Airworthiness Directives; de Havilland Model DHC-8-100 and DHC-8- 300 Series Airplanes

DEPARTMENT OF TRANSPORTATION

14 CFR Part 39

[Docket No. 93-NM-206-AD; Amendment 39-9060; AD 94-22-10]

Airworthiness Directives; de Havilland Model DHC-8-100 and DHC-8-

300 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment adopts a new airworthiness directive (AD),

applicable to certain de Havilland Model DHC-8-100 and DHC-8-300 series

airplanes, that requires a revision to the Airplane Flight Manual (AFM)

to advise flight crew members that certain cockpit indications may

reveal faulty anti-collision strobe light units, and to provide

procedures for subsequent flight crew action. This amendment also

requires a modification that eliminates the need for the AFM revision.

This amendment is prompted by reports that the function of the

proximity switch electronics unit (PSEU) may be adversely affected

during operation of the white anti-collision lights. The actions

specified by this AD are intended to ensure correct operation of the

PSEU and its associated systems.

DATES: Effective December 15, 1994.

The incorporation by reference of certain publications listed in

the regulations is approved by the Director of the Federal Register as

of December 15, 1994.

ADDRESSES: The service information referenced in this AD may be

obtained from de Havilland, Inc., Garratt Boulevard, Downsview, Ontario

M3K 1Y5, Canada. This information may be examined at the Federal

Aviation Administration (FAA), Transport Airplane Directorate, Rules

Docket, 1601 Lind Avenue, SW., Renton, Washington; or at the FAA,

Engine and Propeller Directorate, New York Aircraft Certification

Office, 181 South Franklin Avenue, room 202, Valley Stream, New York;

or at the Office of the Federal Register, 800 North Capitol Street,

NW., suite 700, Washington, DC.

FOR FURTHER INFORMATION CONTACT: Michele Maurer, Aerospace Engineer,

Systems and Equipment Branch, ANE-173, New York Aircraft Certification

Office, FAA, Engine and Propeller Directorate, 181 South Franklin

Avenue, room 202, Valley Stream, New York 11581; telephone (516) 791-

6427; fax (516) 791-9024.

SUPPLEMENTARY INFORMATION: 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 certain de Havilland Model DHC-8-

100 and DHC-8-300 series airplanes was published in the Federal

Register on APRIL 4, 1994 (59 FR 15873). That action proposed to

require a revision to the Airplane Flight Manual (AFM) to advise flight

crew members that certain cockpit indications may reveal faulty anti-

collision strobe light units, and to provide procedures for subsequent

flight crew action. It also proposed to require a modification that

eliminates the need for the AFM revision.

Interested persons have been afforded an opportunity to participate

in the making of this amendment. Due consideration has been given to

the comments received.

One commenter supports the proposal.

Another commenter requests that the proposal be revised to permit

accomplishment of the modification in accordance with later revisions

of the referenced service bulletin that may be approved in the future

by Transport Canada. The commenter states that this would allow

operators to use the most current information when performing the

required modification. The FAA does not concur. To include the phrase,

``or later approved revisions,'' in an AD when referring to a service

bulletin, violates Office of the Federal Register (OFR) regulations

regarding approval of materials that are ``incorporated by reference''

in rules. In general terms, these OFR regulations require that either

the service document contents be published as part of the actual AD

language, or that the service document be submitted for approval by the

OFR as ``referenced'' material, in which case it may be only referred

to in the text of an AD. The AD may only refer to the service document

that was actually submitted and approved by the OFR for ``incorporation

by reference.'' In order for operators to use later revisions of the

referenced document (issued after the publication of the AD), either

the AD must be revised to reference the specific later revisions, or

operators must request the approval of them as an alternative method of

compliance with this AD [under the provisions of paragraph (d)].

This same commenter suggests that the proposal be revised to make

only the replacement of the power supplies mandatory, not the

replacement of the strobe light assemblies. The commenter points out

that Modification 8/1273, as would be required by proposed paragraph

(c), requires that both the currently-installed strobe light assembly

and power supply be replaced with a Whelen strobe light assembly and

power supply. The commenter states that (1) the addressed unsafe

condition is known to be caused by a capacitor failure in the Grimes

power supply only, not in the Grimes strobe light assemblies; and (2)

the Whelen power supplies work in conjunction with the Grimes strobe

light assemblies. Therefore, the commenter reasons that only the

replacement of the Grimes power supply is necessary to correct the

unsafe condition, and that the replacement of the light assemblies

should be at the operator's discretion. The FAA does not concur. Both

the Grimes and Whelen anti-collision light systems (including both the

power supply and strobe light assembly) are approved under individual

Technical Standard Orders (TSO), for which de Havilland has compliance

data approved only for the installation of each as an individual

system; currently, there is no compliance data approved for

installation of a ``mixed system'' (i.e., Whelen power supplies with

Grimes strobe light assemblies, or vice versa). In light of this, the

FAA has determined that the complete Grimes system (including both the

power supply and the strobe light assembly) must be replaced with a

complete Whelen system.

After careful 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 as proposed.

