No. 14 – last December, each costing $12 million. When No. 12 experienced its failure and was taken out of service because of the damage, the Police Department, as a precaution, grounded No. 14 on the same day.
A third Bell 412, christened “No. 23” in honor of the 23 NYPD officers killed in the 9/11 attacks, remained in service because it had flown since 2002 for more than 1,000 hours, without incident and with no indication that it shared the problem experienced by the newer ship.
No. 23 was originally equipped principally for counterterrorism and other investigative purposes, but with both of the newer 412s out of service, it has been reconfigured to perform air-sea rescue missions as well.
Preliminary findings indicate the failure in No. 12 may have been caused by metal fatigue in its output drive gearshaft assembly, which is housed in a combining-gear box (C-box) of the helicopter. Energy generated by No. 12’s dual Pratt & Whitney engines is directed through the C-box to a single drive-shaft which powers the helicopter’s rotors.
The NYPD’s four other helicopters are Agusta A119s, used for patrol, and are unaffected by the grounding of the two Bell 412s.
The Bell 412s are larger than the Agusta helicopters, and are designed to carry SCUBA divers and rescue equipment. It also is equipped with a hoist and has room to transport accident victims.