Airworthiness directives: de Havilland,
[Federal Register: April 16, 2003 (Volume 68, Number 73)]
[Proposed Rules]
[Page 18571-18575]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr16ap03-19]
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
[Docket No. 2000-CE-64-AD]
RIN 2120-AA64
Airworthiness Directives; Robert E. Rust Models DeHavilland DH.C1 Chipmunk 21, 22, and 22A Airplanes
AGENCY: Federal Aviation Administration, DOT.
ACTION: Supplemental notice of proposed rulemaking (NPRM); Reopening of the comment period.
SUMMARY: This document proposes to revise an earlier proposed airworthiness directive (AD) that would apply to certain Robert E. Rust (R.E. Rust) Models DeHavilland DH.C1 Chipmunk 21, 22, and 22A airplanes. The earlier NPRM would have required you to repetitively inspect the tailplane attachment brackets and replace each bracket. The earlier NPRM would have also required you to repetitively inspect each joint of the port and starboard engine mount frame and the rear upper mount frame tubes for cracks and/or damage and repair any cracks and/or damage found. The earlier NPRM resulted from reports of stress corrosion cracking found on the tailplane attachment brackets and fatigue cracking and chaffing of the engine mount frame. We incorrectly referenced replacing the tailplane attachment brackets (part number C1.TP.167) upon accumulating 9,984 hours time-in-service (TIS). The hour limitation should be 9,984 fatigue hours. Fatigue hours are hours TIS multiplied by the role factor (operational use) as defined in the manufacturer's service information. This proposed supplemental NPRM also adds an hour limitation for performing the repetitive inspection of the tailplane 1 attachment brackets. Since these actions impose an additional burden over that proposed in the NPRM, we are reopening the comment period to allow the public the chance to comment on these additional actions.
DATES: The Federal Aviation Administration (FAA) must receive any comments on this proposed rule on or before June 23, 2003.
ADDRESSES: Submit comments to FAA, Central Region, Office of the Regional Counsel, Attention: Rules Docket No. 2000-CE-64-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: 9-ACE-7-Docket@faa.gov. Comments sent electronically must contain ``Docket No. 2000-CE-64-AD'' in the subject line. If you send comments electronically as attached electronic files, the files must be formatted in Microsoft Work 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: +44 1223 830090, facsimile: +44 1223 830085, e-mail: info@dhsupport.com. 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: (770) 703-6078; facsimile: (770) 703-6097.
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
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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-64-AD.'' We will date stamp and mail the postcard back to you.
Discussion
What Events Have Caused Us To Issue the Earlier NPRM?
We received reports that an unsafe condition exists on certain R.E. Rust Models DeHavilland DH.C1 Chipmunk 21, 22, and 22A airplanes. After reviewing several of these airplanes, stress corrosion cracking was found on the tailplane attachment brackets and fatigue cracks and chaffing were found on the engine mount frame.
Cracks in the engine mount frame were found in the area of the junction of the front and rear top tube and engine mounting foot support brackets and in the front of the frame. We have determined that fatigue is the cause of the cracks. The upper aft mount frame tubes were also found to have damage caused by chaffing by the cowling support rod.
What Are the Consequences if the Condition Is Not Corrected?
These conditions, if not corrected, could result in failure of the tailplane attachment brackets and failure of the engine mount. Such failures could lead to loss of control of the airplane.
Has FAA Taken Any Action to This Point?
We issued a proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to include an AD that would apply to certain R.E. Rust Models DeHavilland DH.C1 Chipmunk 21, 22, and 22A airplanes. This proposal was published in the Federal Register as a notice of proposed rulemaking (NPRM) on November 12, 2002 (67 FR 68536). The NPRM proposed to require you to repetitively inspect the tailplane attachment brackets and replace each bracket. The NPRM also proposed to require you to repetitively inspect each joint of the port and starboard engine mount frame and the rear upper mount frame tubes for cracks and/or damage and repair any cracks and/or damage found.
Was the Public Invited To Comment?
The FAA encouraged interested persons to participate in the making of this amendment. The following presents the comments received on the proposal and FAA's response to each comment:
Comment Issue No. 1: Change the Compliance Time for Replacing the Tailplane Attachment Brackets
What Is the Commenter's Concern?
The commenter states that replacement parts for the tailplane attachment brackets may not be available from the manufacturer within 90 days after the effective date of this AD. Therefore, the commenter suggests allowing more time to acquire parts by changing the compliance time for replacing the tailplane attachment brackets if cracks are found during the initial inspection from 90 days to 12 months after the effective date of this AD.
What Is FAA's Response to the Concern?
The commenter does not offer any solution to ensure the airworthiness of the airplanes until the parts become available. We cannot increase the compliance time unless other means to ensure the continued airworthiness of these airplanes are substantiated.
We will consider an alternative method of compliance if the alternative provides an equivalent level of safety as outlined in paragraph (e) of this AD.
We are not changing the final rule AD action based on this comment.
Comment Issue No. 2: Change the Compliance Time for the Repetitive Inspections of the Tailplane Attachment Brackets
What Is the Commenter's Concern?