The FAA estimates that 74 airplanes of U.S. registry will be

affected by this AD, that it will take approximately 16 work hours per

airplane to accomplish the required actions, and that the average labor

rate is $55 per work hour. Required parts for installation of

Modification 8/1273 at all three locations will cost approximately

$1,397 per airplane. Based on these figures, the total cost impact of

the AD on U.S. operators is estimated to be $168,498, or $2,277 per

airplane.

The total 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 regulations adopted herein will not have substantial direct

effects 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, in

accordance with Executive Order 12612, it is determined that this final

rule does not have sufficient federalism implications to warrant the

preparation of a Federalism Assessment.

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, Incorporation by

reference, 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. App. 1354(a), 1421 and 1423; 49 U.S.C.

106(g); and 14 CFR 11.89.

Sec. 39.13 [Amended]

2. Section 39.13 is amended by adding the following new

airworthiness directive:

94-22-10 de Havilland, Inc.: Amendment 39-9060. Docket 93-NM-206-AD.

Applicability: Model DHC-8-102, -103, -302, and -311 series

airplanes, serial numbers 003 through 214 inclusive; on which

Modification 8/1273 (as described in de Havilland Service Bulletin

S/B No. 8-33-19, Revision `A', dated May 31, 1993) has not been

accomplished; certificated in any category.

Compliance: Required as indicated, unless accomplished

previously.

To ensure correct operation of the proximity switch electronics

unit (PSEU) and its associated systems, accomplish the following:

(a) Within 30 days after the effective date of this AD, revise

the Limitations Section of the FAA-approved Airplane Flight Manual

(AFM) to include the following statement. This may be accomplished

by inserting a copy of this AD into the AFM.

``The electrical power supplies for the white anti-collision

lights may fail and cause the following abnormalities:

--flashing of the landing gear green locked down advisory lights

during cruise;

--fluctuation of cabin pressurization rate needle during cruise; and

--retraction and extension of roll and ground spoilers during ground

operation.

The failure may also result in loss of nose landing gear

steering subsequent to landing, and loss of wheel brakes below 35-40

knots.

If any of these abnormal indications are observed, select A/COL

light switch-RED. Leave the switch in this position for the

remainder of the flight.''

(b) If the flight crew reports the occurrence of any of the

cockpit indications stated in paragraph (a) of this AD: Prior to the

next flight, perform the maintenance procedures to confirm and

isolate the faulty power supply unit, in accordance with paragraph

III., Part B, Accomplishment Instructions of de Havilland Alert

Service Bulletin S.B. A8-33-33, dated May 31, 1993.

(1) If any power supply unit is determined to be faulty, prior

to further flight, replace the unit with a new or serviceable

``Grimes'' unit or a new ``Whelen'' system in accordance with the

alert service bulletin.

(2) If the specific unit causing the faults cannot be

determined, prior to further flight, replace all three units with

new or serviceable ``Grimes'' units or a new ``Whelen'' system in

accordance with the alert service bulletin. Installation of a new

``Whelen'' system at all three locations constitutes terminating

action for the requirements of this AD, and after installation, the

AFM revision required by paragraph (a) of this AD may be removed.

(c) Within 6 months after the effective date of this AD, install

Modification 8/1273 (which entails replacement of the existing anti-

collision strobe lights, brackets, and power supplies with the ``

`Whelen' Anti-Collision Strobe Light System'') at all three

locations, in accordance with de Havilland Service Bulletin S/B No.

8-33-19, Revision ``A'', dated May 31, 1993. Following installation,

the AFM revision required by paragraph (a) of this AD may be

removed.

(d) 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, New York Aircraft Certification

Office (ACO), ANE-170, FAA, Engine and Propeller Directorate.

Operators shall submit their requests through an appropriate FAA

Principal Maintenance Inspector, who may add comments and then send

it to the Manager, New York ACO.

Note: Information concerning the existence of approved

alternative methods of compliance with this AD, if any, may be

obtained from the New York ACO.

(e) 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.

(f) The actions shall be done in accordance with de Havilland

Alert Service Bulletin S.B. A8-33-33, dated May 31, 1993; and de

Havilland Service Bulletin S/B No. 8-33-19, Revision ``A'', dated

May 31, 1993; as applicable. This incorporation by reference was

approved by the Director of the Federal Register in accordance with

5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from de

Havilland, Inc., Garratt Boulevard, Downsview, Ontario M3K 1Y5,

Canada. Copies may be inspected at the FAA, Transport Airplane

Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the

FAA, Engine and Propeller Directorate, New York Aircraft

Certification Office, 181 South Franklin Avenue, Room 202, Valley

Stream, New York; or at the Office of the Federal Register, 800

North Capitol Street, NW., suite 700, Washington, DC.

(g) This amendment becomes effective on December 15, 1994.

Issued in Renton, Washington, on October 26, 1994.

Darrell M. Pederson,

Acting Manager, Transport Airplane Directorate, Aircraft Certification

Service.

[FR Doc. 94-27051 Filed 11-14-94; 8:45 am]

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