Federal Aviation Administration, DOT.
Notice of proposed rulemaking (NPRM).
This document proposes the adoption of a new airworthiness directive (AD) that is applicable to certain Short Brothers Model SD3 series airplanes. This proposal would require repetitive tests (checks) of the power lever movement of the fuel control unit (FCU) lever to ensure the lever is contacting the maximum stop, adjustment of the FCU rigging, if necessary; and an engine ground run for correct gas generator rotational speed. This proposal also would require a static reduced power check on each engine to ensure correct operation of the reserve takeoff power (RTOP) system; and follow-on actions, if necessary. This action is necessary to prevent failure of the engines to reach adequate RTOP boost during takeoff, which could result in reduced controllability of the airplane. This action is intended to address the identified unsafe condition.
Comments must be received by September 27, 2001.
Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 2001-NM-Start Printed Page 45197113-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056. Comments may be inspected at this location between 9:00 a.m. and 3:00 p.m., Monday through Friday, except Federal holidays. Comments may be submitted via fax to (425) 227-1232. Comments may also be sent via the Internet using the following address: email@example.com. Comments sent via fax or the Internet must contain “Docket No. 2001-NM-113-AD” in the subject line and need not be submitted in triplicate. Comments sent via the Internet as attached electronic files must be formatted in Microsoft Word 97 for Windows or ASCII text.
The service information referenced in the proposed rule may be obtained from Short Brothers, Airworthiness & Engineering Quality, P.O. Box 241, Airport Road, Belfast BT3 9DZ, Northern Ireland. This information may be examined at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington.Start Further Info
FOR FURTHER INFORMATION CONTACT:
Todd Thompson, Aerospace Engineer, International Branch, ANM-116, FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 227-1175; fax (425) 227-1149.End Further Info End Preamble Start Supplemental Information
Interested persons are invited to participate in the making of the proposed rule by submitting such written data, views, or arguments as they may desire. Communications shall identify the Rules Docket number and be submitted in triplicate to the address specified above. All communications received on or before the closing date for comments, specified above, will be considered before taking action on the proposed rule. The proposals contained in this action may be changed in light of the comments received.
Submit comments using the following format:
- Organize comments issue-by-issue. For example, discuss a request to change the compliance time and a request to change the service bulletin reference as two separate issues.
- For each issue, state what specific change to the proposed AD is being requested.
- Include justification (e.g., reasons or data) for each request.
Comments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the proposed 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 summarizing each FAA-public contact concerned with the substance of this proposal will be filed in the Rules Docket.
Commenters wishing the FAA to acknowledge receipt of their comments submitted in response to this action must submit a self-addressed, stamped postcard on which the following statement is made: “Comments to Docket Number 2001-NM-113-AD.” The postcard will be date stamped and returned to the commenter.
Availability of NPRMs
Any person may obtain a copy of this NPRM by submitting a request to the FAA, Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 2001-NM-113-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.
The Civil Aviation Authority (CAA), which is the airworthiness authority for the United Kingdom, notified the FAA that an unsafe condition may exist on certain Short Brothers Model SD3 series airplanes. The CAA advises that during Certificate of Airworthiness Renewal Flight Tests on these airplanes, the engines failed to reach the Reserve Takeoff Power (RTOP) boost specified in the Airplane Flight Manual. The cause of this failure is unknown; however, a contributing factor could be reduced fuel flow to the engines. If the engines fail to reach adequate RTOP boost during takeoff, the flightcrew may experience problems maintaining control of the airplane in flight.
Explanation of Relevant Service Information
The manufacturer has issued Shorts Service Bulletins SD3 SHERPA-71-2, SD360 SHERPA-71-2, SD360-71-19, and SD330-71-24; all dated February 5, 2001. The service bulletins describe procedures for repetitive tests (checks) of the power lever movement of the fuel control unit (FCU) lever to ensure the lever is contacting the maximum stop, adjustment of the FCU rigging, if necessary, and an engine ground run to ensure correct gas generator rotational speed is achieved. The service bulletins also describe procedures for a static reduced power check on each engine to ensure correct operation of the reserve takeoff power (RTOP) system; and follow-on actions if the system fails to provide adequate boost. These actions include, but are not limited to, the following:
- A functional check of the RTOP solenoid,
- Replacement of any defective RTOP solenoid with a new solenoid,
- Adjustment of the RTOP system,
- Adjustment to the torque of the FCU Ng servo valve,
- Test for leakage or restrictions of the FCU pnuematic system, and/or
- Overhaul of the FCU.
Additionally, Shorts Service Bulletin SD330-71-24 describes procedures for repetitive tests (checks) of the FCU to ensure correct rigging, and adjustment, if necessary.
Accomplishment of the actions specified in the service bulletins is intended to adequately address the identified unsafe condition.
