[Federal Register Volume 60, Number 12 (Thursday, January 19, 1995)]
[Rules and Regulations]
[Pages 3737-3739]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-1127]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 94-NM-235-AD; Amendment 39-9122; AD 94-22-10 R1]
Airworthiness Directives; De Havilland Model DHC-8-100 and DHC-8-
300 Series Airplanes
AGENCY: Federal Aviation Administration, DOT.
ACTION: Final rule; request for comments.
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SUMMARY: This amendment revises an existing airworthiness directive
(AD), applicable to certain De Havilland Model DHC-8-100 and DHC-8-300
series airplanes, that currently 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 and maintenance action.
That AD also requires a modification that eliminates the need for the
AFM revision. That AD was 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 that AD are intended to ensure correct operation of the
PSEU and its associated systems. This amendment revises the
applicability of the existing AD to add one model of affected
airplanes.
DATES: Effective February 3, 1995.
The incorporation by reference of certain publications listed in
the regulations was approved previously by the Director of the Federal
Register as of December 15, 1994 (59 FR 58765, November 15, 1994).
Comments for inclusion in the Rules Docket must be received on or
before March 20, 1995.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-103,
Attention: Rules Docket No. 94-NM-235-AD, 1601 Lind Avenue, SW.,
Renton, Washington 98055-4056.
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 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.
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: On October 26, 1994, the FAA issued AD 94-
22-10, amendment 39-9060 (59 FR 58765, November 15, 1994), which is
applicable to certain De Havilland Model DHC-8-100 and -300 series
airplanes. That action requires a revision to the FAA-approved Airplane
Flight Manual (AFM) to advise the flight crew that certain cockpit
indications may reveal faulty anti-collision strobe light units, and to
provide procedures for subsequent flight crew and maintenance action.
It also requires the installation of a modification that eliminates the
need for the AFM revision.
That action was prompted by reports indicating that the electrical
power supplies of the white anti-collision lights may develop a fault
that produces greater than normal electrical emissions. The cause of
this fault has been attributed to a capacitor failure in some
``Grimes'' strobe light systems. This electromagnetic interference can
adversely affect the operation of the proximity switch electronics unit
(PSEU) and its associated systems. Incorrect operation of the PSEU and
its associated systems may interfere with or distract the flight crew
in carrying out its regular duties during flight or on the ground, and
thus serve to compromise the safe operation of the airplane. The
requirements of AD 94-22-10 are intended to ensure the correct
operation of the PSEU and its associated systems.
The AFM revision that is required by AD 94-22-01 is intended to
advise the flight crew of the fact that the electrical power supplies
for the white anti-collision lights may fail and cause various abnormal
indications, such as:
[[Page 3738]]
1. flashing of the landing gear green locked down advisory lights
during cruise;
2. fluctuation of cabin pressurization rate needle during cruise;
3. retraction and extension of roll and ground spoilers during
ground operation;
4. loss of nose landing gear steering subsequent to landing; and
5. loss of wheel brakes below 35-40 knots.
The AFM revision advises the flight crew that, if any of these
abnormal indications are observed, they must select the ``A/COL light
switch--RED,'' and leave the switch in this position for the remainder
of the flight.
The flight crew and maintenance procedures that are required by AD
94-22-10 are described in De Havilland Alert Service Bulletin S.B. A8-
33-33, dated May 31, 1993. These procedures are intended to detect
faulty power supply units. The alert service bulletin also describes
procedures for replacement of any faulty ``Grimes'' unit with either a
new or serviceable ``Grimes'' unit or a new ``Whelan'' system
(Modification 8/1273).
The terminating modification that is required by AD 94-22-10 is
described in De Havilland Service Bulletin S/B 8-33-19, ``Revision A'',
dated May 31, 1993. This modification (Modification 8/1273) entails
replacing the existing anti-collision strobe light system (consisting
of anti-collision strobe lights, brackets, and power supplies) at all
three locations with a new, improved ``Whelan'' anti-collision strobe
light system. (The ``Whelan'' system includes new dual strobes, new
brackets, and new power supplies.) This new system is considered more
durable than the currently installed anti-collision strobe light
system. The ``Whelan'' system also has a back-up strobe light at each
position.
Subsequent to the issuance of AD 94-22-10, the FAA identified a
typographical error in the applicability of the rule: The applicability
statement of the AD listed ``de Havilland Model DHC-8-302'' as a series
of airplanes that is subject to the requirements of the rule; however,
that model should have been listed as ``de Havilland Model DHC-8-301.''