The commenter suggests that the repetitive inspections of the tailplane attachment brackets should be changed to every 150 fatigue hour or 6 months, whichever comes first, in order to ensure the airworthiness of these airplanes. The NPRM only proposed inspections every 6 months.
What Is FAA's Response to the Concern?
We concur with the commenter. Requiring repetitive inspections at every 150 fatigue hours or 6 months, whichever comes first, will ensure that the unsafe condition will not go undetected on high usage airplanes for a long period of time and will ensure the airworthiness of the affected airplanes.
We will make this change. Fatigue hours are hours TIS multiplied by the role factor (operational use) as specified in British Aerospace Mandatory Technical News Sheet Series: Chipmunk (C1), No. 138, Issue: 5, dated August 1, 1985. Because adding the fatigue hours requirement to the repetitive inspection compliance time could increase the burden upon the public, we will reopen the comment period and issue a supplemental NPRM.
Comment Issue No. 3: Remove the Grace Period Allowed Beyond the Safe Life Limit for Replacing the Tailplane Attachment Brackets
What Is the Commenter's Concern?
The commenter states that the ultimate safe life limit of 9,984 fatigue hours for part number C1.TP.167 is a never exceed life and cannot be extended. Once an airplane has reached this safe life limit, the tailplane attachment bracket must be replaced before further flight.
What Is FAA's Response to the Concern?
We concur that a life limit is a never exceed limit. However, the safe life limit for the tailplane attachment bracket has not previously been established and enforced for the owners/operators of the affected airplanes. The life limit was not part of the type certificate data and was not previously mandated by an AD. Part of this proposed AD is establishing the safe life limit for this part. Removing the 90 day grace period for these airplanes already over or nearing 9,984 fatigue hours on the tailplane attachment bracket could inadvertently ground these airplanes when the AD becomes effective.
We are not changing the final rule AD action based on this comment.
The Supplemental NPRM
What Events Have Caused FAA To Issue a Supplemental NPRM?
In addition to adding the fatigue hour requirement to the repetitive inspection compliance time, we are correcting reference to the life limit as 9,984 fatigue hours instead of 9,984 hours TIS. Fatigue hours are hours TIS multiplied by the role factor (operational use).
How Will the Changes to the NPRM Impact the Public?
Proposing to change the intervals for performing the repetitive inspections of the tailplane attachment brackets to include an hour limitation and changing hours TIS to fatigue hours go beyond the scope of what was already proposed. Therefore, we are issuing a supplemental NPRM and reopening the comment period to allow the public additional time to comment on the proposed AD.
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How Does the Revision to 14 CFR Part 39 Affect This Proposed AD?
On July 10, 2002, FAA published a new version of 14 CFR part 39 (67 FR 47997, July 22, 2002), which governs FAA's AD system. This regulation now includes material that relate to special flight permits, alternative methods of compliance, and altered products. This material previously was included in each individual AD. Since this material is included in 14 CFR part 39, we will not include it in future AD actions.
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 inspections of the tailplane attachment brackets:
Total cost Total cost Labor cost
Parts cost
per
on U.S. airplane operators
32 workhours x $60 per hour = No parts
$1,920 $1,920 x 54 $1,920.
required.
= $103,680.
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:
Total cost Labor cost
Parts cost
per airplane
3 workhours x $60 per hour = $180 $600 per bracket (2 $180 + $600 per bracket.
brackets per
= $780. airplane).
We estimate the following costs to accomplish the proposed inspections of the engine mount frame:
Total cost Total cost Labor cost
Parts cost
per
on U.S. airplane operators
16 workhours x $60 per hour = No parts
$960 $960 x 54 = $960.
required.
$51,840.
The FAA has no method of determining the number of repairs or replacements each owner/operator would incur over the life of each of the affected airplanes based on the results of the proposed inspections. We have no way of determining the number of airplanes that may need such repair. The extent of damage may vary on each airplane.
Compliance Time of This Proposed AD
What Would Be the Compliance Time of This Proposed AD?
The compliance time for the initial inspection proposed in this AD is ``within the next 90 days after the effective date of this AD.''
Why Is the Proposed Compliance Time Presented in Calendar Time Instead of Hours Time-in-Service (TIS)?
An unsafe condition specified by this proposed AD is caused by corrosion. Corrosion can occur regardless of whether the aircraft is in operation or is in storage. Therefore, to assure that the unsafe condition specified in the proposed AD does not go undetected for a long period of time, the compliance is presented in calendar time instead of TIS.
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:
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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.
Sec. 39.13 [Amended]
2. FAA amends Sec. 39.13 by adding a new airworthiness directive (AD) to read as follows:
Robert E. Rust: Docket No. 2000-CE-64-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 above airplanes 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 tailplane attachment brackets caused by stress corrosion cracking and failure of the engine mount, which could result in loss of the tail section and separation of the engine from the airplane respectively. Such failures could lead to loss of control of the airplane.
