# STC SA4-1531 - Type: Supplemental type certificate - Status: Current, Reissued - Holder: SOUTHWESTERN AERO EXCHANGE INC., United States - Description: Installation of Tricycle landing gear and revised nose assembly with optional radome. - Applied: May 25, 1961 - Status date: February 27, 2006 - Product: Aircraft, Small Multi-Engine - Certification basis: Part 21 - Data sheets: [TCDS A-765](https://openairdocs.org/tcds/A-765) - Certificate PDF: https://openairdocs.org/files/sha256/d3/71/d37198bc115073270544334890e566329f1f1894bbcdc386f80b58fe0db374e6 - FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/2D2E638B6B859278862571260053DF8D.0001 - DRS record last changed: December 5, 2025 - Page: https://openairdocs.org/stc/SA4-1531 ## ADs that name it (4) - [AD 81-18-07](https://openairdocs.org/ad/81-18-07): Tricycle Landing Gear · Textron 3N, 3NM, 3TM and 13 more. Effective Sep 10, 1981. Named in the applicability - [AD 72-16-02 R3](https://openairdocs.org/ad/72-16-02-R3): Volpar Nose Landing Gear Fork · Volpar Mark IV tricycle landing gear (Southwestern Aero Exchange STC SA111WE or 2 others). Effective Apr 16, 1981. Named in the applicability - [AD 72-25-06](https://openairdocs.org/ad/72-25-06): Nose Gear Extension · Volpar Mark IV tricycle landing gear (Southwestern Aero Exchange STC SA111WE or 2 others). Effective Dec 9, 1972. Named in the applicability - [AD 66-30-01](https://openairdocs.org/ad/66-30-01): Static Pressure Line · Volpar Mark IV tricycle landing gear (Southwestern Aero Exchange STC SA111WE or SA4-1531). Named in the applicability ## Approved models (5) - Raytheon Aircraft Company C-45G ([TCDS A-765](https://openairdocs.org/tcds/A-765)) - Raytheon Aircraft Company C-45H ([TCDS A-765](https://openairdocs.org/tcds/A-765)) - Raytheon Aircraft Company D18S ([TCDS A-765](https://openairdocs.org/tcds/A-765)) - Raytheon Aircraft Company TC-45G ([TCDS A-765](https://openairdocs.org/tcds/A-765)) - Raytheon Aircraft Company TC-45H ([TCDS A-765](https://openairdocs.org/tcds/A-765)) ## 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. This Certificate issued to Southwestern Aero Exchange, Inc. 18502 East 108th Street, North Owasso, OK 74055 Part CAR 3 of the Civil Air Regulations. A-765 BEECHCRAFT C-45G, C-45H, TC-45G, TC-45H & D-18S Description of Type Design Change: Installation of Tricycle Landing Gear and Revised Nose Assembly with Optional Radome in accordance with Volpar Drawing List No. 428. Limitations and Conditions: 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 approval of this change in type design applies basically to the Standard Beech Models C-45G & H, TC-45G & H, and D-18S only. This approval should not be extended to other specific airplanes of these models on which other previously approved modifications are incorporated unless it is determined that the interrelationship between this change and any of those other previously approved modifications will introduce no adverse effect upon the airworthiness of that airplane. See Reverse Side for Additional Limitations for Applicability. This certificate and the supporting data, which is the basis 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: May 25, 1961 Date of issuance: June 20, 1961 Date reissued: Jan. 23, 1998; Feb. 27, 2006 Date amended: Sep. 1, 1961; May 29, 1963 ( Signature) Manager, Technical & Administrative Support Staff, Los Angeles Aircraft Certification Office ( Title) Number SA4-1531 **LIMITATIONS OF APPLICABILITY (CONTINUED)** AD-53-6-3 is to be accomplished prior to installation of the new gear assembly. All nose gear cylinder castings are to be inspected per Volpar “Quality Control Procedure Cylinder Casting P/N 309A” dated July 25, 1961. Volpar Airplane Flight Manual Supplement dated September 1, 1961, is required as part of this modification. The agency installing this STC Kit will provide an adequate weight and balance report with each modification. The maximum gross weight of each airplane incorporating this STC must not exceed the FAA approved maximum gross weight for that particular model airplane listed in Aircraft Specification A-765. The airplane gross weight may be increased to 9800 pounds when the provisions of STC’s SA2-820 or SA4-1462 are incorporated. The approved C. G. ranges for airplanes incorporating this new landing gear are as follows: (a) Maximum gross weight of 9300 pounds: 8600 pounds from station 107.0 to station 118.8 9300 pounds from station 109.8 to station 118.8. linear variation between above weights. (b) Maximum gross weight of 9800 pounds: 8600 pounds from station 107.0 to station 118.8 9800 pounds from station 111.7 to station 117.7 linear variation between above weights. - END - ## Every issue (1) - February 27, 2006: Reissued, Current. [certificate](https://openairdocs.org/files/sha256/d3/71/d37198bc115073270544334890e566329f1f1894bbcdc386f80b58fe0db374e6) --- 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.