Swashplate The Focus Of The Action

The FAA is proposing an AD for Bell Helicopter Model 412 and 412EP helicopters. The notice was published in the Federal Register Monday.

The proposed AD is prompted by reports of cracking in the swashplate outer ring assemblies (outer ring). The AD would establish a lower life limit on certain outer rings, requiring a revision of the retirement life on the components' history card or equivalent record, and a revision of the maintenance manual or Instructions for Continued Airworthiness (ICA).

The proposal also would prohibit installing these outer rings on any helicopter. The proposed actions are intended to prevent failure of an outer ring because of cracking, which could lead to the loss of main rotor (M/R) blade pitch control and subsequent loss of helicopter control.

The FAA has reviewed Bell Helicopter Alert Service Bulletin No. 412-08-131, Revision B, dated October 29, 2009 (ASB), which describes procedures for establishing a new retirement life for the outer ring and replacing the outer ring at 2,500 hours TIS. The proposed AD would require the following:

• Within 30 days, establish a new retirement life of 2,500 hours TIS for outer ring P/N 412-010-407-105, and record this on the component history card or equivalent record. Within the same time period, make pen-and-ink changes or insert a copy of the AD into the Airworthiness Limitations section of the applicable maintenance manual or ICA.
• Within 300 hours TIS, for any affected outer ring that has 2,200 or more hours TIS on the effective date of the proposed AD, replace the outer ring with an airworthy outer ring.
• Within 12 months, for any affected outer ring, regardless of the number of hours TIS, replace the outer ring with an airworthy outer ring. The installation of outer ring, P/N 412-010-407-105, would be prohibited on any helicopter.

The FAA estimates that this proposed AD would affect 143 helicopters. They estimate that it would take about one work-hour to revise the component history card or equivalent record, as well as the maintenance manual or ICA, at an average labor rate of $85 per work hour, for a total cost of $85 per helicopter and $12,155 for the U.S. operator fleet. Replacing an outer ring would take 26 work-hours and required parts would cost an estimated $25,725. Based on these figures, the FAA calculates the total cost to be $27,935 per helicopter to replace an outer ring.

The proposed AD is open for comments until November 23, 2012.

(Image from file)

FMI: http://www.gpo.gov/fdsys/pkg/FR-2012-09-24/html/2012-23457.htm