[Federal Register Volume 60, Number 198 (Friday, October 13, 1995)]
[Proposed Rules]
[Pages 53310-53312]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-25439]



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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 95-CE-30-AD]


Airworthiness Directives; HB Flugtechnik GmbH Model HB-23/2400 
Sailplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes to adopt a new airworthiness directive 
(AD) that would apply to HB Flugtechnik GmbH (Flugtechnik) Model HB-23/
2400 sailplanes. The proposed action would require inspecting (one 
time) the elevator control system for incorrect rigging and 
repetitively inspecting the threaded adjustable extension joints in the 
push rod to control lever connection for cracks, and, if cracked, 
replacing the threaded adjustable joints at both ends of the push rod. 
Cracking of the threaded adjustable extension joints and incorrect 
rigging of the elevator control system prompted the proposed action. 
The actions specified by the proposed AD are intended to prevent 
failure of the elevator control system, which, if not detected and 
corrected, could result in possible loss of elevator control and loss 
of the sailplane.

DATES: Comments must be received on or before December 14, 1995.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Central Region, 

[[Page 53311]]
Office of the Assistant Chief Counsel, Attention: Rules Docket No. 95-
CE-30-AD, Room 1558, 601 E. 12th Street, Kansas City, Missouri 64106. 
Comments may be inspected at this location between 8 a.m. and 4 p.m., 
Monday through Friday, holidays excepted.
    Service information that applies to the proposed AD may be obtained 
from HB Flugtechnik GmbH, Dr. Adolf Scharfstr, 42, PF 74, A-4053 Haid, 
Austria, telephone 43.7229.80904. This information also may be examined 
at the Rules Docket at the address above.

FOR FURTHER INFORMATION CONTACT: Mr. Herman Belderok, Sailplane Program 
Officer, Small Airplane Directorate, Airplane Certification Service, 
FAA, 1201 Walnut, suite 900, Kansas City, Missouri 64105; telephone 
(816) 426-6932; facsimile (816) 426-2169.

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 should 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 that summarizes 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 No. 95-CE-30-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, Central Region, Office of the Assistant Chief Counsel, 
Attention: Rules Docket No. 95-CE-30-AD, Room 1558, 601 E. 12th Street, 
Kansas City, Missouri 64106.

Discussion

    The Austro Control GmbH (ACG), which is the airworthiness authority 
for Austria, recently notified the FAA that an unsafe condition may 
exist on certain Flugtechnik Model HB-23/2400 sailplanes. The ACG 
advises that failure of the elevator control system has resulted in 
several incidents and two fatal accidents. Specifically, a fatal 
accident investigation revealed fatigue cracks in the threaded 
adjustable extension joint of the elevator control push rod, thereby 
causing loss of elevator control while in flight.
    In addition, the ACG has received several reports of deformation 
marks on the push rod tubes, bent adjustable extension joints, and 
jamming between the elevator control lever and the elevator push rod 
when the pilot pushes the control lever completely forward. Damage of 
this nature is possibly caused by incorrect rigging or having less than 
specified clearances between the elevator control lever and the 
elevator push rod. HB Flugtechnik GmbH has issued service bulletins 
(SB) HB-23/17/91 and HB-23/18/91, both dated October 28, 1991, 
specifying the following:

--Inspecting (one time) for bending, and dents on the elevator control 
push rod tube and replacing the elevator control push rod tube, if 
damaged,
--Inspecting the clearance between the elevator control lever and the 
elevator control push rod, ensuring the clearance remains at least 3 
mm,
--Inspecting the threaded portion of the adjustable push rod joints 
(located at each end of the push rod), for fatigue cracks and 
deformation, and if cracked or damaged, (based on the fatigue 
evaluation), replace the joints on both ends of the push rod.
--Repetitively inspecting, at intervals not to exceed 500 hours, the 
threaded portion of the adjustable push rod joints for cracks or 
deformation, and if cracked or damaged replacing the joints as 
necessary.

    The ACG classified these service bulletins as mandatory and issued 
ACG AD numbers 66 and 67 in order to assure the continued airworthiness 
of these sailplanes in Austria.
    This sailplane model is manufactured in Austria 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 between Austria and 
the United States. Pursuant to this bilateral airworthiness agreement, 
the ACG has kept the FAA informed of the situation described above. The 
FAA has examined the findings of the ACG, 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 in other Flugtechnik HB-23/2400 sailplanes of the same 
type design, the proposed AD would require inspecting (one time) the 
elevator control system for incorrect rigging, inspecting the threaded 
extension joints for cracks, if cracks are found, replacing the joints, 
and repetitively inspecting the extension joints at intervals not to 
exceed 500 hours time-in-service (TIS) thereafter for cracks or 
deformation, and if cracked or damaged replacing the joints as 
necessary.
    The FAA estimates that one sailplane in the U.S. registry would be 
affected by the proposed AD, that it would take approximately 3 hours 
to accomplish the proposed action, and that the average labor rate is 
approximately $60 an hour. Parts cost approximately $70 per sailplane. 
Based on these figures, the total cost impact of the proposed AD on 
U.S. operators is estimated to be $250. This figure is based on the 
assumption that the affected owner/operator of the affected sailplane 
has not incorporated the proposed modification or accomplished the 
proposed inspections. The FAA has no way of determining the number of 
repetitive inspections completed.
    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 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) 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 has been placed in the Rules Docket. A copy of 
it may be obtained by 

[[Page 53312]]
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 USC 106(g), 40101, 40113, 44701.


Sec.  39.13  [Amended]

    2. Section 39.13 is amended by adding a new airworthiness directive 
(AD) to read as follows:

HB Flugtechnik GMBH: Docket No. 95-CE-30-AD.

    Applicability: Model HB-23/2400 Sailplanes (serial numbers 23001 
through 23048), certificated in any category.

    Note 1: This AD applies to each sailplane 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 sailplanes 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 (f) 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 initially within the next 50 hours time-in-
service (TIS) after the effective date of this AD and as indicated 
in the body of this AD thereafter, unless already accomplished.
    To prevent failure of the elevator control system, which, if not 
detected and corrected, could result in possible loss of elevator 
control and loss of the sailplane, accomplish the following:
    (a) Inspect (one time) for bending, and dents on the elevator 
control push rod tube. Prior to further flight, replace the elevator 
control push rod tube in accordance with Flugtechnick Service 
Bulletin (SB) HB-23/18/91, dated October 28, 1991.
    (b) Inspect the clearance between the elevator control lever and 
the elevator control push rod, ensuring the clearance remains at 
least 3 mm. If clearance is not 3 mm, prior to further flight, 
adjust in accordance with the maintenance manual.
    (c) Inspect the threaded portion of the adjustable push rod 
joints (located at each end of the push rod) for fatigue cracks and 
deformation, and if cracked or damaged, (based on the fatigue 
evaluation), prior to further flight, replace the joints on both 
ends of the push rod, in accordance with Flugtechnick SB HB-23/17/
91, dated October 28, 1991.
    (d) Repetitively inspect the threaded portion of the adjustable 
push rod joints, at intervals not to exceed 500 hours time-in-
service (TIS) thereafter for cracks or deformation, and if cracked 
or damaged, prior to further flight, replace the joints as 
necessary, in accordance with Flugtechnick SB HB-23/17/91, dated 
October 28, 1991.
    (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 sailplane to a location where 
the requirements of this AD can be accomplished.
    (f) An alternative method of compliance or adjustment of the 
initial or repetitive compliance times that provides an equivalent 
level of safety may be approved by the Manager, Small Airplane 
Directorate, FAA, 1201 Walnut, Kansas City, Missouri, 64106. The 
request for the alternative method shall be forwarded through an 
appropriate FAA Maintenance Inspector, who may add comments and then 
send it to the Manager, Small Airplane Directorate.

    Note 2: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Small Airplane Directorate.

    (g) All persons affected by this directive may obtain copies of 
the documents referred to herein upon request to HB Flugtechnik 
GmbH, Dr. Adolf Scharfstr. 42, PF 74, A-4053 Haid, Austria, 
telephone 43.7229.80904, or may examine these documents at the FAA, 
Central Region, Office of the Assistant Chief Counsel, Room 1558, 
601 E. 12th Street, Kansas City, Missouri 64106.

    Issued in Kansas City, Missouri, on October 6, 1995.
Henry A. Armstrong,
Acting Manager, Small Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 95-25439 Filed 10-12-95; 8:45 am]
BILLING CODE 4910-13-U