[Federal Register Volume 63, Number 116 (Wednesday, June 17, 1998)]
[Rules and Regulations]
[Pages 32972-32973]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-16078]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Parts 21 and 29

[Docket No. SW004; Special Conditions No. 29-004-SC]


Special Conditions: Sikorsky Aircraft Corporation, Model S76C; 
Application of Rated 30-Minute Power

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final special conditions; request for comments.

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SUMMARY: These special conditions are issued for the Sikorsky Model 
S76C helicopter. This helicopter will have a novel or unusual design 
feature associated with a new rated 30-minute power. The applicable 
airworthiness regulations do not contain adequate or appropriate safety 
standards for this new rated 30-minute power. These special conditions 
contain the additional safety standards that the Administrator 
considers necessary to establish a level of safety equivalent to that 
established by the existing airworthiness standards.

DATES: The effective date of these special conditions is June 17, 1998. 
Comments must be received on or before July 17, 1998.

ADDRESSES: Comments on these special conditions may be mailed in 
duplicate to: Federal Aviation Administration (FAA), Office of the 
Regional Counsel, Attention: Rules Docket No. SW004, 2601 Meacham 
Blvd., Room 663, Fort Worth, Texas 76137; or delivered in duplicate to 
the Office of the Regional Counsel at the above address. Comments must 
be marked Docket No. SW004. Comments may be inspected in the Rules 
Docket weekdays, except Federal holidays, between 7:30 a.m. and 4:00 
p.m.

FOR FURTHER INFORMATION CONTACT: Scott Horn, FAA, Rotorcraft 
Directorate, Rotorcraft Standards Staff, Fort Worth, Texas 76193-0110, 
telephone (817) 222-5125, fax (817) 222-5961.

SUPPLEMENTARY INFORMATION: The FAA has determined that notice and 
opportunity for prior public comment hereon are impracticable because 
these procedures would significantly delay issuance of the approval 
design and thus delivery of the affected helicopter. The FAA therefore 
finds that good cause exists for making these special conditions 
effective upon issuance.

Comments Invited

    Interested persons are invited to submit such written data, views, 
or arguments as they may desire. Communications should identify the 
regulatory docket and be submitted in duplicate to the address 
specified above. All communications received on or before the closing 
date for comments will be considered. The special conditions may be 
changed in light of the comments received. All comments received 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 rulemaking will be filed in the docket. Commenters 
wishing the FAA to acknowledge receipt of their comments submitted in 
response to this special condition must include a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket No. SW004.'' The postcard will be date stamped and returned 
to the commenter.

Background

    On November 19, 1997, Sikorsky Aircraft Corporation applied for a 
change to Type Certificate (TC) No. H1NE for use of a rated 30-minute 
power on the Model S76C helicopter. The Sikorsky Model S76C is a 
transport category A and B rotorcraft powered by two Turbomeca Arriel 
2S1 engines with a maximum gross weight of 11,700 pounds.
    This new rated 30-minute power is intended for periods of use up to 
30 minutes at any time after takeoff during a flight performing search 
and rescue missions. However, this rating is also suitable for other 
missions that require increased rotorcraft hovering capability and 
duration than the current ratings allow. The Sikorsky Model S76C 
helicopter with the Arriel 2S1 engine installation will have the 
following power ratings: 30-second One-Engine-Inoperative (OEI), 2-
minute OEI, Continuous OEI, 30-minute, Takeoff, and Maximum Continuous 
ratings.
    The current rotorcraft maximum continuous rating is at the same 
torque and RPM limits as the proposed 30-minute rating. As a result, 
the FAA has determined that compliance with the structural and drive 
system requirements of 14 CFR part 29 (part 29) has not been affected 
by this new rating application. In addition, all the power parameter 
limits and ranges for the 30-minute power coincide with the existing 
instrument markings for the takeoff rating. Therefore, these markings, 
applied to the new 30-minute power, have been found to comply with the 
part 29 requirements.
    The applicable airworthiness requirements do not contain a 30-
minute power rating definition and do not contain adequate or 
appropriate safety standards for the type certification of this new and 
unusual engine rating. Due to increased N1 (gas turbine 
speed) and T5 (turbine outlet temperature) limits for this 
new rating, as compared to the existing continuous rating, 
airworthiness requirements must be developed for powerplant cooling and 
operational limitations. Additionally, for use of the 30-minute power 
rating, the engine manufacturer has established a new method to 
determine the engine overhaul time. The new method accelerates the 
engine hours time-in-service when the 30-minute rating is used. For the 
Sikorsky Model S76C helicopter, the pilot is required to record the 30-
minute rating usage, since no means of automatically counting or 
recording is provided. As a result of the additional workload to the 
pilot, the FAA has determined that a two-pilot crew is necessary to 
meet the minimum flight crew requirements of part 29.

