02-23653. Airworthiness Directives; Pilatus Britten-Norman Limited BN-2A and BN2A Mk. III Series Airplanes

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

This document proposes to supersede Airworthiness Directive (AD) 97-14-01, which currently applies to all Pilatus Britten-Norman (Pilatus Britten-Norman) Limited BN-2A and BN2A Mk. III series airplanes. AD 97-14-01 requires repetitively inspecting the left-hand rudder bar assembly for cracks, measuring the slider tube unit wall thickness, and modifying the rudder bar assembly by installing a slider tube unit of improved design as a terminating action for the repetitive inspections. AD 97-14-01 resulted from mandatory continuing airworthiness information (MCAI) issued by the airworthiness authority for the United Kingdom. Reports of cracks being found on the right-hand rudder bar assembly and the inadvertent omission of requiring inspection of the rudder pedal beams prompted this action. This proposed AD would retain the requirements of AD 97-14-01 and require inspections of the right-hand rudder bar assembly and each rudder pedal beam. The actions specified by the proposed AD are intended to prevent failure of the pilot's and co-pilot's rudder bar assemblies, which could result in loss of control of the airplane during landing operations.

DATES:

The Federal Aviation Administration (FAA) must receive any comments on this proposed rule on or before October 25, 2002.

ADDRESSES:

Submit comments to FAA, Central Region, Office of the Regional Counsel, Attention: Rules Docket No. 2002-CE-33-AD, 901 Locust, Room 506, Kansas City, Missouri 64106. You may view any comments at this location between 8 a.m. and 4 p.m., Monday through Friday, except Federal holidays. You may also send comments electronically to the following address: [e-mail]. Comments sent electronically must contain “Docket No. 2002-CE-33-AD” in the subject line. If you send comments electronically as attached electronic files, the files must be formatted in Microsoft Word 97 for Windows or ASCII text.

You may get service information that applies to this proposed AD from B-N Group Limited, Bembridge, Isle of Wight, United Kingdom PO35 5PR; telephone: [phone]; facsimile: [phone]. You may also view this information at the Rules Docket at the address above.

FOR FURTHER INFORMATION CONTACT:

Doug Rudolph, Aerospace Engineer, FAA, Small Airplane Directorate, 901 Locust, Room 301, Kansas City, Missouri 64106; telephone: [phone]; facsimile: [phone].

SUPPLEMENTARY INFORMATION:

Comments Invited

How Do I Comment on This Proposed AD?

The FAA invites comments on this proposed rule. You may submit whatever written data, views, or arguments you choose. You need to include the rule's docket number and submit your comments to the address specified under the caption ADDRESSES. We will consider all comments received on or before the closing date. We may amend this proposed rule in light of comments received. Factual information that supports your ideas and suggestions is extremely helpful in evaluating the effectiveness of this proposed AD action and determining whether we need to take additional rulemaking action.

Are There Any Specific Portions of This Proposed AD I Should Pay Attention To?

The FAA specifically invites comments on the overall regulatory, economic, environmental, and energy aspects of this proposed rule that might suggest a need to modify the rule. You may view all comments we receive before and after the closing date of the rule in the Rules Docket. We will file a report in the Rules Docket that summarizes each contact we have with the public that concerns the substantive parts of this proposed AD.

How Can I Be Sure FAA Receives My Comment?

If you want FAA to acknowledge the receipt of your mailed comments, you must include a self-addressed, stamped postcard. On the postcard, write “Comments to Docket No. 2002-CE-33-AD.” We will date stamp and mail the postcard back to you.

Discussion

Has FAA Taken Any Action to This Point?

Reports of failure of the pilot's rudder bar caused FAA to issue AD 97-14-01 on all Pilatus Britten-Norman BN-2A and BN2A Mk. III series airplanes. Fractures of the central pillar/slider tube adjacent to the welded transverse lugs caused the pilot's rudder bar to fail. AD 97-14-01, Amendment 39-10058 (62 FR 35670, July 2, 1997), currently requires the following:

—Repetitively inspecting the left-hand rudder bar assembly for cracks;

—Measuring the slider tube unit wall thickness; and

—Modifying the rudder bar assembly by installing a slider tube unit of improved design as a terminating action for the repetitive inspections.

