02-5004. Airworthiness Directives; de Havilland Inc. Models DHC-2 Mk. I, DHC-2 Mk. II, and DHC-2 Mk. III 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 de Havilland Inc. (de Havilland) Models DHC-2 Mk. I, DHC-2 Mk. II, and DHC-2 Mk. III airplanes. This proposed AD would require 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 proposed AD is the result of mandatory continuing airworthiness information (MCAI) issued by the airworthiness authority for Canada. The actions specified by this proposed 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.

DATES:

The Federal Aviation Administration (FAA) must receive any comments on this proposed rule on or before March 29, 2002.

ADDRESSES:

Submit comments to FAA, Central Region, Office of the Regional Counsel, Attention: Rules Docket No. 97-CE-70-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 get service information that applies to this proposed AD from Bombardier Inc., Bombardier Regional Aircraft Division, 123 Garratt Boulevard, Downsview, Ontario, Canada M3K 1Y5; telephone: [phone]. You may also view this information at the Rules Docket at the address above.

FOR FURTHER INFORMATION CONTACT:

Mr. Jon Hjelm, Aerospace Engineer, New York Aircraft Certification Office, 10 Fifth Street, 3rd Floor, Valley Stream, New York, 11581-1200, 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 comments, you must include a self-addressed, stamped postcard. On the postcard, write “Comments to Docket No. 97-CE-70-AD.” We will date stamp and mail the postcard back to you.

Discussion

What Events Have Caused This Proposed 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 Are the Consequences if the Condition Is Not Corrected?

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.

Is There Service Information That Applies to This Subject?

De Havilland has issued Beaver Service Bulletin Number 2/50, dated May 9, 1997 (applicable to Models DHC-2 Mk. I and DHC-2 Mk. II airplanes); and Beaver Service Bulletin Number TB/58, dated May 9, 1997 (applicable to Model DHC-2 Mk. III airplanes).

What Are the Provisions of This Service Information?

These service bulletins include procedures for:

—modifying the elevator tip rib on each elevator;

—repetitively inspecting underneath the mass balance weights at the elevator tip rib for corrosion; and

—either removing the corrosion or replacing the corroded elevator tip rib depending on the corrosion damage.

What Action Did Transport Canada Take?

Transport Canada classified these service bulletins as mandatory and issued AD No. CF-97-06, dated May 28, 1997, in order to ensure the continued airworthiness of these airplanes in Canada.

Was This in Accordance With the Bilateral Airworthiness Agreement?

These airplane models are manufactured in Canada 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, Transport Canada has kept FAA informed of the situation described above.

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

What Has FAA Decided?

The FAA has examined the findings of Transport Canada; 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 de Havilland Models DHC-2 Mk. I, DHC-2 Mk. II, and DHC-2 Mk. III of the same type design that are on the U.S. registry;

—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 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.

Cost Impact

How Many Airplanes Would This Proposed AD Impact?

We estimate that this proposed AD affects 160 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 modification and initial inspection:

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

These figures only take into account the proposed modification and initial inspection costs and do not take into account the costs of any of the proposed 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 would incur over the life of each affected airplane or the number of elevator tip ribs that would need to be replaced.

Compliance Time of This Proposed AD

What Would Be the Compliance Time of This Proposed AD?

The compliance time of this proposed 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 proposed 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 proposed.

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:

De Havilland Inc.: 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 install an access cover and ring doubler on the elevator tip rib of each elevator	Within the next 6 calendar months after 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 fabricate and 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 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 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:	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.
(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. You may obtain a P/N C2-TE-103AND elevator tip rib from Viking Air Limited, 9574 Hampden Road, Sidney, BC, Canada VL8 SV5
(5) In addition to the above 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:	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.
(i) use the procedures in the service bulletin to manufacture a new channel replacement, part number 2DKC2TE1020-13, and replace the affected channel with new channel; or
(ii) replace the channel with a part number (P/N) C2-TE-89ND channel. You may obtain a P/N C2-TE-89ND channel from Viking Air Limited, 9574 Hampden Road, Sidney, BC, Canada VL8 SV5

(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 1:

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 York Aircraft Certification Office, 10 Fifth Street, 3rd Floor, Valley Stream, New York, 11581-1200, 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 Bombardier Inc., Bombardier Regional Aircraft Division, 123 Garratt Boulevard, Downsview, Ontario, Canada M3K 1Y5. You may view these documents at FAA, Central Region, Office of the Regional Counsel, 901 Locust, Room 506, Kansas City, Missouri 64106.

Note 2:

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

Issued in Kansas City, Missouri, on February 21, 2002.

Michael Gallagher,

Manager, Small Airplane Directorate, Aircraft Certification Service.