# STC SR09229RC - Type: Supplemental type certificate - Status: Current, Reissued - Holder: Whisper Jet Inc., United States - Description: Installation approval of a 5 blade main rotor system and the Air Research TSE331-10UA-511SW engine - Applied: August 1, 1994 - Status date: June 7, 2010 - Product: Aircraft, Rotorcraft - Certification basis: Part 21 - Data sheets: [TCDS 1H4](https://openairdocs.org/tcds/1H4) - Certificate PDF: https://openairdocs.org/files/sha256/03/11/0311539ac88d639b8cf940b4916e005df1dc34d2d0d0963f60dde4fe72a00dc3 - FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/0F2C9EF6128C68B186257750007D6B6B.0001 - DRS record last changed: December 5, 2025 - Page: https://openairdocs.org/stc/SR09229RC ## ADs that name it (0) None. ## Approved models (1) - Sikorsky Aircraft Corporation S-55 ([TCDS 1H4](https://openairdocs.org/tcds/1H4)) ## What the certificate says Read from the PDF's text layer, without the form's printed wording; the layout is lost and the order can differ. The PDF is the record. Number SR09229RC This certificate issued to Part 6 of the Civil Air Regulations. Description of Type Design Change: Installation approval of a 5 blade main rotor system and the Air Research TSE331-10UA-511SW engine in accordance with Orlando Aviation, Inc., Master Drawing List No. OA-55-00-10000, Rev J, dated November 30, 1999, or later FAA approved revision. Sikorsky S-55 to include replacing 3 blade rotor system with a 5 blade main rotor on helicopters which have STC SH127WE and STC SE00691CH, also including new engine inlet, and exhaust silencing. Limitations and Conditions: This applies only to those helicopters that have incorporated STC SH127WE which installs Air Research TSE331-3U-303N and STC SE00691CH which converts the TSE331-3U to a TSE331-10UA. The limitations and conditions of Helicopter Specification No. 1H4 apply except as outlined in pages 1, 3, and 4, of this STC. A copy of this STC must be included in the permanent records of each airplane modified in accordance with this STC. Whisper Jet, Inc. a Washington Corporation 12515 Willows Road N.E., Suite 200 Kirkland, WA 98034 1H4 Make : Sikorsky Aircraft Model : S-55 Date of application : August 01, 1994 Date of issuance : December 17, 1999 Date reissued : June 07, 2010 Date amended : April 12, 2000 ( Signature) Lance T. Gant, Manager Rotorcraft Certification Office Southwest Region ( Title) FAA Form 8110-2-1(10-69) Page 2 of 4 FAA Form 8110-2-1(10-69) Page 3 of 4 Number SR09229RC Date of Issuance: December 17, 1999 Date Amended: April 12, 2000 Date Reissued: June 7, 2010 Sikorsky S-55 as modified by this STC Weight Limit: Whichever is less: Maximum take-off and landing weight and in ground effect maneuvers is 7700 pounds or as shown in hover in ground effect charts in the Rotorcraft Flight Manual Supplement dated December 17, 1999, or later FAA approved RFM. Center of Gravity: Most forward: 129 inches aft of datum Most rearward: 136 inches aft of datum **AFT CENTER OF GRAVITY MINIMUM WEIGHT IS 6300 LBS.** Engine Garrett TSE331-10UA-511SW Fuels Jet A, A-1, B, JP-1, -4, -5,-8, Jet B. Use of Aviation Gasoline is prohibited. Mil-I-27686D fuel system icing inhibitor, or equivalent, in amounts not to exceed 0.15% by volume is allowed. Maximum EGT Limits EGT °C IOAT EGT °C @ 92%-96%Nr °C @ 96%-101%Nr 600 50 600 595 40 590 585 30 580 575 20 570 565 10 560 555 0 555 545 -10 550 Maximum EGT during starting (1 second limit) is 770° C. Torque: Torque limits for take-off and maximum continuous (100%): 59 psi (1380-ft lb). The turbine engine power output is limited to the MAXIMUM TORQUE VALUE when the temperature and altitude are such that this limit is reached prior to the limiting maximum EGT. Engine RPM Maximum for all steady state operations: 2506rpm (101.0%) Transient over speed limit (5 seconds): 2606rpm (105%) Idle: 1687rpm (68%) Avoid: 447 to 695 rpm (18% - 28%) FAA Form 8110-2-1(10-69) Page 4 of 4 Number SR09229RC Date of Issuance: December 17, 1999 Date Amended: April 12, 2000 Date Reissued: June 7, 2010 Oil Mil-L-23699 A type oils conforming to Air Research Report PE-5065-R, and Mil-L-7808G type oils. Ambient Temperatures Maximum: 115.5 ° F (46.4° C) at sea level Minimum for starting: 14 ° F (-10° C) Minimum for operation: 14 ° F (-10° C) Main Gear Box Limits Oil temperature Maximum: 140 ° C Minimum: -15 ° C Oil pressure Maximum: 120 psi Minimum: 25 psi Main Rotor Limitations Power off: Maximum: 225 rpm Minimum: 170 rpm Power on: Maximum: 221 rpm (101%) Minimum: 201 rpm (92%) cruise only Airspeed Limitations Never exceed speed of 99KIAS from S.L. to 14,000 feet HD at 99-101% RPM Never exceed speed of 85KIAS from S.L. to 14,000 feet HD at 92-98% RPM Never exceed speed 70KIAS power off to 14,000 feet density altitude. This STC must be used in conjunction with Rotorcraft Flight Manual No. OA55-5-10-FM, revision original, dated December 17, 1999, or later FAA approved revision. The installer must determine whether this design change is compatible with previously approved modifications. If the holder agrees to permit another person to use this certificate to alter the product, the holder must give the other person written evidence of that permission. END ## Every issue (1) - June 7, 2010: Reissued, Current. [certificate](https://openairdocs.org/files/sha256/03/11/0311539ac88d639b8cf940b4916e005df1dc34d2d0d0963f60dde4fe72a00dc3) --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.