[Federal Register Volume 59, Number 249 (Thursday, December 29, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-32033]


[[Page Unknown]]

[Federal Register: December 29, 1994]


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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 94-NM-151-AD]

 

Airworthiness Directives; Jetstream Model ATP Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes the supersedure of an existing 
airworthiness directive (AD), applicable to all Jetstream Model ATP 
airplanes, that currently requires revising the Airplane Flight Manual 
(AFM) to prohibit flight in certain freezing precipitation conditions. 
This action would add a requirement to install certain modifications of 
the engine air intake system. This proposal is prompted by the 
development of certain modifications of the engine air intake system 
intended to permit operation of these airplanes in freezing 
precipitation conditions. The actions specified by the proposed AD are 
intended to prevent engine power rollback in flight during freezing 
precipitation conditions.

DATES: Comments must be received by February 9, 1995.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-103, 
Attention: Rules Docket No. 94-NM-151-AD, 1601 Lind Avenue, SW., 
Renton, Washington 98055-4056. Comments may be inspected at this 
location between 9:00 a.m. and 3:00 p.m., Monday through Friday, except 
Federal holidays. -
    The service information referenced in the proposed rule may be 
obtained from Jetstream Aircraft, Inc., P.O. Box 16029, Dulles 
International Airport, Washington, DC 20041-6029. This information may 
be examined at the FAA, Transport Airplane Directorate, 1601 Lind 
Avenue, SW., Renton, Washington.

FOR FURTHER INFORMATION CONTACT: William Schroeder, Aerospace Engineer, 
Standardization Branch, ANM-113, FAA, Transport Airplane Directorate, 
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (206) 
227-2148; fax (206) 227-1320.

