[Federal Register Volume 60, Number 163 (Wednesday, August 23, 1995)]
[Proposed Rules]
[Pages 43727-43728]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-20876]
-----------------------------------------------------------------------
DEPARTMENT OF TRANSPORTATION
14 CFR Part 33
[Docket No. 95-ANE-46; Notice No. 33-ANE-05]
Special Conditions: Turbomeca Model Arriel 2S1 Turboshaft Engine
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Notice of proposed special conditions.
-----------------------------------------------------------------------
SUMMARY: This notice proposes special conditions for the Turbomeca
Model Arriel 2S1 turboshaft engine. This engine will have novel or
unique engine ratings that are not defined by the applicable
airworthiness regulations. This notice proposes the safety standards
for those novel or unique ratings that the Administrator considers
necessary to establish a level of safety equivalent to that established
by the airworthiness standards of part 33 of the Federal Aviation
Regulations (FAR).
DATES: Comments must be submitted on or before September 22, 1995.
ADDRESSES: Comments on this proposal may be submitted in triplicate to:
Federal Aviation Administration (FAA), New England Region, Office of
the Assistant Chief Counsel, Attn: Rules Docket No. 95-ANE-46, 12 New
England Executive Park, Burlington, Massachusetts 01803-5299. Comments
must be marked: Docket No. 95-ANE-46. Comments may be inspected at this
location between 8 a.m. and 4:30 p.m., Monday through Friday, except
Federal holidays.
FOR FURTHER INFORMATION CONTACT:
Chung Hsieh, Engine and Propeller Standards Staff, ANE-110, Engine and
propeller Directorate, Aircraft Certification Service FAA, New England
Region, 12 New England Executive Park, Burlington, Massachusetts 01803-
5229; (617) 238-7115; Fax (617) 238-7199.
SUPPLEMENTARY INFORMATION:
Comments Invited
Interested persons are invited to participate in the making of the
proposed special conditions 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 ADDRESSES. All communications received on or before the closing
date for comments, specified under DATES, will be considered by the
Administrator before taking action on the proposal. The proposal
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 special
conditions. All comments submitted will be available in the Rules
Docket for examination by interested persons, both before and after the
closing date for comments. A report summarizing each substantive public
contact with FAA personnel concerning this proposal will be filed in
the docket.
Comments wishing the FAA to acknowledge receipt of their comments
submitted in response to this notice must submit with those comments a
self addressed, stamped postcard on which the following statement is
made: ``Comments to Docket No. 95-ANE-46.'' The postcard will be date
stamped and returned to the commenter.
Background
On February 25, 1994, Turbomeca applied for an amendment to Type
Certificate No. E19EU to add a new Model Arriel 2S1 turboshaft engine.
The Model Arriel 2S1 turboshaft engine, a derivative of the Arriel 1
turboshaft engine will be rated at 30-Second OEI, 2-Minute one engine
inoparative (OEI), Continuous OEI, Takeoff, and Maximum Continuous
ratings.
The applicable airworthiness requirements do not contain 30-Second
OEI and 2-Minute OEI rating definitions, and do not contain adequate or
appropriate safety standards for the type certification of these new
and unusual engine ratings.
Type Certification Basis
Under the provisions of section 21.101 of the Federal Aviation
Regulations (FAR's) Turbomeca must show that the new Model Arriel 2S1
turboshaft engine meets the applicable provisions of the regulations
incorporated by reference in Type Certificate No. E19EU or the
applicable regulations in effect on the date of application. The FAR's
incorporated by reference in type Certificate No. E19EU are: Section
21.29 and part 33, effective February 1, 1965, as amended.
The Administrator finds that the applicable airworthiness
regulations in part 33, as amended, do not contain adequate or
appropriate safety standards for the Turbomeca Arriel 2S1 turboshaft
engine because of the new and unique engine ratings. Therefore, the
Administrator proposes special conditions under the provisions of
section 21.16 to establish a level of safety equivalent to that
established in the regulations.
Special conditions, as appropriate, are issued in accordance with
section 11.49 of the FAR after public notice and opportunity for
comment, as required by sections 11.28 and 11.29(b), and become part of
the type certification basis in accordance with section 21.17(a)(2).
Conclusion
This action affects only certain novel or unusual design features
on one model engine. It is not a rule of general
[[Page 43728]]
applicability and affects only the manufacturer who applied to the FAA
for approval of these features on the engine.
List of Subjects in 14 CFR Part 33
Air transportation, Aircraft, Aviation safety, Safety.
The authority citation for these special conditions is as follows:
Authority: 49 U.S.C. App. 1354(a), 1421, 1423; 49 U.S.C. 106(g).
The Proposed Special Conditions
Accordingly, the Federal Aviation Administration (FAA) proposes the
following special conditions as part of the type certification basis
for the Turbomeca Arriel 2S1 turboshaft engine:
(a) In addition to the requirements of section 33.7, the following
ratings are defined as:
(1) RATED 30-SECOND ONE-ENGINE-INOPERATIVE (OEI) POWER: The
approved brake horsepower developed statically in standard
atmosphere at sea level, or at a specified altitude and temperature,
for continued one-flight operation after the failure of one engine
in multi-engine rotorcraft, limited to three periods of use, no
greater than 30 seconds each, at rotor shaft rotation speed and gas
temperature established for this rating by part 33 or this special
condition.
(2) RATED 2-MINUTE OEI POWER: The approved brake horsepower,
developed statically in standard atmosphere at sea level, or at a
specified altitude and temperature, for continued one-flight
operation, after failure of one engine in multi-engine rotorcraft,
limited to three periods of use, of up to two minutes each, at rotor
shaft rotation speed and gas temperature established for this rating
by part 33 or this special condition.
(b) In addition to the requirements of section 33.4, the
mandatory inspection and maintenance actions required following the
use of the 30-Second or 2-Minute OEI rating, must be included in the
airworthiness limitations section of the appropriate engine manuals.
(c) In addition to the requirements of section 33.27, the
following additional test requirements must be considered. For 30-
Second and 2-Minute OEI conditions, test for a period of 5 minutes--
(1) At 100 percent of the highest speed that would result from
failure of the most critical component of each turbine and
compressor or system in a representative installation of the engine
when operating at 30-Second and 2-Minute OEI rating conditions.
(2) The test speed must take into account minimum material
properties, maximum operating temperature, and the most adverse
dimensional tolerances.
(3) Following the test, rotor growth and distress beyond
dimensional limits for an overspeed condition is permitted for 30-
Second and 2-Minute OEI rating only, provided the structural
integrity of the rotor is maintained, as shown by a procedure
acceptable to the Administrator.
(d) In addition to the requirements of section 33.29, the engine
must provide for a means:
(1) To indicate when the engine is at either 30-Second and 2-
Minute OEI-rated power level; and
(2) To determine the elapsed time of operation at 2-Minute OEI
and 30-Second OEI-rated power levels.
(e) In addition to the requirements of section 33.67, the engine
must provide for a means for automatic availability and automatic
control of the 30-Second OEI power; and engine test runs must be
performed to demonstrate automatic switching to a 30-Second OEI
rating condition.
(f) In addition to the requirements of section 33.83, the
following additional test requirements must be considered under
section 33.83(a):
(1) For 30-Second and 2-Minute OEI rating conditions, the
vibration survey shall cover the ranges of power, and both the
physical and corrected rotational speeds for each rotor system,
corresponding to operations throughout the range of ambient
conditions in the declared flight envelope, from the minumum rotor
speed up to 103 percent of the maximum rotor speed permitted for 2-
Minute OEI rating, and up to 100 percent of the maximum rotor speed
permitted for 30-Second OEI rating speed. If there is any indication
of a stress peak arising at high physical or corrected rotational
speeds, the surveys shall be extended in order to quantify the
phenomenon and to ensure compliance with the requirements of section
33.63.
(g) In addition to the requirements of section 33.85, tests
performed at the 30-Second and 2-Minute OEI ratings, during the
applicable endurance test prescribed in section 33.87, may be used
to show compliance with the requirements of section 33.85.
(h) In addition to the requirements of section 33.87, an engine
test must be conducted four times, using the following test
sequence, for a total of not less than 120 minutes:
(1) Takeoff Power--three minutes at rated takeoff power.
(2) 30-Second OEI power--thirty seconds at rated 30-Second OEI
power.
(3) 2-Minute OEI power--two minutes at rated 2-Minute OEI power.
(4) 30-Minute OEI, Continuous OEI, or Maximum Continuous power--
five minutes at rated 30-Minute OEI power, or rated Continuous OEI
power, or rated Maximum Continuous power, whichever is greatest,
except that during the first test sequence this period shall be 65
minutes.
(5) 50 percent takeoff power--one minute at 50 percent takeoff
power.
(6) 30-second OEI power--thirty seconds at rated 30-Second OEI
power.
(7) 2-minute OEI power--two minutes at rated 2-Minute OEI power.
(8) Idle power--one minute at Idle power.
(i) In addition to the requirements of section 33.88, the
following must be performed:
(1) For engines that do not provide a means for temperature
limiting; conduct a test for a period of five minutes at the maximum
permissible power-on RPM, with the gas temperature at least 75
degrees Fahrenheit higher than the 30-Second OEI rating operating
temperature limit.
(2) For engines that provide a means for temperature limiting;
conduct a test for a period of four minutes at the maximum
permissible power-on RPM, with the gas temperature at least 35
degrees Fahrenheit higher than the 30-Second OEI rating operating
temperature limit.
(3) A separate test engine may be used for each test.
(4) Following the test, rotor assembly growth and distress
beyond serviceable limits for an overtemperature condition is
permitted, provided the structural integrity of the rotor assembly
is maintained, as shown by a procedure that is acceptable to the
Administrator.
(j) In addition to the requirements of section 33.93, this
special condition requires that the engine be completely
disassembled after completing the additional testing of section
33.87. The engine may exhibit deterioration in excess of that
permitted in section 33.93(b), and may include some engine parts and
components that may be unsuitable for further use. It must be shown
by procedures approved by the Administrator that the structural
integrity of the engine, including mounts, cases, bearing supports,
shafts and rotors, is maintained.
Issued in Burlington, Massachusetts, on August 14, 1995.
Jay J. Pardee,
Manager, Engine and Propeller Directorate, Aircraft Certification
Service.
[FR Doc. 95-20876 Filed 8-22-95; 8:45 am]
BILLING CODE 4910-13-M