This airplane model is manufactured in Canada and is type certificated
for operation in the United States under the provisions of Section
21.29 of the Federal Aviation Regulations and the applicable bilateral
airworthiness agreement.
Note: There is no ``Model DHC-8-302'' that is currently type
certificated.
The FAA has determined that the unsafe condition addressed by AD
94-22-10 is likely to exist or develop in Model DHC-8-301 series
airplanes. Therefore, AD 94-22-10 must be revised to correctly add
these airplanes to its applicability, thereby making them subject to
its requirements.
There currently are no Model DHC-8-301 series airplanes on the U.S.
Register, however. These airplanes are operated currently by non-U.S.
operators under foreign registry; therefore, they are not directly
affected by this AD action. However, the FAA considers that this
revision to the existing AD is necessary to ensure that the unsafe
condition is addressed in the event that any of these airplanes are
imported and placed on the U.S. Register in the future.
Should an affected Model DHC-8-301 series airplane be imported and
placed on the U.S. Register in the future, it would require
approximately 16 work hours to accomplish the required actions, at an
average labor charge of $60 per work hour. Required parts for
installation of Modification 8/1273 at all three locations would cost
approximately $1,397 per airplane. Based on these figures, the total
cost impact of this AD on an operator of a Model DHC-8-301 series
airplane would be $2,357 per airplane.
(The current requirements of AD 94-24-01 affect approximately 74
airplanes of U.S. registry. Accomplishment of the currently required
actions take approximately 16 work hours per airplane, at an average
labor rate of $60 per airplane. Required parts for installation of
Modification 8/1273 at all three locations cost approximately $1,397
per airplane. Based on these figures, the total cost impact of the
current requirements of this rule on U.S. operators is estimated to be
$174,418, or $2,357 per airplane.)
Since this revision action does not affect any airplane that is
currently on the U.S. register, it has no adverse economic impact and
imposes no additional burden on any person. Therefore, notice and
public procedures hereon are unnecessary and the amendment may be made
effective in less than 30 days after publication in the Federal
Register.
Comments Invited
Although this action is in the form of a final rule and was not
preceded by notice and opportunity for public comment, comments are
invited on this rule. Interested persons are invited to comment on this
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 under the caption
ADDRESSES. All communications received on or before the closing date
for comments will be considered, and this rule may be amended in light
of the comments received. Factual information that supports the
commenter's ideas and suggestions is extremely helpful in evaluating
the effectiveness of the AD action and determining whether additional
rulemaking action would be needed.
Comments are specifically invited on the overall regulatory,
economic, environmental, and energy aspects of the rule that might
suggest a need to modify the 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 that
summarizes each FAA-public contact concerned with the substance of this
AD will be filed in the Rules Docket.
Commenters wishing the FAA to acknowledge receipt of their comments
submitted in response to this rule must submit a self-addressed,
stamped postcard on which the following statement is made: ``Comments
to Docket Number 94-NM-235-AD.'' The postcard will be date stamped and
returned to the commenter.
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.
[[Page 3739]]
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 removing amendment 39-9060 (59 FR
58765, November 15, 1994), and by adding a new airworthiness directive
(AD), amendment 39-9122, to read as follows:
94-22-10 R1 De Havilland: Amendment 39-9122. Docket 94-NM-235-AD.
Revises AD 94-22-10, Amendment 39-9060.
Applicability: Model DHC-8-102, -103, -301, and -311 series
airplanes, having 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 the applicable time specified in paragraph (a)(1) or
(a)(2) of this AD, revise the Limitations Section of the FAA-
approved Airplane Flight Manual (AFM) to include the following
statement. The revision of the AFM 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.''
(1) For Model DHC-8-102, -103, and -311 series airplanes:
Accomplish the revision of the AFM within 30 days after December 15,
1994 (the effective date of AD 94-22-01, amendment 39-9060),
(2) For Model DHC-8-301 series airplanes: Accomplish the
revision of the AFM within 30 days after the effective date of this
amendment.
(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, following 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
Secs. 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 previously by the Director of the Federal Register, in
accordance with 5 U.S.C. 552(a) and 1 CFR part 51, as of December
15, 1994 (59 FR 58765, November 15, 1994). 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 February 3, 1995.
Issued in Renton, Washington, on January 11, 1995.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 95-1127 Filed 1-18-95; 8:45 am]
BILLING CODE 4910-13-M
