# STC SA1627WE - Type: Supplemental type certificate - Status: Current, Reissued - Holder: Sierra Industries Ltd., United States - Description: Installation of drooped ailerons in flaps down mode, recontoured wing leading edge, stall fences, aileron centering springs, conical cambered wing tips and flap actuated elevator trim spring. - Applied: October 25, 1967 - Status date: July 31, 2017 - Product: Aircraft, Small Airplane - Certification basis: Part 21 - Data sheets: [TCDS A23EU](https://openairdocs.org/tcds/A23EU), [TCDS A6CE](https://openairdocs.org/tcds/A6CE) - Certificate PDF: https://openairdocs.org/files/sha256/74/0e/740e4e018a4de7baeb888e0a8b81beaa92a3120e296027e70bc02ef7def6f060 - FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/5FF6C17E660EC4708625871F0048B8F3.0001 - DRS record last changed: December 6, 2025 - Page: https://openairdocs.org/stc/SA1627WE ## ADs that name it (1) - [AD 75-09-05](https://openairdocs.org/ad/75-09-05): Pitot System · Drooped ailerons in flaps down mode, recontoured wing leading… (Sierra Industries STC SA1627WE). Effective Apr 22, 1975. Named in the applicability ## Approved models (20) - Textron Aviation Inc. 337 ([TCDS A6CE](https://openairdocs.org/tcds/A6CE)) - Textron Aviation Inc. 337A ([TCDS A6CE](https://openairdocs.org/tcds/A6CE)) - Textron Aviation Inc. 337B ([TCDS A6CE](https://openairdocs.org/tcds/A6CE)) - Textron Aviation Inc. 337C ([TCDS A6CE](https://openairdocs.org/tcds/A6CE)) - Textron Aviation Inc. 337D ([TCDS A6CE](https://openairdocs.org/tcds/A6CE)) - Textron Aviation Inc. 337E ([TCDS A6CE](https://openairdocs.org/tcds/A6CE)) - Textron Aviation Inc. 337F ([TCDS A6CE](https://openairdocs.org/tcds/A6CE)) - Textron Aviation Inc. 337G ([TCDS A6CE](https://openairdocs.org/tcds/A6CE)) - Textron Aviation Inc. 337H ([TCDS A6CE](https://openairdocs.org/tcds/A6CE)) - Textron Aviation Inc. FT337GP ([TCDS A23EU](https://openairdocs.org/tcds/A23EU)) - Textron Aviation Inc. M337B ([TCDS A6CE](https://openairdocs.org/tcds/A6CE)) - Textron Aviation Inc. P337H ([TCDS A6CE](https://openairdocs.org/tcds/A6CE)) - Textron Aviation Inc. T337B ([TCDS A6CE](https://openairdocs.org/tcds/A6CE)) - Textron Aviation Inc. T337C ([TCDS A6CE](https://openairdocs.org/tcds/A6CE)) - Textron Aviation Inc. T337D ([TCDS A6CE](https://openairdocs.org/tcds/A6CE)) - Textron Aviation Inc. T337E ([TCDS A6CE](https://openairdocs.org/tcds/A6CE)) - Textron Aviation Inc. T337F ([TCDS A6CE](https://openairdocs.org/tcds/A6CE)) - Textron Aviation Inc. T337G ([TCDS A6CE](https://openairdocs.org/tcds/A6CE)) - Textron Aviation Inc. T337H ([TCDS A6CE](https://openairdocs.org/tcds/A6CE)) - Textron Aviation Inc. T337H-SP ([TCDS A6CE](https://openairdocs.org/tcds/A6CE)) ## 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. FAA Form 8110-2 (5/14) Page 1 of 9 Reissued on July 31, 2017 to supersede the original STC, which has been lost or misplaced. Number: SA1627WE certifies that the change in the type design for the following product with the limitations and conditions therefore as specified hereon meets the airworthiness requirements as specified on the appropriate Type Certificate Data sheet for each model as specified below. Original Product – Type Certificate Number: A6CE or A23EU Make: Cessna Model: 337, 337A(USAF 02B), 337B, M337B(USAF 02A), 337C, T337B, T337C, 337D, T337D, 337E, T337E, 337F, T337F, 337G, T337G, 337H, T337H, T337H-SP, P337H, AND FT337GP Optional takeoff gross weight increase for Models 337, 337A(USAF 02B), 337B, M337B(USAF 02A), T337B, 337C, T337C, 337D, T337D, 337E, T337E and T337F. For all models, installation of drooped ailerons in flaps down mode, recontoured wing leading edge, stall fence, aileron centering springs, conical cambered win g tips and flap actuated elevator trim spring, in accordance with FAA Sealed Robertson Aircraft