# STC SA4850NM - Type: Supplemental type certificate - Status: Current, Amended - Holder: Coulson Aviation (USA) Inc., United States - Description: Installation of Retardant Tanks for the special purpose of Forest and Wildlife Conservation - Applied: October 4, 1989 - Status date: August 14, 2014 - Product: Aircraft, Large Airplane - Certification basis: Part 21, Part 25 - Data sheets: [TCDS T00019LA](https://openairdocs.org/tcds/T00019LA), [TCDS A15NM](https://openairdocs.org/tcds/A15NM) - Certificate PDF: https://openairdocs.org/files/sha256/b7/62/b76291b34aea44ba31c7174bd491e276e574a854452217dbd5dfae5367a8e746 - Approved model list and other attachments: [AML SA4850NM.pdf](https://openairdocs.org/files/sha256/7e/4e/7e4e22cbad4ff4894256633899adbd09ed175e9325167e077ae0bedaf8ead07c) - FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/538F12FE6655CB4486257D3900605B5D.0001 - DRS record last changed: December 6, 2025 - Page: https://openairdocs.org/stc/SA4850NM ## ADs that name it (0) None. ## Approved models (2) - Coulson Aviation (USA) Inc. EC-130Q ([TCDS T00019LA](https://openairdocs.org/tcds/T00019LA)) - USDA Forest Service C-130A ([TCDS A15NM](https://openairdocs.org/tcds/A15NM)) ## 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 SA4850NM This Certificate issued to Part 25 of the Federal Aviation Regulations. Description of Type Design Change: Installation of Retardant Tanks for the special purpose of Forest and Wildlife Conservation on C-130A and EC-130Q models in accordance with the Master Data Lists noted in AML SA4850NM. The FAA approved Airplane Flight Manual Supplements listed in AML SA4850NM are also required as part of this approval. Limitations and Conditions: The approval of this change applies to the models listed on FAA approved AML SA4850NM only. This installation should not be incorporated in any aircraft unless it is determined that the interrelationship between this change and any previously approved configuration will not introduce any adverse effect upon the airworthiness of the aircraft. 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. Coulson Aviation (USA) Inc. 655 South Rock Blvd. Reno, NV 89502 See AML No. SA4850NM See AML No. SA4850NM See AML No. SA4850NM Original Product Type Certificate Number : Date of application : October 4, 1989 Date of issuance : March 28, 1990 Date reissued : May 29, 2012 Date amended : April 25, 1991; August 23, 2013; August 14, 2014 (Signature) Manager, Airframe Branch Los Angeles Aircraft Certification Office (Title) Number SA4850NM Limitations and Conditions continued Limitations specific to C-130A model Max takeoff gross weight not to exceed 120,000 lbs. Max zero fuel weight shall be 97,000 lbs. Max retardant weight shall be limited to 27,000 lbs. If operations in severe turbulence cannot be avoided, then do not exceed 65 kts above power off stall speed. Power off stall speed to be determined by the instantaneous operating weight using Figure 6-1 of USAF T.O. 1C-130A-1. Turbulent penetration speed not to exceed 180 kts. The eleven vertical cable tie-downs per side and the nine off-vertical cable tie-downs per side for the retardant tanks shall have minimum breaking strength of 7,000 lbs. each. Cable tie-down angles and preload are critical and installation must follow the Installation Drawing 11648-001. Carriage of cargo follows limitations and conditions contained in USAF T.0. 1-130A-9 cargo loading and handling manual and weight and balance requirements contained in USAF T.0. 1-130A- 5 and 1-1B-40 manuals. Material may be carried by removal of the retardant tanks and installation of the cargo floor as defined by the FAA approved Aero Union Report: Aircraft Inspection and Maintenance Manual for the Retardant Aerial Delivery System dated April 8, 1991. The above report defines both the installation and removal of the cargo floor and installation and removal of the retardant tank. Number SA4850NM Limitations and Conditions continued Limitations specific to EC-130Q model Max takeoff gross weight not to exceed 150,718 lbs. without external tanks Max takeoff gross weight not to exceed 155,000 lbs. when external tanks are installed Max zero fuel weight shall be 115,000 lbs. Max retardant weight shall be limited to 31,500 lbs. If operations in severe turbulence cannot be avoided, then do not exceed 65 kts above power off stall speed. Power off stall speed to be determined by the instantaneous operating weight using CAG109, section 2, page 3. Turbulent penetration speed