AD Amdt-39-9713

[Federal Register Volume 61, Number 161 (Monday, August 19, 1996)]
[Rules and Regulations]
[Pages 42773-42776]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 96-20672]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 96-NM-181-AD; Amendment 39-9713; AD 96-17-05]
RIN 2120-AA64


Airworthiness Directives; Saab Model SAAB SF340A and SAAB 340B 
Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule; request for comments.

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SUMMARY: This amendment adopts a new airworthiness directive (AD) that 
is applicable to certain Saab Model SAAB SF340A and SAAB 340B series 
airplanes. This action requires the installation of a mechanical flight 
idle stop on the control quadrant of the flight compartment. This 
action also requires a revision of the Airplane Flight Manual to ensure 
the use of certain operating procedures after the mechanical flight 
idle stop is installed. Additionally, this action provides an optional 
terminating action for the requirements of this AD. This amendment is 
prompted by a report indicating that the means of protection against 
the selection of the ``beta'' range of propeller operation during 
flight has been reduced on certain modified control quadrants. 
Additionally, there have been reports indicating that power levers on 
the control quadrant have been moved aft of the flight idle position 
during flight due to improper usage of the mechanical beta stop. The 
actions specified in this AD are intended to prevent such movement of 
the power lever(s) during flight, which could result in propeller 
overspeed, engine damage, and loss of power to one or both engines.

DATES: Effective September 3, 1996.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of September 3, 1996.
    Comments for inclusion in the Rules Docket must be received on or 
before October 18, 1996.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-103, 
Attention: Rules Docket No. 96-NM-181-AD, 1601 Lind Avenue, SW., 
Renton, Washington 98055-4056.
    The service information referenced in this AD may be obtained from 
SAAB Aircraft AF, SAAB Aircraft Product Support, S-581.88, Linkping, 
Sweden. This information may be examined at the FAA, Transport Airplane 
Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the 
Office of the Federal Register, 800 North Capitol Street, NW., suite 
700, Washington, DC.

FOR FURTHER INFORMATION CONTACT: Ruth E. Harder, Aerospace Engineer, 
Standardization Branch, ANM-113, FAA, Transport Airplane Directorate, 
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (206) 
227-1721; fax (206) 227-1149.

SUPPLEMENTARY INFORMATION: The FAA has received a report from an 
operator of a Model SAAB 340B series airplane indicating that, during 
training, the flightcrew noticed a reduction in the protection 
associated with movement of the power levers aft of the flight idle 
position during flight. Moving the power lever settings aft of the 
flight idle position (or ``below flight idle'') places the airplane in 
the ``beta'' range of operation. ``Beta'' is the range of propeller 
operation intended for use only during taxi, ground idle, or reverse 
operations. If ``beta'' range is selected, either intentionally or 
inadvertently, during flight, it could result in propeller

[[Page 42774]]

overspeed, engine damage, and loss of power to one or both engines.

Automatic Flight Idle Stop Modification

    The airplane involved in the incident referred to above was 
equipped with a modified control quadrant. The installation of a new 
control quadrant is described in Saab Service Bulletins 340-76-032 and 
340-76-037, and is part of the modification necessary to install an 
automatic flight idle stop system that will automatically prevent 
movement of the power levers aft of flight idle during flight.
    The modification also entails the removal of a certain beta stop 
protection device that was a basic original feature of the Saab Model 
340 series airplanes. This original protection device featured 
serrations in the power lever assembly that helped to prevent the 
inadvertent movement of the power levers aft of the flight idle 
position. The modified control quadrant does not provide these 
serrations, however, and thus eliminates what would serve as a ``back-
up'' feature for beta stop protection. This is not an issue of concern 
on airplanes where the automatic flight idle stop system has been 
installed and activated. However, for airplanes on which the modified 
control quadrant is installed, but the automatic flight idle stop 
system is not yet activated, beta stop protection is even further 
reduced.

Mechanical Flight Idle Stop Modification

    Some Saab Model 340 series airplanes have been modified with the 
installation of a mechanical beta stop mechanism on the control 
quadrant in accordance with Saab Service Bulletin 340-76-034. 
(Procedures for installing a mechanical stop are also described in Saab 
Service Bulletins 340-76-036 and 240-76-037.) This mechanical stop is 
manually operated and, if used, prevents any power lever from being 
unintentionally moved into beta range during retardation of the power 
lever during flight. It is considered to be an interim improvement in 
beta protection until the automatic flight idle stop system is 
installed and activated.
    While this mechanical stop serves as a means of beta protection, 
the FAA has received several reports indicating that the flight crew 
did not use the mechanical stop, or used it improperly, and moved the 
power levers into the beta range during flight.

Explanation of Relevant Service Information

    Saab has issued the following service bulletins that pertain to 
beta protection devices:
    1. Saab Service Bulletin 340-76-034, dated January 4, 1995, 
describes procedures for installation of a mechanical flight idle stop 
on the control quadrant in the flight compartment. Accomplishment of 
this installation is intended to prevent the power levers from being 
moved aft of the flight idle stop during flight. The Luftfartsverket 
(LFV), the airworthiness authority for Sweden, has classified this 
service bulletin as mandatory and issued Swedish airworthiness 
directive 1-067, dated January 9, 1995, in order to assure the 
continued airworthiness of these airplanes in Sweden.
    2. Saab Service Bulletin 340-76-032, Revision 2, dated December 8, 
1995; and Revision 3, dated March 25, 1996; describe procedures for 
installation and activation of an automatic flight idle stop system on 
the control quadrant in the flight compartment.
    The installation involves:

--Removing the mechanical beta stop (if installed),
--Removing the old control quadrant,
--Installing a new/modified control quadrant with an automatic flight 
idle stop, and
--Accomplishing a functional test of the flight idle stop system.

    Accomplishment of this installation also will prevent the power 
levers from being moved aft of the flight idle stop during flight. 
Installation and activation of an automatic flight idle stop, if 
accomplished, eliminates the need for installation of a mechanical 
flight idle stop. The LFV classified this service bulletin as mandatory 
and issued Swedish airworthiness directive 1-070, dated April 10, 1995, 
in order to assure the continued airworthiness of these airplanes in 
Sweden.
    3. Saab Service Bulletin 340-76-038, dated December 8, 1995, 
describes procedures to reactivate the automatic flight idle stop 
system for those systems that have been installed previously, but 
deactivated in accordance with Saab Service Bulletin 340-76-036. If 
accomplished, such reactivation also eliminates the need for 
installation of a mechanical flight idle stop. The LFV has approved the 
technical content of this service bulletin.

U.S. Type Certification of the Airplanes

    Saab Model SAAB SF340A and SAAB 340B series airplanes are 
manufactured in Sweden 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.

Explanation of Requirements of 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, this AD is being issued to prevent movement of 
the power lever(s) aft of the flight idle position during flight. That 
situation could result in the overspeed of the propeller and power 
turbine of the engines and consequent loss of power to one or both 
engines, as well as severe engine damage.
    This AD requires the installation of the mechanical flight idle 
stop on the control quadrant in the flight compartment in accordance 
with Saab Service Bulletin 340-76-034, described previously.
    To prevent inappropriate usage of this mechanical stop, this AD 
also requires that the FAA-approved Airplane Flight Manual (AFM) be 
revised to ensure that the flight crews are advised of the specific 
limitations necessary to address flight operations when the mechanical 
flight idle stop is installed.
    Additionally, this AD provides for optional terminating action for 
the requirements of this AD, as installation of the modified control 
quadrant and activation of the automatic flight idle stop.

Determination of Rule's Effective Date

    Since a situation exists that requires the immediate adoption of 
this regulation, it is found that notice and opportunity for prior 
public comment hereon are impracticable, and that good cause exists for 
making this amendment effective in less than 30 days.

Interim Action

    This AD is considered to be interim action. On March 15, 1996, the 
FAA issued a notice of proposed rulemaking (NPRM), Docket 95-NM-243-AD 
(61 FR 11591, March 21, 1996), to require installation and activation 
of the automatic flight idle stop on certain Saab Model SAAB SF340A and 
SAAB 340B series airplanes. However, the FAA has determined that the 
mechanical flight idle stop, as required by this AD, must be provided 
for certain airplanes in the interim until the automatic flight idle 
stops are installed and activated.

Comments Invited

    Although this action is in the form of a final rule that involves 
requirements affecting flight safety and, thus, was not preceded by 
notice and an 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

[[Page 42775]]

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 96-NM-181-AD.'' The postcard will be date stamped and 
returned to the commenter.

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.
    The FAA has determined that this regulation is an emergency 
regulation that must be issued immediately to correct an unsafe 
condition in aircraft, and that it is not a ``significant regulatory 
action'' under Executive Order 12866. It has been determined further 
that this action involves an emergency regulation under DOT Regulatory 
Policies and Procedures (44 FR 11034, February 26, 1979). If it is 
determined that this emergency regulation otherwise would be 
significant under DOT Regulatory Policies and Procedures, a final 
regulatory evaluation will be prepared and placed in the Rules Docket. 
A copy of it, if filed, 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:

96-17-05 SAAB Aircraft AB:  Amendment 39-9713. Docket 96-NM-181-AD.

    Applicability: Model SAAB SF340A and SAAB 340B series airplanes 
on which Saab Service Bulletin 340-76-034, dated January 4, 1995; 
Saab Service Bulletin 340-76-036, dated December 8, 1995; or Saab 
Service Bulletin 340-76-037, dated December 8, 1995, have been 
accomplished; certificated in any category.

    Note 1: This AD applies to each airplane identified in the 
preceding applicability provision, regardless of whether it has been 
otherwise 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 (d) 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 the movement of both power levers aft of the flight 
idle stop during flight, accomplish the following:
    (a) For airplanes on which an automatic flight idle stop system 
has been installed, but deactivated in accordance with Saab Service 
Bulletin 340-76-036, dated December 8, 1995; or on which a control 
quadrant in the flight compartment has been installed in accordance 
with Saab Service Bulletin 340-76-037, dated December 8, 1995: 
Within 7 days after the effective date of this AD, install a 
mechanical flight idle stop on the control quadrant in the flight 
compartment in accordance with Saab Service Bulletin 340-76-034, 
dated January 4, 1995, and accomplish the requirements of paragraph 
(b) of this AD.
    (b) For airplanes subject to paragraph (a) of this AD; and for 
airplanes on which a mechanical flight idle stop has been installed 
on the control panel in accordance with Saab Service Bulletin 340-
76-034, dated January 4, 1995, previous to the effective date of 
this AD: Within 7 days after the effective date of this AD, revise 
the Limitations Section of the FAA-approved Airplane Flight Manual 
(AFM) to include the following operating limitations. This may be 
accomplished by inserting a copy of this AD in the AFM.

``Mechanical Beta Stop Operating Limitations

--The stop must be in the beta open position during all ground 
operations including takeoff run.
--The stop must be lifted and positioned fully forward and down in 
the beta stop position during climb-out after take-off.
--The stop must remain in the beta stop position throughout the 
remainder of the flight until after touchdown.
--The stop must be lifted and positioned in the beta open position 
immediately after touchdown.
--Landing Field Lengths Required must be increased by 5% and 8% for 
flap settings 35 and 20, respectively.''

    (c) Installation and activation of the automatic flight idle 
stop system in accordance with Saab Service Bulletin 340-76-032, 
Revision 2, dated December 8, 1995, or Revision 3, dated March 25, 
1996; or reactivation of the system in accordance with Saab Service 
Bulletin 340-76-038, dated December 8, 1995; constitute terminating 
action for the requirements of this AD. Once the system has been 
activated, the mechanical flight idle stop and the AFM revision 
required by 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, Standardization Branch, ANM-113, 
FAA Transport Airport Directorate. Operators shall submit their 
requests through an appropriate FAA Principal Maintenance Inspector, 
who may add comments and then send it to the Manager, 
Standardization Branch, ANM-113.

    Note 2: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Standardization Branch, ANM-113.

    (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 installation of the mechanical flight idle stop shall be 
done in accordance with Saab Service Bulletin 340-76-034, dated 
January 4, 1995. The installation and activation of the automatic 
flight idle stop system shall be done in accordance with Saab 
Service Bulletin 340-76-032, Revision 2, dated December 8, 1995; or 
Saab Service Bulletin 340-76-032, Revision 3, dated March 25, 1996. 
The reactivation of the system shall be done in accordance with Saab 
Service Bulletin 340-76-038, dated

[[Page 42776]]

December 8, 1995. 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 SAAB Aircraft 
AB, SAAB Aircraft Product Support, S-581.88, Linkoping, Sweden. 
Copies may be inspected at the FAA, Transport Airplane Directorate, 
1601 Lind Avenue, SW., Renton, Washington; or at the Office of the 
Federal Register, 800 North Capitol Street, NW., suite 700, 
Washington, DC.
    (g) This amendment becomes effective on September 3, 1996.

    Issued in Renton, Washington, on August 7, 1996.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 96-20672 Filed 8-16-96; 8:45 am]
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