Type Certification Basis

    Under the provisions of 14 CFR 21.101, Sikorsky Aircraft 
Corporation must show that the Model S76C helicopter with the Arriel 
2S1 engine installation meets the applicable provisions of the 
regulations in effect on the date of the application or the applicable 
provisions of the regulations as referenced in TC Number H1NE. The 
regulations incorporated by reference in the TC are commonly referred 
to as the ``original type certification basis.'' The regulations 
incorporated by reference in TC Number H1NE are as follows:
    Part 29, effective February 1, 1965, plus Amendments 29-1 through 
29-11;

[[Page 32973]]

in addition, portions of Amendments 29-12, specifically, Secs. 29.67, 
29.71, 29.75, 29.141, 29.173, 29.175, 29.931, 29.1189(a)(2), 
29.1555(c)(2), 29 1557(c), and portions of Amendment 29-13, 
specifically Sec. 29.965, and Amendment 29-21. In addition, for the 
Sikorsky Model S76C (with Arriel 2S1 Engine Configuration): Amendment 
29-34 specifically 29.67(a)(1)(i), 29.923(a), (b)(1) and (b)(3), 
29.1143(f), 29.1305(a)(24) and (a)(25), 29.1521(i) and (j), and 
29.1549(e) and Amendment 36-20 of FAR 36, Appendix H; also Special 
Condition No. 96-ASW-16. In addition, the certification basis includes 
certain special conditions, exemptions and later amended sections of 
the applicable Part that are not relevant to these special conditions.
    If the Administrator finds that the applicable airworthiness 
regulations for part 29 do not contain adequate or appropriate safety 
standards for the Sikorsky Model S76C because of a novel or unusual 
design feature, special conditions are prescribed under the provisions 
of Sec. 21.16.
    In addition to the applicable airworthiness regulations and special 
conditions, the Sikorsky Model S76C must comply with the noise 
certification requirements of part 36, and the FAA must issue a finding 
of regulatory adequacy pursuant to Sec. 611 of Public Law 92-574, the 
``Noise Control Act of 1972.''
    Special conditions, as appropriate, are issued in accordance with 
Sec. 11.49, as required by Secs. 11.28 and 11.29(b), and become part of 
the type certification basis in accordance with Sec. 21.101(b)(2).
    Special conditions are initially applicable to the model for which 
they are issued. Should the TC for that model be amended later to 
include any other model that incorporates the same novel or unusual 
design feature, or should any other model already included on the same 
TC be modified to incorporate the same novel or unusual design feature, 
the special conditions would also apply to the other model under the 
provisions of Sec. 21.101(a)(1).

Novel or Unusual Design Features

    The Sikorsky Model S76C will incorporate the following novel or 
unusual design features: A new rated 30-minute power which will require 
a special condition for hovering cooling test procedures and powerplant 
limitations.

Applicability

    As discussed above, these special conditions are applicable to the 
Sikorsky Model S76C. Should Sikorsky Aircraft Corporation apply at a 
later date for a change to the TC to include another model 
incorporating the same novel or unusual design feature, the special 
conditions would apply to that model as well under the provisions of 
Sec. 21.101(a)(1).

Conclusion

    This action affects only certain novel or unusual design features 
on one model of helicopter. It is not a rule of general applicability 
and affects only the applicant who applied to the FAA for approval of 
these features on the helicopter.
    Under standard practice, the effective date of final special 
conditions would be 30 days after the date of publication in the 
Federal Register; however, as the certification date for the Sikorsky 
Model S76C is imminent, the FAA finds that good cause exists to make 
these special conditions effective upon issuance. The FAA is requesting 
comments to allow interested persons to submit views that may not have 
been submitted in response to the prior opportunities for comment 
described above.

List of Subjects in 14 CFR Parts 21 and 29

    Aircraft, Air transportation, Aviation safety, Rotorcraft, Safety.

    The authority citation for these special conditions is as follows:

    Authority: 42 U.S.C. 7572; 49 U.S.C. 106(g), 40105, 40113, 
44701-44702, 44704, 44709, 44711, 44713, 44715, 45303.

The Special Conditions

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the following special conditions are issued as part of 
the type certification basis for Sikorsky Model S76C helicopters.

1. Section 29.1049  Hovering Cooling Test Procedures

    In addition to the requirements of Sec. 29.1049, acceptable 
hovering cooling provisions must be shown for the following conditions:
    (a) At the maximum weight, or at the greatest weight at which the 
rotorcraft can hover (if less), at sea level, with the power required 
to hover but not more than 30-minute power, in-ground effect in still 
air, until at least 5 minutes after the occurrence of the highest 
temperature recorded or until the expiration of the 30-minute power 
application period, whichever occurs first; and,
    (b) With 30-minute power, maximum weight, and at the altitude 
resulting in zero rate of climb for this configuration, until at least 
5 minutes after the occurrence of the highest temperature recorded or 
until the expiration of the 30-minute power application period, 
whichever occurs first.

2. Section 29.1521  Powerplant limitations

    In addition to the requirements of Sec. 29.1521 the limitations for 
rated 30-minute power usage must be established as follows:
Rated 30-Minute Power Operations
    The powerplant rated 30-minute power operation must be limited to 
use for periods not to exceed 30 minutes for hovering operations only 
and by:
    (a) The maximum rotational speed which may not be greater than--
    (i) The maximum value determined by the rotor design; or
    (ii) The maximum value shown during the type tests;
    (b) The maximum allowable turbine outlet gas temperature;
    (c) The maximum allowable engine and transmission oil temperatures.
    (d) The maximum allowable power or torque for each engine, 
considering the power input limitations of the transmission with all 
engines operating; and
    (e) The maximum allowable power or torque for each engine 
considering the power input limitations of the transmission with one-
engine-inoperative.

    Issued in Fort Worth, Texas, on June 5, 1998.
Eric Bries,
Acting Manager, Rotorcraft Directorate, Aircraft Certification Service, 
ASW-100.
[FR Doc. 98-16078 Filed 6-16-98; 8:45 am]
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