Airworthiness Directives; Bell Helicopter Textron Canada Model 407 Helicopters

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Final rule; request for comments.

SUMMARY:

This document publishes in the Federal Register an amendment adopting Airworthiness Directive (AD) 2000-02-12, which was sent previously to all known U.S. owners and operators of Bell Helicopter Textron Canada (BHTC) Model 407 helicopters by individual letters. This AD requires inspecting engine oil cooler blower shaft bearings (bearings) for roughness at specified time intervals and replacing any rough bearings before further flight. This amendment is prompted by several bearing failures. The actions specified by this AD are intended to prevent bearing failure, loss of tail rotor drive, and a subsequent forced landing.

DATES:

Effective March 3, 2000, to all persons except those persons to whom it was made immediately effective by Emergency AD 2000-02-12, issued on January 21, 2000, which contained the requirements of this amendment.

Comments for inclusion in the Rules Docket must be received on or before April 17, 2000.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Office of the Regional Counsel, Southwest Region, Attention: Rules Docket No. 99-SW-79-AD, 2601 Meacham Blvd., Room 663, Fort Worth, Texas 76137.

FOR FURTHER INFORMATION CONTACT:

Paul Madej, Aerospace Engineer, FAA, Rotorcraft Directorate, Rotorcraft Standards Staff, Fort Worth, Texas 76193-0110, telephone (817) 222-5125, fax (817) 222-5961.

SUPPLEMENTARY INFORMATION:

On January 21, 2000, the FAA issued Emergency AD 2000-02-12, applicable to BHTC Model 407 helicopters, which requires inspecting bearings for roughness at specified time intervals and replacing any rough bearings before further flight. That action was prompted by several bearing failures. This condition, if not corrected, could result in loss of tail rotor drive and a subsequent forced landing.

Transport Canada, the airworthiness authority for Canada, notified the FAA that an unsafe condition may exist on BHTC Model 407 helicopters. Transport Canada advises that failure of a bearing, part number (P/N) 407-340-339-101 or -103, may lead to failure in the power train. Transport Canada issued AD CF-2000-02, dated January 14, 2000, applicable to BHTC Model 407 helicopters.

The FAA has reviewed Bell Helicopter Textron Alert Service Bulletin No. 407-98-23, dated December 11, 1998, which describe procedures for replacing the oil cooler blower fan bearings, introduces the use of a new grease with better high temperature properties, and specifies adding a warning decal advising that only a certain type of grease should be used.

Since the unsafe condition described is likely to exist or develop on other BHTC Model 407 helicopters of the same type design, the FAA issued Emergency AD 2000-02-12 to prevent bearing failure, loss of tail rotor drive, and a subsequent forced landing. The AD requires the following: Within 10 hours time-in-service (TIS), inspect the bearings, P/N 407-340-339-101 or -103, for roughness by hand-rotating the driveshaft with the oil cooler drive shaft connected. Within 25 hours TIS, inspect for bearing roughness by hand-rotating the driveshaft with the oil cooler driveshaft disconnected at both ends and lubricate the bearings with grease after the inspection. At intervals not to exceed 25 hours TIS, inspect for bearing roughness by hand-rotating the driveshaft with the oil cooler drive shaft connected and lubricate the bearings with grease after each recurring inspection. Replace any rough bearing before further flight. The short compliance time involved is required because the previously described critical unsafe condition can adversely affect the structural integrity and controllability of the helicopter. Therefore, inspecting the bearings for roughness is required within 10 and 25 hours TIS and thereafter, at intervals not to exceed 25 hours TIS and replacing any rough bearing is required before further flight, and this AD must be issued immediately.

Since it was found that immediate corrective action was required, notice and opportunity for prior public comment thereon were impracticable and contrary to the public interest, and good cause existed to make the AD effective immediately by individual letters issued on January 21, 2000, to all known U.S. owners and operators of BHTC Model 407 helicopters. These conditions still exist, and the AD is hereby published in the Federal Register as an amendment to section 39.13 of the Federal Aviation Regulations (14 CFR 39.13) to make it effective to all persons.

The FAA estimates that 350 helicopters of U.S. registry will be affected by this AD, that it will take approximately 0.5 work hour per helicopter for the initial 10-hour TIS inspection; 1.5 work hours per helicopter for the 25-hour TIS inspection; 0.5 work hour for the repetitive inspections; and 4 work hours per helicopter to replace the bearing, if necessary. The average labor rate is $60 per work hour. Required parts will cost approximately $1,926 per helicopter to replace the bearing, if necessary. Based on these figures, the total cost impact of the AD on U.S. operators is estimated to be $462,000, assuming one 10-hour TIS inspection, one 25-hour TIS inspection, 40 repetitive inspections per helicopter, and no bearing replacements.