What Has Happened Since AD 97-14-01 To Initiate This Action?

The Civil Aviation Authority (CAA), which is the airworthiness authority for the United Kingdom, recently notified FAA of the need to change AD 97-14-01. The CAA reports that fractures in the central pillar/slider tube adjacent to the welded transverse lugs have been found on the co-pilot's (or dual) rudder bar assembly. These reports prompted a need to require inspections of the right-hand rudder bar assembly in addition to the left-hand rudder bar assembly. We also realized we inadvertently omitted from AD 97-14-01 repetitive inspections of the rudder pedal beam as specified in Britten-Norman Service Bulletin No. BN-2/SB. 56, Issue 2, dated February 13, 1978.

Is There Service Information That Applies to This Subject?

B-N Group Ltd. has issued Service Bulletin Number SB 111, Issue 2, dated April 1, 2002.

What Are the Provisions of This Service Bulletin?

The service bulletin includes procedures for:

—Repetitively inspecting the left-hand and right-hand rudder bar assembly for cracks;

—Measuring the slider tube unit wall thickness; and

—Modifying the rudder bar assembly by installing a slider tube unit of improved design as terminating action for the repetitive inspections.

What Action Did the CAA Take?

The CAA classified this service bulletin as mandatory in order to assure the continued airworthiness of these airplanes in the United Kingdom. The CAA classifying a service bulletin as mandatory is the same in the United Kingdom as the FAA issuing an AD in the United States.

Was This in Accordance With the Bilateral Airworthiness Agreement?

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 FAA informed of the situation described above.

The FAA's Determination and an Explanation of the Provisions of the Proposed AD

What Has FAA Decided?

The FAA has examined the findings of the CAA; reviewed all available information, including the service information referenced above; and determined that:

—The unsafe condition referenced in this document exists or could develop on other Pilatus Britten-Norman BN-2A and BN2A Mk. III series airplanes of the same type design that are on the U.S. registry;

—The actions of AD 97-14-01 should be retained, and the right-hand (co-pilot's) rudder bar assembly and the rudder pedal beams should be included in the inspection requirements; and

—AD action should be taken in order to correct this unsafe condition.

What Would the Proposed AD Require?

This proposed AD would supersede AD 97-14-01 with a new AD that would retain the actions of AD 97-14-01 and require inspections of the right-hand (co-pilot's) rudder bar assembly and the rudder pedal beams.

Cost Impact

How Many Airplanes Would the Proposed AD Impact?

We estimate that this proposed AD affects 113 airplanes in the U.S. registry.

What Would Be the Cost Impact of the Proposed AD on Owners/Operators of the Affected Airplanes?

We estimate the following costs to accomplish the proposed inspection:

Labor cost	Parts cost	Total cost per airplane	Total cost on U.S. operators
6 workhours × $60 = $360	No parts required	$360.	$360 × 113 = $40,680

We estimate the following costs to accomplish any necessary replacements that would be required based on the results of the proposed inspection. We have no way of determining the number of airplanes that may need such replacement:

Labor cost	Parts cost	Total cost per airplane
10 workhours × $60 = $600	$1,300	$600 + $1,300 = $1,900

Compliance Time of This Proposed AD

What Would Be the Compliance Time of This Proposed AD?

The compliance time of this proposed AD is based on number of landings rather than hours time-in-service (TIS).

Why Is the Compliance Time Presented in Landings Instead of Hours Time-in-Service?

The reason for this type of compliance is that the area that is showing fatigue is the pilot's and co-pilot's rudder bar assemblies and pillar/slider tube unit. This area of the airplane is used during the landing operation.

Furthermore, the stress and fatigue is greater in the thinner gauged metal slider tube unit upon landing. We have determined to use the number of landings as the compliance time for this proposed AD.

