02-28999. Airworthiness Directives; Robert E. Rust Models DeHavilland DH.C1 Chipmunk 21, 22, and 22A Airplanes

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

This document proposes to adopt a new airworthiness directive (AD) that would apply to certain Robert E. Rust (R.E. Rust) Models DeHavilland DH.C1 Chipmunk 21, 22, and 22A airplanes. This proposed AD would require you to inspect the fuselage to determine if a steel fuselage center-section tie bar fitted with bushings in the end lug bolt holes is installed. If this bushed steel fuselage center-section tie bar is installed, this proposed AD would decrease the safe life limit. This proposed AD is the result of reports that certain replacement steel fuselage center-section tie bars installed on the affected airplanes could fail before the originally published safe life limit. The actions specified by this proposed AD are intended to prevent early failure of these bushed steel fuselage center-section tie bars, which could result in reduced structural integrity of the wings. Such a condition could lead to loss of control of the airplane.

DATES:

The Federal Aviation Administration (FAA) must receive any comments on this proposed rule on or before January 22, 2003.

ADDRESSES:

Submit comments to FAA, Central Region, Office of the Regional Counsel, Attention: Rules Docket No. 2000-CE-63-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. 2000-CE-63-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 DeHavilland Support Limited, Duxford Airfield, Bldg. 213, Cambridgeshire, CB2 4QR, United Kingdom, telephone: [phone], facsimile: [phone], e-mail: [e-mail]. You may also view this information at the Rules Docket at the address above.

FOR FURTHER INFORMATION CONTACT:

Cindy Lorenzen, Aerospace Engineer, FAA, Atlanta Aircraft Certification Office, 1895 Phoenix Boulevard, Suite 450, Atlanta, Georgia; 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. 2000-CE-63-AD.” We will date stamp and mail the postcard back to you.

Discussion

What Events Have Caused This Proposed AD?

The FAA has received reports that an unsafe condition may exist on certain R.E. Rust Models DeHavilland DH.C1 Chipmunk 21, 22, and 22A airplanes. After a review of several of these airplanes, we have determined that steel fuselage center-section tie bars, part number RD.C1.FS.107, are being installed as replacements parts. Some of these part numbers have been fitted with bushings in the end lugs to cover scored or oversized holes.

The use of bushings in the end of the lugs on these parts severely reduces the safe life limit. The original safe life limit established for the steel fuselage center-section tie bar was 30,000 fatigue hours. Fatigue hours are hours time-in-service multiplied by the role factor (operational use).

What Are the Consequences If the Condition Is Not Corrected?

This condition, if not corrected, could result in failure of the steel fuselage center-section tie bar. Such failure could lead to loss of control of the airplane.

Is There Service Information That Applies to This Subject?

British Aerospace (now DeHavilland Support Limited) has issued Mandatory Technical News Sheet No. 175, Issue: 1, dated August 1, 1985 and Mandatory Technical News Sheet No. 138, Issue 5, dated August 1, 1985.

What Are the Provisions of This Service Information?

These Technical News Sheets include procedures for inspecting the steel fuselage center-section tie bar to determine if the bolt holes in the lug have bushings and procedures for calculating fatigue hours.

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

What Has FAA Decided?

After examining the circumstances and reviewing all available information related to the incidents described above, we have determined that:

—The unsafe condition referenced in this document exists or could develop on other R.E. Rust Models DeHavilland DH.C1 Chipmunk 21, 22, and 22A airplanes of the same type design;

—The actions specified in the previously-referenced service information should be accomplished on the affected airplanes; and

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

What Would This Proposed AD Require?

This proposed AD would require you to check the airplane logbook to determine if a steel fuselage center-section tie bar, part number RD.C1.FS.107, is installed on the airplane. If this part number is installed, this proposed AD would require you to inspect the end lugs to determine if bushings are installed in the bolt holes. If bushings are present, this proposed AD would also reduce the safe life of that part from 30,000 fatigue hours to 16, 000 fatigue hours.

Cost Impact

How Many Airplanes Would This Proposed AD Impact?

We estimate that this proposed AD affects 54 airplanes in the U.S. registry.

What Would Be the Cost Impact of This 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
12 workhours × $60 per hour = $720	No parts required	$720	$720 × 54 = $38,880

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
80 workhours × $60 per hour = $4,800	$2,250	$4,800 + $2,250 = $7,050

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 proposed 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 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.

§ 39.13

[Amended]

2. FAA amends § 39.13 by adding a new airworthiness directive (AD) to read as follows:

Robert E. Rust: Docket No. 2000-CE-63-AD.

(a) What airplanes are affected by this AD? This AD affects R.E. Rust Models DeHavilland DH.C1 Chipmunk 21, 22, and 22A airplanes, serial numbers C1-001 through C1-1014, that are type certificated in any category.

Note 1:

We recommend all owners/operators of DeHavilland DH.C1 Chipmunk 21, 22, and 22A airplanes, serial numbers C1-001 through C1-1014, with experimental airworthiness certificates comply with the actions required in this AD.

(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 steel fuselage center-section tie bar prior to the originally published safe life, which could result in reduced structural integrity of the wings. Such a condition could lead to loss of control of the airplane. Steel fuselage center-section tie bars fitted with bushings in the end lug bolt holes have a reduced safe life of 16,000 fatigue hours.

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

Actions	Compliance	Procedures
(1) Check the airplane logbook to determine if a steel fuselage center-section tie bar, part number (P/N) RD.C1.FS.107, is installed. Initial steel tie bar fitments were done under cover of Repair Drawings R.C1.FS.191 and RD.C1.FS.106. Later these drawings were included in Modification H.288 so fitment may be logged under either	Upon accumulating 16,000 fatigue hours or within the next 100 hours time-in-service (TIS) after the effective date of this AD, whichever occurs later	The owner/operator holding at least a private pilot certificate as authorized by section 43.7 of the Federal Aviation Regulations (14 CFR 43.7) may check the airplane logbook. Calculate fatigue hours by multiplying the TIS by the role factor in accordance with British Aerospace Mandatory Technical News Sheet Series: Chipmunk (C1), No. 138, Issue: 5, dated August 1, 1985.
(2) If, by checking the airplane logbook, you can positively determine that a steel fuselage center-section tie bar, P/N RD.C1.FS.107, is not installed:
(i) you must make an entry into the aircraft records that shows compliance with paragraphs (d)(1) and (d)(2) of this AD in accordance with section 43.9 of the Federal Aviation Regulations (14 CFR 43.9); and
(ii) continue to comply with the published life limits of the installed tie bar.	Not applicable	The owner/operator holding at least a private pilot certificate as authorized by section 43.7 of the Federal Aviation Regulations (14 CFR 43.7) may check the airplane logbook.
(3) If, by checking the airplane logbook, you determine that a steel fuselage center-section tie bar, P/N RD.C1.FS.107, is installed, or cannot positively show that one is not installed:
(i) inspect the lug bolt holes to determine if bushings have been installed;
(ii) if bushings have been installed, the safe life limit for that part is now 16,000 fatigue hours;
(iii) if bushing have not been installed, the safe life limit for that part remains at 30,000 fatigue hours; and
(iv) make an entry into the aircraft records that shows compliance with this portion of the AD in accordance with section 43.9 of the Federal Aviation Regulations (14 CFR 43.9).	Prior to further flight after the logbook check required in paragraph (d)(1) of this AD	In accordance with British Aerospace Mandatory Technical News Sheet No. 175, Issue 1, dated August 1, 1985.
(4) The following are the safe life limit for steel fuselage center-section tie bars, P/N RD.C1.FS.107:
(i) If fitted with bushings in the end lug bolt holes: 16,000 fatigue hours; and
(ii) If not fitted with bushings in the end lug bolt holes: 30,000 fatigue hours.	As of the effective date of this AD	Not applicable.

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

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

(2) The Manager, Atlanta Aircraft Certification Office (ACO), approves your alternative. Submit your request through an FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, Atlanta ACO.

Note:

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 Cindy Lorenzen, Aerospace Engineer, FAA, Atlanta Aircraft Certification Office, 1895 Phoenix Boulevard, Suite 450, Atlanta, Georgia; 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 §§ sections 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 get copies of the documents referenced in this AD from DeHavilland Support Limited, Duxford Airfield, Bldg. 213, Cambridgeshire, CB2 4QR, United Kingdom, telephone: [phone], facsimile: [phone], e-mail: [e-mail]. You may view these documents at FAA, Central Region, Office of the Regional Counsel, 901 Locust, Room 506, Kansas City, Missouri 64106.

Issued in Kansas City, Missouri, on November 6, 2002.

Michael Gallagher,

Manager, Small Airplane Directorate, Aircraft Certification Service.