Comments Invited

Although this action is in the form of a final rule that involves requirements affecting flight safety and, thus, was not preceded by notice and an opportunity for public comment, comments are invited on this rule. Interested persons are invited to comment on this rule by submitting such written data, views, or arguments as they may desire. Communications should identify the Rules Docket number and be submitted in triplicate to the address specified under the caption ADDRESSES. All communications received on or before the closing date for comments will be considered, and this rule may be amended in light of the comments received. Factual information that supports the commenter's ideas and suggestions is extremely helpful in evaluating the effectiveness of the AD action and determining whether additional rulemaking action would be needed.

Comments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the rule that might suggest a need to modify the rule. All comments submitted will be available, both before and after the closing date for comments, in the Rules Docket for examination by interested persons. A report that summarizes each FAA-public contact concerned with the substance of this AD will be filed in the Rules Docket.

Commenters wishing the FAA to acknowledge receipt of their comments submitted in response to this rule must submit a self-addressed, stamped postcard on which the following statement is made: “Comments to Docket No. 99-SW-79-AD.” The postcard will be date stamped and returned to the commenter.

The regulations adopted herein will not have a substantial direct effect on the States, on the relationship between the national Government and the States, or on the distribution of power and responsibilities among the various levels of government. Therefore, it is determined that this final rule does not have federalism implications under Executive Order 13132.

The FAA has determined that this regulation is an emergency regulation that must be issued immediately to correct an unsafe condition in aircraft, and that it is not a “significant regulatory action” under Executive Order 12866. It has been determined further that this action involves an emergency regulation under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979). If it is determined that this emergency regulation otherwise would be significant under DOT Regulatory Policies and Procedures, a final regulatory evaluation will be prepared and placed in the Rules Docket. A copy of it, if filed, may be obtained from the Rules Docket at the location provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

• Air transportation
• Aircraft
• Aviation Safety
• Safety

Adoption of the Amendment

Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration amends part 39 of the Federal Aviation Regulations (14 CFR part 39) as follows:

PART 39—AIRWORTHINESS DIRECTIVES

1. The authority citation for part 39 continues to read as follows:

Authority: 49 U.S.C. 106(g), 40113, 44701.

2. Section 39.13 is amended by adding a new airworthiness directive to read as follows:

AD 2000-02-12 Bell Helicopter Textron Canada: Amendment 39-11579, Docket No. 99-SW-79-AD.

Applicability: Model 407 helicopters, with oil cooler blower shaft bearing (bearing), part number (P/N) 407-340-339-101 or -103, installed, certificated in any category.

Note 1:

This AD applies to each helicopter identified in the preceding applicability provision, regardless of whether it has been otherwise modified, altered, or repaired in the area subject to the requirements of this AD. For helicopters that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must request approval for an alternative method of compliance in accordance with paragraph (d) of this AD. The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by this AD; and, if the unsafe condition has not been eliminated, the request should include specific proposed actions to address it.

Compliance: Required as indicated, unless accomplished previously.

To prevent bearing failure, loss of tail rotor drive, and a subsequent forced landing, accomplish the following:

(a) Within 10 hours time-in-service (TIS), inspect the forward and aft bearings for roughness by hand-rotating the driveshaft with the oil cooler driveshaft connected. Replace any rough bearing before further flight.

(b) Within 25 hours TIS, inspect the forward and aft bearings for roughness by hand-rotating the driveshaft with the oil cooler driveshaft disconnected at both ends. Replace any rough bearing before further flight. After the inspection, lubricate the bearings with MIL-G-25013 grease.

(c) Following the inspection of paragraph (b) and at intervals not to exceed 25 hours TIS, repeat the inspection of paragraph (a). Replace any rough bearing before further flight. After each recurring inspection, lubricate the bearings with MIL-G-25013 grease.

(d) An alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may be used if approved by the Manager, Regulations Group, Rotorcraft Directorate, FAA. Operators shall submit their requests through an FAA Principal Maintenance Inspector, who may concur or comment and then send it to the Manager, Regulations Group.

Note 2:

Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Regulations Group.

(e) Special flight permits will not be issued.

(f) This amendment becomes effective on March 3, 2000, to all persons except those persons to whom it was made immediately effective by Emergency AD 2000-02-12, issued January 21, 2000, which contained the requirements of this amendment.

Note 3:

The subject of this AD is addressed in Transport Canada (Canada) AD CF-2000-02, dated January 14, 2000.