# STC SH127WE - Type: Supplemental type certificate - Status: Current, Reissued - Holder: Whisper Jet Inc., United States - Description: Installation of AiResearch TSE-331-3U-303N engine and related changes. - Applied: August 8, 1968 - Status date: October 13, 2000 - Product: Aircraft, Rotorcraft - Certification basis: Part 21, Part 29, Part 91 - Data sheets: [TCDS 1H4](https://openairdocs.org/tcds/1H4) - Certificate PDF: https://openairdocs.org/files/sha256/c3/d8/c3d89a4341b3eabf283636b6fda1feb2952e8cf7ef8fb7b630883bb1605e4fb4 - FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/9022D1273586D1E785256CC2005C2E4B.0001 - DRS record last changed: December 6, 2025 - Page: https://openairdocs.org/stc/SH127WE ## ADs that name it (2) - [AD 75-22-12](https://openairdocs.org/ad/75-22-12): Inflight Power Loss · Sikorsky S-55, S-55B and S-55C with STC SH125WE or SH127WE. Effective Oct 31, 1975. Named in the applicability - [AD 73-16-01](https://openairdocs.org/ad/73-16-01): Engine Turbine Failure · Sikorsky S-55, S-55B and S-55C with STC SH127WE. Effective Jul 31, 1973. Named in the applicability ## Approved models (3) - Sikorsky Aircraft Corporation S-55 ([TCDS 1H4](https://openairdocs.org/tcds/1H4)) - Sikorsky Aircraft Corporation S-55B ([TCDS 1H4](https://openairdocs.org/tcds/1H4)) - Sikorsky Aircraft Corporation S-55C ([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 SH127WE (This is a duplicate to replace the original which was lost. Issued 8/30/02) This certificate, issued to Whisper Jet, Inc. 2923 Carrier Ave. Sanford, FL 32773 Part of the Regulations, See Page 5? of this STC for certification basis. Original ProductType Certificate Number: 1H4 Make: Sikorsky Model: S-55, S-55B, S-55C Description of the Type Design Change: Installation of AiResearch TSE 331-3U-303N engine and related changes in accordance with FAA Sealed Aviation Specialties Master Drawing List No. AS55-01-00000, Revision G, or later FAA approved revision. Limitations and Conditions: The limitations and conditions of Helicopter Specification No. 1H4 apply except as outlined in pages 3 through 7 of this STC. A copy of this STC must be included in the permanent records of each airplane modified in accordance with this STC. Approval of this change in type design applies to the above model rotorcraft only. This approval should not be extended to other rotorcraft of these models on which other previously approved modifications are incorporated unless it is determined that the relationship between this change and any of those other previously approved modifications, including changes in type design, will introduce no adverse effect upon the airworthiness of that rotorcraft. A copy of this Certificate and FAA Approved Rotorcraft Flight Manual Supplement 22-206-DP-01, dated September 10, 1980, or later FAA approved revision, must be maintained as part of the permanent records for the modified rotorcraft. If the holder agrees to permit another person to use this certificate to alter the product, the holder shall give the other person written evidence of that permission. This certificate and the supporting data which is the ba sis for approval shall remain in effect until surrendered, suspended, revoked, or a termination date is otherwise established by the Administrator of the Federal Aviation Administration. Date of application: August 8, 1968 Date reissued: 1/30/74; 12/27/83; 9/27/91; 9/2/92; 9/20/00; 8/30/02 Date of issuance: May 13, 1971 Date amended: 6/25/71; 9/9/71; 1/10/73; 6/13/73; 8/30/02 (Signature) Acting Manager, Seattle Aircraft Certification Office (Title) Number SH127WE Issued to: Whisper Jet, Inc. Date of Issuance: May 3, 1971 Date of Reissuance: 1/30/74; 12/27/83; 9/27/91; 9/2/92; 9/20/00; 8/30/02 Date Amended: 6/25/71; 9/9/71; 1/10/73; 6/13/73; 8/30/02 Limitations and Conditions: (cont’d) I – Sikorsky S-55, S-55B, or S-55C as modified by this STC Engine AiResearch TSE 331-3U-303N conforming to AiResearch Equipment List No. 894870, Revision C, or subsequent FAA approved revision. Fuel Fuels conforming to AiResearch Manufacturing Company of Arizona Report PE-5064-R and revisions thereto. Not eligible for operation with aviation gasoline. Oil MIL-L-23699A or MIL-L-7808 type oils conforming to AiResearch Manufacturing Company of Arizona Report PE-5065-R and revisions thereto. Engine Rating 650 SHP for all operations – (See Note 4) Engine Limits 2,544 RPM (102.5%) maximum for all steady state operations. Output Shaft Speed Note: The fuel control must be rigged in accordance with AiResearch Engineering Test Instructions No. 8002 dated December 1, 1970. When so rigged, the governor droop characteristics will vary maximum RPM from 102.25 + .25% at or below an interstage turbine temperature (ITT) of 110ºF to approximately 99% at an ITT of 169ºF. 2606 RPM transient for 5 seconds. Torque 1,380 lb ft (59 psi) maximum for all operations. Interstage turbine 1,693ºF (923ºC) maximum for all steady state operations. temperature 2,100ºF (1,149ºC) one second starting transient limit. Ambient temperature -40ºF. (-40ºF C) minimum for starting -65ºF. (-54ºF C) minimum for operation 115.5ºF. (46.4ºC) minimum for sea level. Refer to the Rotorcraft Flight Manual for other altitudes. FAA FORM 8110-2- 1 (10-69) PAGE 3 OF 7 PAGES United States of America Number SH127WE Issued to: Whisper Jet, Inc. Date of Issuance: May 3, 1971 Date of Reissuance: 1/30/74; 12/27/83; 9/27/91; 9/2/92; 9/20/00; 8/30/02 Date Amended: 6/25/71; 9/9/71; 1/10/73; 6/13/73; 8/30/02 Oil inlet temperature Maximum: 260ºF. (127ºC) for ground idle 230ºF. (110ºC) for all other operations Minimum: -40ºF. (-40ºC) Rotor Limits Power on: 224 rp m maximum at minimum rotor pitch 219 rpm maximum at maximum power 213 rpm minimum Power off: 245 rpm maximum 180 rpm minimum Airspeed limits V NE (never exceed) 114 MPH (99 KTS) IAS at sea level. Refer to Rotorcraft Flight Manual for reduction of V NE with altitude and temperature. C.G. range (+125.0) to +136.0) Maximum Weight 7200 lbs. Number of seats Same as basic S-55 series. See Helicopter Specification 1H4. Maximum baggage Same as basic S-55 series. See Helicopter Specification 1H4. Fuel capacity 104 gal. (+116) in main tank 85 gal. (+184) in auxiliary tank See NOTE 1(b). Oil capacity 6.25 qt. (+44.5) Rotor blade rigging Same as basic S-55 series except collective down travel increased 1/2º. Refer to applicable S-55 series Maintenance Manual and Aviation Specialties Maintenance Manual Supplement. Serial Numbers eligible Same as shown on Helicopter Specification 1H4. **FAA FORM 8110-2- 1 (10-69) PAGE 4 OF 7 PAGES** Number SH127WE Issued to: Whisper Jet, Inc. Date of Issuance: May 3, 1971 Date of Reissuance: 1/30/74; 12/27/83; 9/27/91; 9/2/92; 9/20/00; 8/30/02 Date Amended: 6/25/71; 9/9/71; 1/10/73; 6/13/73; 8/30/02 Data Pertinent to All Models Datum 130.6 in. forward of center main rotor hub. Leveling means Plumb line from top of cargo door frame. Certification Basis 1. CAR 6, effective May 24, 1946 2. The following portions of FAR 29 (Category B) including Amendment 29-1 through 29-3: 29.95; 29.27; 29.33; 29.45; 29.73(b); 29.143; 29.901 through 29.921; 29.927 through 29.961; 29.997 through 29.1203; 29.1303(e); 29.1305; 29.1337; 29.1505; 29.1509(c); 29.1519; 29.1521; 29.1529; 29.1549 through 29.1555; 29.1557(c); 29.1559; 29.1583(b); 29.1587(b). 3. Special conditions 29-26-WE-9, dated June 23, 1970 and Amendment 1 dated November 3, 1970 thereto. Production Basis None. An in-flight operation check must be conducted in accordance with FAR 91.167(a) for each aircraft modified to incorporate this Supplemental Type Certificate. When original airworthiness certification has not previously been accomplished, the applicant must also comply with FAR 21.130 and 21.183(d). Equipment The following must be installed in the rotorcraft for airworthiness certification subsequent to the incorporation of this STC. 1. The basic required equipment as prescribed in the applicable airworthiness regulations (See Certification Basis outlined above). 