Since airplane operators are not required to keep track of landings, we will provide a method of calculating hours TIS into landings.

Regulatory Impact

Would This Proposed AD Impact Various Entities?

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 proposed rule would not have federalism implications under Executive Order 13132.

Would This Proposed AD Involve a Significant Rule or Regulatory Action?

For the reasons discussed above, I certify that this action (1) is not a “significant regulatory action” under Executive Order 12866; (2) is not a “significant rule” under 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 has been placed in the Rules Docket. A copy of it may be obtained by contacting 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

The Proposed Amendment

Accordingly, under the authority delegated to me by the Administrator, the Federal Aviation Administration proposes to amend 14 CFR part 39 of the Federal Aviation Regulations 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.

§ 39.13

[Amended]

2. FAA amends § 39.13 by removing Airworthiness Directive (AD) 97-14-01, Amendment 39-10058 (62 FR 35670, July 2, 1997), and by adding a new AD to read as follows: -

Pilatus Britten-Norman Limited: Docket No. 2002-CE-33-AD; Supersedes AD 97-14-01, Amendment 39-10058

(a) What airplanes are affected by this AD? This AD affects the following airplane models, all serial numbers, that are certificated in any category:

Models

BN-2A, BN-2A-2, BN-2A-3, BN-2A-6, BN-2A-8, BN-2A-9, BN-2A-20, BN-2A-21, BN-2A-26, BN-2A-27, BN2A MK. III, BN2A MK. III-2, and BN2A MK. III-3

(b) Who must comply with this AD? Anyone who wishes to operate any of the airplanes identified in paragraph (a) of this AD must comply with this AD.

(c) What problem does this AD address? The actions specified by this AD are intended to prevent failure of the pilot's and co-pilot's rudder bar assemblies, which could result in loss of control of the airplane during landing operations.

(d) What actions must I accomplish to address this problem? To address this problem, you must accomplish the following:

(1) Right-hand and left-hand slider tube and vertical pillar of the rudder bar. Within 500 landings after the last inspection required by AD 97-14-01 or the next 100 landings after the effective date of this AD, whichever occurs later, inspect (visually and using a dye penetrant method) the left-hand and right-hand slider tube and vertical pillar of the rudder bar unit for cracks and measure the slider tube wall to determine thickness. Accomplish this inspection and follow-up actions below in accordance with the instructions specified in B-N Group Ltd. Service Bulletin Number SB 111, Issue 2, dated April 1, 2002 (Part of this accomplishment is the incorporation of Britten-Norman Service Bulletin No. BN-2/SB. 56, Issue 2, dated February 13, 1978; and Britten-Norman Service Bulletin No. BN-2/SB. 111, Issue 1, dated October 25, 1977.):

If	Then	When
(i) No cracks are found during the inspection required in paragraph (d)(1) of this AD and the slider tube wall thickness is 0.056-inch (17 s.w.g.)	Repetitively inspect the left-hand and right-hand slider tub and vertical pillar of the rudder bar unit and install Modification NB/M/948, part number (P/N) NB-45-A1-2975 or FAA-approved equivalent part number, on the left-hand and right-hand slider tube and vertical pillar of the rudder bar unit. When this modification is incorporated, the repetitive inspections in that area may be terminated	Repetitively inspect at intervals not to exceed 500 landings after the initial inspection required in paragraph (d)(1) of this AD. Incorporate modification upon the accumulation of 5,000 landings after August 18, 1997 (the effective date of AD 97-14-01) or within the next 500 landings after the effective date of this AD, whichever occurs later (unless any crack(s) is/are found during an inspection).
(ii) No cracks are found during inspection required in paragraph (d)(1) of this AD and the slider tube wall thickness is 0.036-inch (20 s.w.g.)	Repetitively inspect the left-hand and right-hand slider tube and vertical pillar of the rudder bar unit inspection and install Modification NB/M/948, part number (P/N) NB-45-A1-2975 or FAA-approved equivalent part number, on the left-hand and right-hand slider tube and vertical pillar of the rudder bar unit. When this modification is incorporated, the repetitive inspections in that area may be terminated	Repetitively inspect at intervals not to exceed 250 landings after the initial inspection. Incorporate the modification upon the accumulation of 2,500 landings after August 18, 1997 (the effective date of AD 97-14-01) or within the next 250 landings after the effective date of this AD, whichever occurs later (unless any crack(s) is/are found during an inspection).
(iii) if any crack(s) is/are found during any inspection on the left-hand or right-hand slider tube and vertical pillar of the rudder bar unit	Install Modification NB/M/948, P/N NB-45-A1-2975 or FAA-approved equivalent part number, on the cracked slider tube and vertical pillar of the rudder bar unit. When this modification is incorporated, the repetitive inspections in that area may be terminated	Prior to further flight after the inspection where the crack(s) is/are found.
(iv) Only install rudder bar assemblies that incorporate Modification NB/M/948	As of the effective date of this AD	Not applicable