Drawing List No. 14. Date of Application: October 25, 1967 Date Reissued: 1/15/69; 1/16/73; 11/5/73; 11/8/84; 10/10/86; 9/8/05; 7/31/17 Date of Issuance: March 05, 1968 Date Amended: 7/2/68; 9/25/68; 2/26/69; 8/4/69; 4/3/70; 2/26/71; 12/3/71; 1/16/73; 7/13/78; 10/10/78; 4/1/80; 9/25/80; 12/30/85 Signature Title Jim Grigg Manager, Fort Worth A CO Branch, Compliance & Airworthiness Division Sierra Industries, Ltd. 122 Howard Langford Drive Uvalde, TX 78801 FAA Form 8110-2 (5/14) Page 2 of 9 Transfer the ownership of Supplemental Type Certificate Number: SA1627WE To (Name and address of transferee) From (Name and address of grantor) United States of America Department of Transportation Federal Aviation Administration Supplemental Type Certificate (Continuation Sheet) Number: SA1627WE FAA Form 8110-2 (5/14) Page 3 of 9 Date of Issuance: March 05, 1968 Date Amended: December 30, 1985 Date of Reissuance: July 31, 2017 The approval of this change in type design applies basically to the above model aircraft only. This approval should not be extended to other aircraft of this model on which other previously approved modifications are incorporated unless it is determined that the interrelationship between this change and any other type design changes or previously approved modifications will introduce no adverse effect upon the airworthiness of that aircraft. A copy of this Certificate and Addendum SA1627WE shall be maintained as part of the permanent records for the modified aircraft. The appropriate conditions and limitations of Type Certificate Data Sheet A6CE or A23EU apply except as follows: This Addendum, which is part of Supplemental Type Certificate No. SA1627WE prescribes conditions and limitations under which the product for which the STC was issued meets the appropriate airworthiness requirements. A copy of this Addendum shall be maintained as part of the modified aircraft permanent records. Supplemental Type Certificate Holder: R/STOL SYSTEMS, INC. I. Model 337, (Normal Category), Approved October 8, 1964 Model 337A(USAF 02B), (Normal Category), Approved August 11, 1965 *Airspeed Limits Never Exceed 219 mph (190 knots) Max. Structural Cruising 178 mph (155 knots) Flaps Extended 108 mph ( 94 knots) Maneuvering 150 mph (130 knots) Landing Gear Extended 140 mph (122 knots) C.G. Range (Landing Gear Extended) (+137.8) to (+142.5) at 4421 lb. (+134.5) to (+142.5) at 3500 lb. or less straight line variation between points given. *Maximum Weight Take-off 4421 lb., landing 4200 lb. All weight above landing weight must be carried as fuel in wing tanks. Control Surface Movements Ailerons (±2°) Flap Position Aileron Droop Position Aileron Movement 0° 0° 20° UP 14° DN 20° 13° 8° UP 27° DN 25° 11° 10° UP 25° DN United States of America Department of Transportation Federal Aviation Administration Supplemental Type Certificate (Continuation Sheet) Number: SA1627WE FAA Form 8110-2 (5/14) Page 4 of 9 Date of Issuance: March 05, 1968 Date Amended: December 30, 1985 Date of Reissuance: July 31, 2017 II. Model 337B, (Normal Category) Approved June 22, 1966 Same conditions and limitations as Model T337B. III. Model T337B, (Normal Category) Approved October 25, 1966 *Airspeed Limits Never Exceed 221 mph (190 knots) Max. Structural Cruising 180 mph (156 knots) Flaps Extended 108 mph ( 94 knots) Maneuvering 152 mph (132 knots) Landing Gear Extended 140 mph (122 knots) C.G. Range (Landing Gear Extended) (+137.7) to (+143.3) at 4525 lb. (+134.5) to (+143.3) at 3600 lb. or less straight line variation between points given. *Maximum Weight Take-off 4525 lb., Landing 4300 lb. All weight above landing weight must be carried as fuel in wing tanks. Control Surface Movements Ailerons (±2°) Flap Position Aileron Droop Position Aileron Movement 0° 0° 20° UP 14° DN 20° 13° 8° UP 27° DN 25° 11° 10° UP 