not to exceed 180 kts. Carriage of cargo follows limitations and conditions contained in Coulson AFM, Chapter 6, pages 19 and 20, cargo loading and handling manual and weight and balance requirements contained in Coulson AFM, Chapter 6. Material may be carried by removal of the retardant tank and installation of the cargo floor as defined by the Instructions for Continued Airworthiness, Coulson document CAG1126, Revision NC or later FAA accepted revision. The above report defines both the installation and removal of the cargo floor and installation and removal of the retardant tank. Number SA4850NM Limitations and Conditions continued Limitations for all models Retardant drop shall be limited to speeds less than 150 knots and greater than 1.25 Vs and greater than Vmc. Max vertical acceleration at the C. G. shall be limited to 2.5 G flight load factor, flaps retracted. Outboard wing fuel must exceed inboard wing fuel by 617 lbs. per side or more. If a cross wind landing with full retardant tanks results in severe misalignment at touchdown, a special inspection is necessary before further flight for main landing gear structural components and supporting structure, the fuselage structure between the main gears, and the nose landing gear structures. The airplane operation is limited to wind conditions in the drop zone of 40 kts over the ridges. The fuselage pressure relief valve setting must not exceed 5.14 psi. (10.46 in Hg) This STC installs retardant tanks for the special purpose of Forest and Wildlife Conservation in Restricted Category in accordance with CFR 21.25(b)(2). Persons may be carried provided they perform an essential function necessary for the accomplishment of the special purpose of forest and wildlife conservation. Carriage of cargo also follows limitations and conditions contained in CFR 91.313: No operations for other than the special purpose of forest and wildlife conservation; carriage of persons or cargo for compensation or hire is prohibited. A special purpose operation for forest and wildlife conservation involving the carriage of persons or material is not considered the carriage of persons or property for compensation or hire. - END - ### AML SA4850NM.pdf This is OCR from the scanned FAA attachment. OCR can misread letters and numbers. *14 CFR requirements of Part 25 given in Aero Union Report 1130 "Compliance Plan", dated November 14, 1989. Item Revision IR: Initial Release Inc. (USA) Aviation Coulson Service Forest USDA Make Aircraft EC-130Q C-130A Model Aircraft T00019LA AI5NM Number Certificate Type Original INSTALLATION OF RETARDANT AERIAL DELIVERY SYSTEM (RADS) T00019LA forth in TCDS certification basis is set 21.25(b)(2), forth in TCDS A15NM certification basis is set 21.25(b)(2), Alteration Certification Basis for FAA APPROVED MODEL LIST (AML) NO. SA4850NM Page 1 of 1 FAA approved revision dated 8/21/13, or later CAG1128, Rev. IR, approved revision 3/21/90, or later FAA Supplement dated Aero Union AFM Supplement Airplane Flight Manual For COULSON AVAITION GROUP Los Angeles Aircraft Certification Office Manager, Airframe Branch FAA Approved: St approved revision approved revision 8/7/13, or later FAA 8/4/13, or later FAA CAG1126, Rev NC, dated 11663, Rev. C, dated approved revision approved revision 4/6/91, or later FAA 11/27/90, or later FAA 1126, Rev. IR, dated 11663-101, dated Airworthiness (ICA) Master Drawing List Instructions for Continued FAA Approved Issue Date: dated 8/23/13 Rev IR, dated 8/23/13 Rev IR, Number Amendment AML Aug 23, 2013 ## Every issue (4) - August 14, 2014: Amended, Current. [certificate](https://openairdocs.org/files/sha256/b7/62/b76291b34aea44ba31c7174bd491e276e574a854452217dbd5dfae5367a8e746), [AML SA4850NM.pdf](https://openairdocs.org/files/sha256/7e/4e/7e4e22cbad4ff4894256633899adbd09ed175e9325167e077ae0bedaf8ead07c) - August 23, 2013: Amended, Historical. [certificate](https://openairdocs.org/files/sha256/d9/d1/d9d1d4338bfd8218e8fb090f31cb6b530a2e50c95b5b23fd774dd6233c9592d1), [AML SA4850NM.pdf](https://openairdocs.org/files/sha256/7e/4e/7e4e22cbad4ff4894256633899adbd09ed175e9325167e077ae0bedaf8ead07c) - May 29, 2012: Reissued, Historical. [certificate](https://openairdocs.org/files/sha256/b9/ff/b9ff2d0d49d6dc554514ea10874609041aa922e064428b01ef92403cfdbea8fb) - April 25, 1991: Amended, Historical. [certificate](https://openairdocs.org/files/sha256/d2/6c/d26c5f9c5e50cc0acedd974c98391bccb10b781ec6392958a71a83a0a175305b) --- 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.