The CAA classified these service bulletins as mandatory and issued British airworthiness directives 002-02-2001, 003-02-2001, 004-02-2001, and 005-02-2001 in order to assure the continued airworthiness of these airplanes in the United Kingdom.
These airplane models are manufactured in the United Kingdom and are type certificated for operation in the United States under the provisions of section 21.29 of the Federal Aviation Regulations (14 CFR 21.29) and the applicable bilateral airworthiness agreement. Pursuant to this bilateral airworthiness agreement, the CAA has kept the FAA informed of the situation described above. The FAA has examined the findings of the CAA, reviewed all available information, and determined that AD action is necessary for products of this type design that are certificated for operation in the United States.
Explanation of Requirements of Proposed Rule
Since an unsafe condition has been identified that is likely to exist or develop on other airplanes of the same type design registered in the United States, the proposed AD would require accomplishment of the actions specified in the service bulletins described previously.
The FAA estimates that 46 airplanes of U.S. registry would be affected by this proposed AD, that it would take approximately 3 work hours per airplane to accomplish the proposed tests (checks), and that the average labor rate is $60 per work hour. Based on these figures, the cost impact of the proposed AD on U.S. operators is estimated to be $8,280, or $180 per airplane.
The cost impact figure discussed above is based on assumptions that no Start Printed Page 45198operator has yet accomplished any of the proposed requirements of this AD action, and that no operator would accomplish those actions in the future if this AD were not adopted. The cost impact figures discussed in AD rulemaking actions represent only the time necessary to perform the specific actions actually required by the AD. These figures typically do not include incidental costs, such as the time required to gain access and close up, planning time, or time necessitated by other administrative actions.
The regulations proposed herein would 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 proposal would not have federalism implications under Executive Order 13132.
For the reasons discussed above, I certify that this proposed regulation (1) is not a “significant regulatory action” under Executive Order 12866; (2) is not a “significant rule” under the DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and (3) if promulgated, will not have a significant economic impact, positive or negative, on a substantial number of small entities under the criteria of the Regulatory Flexibility Act. A copy of the draft regulatory evaluation prepared for this action is contained in the Rules Docket. A copy of it may be obtained by contacting the Rules Docket at the location provided under the caption ADDRESSES.Start List of Subjects
List of Subjects in 14 CFR Part 39
- Air transportation
- Aviation safety
The Proposed Amendment
Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration proposes to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) as follows:Start Part
PART 39—AIRWORTHINESS DIRECTIVES
1. The authority citation for part 39 continues to read as follows:
2. Section 39.13 is amended by adding the following new airworthiness directive:
Short Brothers PLC: Docket 2001-NM-113-AD.
Applicability: All Model SD3-SHERPA, SD3-60, and SD3-60 SHERPA series airplanes; and Model SD3-30 series airplanes having PT6A-45R series engines; certificated in any category.
This AD applies to each airplane identified in the preceding applicability provision, regardless of whether it has been modified, altered, or repaired in the area subject to the requirements of this AD. For airplanes 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 (b) 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 failure of the engines to reach adequate reserve takeoff power (RTOP) boost during takeoff, which could result in reduced controllability of the airplane, accomplish the following:
Repetitive Inspections/Corrective Action
(a) Within 100 flight cycles or 90 days after the effective date of this AD, whichever comes later: Do a test (check) of the power lever movement of the fuel control unit (FCU) lever to ensure the lever is contacting the maximum stop, and adjustment of the FCU rigging if the lever is not contacting the stop; an engine ground run for correct gas generator rotational speed, and a static reduced power check on each engine to ensure correct operation of the RTOP system; per Shorts Service Bulletin SD3 SHERPA-71-2, SD360 SHERPA-71-2, SD360-71-19, or SD330-71-24; all dated February 5, 2001; as applicable. Before further flight, do any follow-on actions necessary (includes a functional check of the RTOP solenoid, replacement of any defective RTOP solenoid with a new solenoid, adjustment of the RTOP system if system fails to provide adequate boost, adjustment to the torque of the FCU Ng servo valve, test for leakage or restrictions of the FCU pneumatic system, or overhaul of the FCU), per the applicable service bulletin. Repeat the tests (checks) after that at intervals not to exceed 90 days.
Alternative Methods of Compliance
(b) 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, International Branch, ANM-116, Transport Airplane Directorate, FAA. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, International Branch, ANM-116.
Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the International Branch, ANM-116.
Special Flight Permits
(c) Special flight permits may be issued in accordance with sections 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate the airplane to a location where the requirements of this AD can be accomplished.
The subject of this AD is addressed in British airworthiness directives 002-02-2001, 003-02-2001, 004-02-2001, and 005-02-2001.
Issued in Renton, Washington, on August 21, 2001.
Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.
[FR Doc. 01-21630 Filed 8-27-01; 8:45 am]
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