Airworthiness directives: Constucciones Aeronauticas, S.A.,

[Federal Register: January 5, 2000 (Volume 65, Number 3)]

[Proposed Rules]

[Page 399-400]

From the Federal Register Online via GPO Access [wais.access.gpo.gov]

[DOCID:fr05ja00-18]

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99-NM-261-AD]

RIN 2120-AA64

Airworthiness Directives; Construcciones Aeronauticas, S.A. (CASA) Model CN-235-100 and CN-235-200 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

SUMMARY: This document proposes the adoption of a new airworthiness directive (AD) that is applicable to all CASA Model CN-235-100 and CN- 235-200 series airplanes. This proposal would require replacement of existing anti-icing distributor valves with new, improved valves. This proposal is prompted by issuance of mandatory continuing airworthiness information by a foreign civil airworthiness authority. The actions specified by the proposed AD are intended to prevent ice accumulation on the wings or tail of the airplane, which could result in reduced controllability of the airplane.

DATES: Comments must be received by February 4, 2000.

ADDRESSES: Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 99-NM-261-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056. Comments may be inspected at this location between 9 a.m. and 3 p.m., Monday through Friday, except Federal holidays.

The service information referenced in the proposed rule may be obtained from Construcciones Aeronauticas, S.A., Getafe, Madrid, Spain. This information may be examined at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington.

FOR FURTHER INFORMATION CONTACT: Norman B. Martenson, Manager, International Branch, ANM-116, FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 227-2110; fax (425) 227-1149.

SUPPLEMENTARY INFORMATION:

Comments Invited

Interested persons are invited to participate in the making of the proposed rule by submitting such written data, views, or arguments as they may desire. Communications shall identify the Rules Docket number and be submitted in triplicate to the address specified above. All communications received on or before the closing date for comments, specified above, will be considered before taking action on the proposed rule. The proposals contained in this notice may be changed in light of the comments received.

Comments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the proposed rule. All comments submitted will be available, both before and after the closing date for comments, in the Rules Docket for examination by interested persons. A report summarizing each FAA-public contact concerned with the substance of this proposal will be filedin the Rules Docket.

Commenters wishing the FAA to acknowledge receipt of their comments submitted in response to this notice must submit a self-addressed, stamped postcard on which the following statement is made: ``Comments to Docket Number 99-NM-261-AD.'' The postcard will be date stamped and returned to the commenter.

Availability of NPRMs

Any person may obtain a copy of this NPRM by submitting a request to the FAA, Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 99-NM-261-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.

Discussion

On December 26, 1989, a British Aerospace Jetstream Model BA-3101 series airplane impacted the ground approximately 400 feet short of the runway while executing an instrument landing system (ILS) approach. The accident occurred at the Tri-Cities Airport, Pasco, Washington. The National Transportation Safety Board (NTSB) determined that the probable cause of the accident was the flightcrew's decision to continue an unstabilized ILS approach that led to a stall, most likely of the horizontal stabilizer, and loss of control at low altitude. Contributing to the stall and loss of control was the accumulation of leading edge ice, which degraded the aerodynamic performance of the airplane.

One result of the NTSB investigation was the determination that the flight deck wing de-icing light illuminated at a lower pressure than the pressure required to fully inflate the de-icing boots. The premature illumination of the wing de-icing light was due to a failure within the wing de-icing boot system, which allowed sufficient air pressure to give the appearance of normal operation based on the de- icing light, without actually inflating the boots sufficiently to remove ice.

Based on an NTSB Safety Recommendation, the FAA reviewed the pneumatic de-icing boot system designs for airplanes operated under parts 121 and 135 of the Federal Aviation Regulations to ensure that the pneumatic pressure threshold at which each de-icing boot indication light is designed to illuminate is sufficient pressure for effective operation of the pneumatic de-icing boots. The FAA has determined that the existing design of the flight deck pneumatic de-icing boot pressure indicator switch on CASA Model CN-235-100 and CN-235-200 series airplanes may allow the flight deck indicator light to illuminate at a lower pressure than the pressure required to fully inflate the de-icing boots [15 pounds per square inch gage (psig)]. Illumination of the light at a lower pressure would indicate to the flightcrew that the pneumatic ice boots are operating normally, though the boots may not be sufficiently inflated to shed ice. This condition, if not corrected, could result in ice accumulation on the wings or tail of the airplane, which could result in reduced controllability of the airplane.