(d) What actions must I accomplish to address this problem? To address this problem, you must accomplish the following:
(1) Tailplane Attachment Brackets
Compliance
Actions
Procedures
(i) Initially inspect within the Inspect, using In accordance next 90 days after the effective dye penetrant, with British date of this AD.
the tailplane Aerospace (A) Inspect thereafter at intervals attachment
Military not to exceed 6 months or 150
brackets, part- Aircraft and fatigue hours, whichever occurs number (P/N) Aerostructures first, until the modification
C1.TP.167 (or (BAe Aircraft) required by paragraph (d)(1)(ii) FAA-approved Mandatory of this AD is incorporated.
equivalent part) Technical News (B) When the modification required for cracks.
Sheet CT (C1) by paragraph (d)(1)(ii) is
No. 176, Issue incorporated, you may terminate
2, dated the repetitive inspections of the
November 1, tailplane attachment brackets.
1997; and Civil Modification Mandatory Modification No. Chipmunk H357, dated March 12, 1984. 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.
(ii) At whichever of the following Replace the
In accordance that occurs first:
tailplane
with British (A) Prior to further flight after attachment
Aerospace the inspection where any crack is bracket by
Military found; or
incorporating Aircraft and (B) Upon accumulating 9,984 fatigue Modification Aerostructures hours or within the next 90 days H357 (P/N
(BAe Aircraft) after the effective date of this C1.TP.313) or Mandatory AD, whichever occurs later
FAA-approved Technical News equivalent part Sheet CT (C1) number.
No. 176, Issue Installing P/N 2, dated C1.TP.313 (or November 1, FAA-approved 1997; and Civil equivalent part Modification number)
Mandatory terminates the Modification repetitive
No. Chipmunk inspection
H357, dated requirement of March 12, 1984. the tailplane Calculate attachment
fatigue hours brackets.
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. (iii) As of the effective date of Only install a Not applicable. this AD
tailplane attachment bracket that is P/N C1.TP.313. or FAA-approved equivalent part number. (iv) As of the effective date of Incorporate the In accordance this AD
following into with British the Aircraft Aerospace Logbook: ``In Military accordance with Aircraft and AD **-**-**, the Aerostructures tailplane
(BAe Aircraft) attachment
Mandatory bracket is life Technical News limited to 9,984 Sheet CT (C1) fatigue hours.''. No. 176, Issue 2, dated November 1, 1997.
(2) Engine Mount Frames
Actions
Compliance
Procedures
(i) Inspect each joint of the Initially inspect In accordance with port and starboard engine mount within the next British Aerospace frame and the rear upper mount 90 days after the Aerostructures frame tubes for cracks and/or effective date of Limited (BAe damage.
this AD.
Aircraft) Repetitively
Mandatory inspect
Technical News thereafter at Sheet CT (C1) No. intervals not to 190, Issue 2, exceed 600 hours dated April 1, TIS.
1995.
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(ii) If cracks and/or damage is Prior to further Repair in found during any inspection flight after the accordance with required in paragraph (d)(2)(i) inspection in AC 43.13-1B, of this AD.
which any crack Change 1, dated (A) obtain a repair scheme from and/or damage is September 27, the manufacturer through the found.
2001, Chapter 4, FAA at the address specified in Repetitively
Paragraph 4-99 or paragraph (f) of this AD and inspect as
in accordance incorporate this repair scheme, required in
with the repair or repair in accordance with paragraph
scheme obtained FAA Advisory Circular (AC)
(d)(2)(i) of this from DeHavilland 43.13-1B, Change 1, dated
AD.
Support Limited, September 27, 2001, Chapter 4,
Duxford Airfield, Paragraph 4-99; or.
Bldg. 213, (B) replace with a new or
Cambridgeshire, serviceable part.
CB2 4QR, United Kingdom. Obtain this repair scheme through the FAA at the address specified in paragraph (f) of this AD. Replace in accordance with British Aerospace Aerostructures Limited (BAe Aircraft) Mandatory Technical News Sheet CT (C1) No. 190, Issue 2, dated April 1, 1995, or AC 43.13- 1B, Change 1, dated September 27, 2001, Chapter 4, Paragraph 4- 99.
(iii) Bind the rear upper mount Prior to further In accordance with frame tubes with a high density flight after the British Aerospace polythene tape at the location initial
Aerostructures where the cowling support rod inspection
Limited (BAe clip is secured.
required in
Aircraft) paragraph (d)(1) Mandatory of this AD.
Technical News Sheet CT (C1) No. 190, Issue 2, dated April 1, 1995.
(e) Can I comply with this AD in any other way? To use an alternative method of compliance or adjust the compliance time, follow the procedures in 14 CFR 39.13. Send these requests to the Manager, Atlanta Aircraft Certification Office (ACO). Contact Cindy Lorenzen, Aerospace Engineer, FAA, Atlanta Aircraft Certification Office, 1895 Phoenix Boulevard, Suite 450, Atlanta, Georgia; telephone: (770) 703-6078; facsimile: (770) 703-6097.
(f) 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: +44 1223 830090, facsimile: +44 1223 830085, e-mail: info@dhsupport.com. 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 April 10, 2003. Dorenda D. Baker, Acting Manager, Small Airplane Directorate, Aircraft Certification Service.
[FR Doc. 03-9304 Filed 4-15-03; 8:45 am]
BILLING CODE 4910-13-P
