[Federal Register Volume 64, Number 147 (Monday, August 2, 1999)]
[Rules and Regulations]
[Pages 41778-41780]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-19297]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 98-NM-372-AD; Amendment 39-11238; AD 99-16-03]
RIN 2120-AA64
Airworthiness Directives; Learjet Model 23, 24, 25, 28, 29, 31,
55, and 60 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 Learjet Model 23, 24, 25, 28, 29, 31, 55, and 60
series airplanes, that requires a one-time detailed visual inspection
of the electrical wire leads of the horizontal stabilizer anti-ice
system to verify that the numbers on the wire leads correctly
correspond to the numbers on the connected airframe wiring;
installation of a wire ID strap on the left-and right-hand sides of
each terminal block; and installation of a warning placard. This
amendment is prompted by a report of severe flight control buffeting of
a Learjet Model 55 series airplane due to a malfunction of the
horizontal stabilizer anti-ice system. The actions specified by this AD
are intended to prevent undetected accretion of ice on the leading edge
of the horizontal
[[Page 41779]]
stabilizer, which could result in the loss of pitch control and
consequent reduced controllability of the airplane.
DATES: Effective September 7, 1999.
The incorporation by reference of certain publications listed in
the regulations is approved by the Director of the Federal Register as
of September 7, 1999.
ADDRESSES: The service information referenced in this AD may be
obtained from Learjet, Inc., One Learjet Way, Wichita, Kansas 67209-
2942. 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, Small
Airplane Directorate, Wichita Aircraft Certification Office, 1801
Airport Road, Room 100, Mid-Continent Airport, Wichita, Kansas; or at
the Office of the Federal Register, 800 North Capitol Street, NW.,
suite 700, Washington, DC.
FOR FURTHER INFORMATION CONTACT: Jose Flores, Senior Aerospace
Engineer, Systems and Propulsion Branch, ACE-116W, FAA, Small Airplane
Directorate, Wichita Aircraft Certification Office, 1801 Airport Road,
Room 100, Mid-Continent Airport, Wichita, Kansas 67209; telephone (316)
946-4133; fax (316) 946-4407.
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 Learjet Model 23, 24, 25,
28, 29, 31, 55, and 60 series airplanes was published in the Federal
Register on May 17, 1999 (64 FR 26703). That action proposed to require
a one-time detailed visual inspection of the electrical wire leads of
the horizontal stabilizer anti-ice system to verify that the numbers on
the wire leads correctly correspond to the numbers on the connected
airframe wiring; installation of a wire ID strap on the left-and right-
hand sides of each terminal block; and installation of a warning
placard.
Comments
Interested persons have been afforded an opportunity to participate
in the making of this amendment. No comments were submitted in response
to the proposal or the FAA's determination of the cost to the public.
Conclusion
The FAA has determined that air safety and the public interest
require the adoption of the rule as proposed.
Cost Impact
There are approximately 1,010 airplanes of the affected design in
the worldwide fleet. The FAA estimates that 806 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 inspection and
installations, and that the average labor rate is $60 per work hour.
Required parts will be provided by the manufacturer at no cost to the
operators. Based on these figures, the cost impact of the required AD
on U.S. operators is estimated to be $48,360, or $60 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 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. 106(g), 40113, 44701.
Sec. 39.13 [Amended]
2. Section 39.13 is amended by adding the following new
airworthiness directive:
99-16-03 Learjet: Amendment 39-11238. Docket 98-NM-372-AD.
Applicability: Model 23, 24, 25, 28, 29, 31, 55, and 60 series
airplanes; as listed in Learjet Service Bulletins SB 23/24/25-30-3,
SB 28/29-30-3, SB 31-30-05, SB 55-30-3, and SB 60-30-4, all dated
October 27, 1998; 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 (b) 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 undetected accretion of ice on the leading edge of
the horizontal stabilizer, which could result in the loss of pitch
control and consequent reduced controllability of the airplane,
accomplish the following:
One-Time Inspection
(a) Within 100 flight hours after the effective date of this AD:
Perform a one-time detailed visual inspection of the electrical wire
leads of the horizontal stabilizer anti-ice system to verify that
the numbers on the wire leads correctly correspond to the numbers on
the connected airframe wiring, in accordance with Learjet Service
Bulletins SB 23/24/25-30-3, (for Model 23, 24, and 25 series
airplanes), SB 28/29-30-3 (for Model 28 and 29 series airplanes), SB
31-30-5 (for Model 31 series airplanes), SB 55-30-3 (for Model 55
series airplanes), or SB 60-30-4 (for Model 60 series airplanes);
all dated October 27, 1998; as applicable.
Note 2: For the purposes of this AD, a detailed inspection is
defined as: ``An intensive visual examination of a specific
structural area, system, installation or assembly to detect damage,
failure or irregularity. Available lighting is normally supplemented
with a direct source of good lighting at intensity deemed
appropriate by the inspector. Inspection aids such as mirror,
magnifying lenses, etc. may be used. Surface cleaning and elaborate
access procedures may be required.''
[[Page 41780]]
Corrective Action
(1) If no discrepancy is detected during the inspection required
by paragraph (a) of this AD: Concurrent with the inspection, install
a wire ID strap on the left-and right-hand sides of each terminal
block, and install a warning placard on each terminal block, in
accordance with the applicable service bulletin.
(2) If any discrepancy is detected during the inspection
required by paragraph (a) of this AD: Prior to further flight,
repair the discrepancy in accordance with the procedures specified
in Chapter 30 of the Learjet Airplane Wiring Manual. Concurrent with
the repair, install a wire ID strap on the left-and right-hand sides
of each terminal block, and install a warning placard on each
terminal block; in accordance with the applicable service bulletin.
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, Wichita Aircraft Certification
Office (ACO), FAA, Small 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, Wichita ACO.
Note 3: Information concerning the existence of approved
alternative methods of compliance with this AD, if any, may be
obtained from the Wichita ACO.
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.
Incorporation by Reference
(d) Except as provided by paragraph (a)(2) of this AD, the
actions shall be done in accordance with Learjet Service Bulletin SB
23/24/25-30-3, dated October 27, 1998; Learjet Service Bulletin SB
28/29-30-3, dated October 27, 1998; Learjet Service Bulletin SB 31-
30-5, dated October 27, 1998; Learjet Service Bulletin SB 55-30-3,
dated October 27, 1998; or Learjet Service Bulletin SB 60-30-4,
dated October 27, 1998, 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 Learjet, Inc., One Learjet Way, Wichita, Kansas 67209-
2942. Copies may be inspected at the FAA, Transport Airplane
Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the
FAA, Small Airplane Directorate, Wichita Aircraft Certification
Office, 1801 Airport Road, Room 100, Mid-Continent Airport, Wichita,
Kansas; or at the Office of the Federal Register, 800 North Capitol
Street, NW., suite 700, Washington, DC.
(e) This amendment becomes effective on September 7, 1999.
Issued in Renton, Washington, on July 22, 1999.
D. L. Riggin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 99-19297 Filed 7-30-99; 8:45 am]
BILLING CODE 4910-13-U
