AD 2001-16-10

This amendment adopts a new airworthiness directive (AD), applicable to all Aerospatiale Model ATR42-200, -300, -320, and -500 series airplanes; and all Model ATR72 series airplanes. The AD requires revising the Airplane Flight Manual to modify procedures for calculating takeoff performance when Type II or IV de-icing or anti-icing fluids have been used. This amendment is prompted by reports that use of these de-icing or anti-icing fluids may result in an increase in the pitch forces necessary to rotate the airplane during takeoff. This condition could result in a delayed takeoff or even late aborted takeoff. The actions specified by this AD are intended to ensure that the flight crew is advised of the potential effects of Type II or IV de-icing or anti-icing fluids on the airplane's performance during takeoff, and to ensure that the flight crew is advised of the revised performance calculations for takeoff to address these effects.

Final rule.

2001-16-10 Aerospatiale: Amendment 39-12379. Docket 2000-NM-379-AD.

Applicability: All Model ATR42-200, -300, -320, and "500 series airplanes; and all Model ATR72 series airplanes; certificated in any category.

Compliance: Required as indicated, unless accomplished previously.

To ensure that the flight crew is advised of the potential effects of Type II or IV de-icing or anti-icing fluids on the airplane's performance during takeoff, and to ensure that the flight crew is advised of the revised performance calculations for takeoff to address these effects, accomplish the following:

Revision of the Airplane Flight Manual (AFM)

(a) Within 15 days after the effective date of this AD, revise the Appendices and Supplements chapter of the FAA-approved AFM by including either the following manufacturer's Appendix "Takeoff after use of Fluid Type II or IV" or a copy of this AD in the AFM.

"Takeoff After Use of Fluid Type II or IV

This appendix applies only to aircraft de-iced or anti-iced before takeoff, using fluid Type II or IV.

These types of fluid may lead to an increase in control forces necessary to rotate, and then to a modification of takeoff performance.

Therefore, this flight manual must be modified as follows:

1. General

The general information in Section 1 is applicable.

2. Limitations

The limitations in Section 2 are applicable.

3. Normal Procedures

The normal procedures in Section 3 are applicable.

4. Emergency Procedures

The emergency procedures in Section 4 are applicable.

5. Procedures Following Failures

The procedures following failures in Section 5 are applicable.

6. Performances

The performances in Section 6 for dry runways and in Section 7.03 for non-dry runways (advisory materials) are applicable with the addition of the following for takeoff computations:

--Determine VR for the lowest available V2,

--Assume V1=VR,

--Increase TOR, TOD, ASD by20%.

7. Appendices and Supplements

Data of Section 7 are applicable by adding what follows:

For the dispatch cases:

--Apply takeoff penalties due to the system failure,

--Then apply takeoff penalties due to the use of fluids Type II or IV.

Dispatch is not authorized in the following cases:

--Ferry flight with pitch elevators disconnected,

--Takeoff with flaps retracted."

Alternative Methods of Compliance

(b) An alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may be used if approved by the Manager, International Branch, ANM-116, Transport Airplane Directorate, FAA. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, International Branch, ANM-116.

Note 1: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the International Branch, ANM-116.

Special Flight Permits

(c) Special flight permits may be issued in accordance with sections 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate the airplane to a location where the requirements of this AD can be accomplished.

Note 2: The subject of this AD is addressed in French airworthiness directives 2000-449-082(B) and 2000-448-053(B), both dated October 31, 2000.

Effective Date

(d) This amendment becomes effective on September 26, 2001.

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to include an airworthiness directive (AD) that is applicable to all Aerospatiale Model ATR42-200, -300, -320, and -500 series airplanes, and all Model ATR72 series airplanes, was published in the Federal Register on April 12, 2001 (66 FR 18882). That action proposed to require revising the Airplane Flight Manual (AFM) to modify procedures for takeoff when Type II or IV de-icing fluids have been used.

Comments

Interested persons have been afforded an opportunity to participate in the making of this amendment. Due consideration has been given to the comments received.

Request To Revise Unsafe Condition

One commenter (the manufacturer) disagrees with certain characterizations in the proposed AD related to the unsafe condition's potential effects on the affected airplanes. The commenter suggests that application of Type II or IV de-icing or anti-icing fluids may induce a stick force increase at rotation, but no performance degradation. Between 1991 and 1998, there were five reported cases of aborted takeoff (above V1) after use of Type II or IV fluids, but no change in the performance of those airplanes. To provide the necessary margins for a delayed takeoff or even a late aborted takeoff on limited runways, the manufacturer has recommended increasing the takeoff distance for airplanes using Type II or IV fluids, as reflected in the revised takeoff performance calculations in the AFM. Accordingly, the commenter requests the following changes to the proposed AD:

The commenter requests that "Type II or IV de-icing fluids" also refer to "anti-icing fluids."

The commenter requests that the effect on the airplane resulting from the unsafe condition be revised from "reduced controllability of the airplane" to "delayed or even late aborted takeoff."

The commenter requests that the description of the revised AFM procedures be revised from "procedures for takeoff" to "procedures for calculating takeoff performance."

The FAA partially concurs. The FAA finds that, while the requested changes are not substantive and will not have a significant bearing on how operators will comply with the AD, the changes provide a more accurate description of the effect of the fluids on the performance of the airplane. The final rule has been revised accordingly.

Request To Revise Cost Impact

This same commenter (the manufacturer) requests a revision of the number of affected U.S.-registered airplanes identified in the Cost Impact section of the proposed AD. According to the manufacturer's data, the number
of affected airplanes should be 159, not 69. The FAA concurs and has revised the final rule accordingly.

Additional Change to Final Rule

The introductory language of paragraph (a) of this final rule has been revised to provide a better explanation of the actions required by that paragraph.

Conclusion

Aftercareful review of the available data, including the comments noted above, the FAA has determined that air safety and the public interest require the adoption of the rule with the changes described previously. The FAA has determined that these changes will neither significantly increase the economic burden on any operator nor increase the scope of the AD.

Cost Impact

The FAA estimates that 159 airplanes of U.S. registry will be affected by this AD, that it will take approximately 1 work hour per airplane to accomplish the required actions, and that the average labor rate is $60 per work hour. Based on these figures, the cost impact of the AD on U.S. operators is estimated to be $9,540, or $60 per airplane.

The cost impact figure discussed above is based on assumptions that no operator has yet accomplished any of the requirements of this AD action, and that no operator would accomplish those actions in the future if this AD were not adopted. The cost impact figures discussed in AD rulemaking actions represent only the time necessary to perform the specific actions actually required by the AD. These figures typically do not include incidental costs, such as the time required to gain access and close up, planning time, or time necessitated by other administrative actions.

Regulatory Impact

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.

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 final evaluation has been prepared for this action and it is contained in the Rules Docket. A copy of it may be obtained from 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.

Adoption of the Amendment

Accordingly, pursuant to 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. Section 39.13 is amended by adding the following new airworthiness directive: