AD 2002-13-08

This amendment adopts a new airworthiness directive (AD) that applies to certain de Havilland Inc. (de Havilland) Models DHC-2 Mk. I, DHC-2 Mk. II, and DHC-2 Mk. III airplanes. This AD requires you to modify the elevator tip rib on each elevator; repetitively inspect underneath the mass balance weights at each elevator tip rib for corrosion; and either remove the corrosion or replace a corroded elevator tip rib depending on the corrosion damage. This AD is the result of mandatory continuing airworthiness information (MCAI) issued by the airworthiness authority for Canada. The actions specified by this AD are intended to detect and correct corrosion in the mass balance weights at the elevator tip ribs, which could result in loss of balance weight during flight and the elevator control surface separating from the airplane.

Final rule.

2002-13-08 de Havilland Inc.: Amendment 39-12796; Docket No. 97-CE-70-AD.

(a) What airplanes are affected by this AD? This AD affects Models DHC-2 Mk. I, DHC-2 Mk. II, and DHC-2 Mk. III airplanes, all serial numbers, certificated in any category.

(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 detect and correct corrosion in the mass balance weights at the elevator tip ribs, which could result in loss of balance weight during flight and the elevator control surface separating from the airplane.

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

Actions
Compliance
Procedures
(1) For all affected airplanes: cut an access hole and fabricate and install an access cover and ring doubler on the elevator tip rib of each elevator.
Within the next 6 calendar months after August 13, 2002 (the effective date of this AD).
In accordance with the ACCOMPLISHMENT INSTRUCTIONS section of either de Havilland Beaver Service Bulletin Number 2/50, dated May 9, 1997 (for Models DHC-2 Mk. I and DHC-2 Mk. II airplanes); or de Havilland Beaver Service Bulletin Number TB/58, dated May 9, 1997 (for Model DHC-2 Mk. III airplanes), as applicable.
(2) For all affected airplanes: inspect underneath the mass balance weights at each elevator tip rib for corrosion.
Within the next 6 calendar months after August 13, 2002 (the effective date of this AD) and thereafter at intervals not to exceed 5 years.
In accordance with the ACCOMPLISHMENT INSTRUCTIONS section of either de Havilland Beaver Service Bulletin Number 2/50, dated May 9, 1997 (for Models DHC-2 Mk. I and DHC-2 Mk. II airplanes); or de Havilland Beaver Service Bulletin number TB/58, dated May 9, 1997 (for Model DHC-2 Mk. III airplanes), as applicable.(3) For all affected airplanes: if corrosion is found (during any inspection required by paragraph (d)(2) of this AD) that is equal to or less than 0.004 inches depth, remove the corrosion.
Prior to further flight after any inspection required in paragraph d(2) of this AD where the applicable corrosion is found.
In accordance with the ACCOMPLISHMENT INSTRUCTIONS section of either de Havilland Beaver Service Bulletin Number 2/50, dated May 9, 1997 (for Models DHC-2 Mk. I and DHC-2 Mk. II airplanes); or de Havilland Beaver Service Bulletin Number TB/58, dated May 9, 1997 (for Model DHC-2 Mk. III airplanes), as applicable.
(4) For all affected airplanes: if corrosion is found (during any inspection required by paragraph (d)(2) of this AD) that is greater than 0.004 inches depth, accomplish one of the following:.

(i) use the procedures in the service bulletin to manufacture a new tip rib, part number 2DKC2-TE-77, and replace the affected tip rib with this new tip rib; or

(ii)replace any affected elevator tip rib with a part number (P/N) C2-TE-103AND elevator tip rib. You may obtain a P/N C2-TE-103AND elevator tip rib from Viking Air Limited, 9574 Hampden Road, Sidney, BC, Canada VL8 SV5.

Prior to further flight after any inspection required in paragraph d(2) of this AD where the applicable corrosion is found.
In accordance with the ACCOMPLISHMENT INSTRUCTIONS section of either de Havilland Beaver Service Bulletin Number 2/50, dated May 9, 1997 (for Models DHC-2 Mk. I and DHC-2 Mk. II airplanes); or de Havilland Beaver Service Bulletin Number TB/58, dated May 9, 1997 (for Model DHC-2 Mk. III airplanes), as applicable.
(5) In addition to that required by paragraph (d)(4) of this AD for the affected DHC-2 MK III airplanes: if corrosion is found (during any inspection required by paragraph (d)(2) of this AD) that is greater than 0.004 inches depth on the channel, accomplish one of the following:.

(i) use the procedures in the service bulletin to manufacture a new channel replacement, part number 2DKC2TE1020-13, and replace the affected channel with this new channel; or

(ii) replace the channel with a part number (P/ N) C2-TE0-89ND channel. You may obtain a P/N C2-TE-89ND channel from Viking Air Limited, 9574 Hampden Road, Sidney, BC, Canada VL8 SV5.
Prior to further flight after any inspection required in paragraph d(2) of this AD where the applicable corrosion is found.
In accordance with the ACCOMPLISHMENT INSTRUCTIONS section of de Havilland Beaver Service Bulletin Number TB/58, dated May 9, 1997.