[[Page 400]]

Explanation of Relevant Service Information

CASA has issued Service Bulletin SB-235-30-14, dated August 13, 1999, which describes procedures for replacement of existing anti-icing distributor valves in the wing and tail areas of the airplane with new, improved valves. The new, improved valves increase the weak pressure of the anti-icing distributor valves pressure sensor to 15.5 psig (0/5 psig). Accomplishment of the actions specified in the service bulletin is intended to adequately address the identified unsafe condition. The Direccion General de Aviacion Civil (DGAC), which is the airworthiness authority for Spain, classified this service bulletin as mandatory and issued Spanish airworthiness directive 04/99, dated July 30, 1999, in order to assure the continued airworthiness of these airplanes in Spain.

FAA's Conclusions

These airplane models are manufactured in Spain 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, the DGAC has kept the FAA informed of the situation described above. The FAA has examined the findings of the DGAC, reviewed all available information, and determined that AD action is necessary for products of this type design that are certificated for operation in the United States.

Explanation of Requirements of Proposed Rule

Since an unsafe condition has been identified that is likely to exist or develop on other airplanes of the same type design registered in the United States, the proposed AD would require accomplishment of the actions specified in the service bulletin described previously.

Cost Impact

The FAA estimates that 2 airplanes of U.S. registry would be affected by this proposed AD, that it would take approximately 30 work hours per airplane to accomplish the proposed replacement, and that the average labor rate is $60 per work hour. Required parts would cost approximately $4,671 per airplane. Based on these figures, the cost impact of the proposed AD on U.S. operators is estimated to be $12,942, or $6,471 per airplane.

The cost impact figure discussed above is based on assumptions that no operator has yet accomplished any of the proposed requirements of this AD action, and that no operator would accomplish those actions in the future if this AD were not adopted.

Regulatory Impact

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 proposal would not have federalism implications under Executive Order 13132.

For the reasons discussed above, I certify that this proposed regulation (1) Is not a ``significant regulatory action'' under Executive Order 12866; (2) Is not a ``significant rule'' under the 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 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, Safety.

The Proposed Amendment

Accordingly, pursuant to 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.

    Sec. 39.13 [Amended]

  2. Section 39.13 is amended by adding the following new airworthiness directive:

    Construcciones Aeronauticas, S.A. (CASA): Docket 99-NM-261-AD.

    Applicability: All Model CN-235-100 and CN-235-200 series airplanes, certificated in any category.

    Note 1: This AD applies to each airplane identified in the preceding applicability provision, 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 (c) 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 the unsafe condition has not been eliminated, the request should include specific proposed actions to address it.

    Compliance: Required as indicated, unless accomplished previously.

    To prevent ice accumulation on the wings or tail of the airplane, which could result in reduced controllability of the airplane, accomplish the following:

    Replacement

    (a) Within 4 months after the effective date of this AD, replace the existing anti-icing distributor valves, having part number (P/N) AC960013, in the wing and tail areas of the airplane, with new, improved valves, having P/N AC911016, in accordance with CASA Service Bulletin SB-235-30-14, dated August 13, 1999.

    (b) As of the effective date of this AD, no person shall install a distributor valve having P/N AC960013 on any airplane.

    Alternative Methods of Compliance

    (c) 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, FAA, Transport Airplane Directorate. 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 2: 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

    (d) 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 3: The subject of this AD is addressed in Spanish airworthiness directive 04/99, dated July 30, 1999.

    Issued in Renton, Washington, on December 29, 1999. D.L. Riggin, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.

    [FR Doc. 00-136Filed1-4-00; 8:45 am]

    BILLING CODE 4910-13-U

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