(2) Rudder pedal beams. Accomplish the following on the rudder pedal beams:

Action	Compliance	Procedures
(i) Inspect (visually and using a dye penetrant inspection method) each rudder pedal beam for cracks and replace any cracked beam with a P/N NB-45-C-2153 (Post Mod No. BB/M/341) rudder pedal beam	Inspect within the next 100 landings after the effective date of this AD and thereafter at intervals not to exceed 500 landings. Replace prior to further flight after the inspection where any crack(s) is/are found. Continue with repetitive inspection intervals	In accordance with Britten-Norman Service Bulletin No. BN-2/SB. 56, Issue 2, dated February 13, 1978.
(ii) Only install P/N NB-45-C-2153 (Post Mod No. BB/M/341) rudder pedal beams	As of the effective date of this AD	Not Applicable.

Note 1:

If operators have not recorded the number of landings, the landings can be calculated by multiplying 3 landings per 1 hour TIS.

(e) Can I comply with this AD in any other way? (1) You may use an alternative method of compliance or adjust the compliance time if:

(i) Your alternative method of compliance provides an equivalent level of safety; and

(ii) The Standards Office Manager, Small Airplane Directorate, approves your alternative. Submit your request through an FAA Principal Maintenance Inspector, who may add comments and then send it to the Standards Office Manager.

(2) Alternative methods of compliance approved in accordance with AD 97-14-01, which is superseded by this AD, are not approved as alternative methods of compliance with this AD.

Note 2:

This AD applies to each airplane identified in paragraph (a) of this AD, 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 (e) 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 you have not eliminated the unsafe condition, specific actions you propose to address it.

(f) Where can I get information about any already-approved alternative methods of compliance? Contact Doug Rudolph, Aerospace Engineer, FAA, Small Airplane Directorate, 901 Locust, Room 301, Kansas City, Missouri 64106; telephone: [phone]; facsimile: [phone].

(g) What if I need to fly the airplane to another location to comply with this AD? The FAA can issue a special flight permit under § § 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate your airplane to a location where you can accomplish the requirements of this AD.

(h) How do I get copies of the documents referenced in this AD? You may obtain copies of the documents referenced in this AD from B-N Group Limited, Bembridge, Isle of Wight, United Kingdom PO35 5PR; telephone: [phone]; facsimile: [phone]. You may examine these documents at FAA, Central Region, Office of the Regional Counsel, 901 Locust, Room 506, Kansas City, Missouri 64106.

(i) Does this AD action affect any existing AD actions? This amendment supersedes AD 97-14-01, Amendment 39-10058.

Note 3:

The subject of this AD is addressed in B-N Group Ltd. Service Bulletin Number SB 111, Issue 2, dated April 1, 2002. This service bulletin is classified as mandatory by the United Kingdom Civil Aviation Authority (CAA).

Issued in Kansas City, Missouri, on September 11, 2002.

Michael Gallagher,

Manager, Small Airplane Directorate, Aircraft Certification Service.