2. The additional required items shown in FAA sealed Aviation Specialties Equipment List No. AF-10. FAA FORM 8110-2- 1 (10-69) PAGE 5 OF 7 PAGES United States of America Number SH127WE Issued to: Whisper Jet, Inc. Date of Issuance: May 3, 1971 Date of Reissuance: 1/30/74; 12/27/83; 9/27/91; 9/2/92; 9/20/00; 8/30/02 Date Amended: 6/25/71; 9/9/71; 1/10/73; 6/13/73; 8/30/02 NOTE: Equipment items approved fo r the basic Sikorsky S-55, S-55B or S-55C are not eligible with this STC unless such items are also shown on the above noted equipment list, or unless it is determined that the interrelationship between those items and the modifications covered by the STC will introduce no adverse effect on the airworthiness of that aircraft. 3. Deleted 4. Main gear box takeoff bevel gear retention studs, Sikorsky P/N S14-05-3652, installed in lieu of AN75-5 bolts in accordance with the Sikorsky Service Digest. 5. Main rotor blade assembly, Sikorsky P/N S14-10-2100 or P/N S14-10-2201-1, -3, -6, -7, or -9. 6. Main gear box, Sikorsky P/N S14-35-4300-16 or -17, or S14-35-4500-0 or -1. Transmission eligible with or without Service Information Circular No. 1435-551 incorporated. The FAA approved Aviation Specialties Rotorcraft Flight Manual, dated September 27, 1971 is required in lieu of that specified in Helicopter Specification 1H4. NOTE 1: (a) Current weight and balance data including a list of equipment included in the certificated empty weight and loading instructions, when necessary, must be provided at the time of airworthiness certification of return to service. (b) The certificated empty weight and correspondence center of gravity locations must include system fuel (unusable) of 32 lb. at (+116) and 17 lb. at (+184) based on fuel density of 6.7 lb./gallon. NOTE 2: Refer to applicable FAA approved Rotorcraft Flight Manual for required placards and instruments markings. FAA FORM 8110-2- 1 (10-69) PAGE 6 OF 7 PAGES United States of America Number SH127WE Issued to: Whisper Jet, Inc. Date of Issuance: May 3, 1971 Date of Reissuance: 1/30/74; 12/27/83; 9/27/91; 9/2/92; 9/20/00; 8/30/02 Date Amended: 6/25/71; 9/9/71; 1/10/73; 6/13/73; 8/30/02 NOTE 3: Information essential to the proper maintenance of the helicopter modified in accordance with the STC is contained in the Aviation Specialties Maintenance Manual Supplement and, except for areas superseded by the Aviation specialties Supplement, in the applicable Sikorsky S-55 Maintenance Manual. Retirement times of critical parts are the same as those of the basic S-55, S-55B, or S-55C. Refer to NOTE 3 of the Helicopter Specification No. 1H4 and the applicable Sikorsky S-55 Maintenance Manual. NOTE 4: The rating shown for the TSE 331-3U-303N engine is available at sea level throughout the approved ambient temperature range and to 10,000 ft. on a standard temperature day. This is based on dry air, no external accessory loads, no air bleed or anti-icing. NOTE 5: The approval of this change in type design applies to the basic aircraft of these models that are otherwise unmodified. This approval should not be extended to other aircraft of these models on which other previously approved modifications are incorporated unless it is determined by the installer that the interrelationship between this change and any of those other previously approved modifications will introduce no adverse effect upon the airworthiness of that aircraft. -- END -- **FAA FORM 8110-2- 1 (10-69) PAGE 7 OF 7 PAGES** ## Every issue (1) - October 13, 2000: Reissued, Current. [certificate](https://openairdocs.org/files/sha256/c3/d8/c3d89a4341b3eabf283636b6fda1feb2952e8cf7ef8fb7b630883bb1605e4fb4) --- From OpenAirDocs.org, an independent open copy of FAA and NTSB data. Only the Federal Register edition on govinfo.gov is the official legal text of an AD.