Note 1: General maintenance procedures specify that the elevators should be rebalanced any time work is done in that area.

(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, New York 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, New York ACO.

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 Mr. Jon Hjelm, Aerospace Engineer, New YorkAircraft Certification Office, 10 Fifth Street, 3rd Floor, Valley Stream, New York, 11581-1200, telephone: (516) 256-7523, facsimile: (516) 568-2716.

(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) Are any service bulletins incorporated into this AD by reference? Actions required by this AD must be done in accordance with de Havilland Beaver Service Bulletin Number 2/50, dated May 9, 1997 or de Havilland Beaver Service Bulletin Number TB/58, dated May 9, 1997. The Director of the Federal Register approved this incorporation by reference under 5 U.S.C. 552(a) and 1 CFR part 51. You may get copies from Bombardier Inc., Bombardier Regional Aircraft Division, 123 Garratt Boulevard, Downsview, Ontario, Canada M3K 1Y5. You may view copies at the FAA, Central Region, Office of the Regional Counsel, 901 Locust, Room 506, Kansas City, Missouri, or at the Office of the Federal Register, 800 North Capitol Street, NW, suite 700, Washington, DC.

Note 3: The subject of this AD is addressed in Canadian AD No. CF-97-06, dated May 28, 1997.

(i) When does this amendment become effective? This amendment becomes effective on August 13, 2002.

Discussion

What Events Have Caused This AD?

Transport Canada, which is the airworthiness authority for Canada, notified FAA that an unsafe condition may exist on certain de Havilland Models DHC-2 Mk. I, DHC-2 Mk. II, and DHC-2 Mk. III airplanes. Transport Canada reports incidents of corrosion found in the area of the elevator tip rib underneath the mass balance weights on several of the above-referenced airplanes.

What Is the Potential Impact if FAA Took no Action?

These conditions, if not detected and corrected, could result in loss of balance weight during flight and the elevator control surface separating from 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 de Havilland Models DHC-2 Mk. I, DHC-2 Mk. II, and DHC-2 Mk. III airplanes. This proposal was published in the Federal Register asa notice of proposed rulemaking (NPRM) on March 4, 2002 (67 FR 9627). The NPRM proposed to require you to modify the elevator tip rib on each elevator; repetitively inspect underneath the mass balance weights at the elevator rib tip for corrosion; and either remove the corrosion or replace the corroded elevator tip rib depending on the corrosion damage.

Was the Public Invited To Comment?

The FAA encouraged interested persons to participate in the making of this amendment. We did not receive any comments on the proposed rule or on our determination of the cost to the public.

FAA's Determination

What Is FAA's Final Determination on This Issue?

After careful review of all available information related to the subject presented above, we have determined that air safety and the public interest require the adoption of the rule as proposed except for minor editorial corrections. We have determined that these minor corrections:

--Provide the intent that was proposed in the NPRM for correcting the unsafe condition; and

--Do not add any additional burden upon the public than was already proposed in the NPRM.

Cost Impact

How Many Airplanes Does This AD Impact?

We estimate that this AD affects 160 airplanes in the U.S. registry.

What is the Cost Impact of This AD on Owners/Operators of the Affected Airplanes?

We estimate the following costs to accomplish the modification and initial inspection:

Labor cost
Parts cost
Total cost per airplane
Total cost on U.S. operators
13 workhours x $60 = $780
No parts cost required
$780
$780 x 160 = $124,800

These figures only take into account the modification and initial inspection costs and do not take into account the costs of any of the repetitive inspections or the cost to replace any elevator tip rib that would be found corroded past a certain extent. We have no way of determining the number of repetitive inspections each owner/operator will incur over the life of each affected airplane or the number of elevator tip ribs that will need to be replaced.

Compliance Time of This AD

What Will be the Compliance Time of This AD?

The compliance time of this AD is "within the next 6 calendar months after the effective date of this AD."

Why Is the Compliance Time Presented in Calendar Time Instead of Hours Time-in-Service (TIS)?

We have determined that a calendar time compliance is the most desirable method because the unsafe condition described in this AD is caused by corrosion. Corrosion develops regardless of whether the airplane is in service and is not a result of airplane operation. Therefore, to ensure that the above-referenced condition is detected and corrected on all airplanes within a reasonable period of time without inadvertently grounding any airplanes, a compliance schedule based upon calendar time instead of hours TIS is required.

Regulatory Impact

Does This AD Impact Various Entities?

The regulations adopted herein will 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 final rule does not have federalism implications under Executive Order 13132.

Does this 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) 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 final 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.

List of Subjects in 14 CFR Part 39

Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.

Adoption of the Amendment

Accordingly, under the authority delegated to me by the Administrator, the Federal Aviation Administration amends 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.

Sec. 39.13 [Amended]

2. FAA amends 39.13 by adding a new AD to read as follows: