AD Amdt-39-10908

[Federal Register Volume 63, Number 226 (Tuesday, November 24, 1998)]
[Rules and Regulations]
[Pages 64849-64854]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 98-31328]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-SW-45-AD; Amendment 39-10908; AD 98-21-09]


Airworthiness Directives; Robinson Helicopter Company Model R22 
Helicopters

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule; request for comments.

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SUMMARY: This document publishes in the Federal Register an amendment 
adopting Airworthiness Directive (AD) 98-21-09, which was sent 
previously to all known U.S. owners and operators of Robinson 
Helicopter Company (RHC) Model R22 helicopters by individual letters. 
This AD requires installing fuel tank vent tube(s), with modified 
attachment to the mast tube, if not previously accomplished; installing 
a spring into the flexible tube leading to the main fuel tank; and 
installing a spring into the flexible tube leading to the auxiliary 
fuel tank, if an auxiliary fuel tank is installed. This amendment is 
prompted by an incident in which the flexible vent connecting the rigid 
vent tube to the main fuel tank kinked, resulting in fuel starvation 
and a hard landing after uncommanded engine shutdown. The actions 
specified by this AD are intended to prevent fuel starvation, loss of 
engine power, and a subsequent forced landing.

DATES: Effective December 9, 1998, to all persons except those persons 
to whom it was made immediately effective by Priority Letter AD 98-21-
09, issued on September 28, 1998, which contained the requirements of 
this amendment.
    Comments for inclusion in the Rules Docket must be received on or 
before January 25, 1999.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Office of the Regional Counsel, Southwest Region, 
Attention: Rules Docket No. 98-SW-45-AD, 2601 Meacham Blvd., Room 663, 
Fort Worth, Texas 76137.

FOR FURTHER INFORMATION CONTACT: Ms. Elizabeth Bumann, Aerospace 
Engineer, FAA, Los Angeles Aircraft Certification Office, Propulsion 
Branch, 3960 Paramount Blvd., Lakewood, California 90712, telephone 
(562) 627-5265, fax (562) 627-5210.

SUPPLEMENTARY INFORMATION: On September 28, 1998, the FAA issued 
Priority Letter AD 98-21-09, applicable

[[Page 64850]]

to RHC Model R22 helicopters, which requires installing fuel tank vent 
tube(s), with modified attachment to the mast tube, if not previously 
accomplished; installing a spring into the flexible tube leading to the 
main fuel tank; and installing a spring into the flexible tube leading 
to the auxiliary fuel tank, if an auxiliary fuel tank is installed. 
That action was prompted by an incident in which a hard landing 
resulted from an uncommanded engine shutdown. The pilot reported that 
the fuel quantity gauges indicated fuel consumption from the auxiliary 
fuel tank only, with the main fuel tank indication remaining at or near 
full. When the auxiliary fuel tank quantity gauge reached empty, the 
engine misfired and then stopped. An inspection revealed a kink in the 
flexible vent tube connecting the rigid vent tube to the main fuel 
tank. Two similar incidents have occurred with this single vent design. 
This condition, if not corrected, could result in fuel starvation, loss 
of engine power, and a subsequent forced landing.
    The FAA has reviewed RHC R22 Service Bulletin SB-83 dated March 4, 
1997 (SB-83), which describes procedures for modifying attachment of 
the fuel tank vent(s); and RHC R22 Service Bulletin SB-84 dated 
September 8, 1998 (SB-84), which describes procedures for installing 
springs in the vent tubes to prevent kinks. RHC kit instructions KI-
118-1 R22 Fuel Tank Vent Upgrade For Ships Without Auxiliary Tank, 
dated March 4, 1997, and RHC KI-118-2 R22 Fuel Tank Vent Upgrade For 
Ships With Auxiliary Tank, dated April 29, 1997, which describe 
procedures for installing fuel tank vent tube(s), part number (P/N) 
A731-3, are attached to SB-83. RHC kit instructions KI-140 R22 Fuel 
Tank Vent Upgrade For Fuel Tanks With Single Vent, dated September 3, 
1998, which describe procedures for installing springs into the 
flexible tube leading to the main fuel tank, and, if an auxiliary fuel 
tank is installed, into the flexible tube leading to the auxiliary fuel 
tank, are attached to SB-84.
    Since the unsafe condition described is likely to exist or develop 
on other RHC Model R22 helicopters of the same type design, the FAA 
issued priority letter AD 98-21-09 to prevent fuel starvation, loss of 
engine power, and a subsequent forced landing. The AD requires, within 
25 hours time-in-service (TIS) or 30 calendar days after the effective 
date of this AD, whichever occurs first, installing fuel tank vent 
tube(s), P/N A731-3, with modified attachment to the mast tube, if not 
previously accomplished; installing a spring, P/N B408-2, into the 
flexible tube leading to the main fuel tank; and installing a spring, 
P/N B408-1, into the flexible tube leading to the auxiliary fuel tank, 
if an auxiliary fuel tank is installed. The short compliance time 
involved is required because the previously described critical unsafe 
condition can adversely affect the controllability of the helicopter. 
Therefore, the installations are required prior to further flight, and 
this AD must be issued immediately.
    Since it was found that immediate corrective action was required, 
notice and opportunity for prior public comment thereon were 
impracticable and contrary to the public interest, and good cause 
existed to make the AD effective immediately by individual letters 
issued on September 28, 1998, to all known U.S. owners and operators of 
RHC Model R22 helicopters. These conditions still exist, and the AD is 
hereby published in the Federal Register as an amendment to Sec. 39.13 
of the Federal Aviation Regulations (14 CFR 39.13) to make it effective 
to all persons.
    The only change to the priority letter in this published version of 
this AD is that the reference in Note 1 to the alternative methods of 
compliance is corrected from paragraph ``(d)'' to paragraph ``(c)''.
    The FAA estimates that 700 helicopters of U.S. registry will be 
affected by this AD, that it will take approximately 2 work hours per 
helicopter to accomplish the required actions, and the average labor 
rate is $60 per work hour. Required parts will cost approximately $65 
for each helicopter without an auxiliary fuel tank installed or $105 
for each helicopter with an auxiliary fuel tank installed. Based on 
these figures, the total cost impact of the AD on U.S. operators is 
estimated to be $225 per helicopter for helicopters with an auxiliary 
fuel tank installed, or $185 per helicopter for helicopters without an 
auxiliary fuel tank installed.

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 arguments as they may desire. 
Communications should 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 No. 98-SW-45-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.
    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, Safety.

Adoption of the Amendment

    Accordingly, pursuant to the authority delegated to me by the

[[Page 64851]]

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 a new airworthiness directive 
to read as follows:

98-21-09  Robinson Helicopter Company: Amendment 39-10908. Docket 
No. 98-WW-45-AD.

    Applicability: Model R22 helicopters, serial numbers 0002 
through 1451, inclusive, certificated in any category.

    Note 1: This AD applies to each helicopter 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 helicopters 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 (c) 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 helicopter from the applicability of this AD.

    Compliance: Required within 25 hours time-in-service or 30 
calendar days after the effective date of this AD, whichever occurs 
first, unless accomplished previously.
    To prevent fuel starvation, loss of engine power, and a 
subsequent forced landing, for helicopters overhauled by Robinson 
Helicopter Company (RHC) prior to January 1, 1991, which do not have 
a main fuel tank (only) with dual vent tubes, or, if the auxiliary 
fuel tank is installed, do not have a crossover vent tube between 
the fuel tanks, accomplish the following:
    (a) Visually inspect the fuel tank vent tube(s) in the mast 
fairing. If each fuel tank vent tube is attached only to the mast 
tube at two locations, the helicopter complies with the requirements 
of paragraph (a) of this AD. If each fuel tank vent tube is attached 
to the mast tube at one location, and to the rain scupper (channel), 
part number (P/N) A032-16, on the fuel tank cowling at another 
location:
    (1) For helicopters without an auxiliary fuel tank installed, 
remove the existing vent tube, P/N A731-1, and install an airworthy 
vent tube, P/N A731-3, with flexible tube, P/N A729-7, using an 
MS27039C0806 screw and AN960-8L washer (alternate P/N NAS1149FN816P) 
at the lower clamp, P/N A695-1 (see Figure 1).
    (2) For helicopters with an auxiliary fuel tank installed, 
remove the existing main fuel tank vent tube, P/N A731-1, and 
auxiliary fuel tank vent tube, P/N A731-2, and install airworthy 
vent tubes, P/N A731-3, with flexible tube, P/N A729-7, for main 
tank and flexible tube, P/N A729-17, for auxiliary tank using 
MS27039C0807 screw and AN960-8L washer (alternate P/N NAS1149FN816P) 
at lower clamp, P/N A695-1 (see Figure 2).
    (b) Install spring, P/N B408-2, into the flexible vent tube, P/N 
A729-7, leading to the main fuel tank; and install spring, P/N B408-
1, into the flexible vent tube, P/N A729-17, leading to the 
auxiliary fuel tank (if an auxiliary fuel tank is installed), in 
accordance with RHC kit instructions KI-140 R22 Fuel Tank Vent 
Upgrade For Fuel Tanks With Single Vent, dated September 3, 1998.

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    Note 2: RHC R22 Service Bulletin SB-83, dated March 4, 1997, and 
RHC R22 Service Bulletin SB-84, dated September 8,1998, pertain to 
the subject of this AD.

    (c) 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, Los Angeles Aircraft Certification 
Office, FAA. Operators shall submit their requests through an FAA 
Principal Maintenance Inspector, who may concur or comment and then 
send it to the Manager, Los Angeles Aircraft Certification Office.

    Note 3: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Los Angeles Aircraft Certification Office. 

    (d) 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 helicopter to a location where 
the requirements of this AD can be accomplished.
    (e) This amendment becomes effective on December 9, 1998, to all 
persons except those persons to whom it was made immediately 
effective by Priority Letter AD 98-21-09, issued September 28, 1998, 
which contained the requirements of this amendment.

    Issued in Fort Worth, Texas, on November 17, 1998.
Eric Bries,
Acting Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. 98-31328 Filed 11-23-98; 8:45 am]
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