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 filed in 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 94-NM-151-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-103, Attention: Rules 
Docket No. 94-NM-151-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    On March 31, 1994, the FAA issued AD 94-08-01, amendment 39-8872 
(59 FR 25290, May 16, 1994), applicable to all British Aerospace Model 
ATP airplanes, which requires revision of the Limitations Section of 
the FAA-approved Airplane Flight Manual (AFM) Limitations Section to 
prohibit flight in certain freezing precipitation conditions. That 
action was prompted by reports of engine power rollback (loss of engine 
power) that occurred during flight in environmental conditions 
involving freezing precipitation. The required AFM revision was 
intended as an interim measure to prevent loss of multiple engine power 
during flight in freezing precipitation.
    AD 94-08-01 also provided for certain optional actions that, when 
all of them were accomplished, would terminate the required prohibition 
of flight into certain icing conditions. These actions were:
    1. Revising the Limitations Section and the Normal Procedures 
Section of the FAA-approved AFM to include specific procedures for 
operation in icing conditions;
    2. Incorporating a revision into the FAA-approved maintenance 
program that provides for replacement of engine igniter plugs at 
specific intervals;
    3. Installing an eductor plate over the exhaust port of the engine 
air intake system;
    4. Installing engine air inlet ducts that incorporate electrical 
de-ice heaters, and perform associated electrical system changes; and
    5. Revising the FAA-approved maintenance program to include 
repetitive visual inspections of the heater mats for damage at specific 
intervals.
    In the preamble to AD 94-08-01, the FAA indicated that the actions 
required by that AD were considered ``interim action'' and that further 
rulemaking action was being considered. The FAA has now determined that 
the installation of these previously optional modifications and certain 
revision of the AFM will positively address the unsafe condition that 
is the subject of AD 94-08-01 by preventing loss of engine power during 
flight in freezing precipitation. The actions proposed in this notice 
follow from that determination.
    Since the issuance of AD 94-08-01, Jetstream has issued two 
revisions of the Limitations, Normal Procedures, and Abnormal 
Procedures Sections of the AFM to include the information specified in 
Temporary Revision T/33, Issue 1, dated November 1, 1993; and Temporary 
Revision T/38, Issue 1, dated February 16, 1994. These documents 
provide procedures to the flight crew for operation in icing 
conditions.
    Jetstream Service Bulletin ATP-80-06, Revision 2, dated October 16, 
1994, describes procedures for replacing the engine igniter plug at 
repetitive intervals.
    Additionally, Jetstream has issued three service bulletins 
describing various actions that, if accomplished, eliminate the need 
for the repetitive replacement of the engine igniter plugs. These 
service bulletins are:
    1. Jetstream ATP-30-39-30146A, dated July 29, 1994, which describes 
procedures for installation of new de-ice timers on both engines.
    2. Jetstream ATP-30-37-30143A, dated August 1, 1994; and Revision 
1, dated September 5, 1994; which describe procedures for associated 
wiring changes to the automatic duct heat.
    3. Jetstream ATP-80-7-30141A, Revision 2, dated November 4, 1994, 
which describes procedures for installation of an automatic ignition 
system for the engine and revision of the Airplane Flight Manual by 
installation of information in Temporary Revision T/42, Issue 1, dated 
August 12, 1994.
    Jetstream also has issued Service Bulletins ATP-54-12-35274A, dated 
September 28, 1993; and Revision 1, dated December 15, 1993; which 
describe procedures for installation of an eductor plate over the 
exhaust port of the engine air intake system. (Revision 1 of this 
service bulletin contains additional procedures for an inspection to 
detect any aperture profile mismatch on any eductor plate that was 
installed in accordance with the original issue of the service 
bulletin.)
    Additionally, Jetstream has issued Service Bulletins ATP-54-13-
35274B, Revision 1 (Modification 35274B), dated July 8, 1994; and 
Revision 2, dated August 18, 1994; which describe procedures for 
installing an improved engine air intake modification. These service 
bulletins specify a separate modification configuration for each of two 
serial number blocks of airplanes. Revision 2 of this service bulletin 
also references an acceptable alternative modification of the engine 
air intake system (which is described in Jetstream Service Bulletin ATP 
54-15-35274E, dated July 27, 1994.) The Civil Aviation Authority (CAA), 
which is the airworthiness authority for the United Kingdom, has 
classified Jetstream Service Bulletin ATP-54-13-35274B, Revision 2, 
dated August 18, 1994, as mandatory in order to assure the continued 
airworthiness of these airplanes in the United Kingdom.
    Jetstream also has issued Service Bulletin ATP-54-14, dated October 
14, 1993, which describes procedures for repetitive visual inspections 
of the heater mats for damage, and replacement, if necessary.
    This airplane model is manufactured in the United Kingdom and is 
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 CAA has kept the FAA 
informed of the situation described above. The FAA has examined the 
findings of the CAA, 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.
    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 supersede AD 94-08-01 to 
require the following actions:
    1. Revision of the Limitations, Normal Procedures, and Abnormal 
Procedures Sections of the FAA-approved AFM to include the information 
specified in Temporary Revision T/33, Issue 1, dated November 1, 1993, 
and Temporary Revision T/38, Issue 1, dated February 16, 1994, which 
provide procedures for operation in icing conditions;
    2. Revision of the FAA-approved maintenance program to include 
replacement of engine igniter plugs at certain specified intervals;
    3. Installation of an eductor plate over the exhaust port of the 
engine air intake system;
    4. Installation of certain modifications of the engine air intake 
system; and
    5. Revision of the FAA-approved maintenance program to include 
repetitive visual inspections of the heater mats for damage at specific 
intervals, and replacement of the engine air intake, if necessary.
    These proposed actions would be required to be accomplished in 
accordance with the service bulletins described previously.
    This proposed AD would also provide for an optional terminating 
action for the proposed repetitive visual inspections of the heater 
mats on airplanes that have accomplished the alternative engine air 
intake modification in accordance with Jetstream Service Bulletin ATP-
54-15-35274E, dated July 27, 1994.
    This proposed AD would also provide optional terminating actions 
for the proposed requirement to repetitively replace the engine igniter 
plugs.
    Additionally, this action would revise the applicability of the 
proposed rule by limiting the affected airplanes to those called out in 
Jetstream Service Bulletin ATP 54-13-35274B, Revision 2, dated August 
18, 1994.
    As a result of recent communications with the Air Transport 
Association (ATA) of America, the FAA has learned that, in general, 
some operators may misunderstand the legal effect of AD's on airplanes 
that are identified in the applicability provision of the AD, but that 
have been altered or repaired in the area addressed by the AD. The FAA 
points out that all airplanes identified in the applicability provision 
of an AD are legally subject to the AD. If an airplane has been altered 
or repaired in the affected area in such a way as to affect compliance 
with the AD, the owner or operator is required to obtain FAA approval 
for an alternative method of compliance with the AD, in accordance with 
the paragraph of each AD that provides for such approvals. A note has 
been included in this notice to clarify this requirement.
    The FAA estimates that 10 airplanes of U.S. registry would be 
affected by this proposed AD, that it would take approximately 150 work 
hours per airplane to accomplish the proposed actions, and that the 
average labor rate is $60 per work hour. Required parts would be 
provided by the manufacturer at no cost to the operator. Based on these 
figures, the total cost impact of the proposed AD on U.S. operators is 
estimated to be $90,000, or $9,000 per airplane.
    The total 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.
    The regulations proposed herein would 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 
proposal would not have sufficient federalism implications to warrant 
the preparation of a Federalism Assessment.
    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. 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 39-8872 (59 FR 
25290, May 16, 1994), and by adding a new airworthiness directive (AD), 
to read as follows:

Jetstream Aircraft Limited (Formerly British Aerospace Commercial 
Aircraft, Limited): Docket 94-NM-151-AD. Supersedes AD 94-08-01, 
Amendment 39-8872.

    Applicability: Model ATP airplanes, as listed in Jetstream 
Service Bulletin ATP 54-13-35274B, Revision 2, dated August 18, 
1994, 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 use the authority 
provided in paragraph (e) to request approval from the FAA. This 
approval may address either no action, if the current configuration 
eliminates the unsafe condition; or different actions necessary to 
address the unsafe condition described in this AD. Such a request 
should include an assessment of the effect of the changed 
configuration on the unsafe condition addressed by this AD. In no 
case does the presence of any modification, alteration, or repair 
remove any airplane from the applicability of this AD.

    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent loss of multiple engine power during flight in 
freezing precipitation, accomplish the following:
    (a) Within 30 days after June 15, 1994 (the effective date of AD 
94-08-01, amendment 39-8872), 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 
in the AFM.
    ``Flight is prohibited into forecast or reported freezing 
precipitation conditions where the outside air temperature is 
between +5 deg.C and -5 deg.C.''
    (b) Within 72 days after the effective date of this AD, 
accomplish the actions specified in paragraphs (b)(1), (b)(2), 
(b)(3), (b)(4), (b)(5), and (b)(6), which will constitute 
terminating action for the AFM revision required by paragraph (a) of 
this AD. Once these actions are completed, the AFM revision required 
by paragraph (a) may be removed.
    (1) Revise the Limitations Section and the Normal Procedures 
Section of the FAA-approved AFM, to include the information 
specified in Temporary Revision T/33, Issue 1, dated November 1, 
1993, and Temporary Revision T/38, Issue 1, dated February 16, 1994, 
which introduce procedures for operation in icing conditions, as 
specified in the temporary revision; and operate the airplane in 
accordance with those limitations and procedures.

    Note 2: This may be accomplished by inserting copies of 
Temporary Revision T/33 and T/38 in the AFM. When these temporary 
revisions have been incorporated into general revisions of the AFM, 
the general revisions may be inserted in the AFM, provided the 
information contained in the general revision is identical to that 
specified in Temporary Revision T/33 and T/38.

    (2) Incorporate a revision into the FAA-approved maintenance 
program that provides for replacement of engine igniter plugs at the 
intervals specified in Jetstream Service Bulletin ATP-80-06, 
Revision 1, dated October 22, 1993, or Revision 2, dated October 16, 
1994. Initial replacement of an engine igniter plug with a new plug 
shall be accomplished prior to the accumulation of 200 total hours 
time-in-service on the engine igniter plug, or within 50 hours time-
in-service after incorporating the maintenance program revision, 
whichever occurs later.
    (3) Install an eductor plate over the exhaust port of the engine 
air intake system in accordance with Jetstream Service Bulletin ATP-
54-12-35274A, dated September 28, 1993, or Revision 1, dated 
December 15, 1993. Any eductor plate installed in accordance with 
the original issue of the service bulletin must be inspected for any 
aperture profile mismatch, in accordance with paragraph 2., Part B., 
of the Accomplishment Instructions of Revision 1 of the service 
bulletin. If any mismatch is found that exceeds the limit specified 
in that service bulletin, prior to further flight, the discrepancy 
must be corrected in accordance with paragraph 2., Part C, of 
Revision 1 of the service bulletin.
    (4) For airplanes having constructor numbers 2007, 2010 through 
2016 inclusive, 2020 through 2022 inclusive, 2028, 2029, 2032, 2034 
through 2037 inclusive, 2041 through 2044 inclusive, 2051, 2053, and 
2056: Install engine air inlet ducts that incorporate electrical de-
ice heaters with increased power and area, and perform associated 
electrical system changes, in accordance with the Accomplishment 
Instructions, in Jetstream Service Bulletin ATP-54-13-35274B dated 
October 9, 1993, or Parts A through F of Revision 1, dated July 8, 
1994, or Revision 2, dated August 18, 1994.
    (5) For airplanes having constructor numbers 2002 through 2006 
inclusive, 2008, 2009, 2017 through 2019 inclusive, 2023 through 
2027 inclusive, 2030, 2031, 2033, 2038 through 2040 inclusive, 2045 
through 2050 inclusive, 2052, 2054 through 2055 inclusive, and 2057 
through 2063 inclusive: Install engine air inlet ducts that 
incorporate electrical de-ice heaters with increased power, in 
accordance with the Accomplishment Instructions, Part G, of 
Jetstream Service Bulletin ATP-54-13-35274B, Revision 2, dated 
August 18, 1994.

    Note 3: Installation of engine air inlet ducts in accordance 
with Jetstream Service Bulletin ATP-54-15-35274E, dated July 27, 
1994, is considered acceptable for compliance with either paragraph 
(b)(4) or (b)(5) of this AD.

    (6) Revise the FAA-approved maintenance program to include 
repetitive visual inspections for damage of the heater mats at 
intervals not to exceed 50 hours time-in-service, in accordance with 
Jetstream Service Bulletin ATP-54-14, dated October 14, 1993; and, 
if any damage is found, prior to further flight, replace the engine 
air intake in accordance with the service bulletin.
    (c) The following installations on both engines constitute 
terminating action for the repetitive replacement of the engine 
igniter plugs required by paragraph (b)(2) of this AD:
    (1) Installation of new de-ice timers in accordance with 
Jetstream Service Bulletin ATP-30-39-30146A dated July 29, 1994,
    (2) Wiring changes to incorporate automatic duct heat when 
engine air intake lip heat is selected ``on,'' in accordance with 
Jetstream Service Bulletin ATP-30-37-30143A, dated August 1, 1994, 
or Revision 1, dated September 5, 1994, and
    (3) Installation of an engine automatic ignition system in 
accordance with Jetstream Service Bulletin ATP 80-7-30141A, Revision 
2, dated November 4, 1994; and an associated revision of the FAA-
approved Airplane Flight Manual (AFM) by incorporating the 
information contained in Temporary Revision T/42, Issue 1, dated 
August 12, 1994.
    (d) For airplanes on which the engine air intake (Modification 
35274E) has been installed in accordance with Jetstream Service 
Bulletin ATP-54-15-35274E, dated July 27, 1994: The installation of 
engine duct de-ice overheat protection (Modification 35274D) in 
accordance with Jetstream Service Bulletin ATP-30-44-35274D, dated 
August 12, 1994, constitutes terminating action for the repetitive 
inspections required by paragraph (b)(6) of this AD.
    (e) 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, Standardization Branch, ANM-113, 
FAA, Transport Airplane Directorate. Operators shall submit their 
requests through an appropriate FAA Principal Inspector, who may add 
comments and then send it to the Manager, Standardization Branch, 
ANM-113.

    Note 4: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Standardization Branch, ANM-113.

    (f) 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.

    Issued in Renton, Washington, on December 22, 1994.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 94-32033 Filed 12-28-94; 8:45 am]
BILLING CODE 4910-13-P