25° DN IV. Model 337C, (Normal Category) Approved September 15, 1967 *Airspeed Limits Never Exceed 225 mph (196 knots) Max. Structural Cruising 183 mph (159 knots) Flaps Extended 108 mph ( 94 knots) Maneuvering 155 mph (135 knots) Landing Gear Extended 140 mph (122 knots) *Maximum Weight Take-off 4630 lb., Landing 4400 lb. All weight above landing weight must be carried as fuel in wing tanks. United States of America Department of Transportation Federal Aviation Administration Supplemental Type Certificate (Continuation Sheet) Number: SA1627WE FAA Form 8110-2 (5/14) Page 5 of 9 Date of Issuance: March 05, 1968 Date Amended: December 30, 1985 Date of Reissuance: July 31, 2017 Control Surface Movements Ailerons (±2°) Flap Position Aileron Droop Position Aileron Movement 0° 0° 20° UP 14° DN 20° 13° 8° UP 27° DN 25° 11° 10° UP 25° DN V. Model T337C, (Normal Category) Approved September 15, 1967 *Airspeed Limits Never Exceed 225 mph (196 knots) Max. Structural Cruising 183 mph (159 knots) Flaps Extended 108 mph ( 94 knots) Maneuvering 155 mph (135 knots) Landing Gear Extended 140 mph (122 knots) C.G. Range (Landing Gear Extended) (+138.4) to (+143.3) at 4700 lb. (+134.5) to (+143.3) at 3600 lb. or less *Maximum Weight Take-off 4700 lb., Landing 4465 lb. All weight above 4,500 pounds must be carried as fuel in wing tanks. Control Surface Movements Ailerons (±2°) Flap Position Aileron Droop Position Aileron Movement 0° 0° 20° UP 14° DN 20° 13° 8° UP 27° DN 25° 11° 10° UP 25° DN VI. Model 337D, (Normal Category) Approved July 23, 1968 *Airspeed Limits Never Exceed 225 mph (196 knots) Max. Structural Cruising 183 mph (159 knots) Flaps Extended 108 mph ( 94 knots) Maneuvering 155 mph (135 knots) Landing Gear Extended 140 mph (122 knots) United States of America Department of Transportation Federal Aviation Administration Supplemental Type Certificate (Continuation Sheet) Number: SA1627WE FAA Form 8110-2 (5/14) Page 6 of 9 Date of Issuance: March 05, 1968 Date Amended: December 30, 1985 Date of Reissuance: April 10, 2017 C.G. Range (Landing Gear Extended) (+138.6) to (+143.0) at 4630 lb. (+134.5) to (+143.0) at 3837 lb. or less *Maximum Weight Take-off 4630 lb., Landing 4400 lb. All weight above landing weight must be carried as fuel in wing tanks. Control Surface Movements Ailerons (±2°) Flap Position Aileron Droop Position Aileron Movement 0° 0° 20° UP 14° DN 20° 13° 8° UP 27° DN 25° 11° 10° UP 25° DN VII. Model T337D, (Normal Category) Approved July 23, 1968 *Airspeed Limits Never Exceed 225 mph (196 knots) Max. Structural Cruising 183 mph (159 knots) Flaps Extended 108 mph ( 94 knots) Maneuvering 155 mph (135 knots) Landing Gear Extended 140 mph (122 knots) C.G. Range (Landing Gear Extended) (+138.7) to (+143.0) at 4700 lb. (+134.7) to (+143.0) at 3837 lb. or less *Maximum Weight Take-off 4700 lb., Landing 4465 lb. All weight above 4500 lb. must be carried as fuel in wing tanks. Control Surface Movements Ailerons (±2°) Flap Position Aileron Droop Position Aileron Movement 0° 0° 20° UP 14° DN 20° 13° 8° UP 27° DN 25° 11° 10° UP 25° DN United States of America Department of Transportation Federal Aviation Administration Supplemental Type Certificate (Continuation Sheet) Number: SA1627WE FAA Form 8110-2 (5/14) Page 7 of 9 Date of Issuance: March 05, 1968 Date Amended: December 30, 1985 Date of Reissuance: July 31, 2017 VIII. Model M337B (USAF 02A), (Normal Category), Approved March 22, 1967 Same conditions and limitations as Model T337B IX. Model 337E, (Normal Category), Approved August 5, 1969 *Airspeed Limits Never Exceed 225 mph (196 knots) Max. Structural Cruising 183 mph (159 knots) Flaps Extended 108 mph ( 94 knots) Maneuvering 155 mph (135 knots) Landing Gear Extended 160 mph (139 knots) C.G. Range (Landing Gear Extended) (+138.6) to (+143.0) at 4630 lb. (+134.5) to (+143.0) at 3837 lb. or less *Maximum Weight Take-off 4630 lb., Landing 4400 lb. All weight above 4,440 pounds must be carried as fuel in wing tanks. Control Surface Movements Ailerons (±2°) Flap Position Aileron Droop Position Aileron Movement 0° 0° 20° UP 14° DN 20° 13° 8° UP 27° DN 25° 11° 10° UP 25° DN X. Model T337E, (Normal Category), Approved August 5, 1969 Model T337F, (Normal Category), Approved September 8, 1970 *Airspeed Limits Never Exceed 228 mph (198 knots) Max. Structural Cruising 183 mph (159 knots) Flaps Extended 108 mph ( 94 knots) Maneuvering 155 mph (135 knots) Landing Gear Extended 160 mph (139 knots) C.G. Range (Landing Gear Extended) (+138.7) to (+143.0) at 4700 lb. (+134.5) to (+143.0) at 3837 lb. or less United States of America Department of Transportation Federal Aviation Administration Supplemental Type Certificate (Continuation Sheet) Number: SA1627WE FAA Form 8110-2 (5/14) Page 8 of 9 Date of Issuance: March 05, 1968 Date Amended: December 30, 1985 Date of Reissuance: July 31, 2017 *Maximum Weight Take-off 4700 lb., Landing 4465 lb. All weight above 4630 lb. must be carried as fuel in wing tanks. Control Surface Movements Ailerons (±2°) Flap Position Aileron Droop Position Aileron Movement 0° 0° 20° UP 14° DN 20° 13° 8° UP 27° DN 25° 11° 10° UP 25° DN XI. Model 337F, (Normal Category), Approved September 8, 1970 *Airspeed Limits Never Exceed 228 mph (198 knots) Max. Structural Cruising 183 mph (159 knots) Flaps Extended 108 mph ( 94 knots) Maneuvering 155 mph (135 knots) Landing Gear Extended 160 mph (139 knots) Control Surface Movements Ailerons (±2°) Flap Position Aileron Droop Position Aileron Movement 0° 0° 20° UP 14° DN 20° 13° 8° UP 27° DN 25° 11° 10° UP 25° DN XII. Model T337G, (Normal Category), Approved February 2, 1972, and Model FT337GP (Normal Category), Approved June 22, 1973. *Airspeed Limits *Flaps Extended 1/3 141 KIAS (139 KCAS) *Flaps Extended Full 94 KIAS (139 KCAS) Control Surface Movements (No Change Except) Ailerons (±2°) Flap Position Aileron Droop Position Aileron Movement 0° 0° 20° UP 14° DN 20° 13° 8° UP 27° DN 25° 11° 10° UP 27° DN United States of America Department of Transportation Federal Aviation Administration Supplemental Type Certificate (Continuation Sheet) Number: SA1627WE FAA Form 8110-2 (5/14) Page 9 of 9 Date of Issuance: March 05, 1968 Date Amended: December 30, 1985 Date of Reissuance: July 31, 2017 Center of Gravity Limits (No Change Except): AFT C.G. Limit (+140.0) at all weights Fuel Capacity (Applies only to airplane models equipped with long range fuel tanks). *145.2 gal. (142.6 gal. usable) (2 tanks 72.6 gal. each at +150) XIII. Model 337G, (Normal Category), Approved December 18, 1972 Same conditions and limitations as Model T337G XIV. Model 337H and T337H, (Normal Category), Approved June 6, 1978, and October 10, 1978, respectively Same conditions and limitations as Model T337G XV. Model P337H (Normal Category), Approved September 11, 1980 Same conditions and limitations as Model T337G XVI. Model T337H-SP (Normal Category), Approved April 1, 1980 Same conditions and limitations as Model T337G *Items marked by an asterisk under Sections I thru XVI must be permanently displayed as placards or markings. -END- United States of America Department of Transportation Federal Aviation Administration Supplemental Type Certificate (Continuation Sheet) Number: SA1627WE FAA Form 8110-2 (5/14) Page 10 of 9 ## Every issue (2) - July 31, 2017: Reissued, Current. [certificate](https://openairdocs.org/files/sha256/74/0e/740e4e018a4de7baeb888e0a8b81beaa92a3120e296027e70bc02ef7def6f060) - September 8, 2005: Reissued, Historical. [certificate](https://openairdocs.org/files/sha256/e0/49/e0491b0fb20bf0236a4b598a3fea92a448aa05ba0fd36f662d9773710ca5b0ba) --- 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.