Federal Aviation Administration, DOT.
Notice of proposed rulemaking (NPRM).
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 check the airplane logbook to determine whether certain modifications have been incorporated on the airplane and incorporate the modifications that have not already been accomplished. This proposed AD is the result of the manufacturer performing a design study on the structural integrity of certain parts and reports of service failure of other parts installed on the affected airplanes. The actions specified by this proposed AD are intended to prevent reduced structural integrity in the primary structure of the airplane, which could result in failure of the rudder torque tube, elevator fasteners, and the vertical fin rear spar, or jamming or damage to the elevator. Such failures could lead to loss of control of the airplane.
The Federal Aviation Administration (FAA) must receive any comments on this proposed rule on or before January 13, 2003.
Submit comments to FAA, Central Region, Office of the Regional Counsel, Attention: Rules Docket No. 2000–CE–66–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:
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:
Cindy Lorenzen, Aerospace Engineer, FAA, Atlanta Aircraft Certification Office, 1895 Phoenix Boulevard, Suite 450, Atlanta, Georgia; telephone: (770) 703–6078; facsimile: (770) 703–6097.
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
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.
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–66–AD.” We will date stamp and mail the postcard back to you.
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. Failure reports of the rudder torque tube and elevator control fasteners on in-service airplanes and design studies by the manufacturer on the structural integrity of the glider towing attachment bolt and the vertical fin rear spar prompted us to issue this proposed AD.
We have determined that failure of the rudder torque tube, the elevator control fasteners, the vertical fin rear spar, and the glider towing attachment bolt is caused by fatigue cracking and overload. As a result of the design studies, the manufacturer developed specific modifications to strengthen the affected areas of the airplane.
These conditions, if not corrected, could result in failure of the rudder torque tube, elevator fasteners, and the vertical fin rear spar, or jamming or damage to the elevator. Such failures could lead to loss of control of the airplane.
British Aerospace Aerostructures Limited (now DeHavilland Support Limited) has issued BAe Aircraft Technical News Sheet CT (C1) No. 200, Issue 1, dated March 1, 1997.
The service information includes procedures for inspecting the airplane to:
The service information also specifies incorporating these modifications if not already incorporated.
After examining the circumstances and reviewing all available information related to the incidents described above, we have determined that:
This proposed AD would require you to check the airplane logbook to determine whether certain modifications have been incorporated on the airplane and incorporate the modifications that have not already been accomplished
We estimate that this proposed AD affects 54 airplanes in the U.S. registry.
We estimate the following costs to accomplish any necessary modifications that would be required based on the results of the proposed logbook check We have no way of determining the number of airplanes that may need such modification.
The compliance time of this proposed AD is “within the next 90 days after the effective date of this AD.”
Failure of the rudder torque tube, the elevator control fasteners, the vertical fin rear spar, and the glider towing attachment bolt is only unsafe during airplane operation. However, this unsafe condition is not a result of the number of times the airplane is operated. The chance of this situation occurring is the same for an airplane with 50 hours time-in-service (TIS) as it would be for as airplane with 1,000 hours TIS.
For this reason, the FAA has determined that a compliance based on calendar time should be utilized in this proposed AD in order to assure that the unsafe condition is addressed on all airplanes in a reasonable time period.
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.
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
Air transportation, Aircraft, Aviation safety, Safety.
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:
1. The authority citation for part 39 continues to read as follows:
49 U.S.C. 106(g), 40113, 44701.
2. FAA amends § 39.13 by adding a new airworthiness directive (AD) to read as follows:
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)
(c)
(d)
Although not required by this AD, FAA highly recommends you incorporate Modification H 282.
(e)
(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.
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)
(g)
(h)