# STC SA253NW - Type: Supplemental type certificate - Status: Current, Reissued - Holder: Avcon Industries Inc, United States - Description: Installation of the Mark II performance system, including recontoured wing leading edge, recontoured flap leading edge, wing vortex generator removal, installation of wing stall strips and other minor refinements in accordance with Avcon Master Drawing List No. 1084 dated November 16, 2010, or later FAA approved revision. 350 Knot Vmo authorized if equipped in accordance with Avcon Master Drawing List No. 1084 dated November 16, 2010 or later FAA approved revision. An FAA Approved Airplane Flight Manual Supplement is required for each model. - Applied: March 10, 1975 - Status date: November 16, 2010 - Product: Aircraft, Small Multi-Engine - Certification basis: Part 21, Part 25 - Data sheets: [TCDS A10CE](https://openairdocs.org/tcds/A10CE) - Certificate PDF: https://openairdocs.org/files/sha256/72/5d/725ddaf7ee486f669433fc8439bbca927bfce206d30e6b6fd192c2c6af94a9af - FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/C407BE09628D87C38625783A00558CDA.0001 - DRS record last changed: December 6, 2025 - Page: https://openairdocs.org/stc/SA253NW ## ADs that name it (0) None. ## Approved models (2) - Learjet Inc. Learjet 24 ([TCDS A10CE](https://openairdocs.org/tcds/A10CE)) - Learjet Inc. Learjet 24A ([TCDS A10CE](https://openairdocs.org/tcds/A10CE)) ## 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: AVCON Industries, Inc 714 N. Oliver Road Newton, KS 67114-9444 Part 25 of the Federal Aviation Regulations. Original Product - Type Certificate Number: A10CE Make: Learjet, Inc Model: 24, 24A Description of Type Design Change: Installation of the Mark II performance system, including recontoured wing leading edge, recontoured flap leading edge, wing vortex generator removal, installation of wing stall strips and other minor refinements in accordance with Avcon Master Drawing List No. 1084 dated November 16, 2010, or later FAA approved revision. 350 Knot Vmo authorized if equipped in accordance with Avcon Master Drawing List No. 1084 dated November 16, 2010 or later FAA approved revision. An FAA Approved Airplane Flight Manual Supplement is required for each model. Date of application: March 10, 1975 Date of issuance: January 20, 1976 Date reissued: December 1, 1999; June 03, 2010; November 16, 2010 Date amended: May 08, 2001 Original signed by Grant E. Youngdahl ( Signature) Grant E. Youngdahl Program Manager Wichita Aircraft Certification Office (Title) FAA Form 8110-2-1(10-69) Page 2 of 3 FAA Form 8110-2-1(10-69) Page 3 of 3 Number SA253NW Date of Issuance: January 20, 1976 Date Amended: May 8, 2001 Reissuance Date: November 16, 2010 Limitations and Conditions (Continued): 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 previously approved modifications will introduce no adverse effect upon the airworthiness of that aircraft. 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 a product, the holder must give the other person written evidence of that permission. A copy of this Certificate and Addendum No. SA253NW shall be maintained as part of the permanent records for the modified aircraft. **SUPPLEMENTAL TYPE CERTIFICATE ADDENDUM NO. SA253NW** The limitations noted in Type Certificate Data Sheet No. A10CE are applicable except as follows: Section III Airspeed Limits (CAS) V a (Maneuvering) Sea Level 228 Knots 40,500 ft. 243 Knots V mc (Minimum Control Speed) Air 85 Knots V fe (Flaps extended) Landing 150 Knots Flaps 20° 200 Knots Flaps 10° 250 Knots V mo (Maximum operating) 300 Knots V mo 300 Knots from Sea Level to 14,000 ft. 350 Knots above 14,000 ft. Stabilizer Travel Limits Upper limit –0 052’ to –108’ Lower Limit –7 0 to –7030’ --END-- ## Every issue (2) - November 16, 2010: Reissued, Current. [certificate](https://openairdocs.org/files/sha256/72/5d/725ddaf7ee486f669433fc8439bbca927bfce206d30e6b6fd192c2c6af94a9af) - September 8, 2005: Reissued, Historical. [certificate](https://openairdocs.org/files/sha256/f7/d8/f7d87f5ddf2ec5327ded691f4264bee50c1b8fb3adc116241b6d6e2309ebd313) --- 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.