# STC SA525NW - Type: Supplemental type certificate - Status: Current, Reissued - Holder: Kenmore Air Harbor LLC, United States - Description: Installation of Continental IO-520-D engine and McCauley D2A34C58/90AT-4 propeller. - Applied: September 20, 1977 - Status date: April 5, 2019 - Product: Aircraft, Small Airplane - Certification basis: Part 3, Part 21 - Data sheets: [TCDS 3A24](https://openairdocs.org/tcds/3A24) - Certificate PDF: https://openairdocs.org/files/sha256/03/85/0385397210cdf7e7978889da069da06646b5f9c306740b3f37483599c81a205f - FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/F2AEF41E5E5A9BD7862585CE00548B2F.0001 - DRS record last changed: December 6, 2025 - Page: https://openairdocs.org/stc/SA525NW ## ADs that name it (0) None. ## Approved models (7) - The Cessna Aircraft Company 185 ([TCDS 3A24](https://openairdocs.org/tcds/3A24)) - The Cessna Aircraft Company 185A ([TCDS 3A24](https://openairdocs.org/tcds/3A24)) - The Cessna Aircraft Company 185B ([TCDS 3A24](https://openairdocs.org/tcds/3A24)) - The Cessna Aircraft Company 185C ([TCDS 3A24](https://openairdocs.org/tcds/3A24)) - The Cessna Aircraft Company 185D ([TCDS 3A24](https://openairdocs.org/tcds/3A24)) - The Cessna Aircraft Company 185E ([TCDS 3A24](https://openairdocs.org/tcds/3A24)) - The Cessna Aircraft Company A185F ([TCDS 3A24](https://openairdocs.org/tcds/3A24)) ## 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 SA525NW This certificate, issued to Kenmore Air Harbor, LLC. 6321 NE 175th Street Kenmore, WA 98028 Part 3 of the Civil Air Regulations,dated May 15, 1956, as amended by 3-1 though 3-5. Original ProductType Certificate Number: 3A24 Make: Cessna Model: 185 Through 185E Description of the Type Design Change: Installation of a Continental IO-520-D engine and a McCauley D2A34C58/90AT-4 propeller in accordance with Kenmore Air Harbor, Inc. Installation Instructions No. K9341. Limitations and Conditions: Approval of this change in type design applies basically to the above aircraft model 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 of those other previously approved modifications, including changes in type design, will introduce no adverse effect upon the airworthiness of that aircraft. This approval is extended to installation in the above models with Edo Model 582-3430 seaplane floats in accordance with STC SA526NW, and a 3-bladed propeller in accordance with STC SA240NW. A copy of this Certificate and Addendum No. SA525NW shall be maintained as part of the permanent records for the modified 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. Date of application: September 20, 1977 Date reissued: April 5, 2019 Date of issuance: October 11, 1977 Date amended: FAA FORM 8110-2 (5/14) PAGE 1 OF 4 PAGES By direction of the Administrator (Signature) Acting Manager, Seattle ACO Branch (Title) Transfer the ownership of Supplemental Type Certificate Number to (Name of Transferee) (Address of Transferee) (Number and Street) (City, State, and ZIP Code) from (Name of Grantor) (Print or Type) (Address of Grantor) (Number and Street) (City, State, and ZIP Code) Signature of Grantor (In Ink): U.S. GPO: 1987-763-289 Number SA525NW Kenmore Air Harbor, LLC. Issued: October 11, 1977 Reissued: April 5, 2019 **SUPPLEMENTAL TYPE CERTIFICATE ADDENDUM NO. SA525NW** The conditions and limitations of Type Certificate Data Sheet No. 3A24 apply except where superseded by the following: This Addendum, which is part of the Supplemental Type Certificate No. SA525NW, prescribes the conditions and limitations under which the STC was issued and meets the airworthiness requirements of Civil Air Regulations Part 3. A copy of this Addendum shall be maintained as part of the modified aircraft permanent records. SUPPLEMENTAL TYPE CERTIFICATE HOLDER: Kenmore Air Harbor, LLC. **CESSNA 185 THRU 185E, 6PCL-SM (NORMAL CATEGORY) AS MODIFIED BY STC SA525NW** Engine: Continental IO-520-D Fuel: 100/130 octane minimum grade aviation gasoline Engine Limits: Takeoff (5 min.) – 2850 rpm, 300 hp Maximum Continuous Power – 2700 rpm, 285 hp Propeller and: McCauley D2A34C58/90AT (Landplane) Propeller Limits: Diameter: Not over 86”; not under 80.5” Pitch Settings at 36” Sta: Low – 9.5º; High 25.8 º McCauley D2A34C58/90AT (Floatplane) Diameter: Not over 86”; not under 84.5” Pitch Settings at 36” Sta: Low – 8º; High 25º McCauley D3A32C90/82NC-2 (See STC SA240NW) EDO-AIRE Hydraulic Governor 34-828-01-1 Cessna Spinner 0752042-1 and Fillet 0752044-1 Woodward Hydraulic Governor A210462 McCauley Hydraulic Governor C290D2/T9 or C290D3/T9 **FAA FORM 8110-2 (5/14) PAGE 3 OF 4 PAGES** Number SA525NW Kenmore Air Harbor, LLC. Issued: October 11, 1977 Reissued: April 5, 2019 SUPPLEMENTAL TYPE CERTIFICATE ADDENDUM NO. SA525NW (Continued) Powerplant Instrument Markings: Oil Temperature: Green Arc 120ºF to 240ºF – normal operating range Oil Pressure: Green Arc 30 to 60 psi – normal operating range Red Line 20 psi minimum; 100 psi maximum Tachometer: Green Arc 2200 to 2550 rpm – normal operating range Red Line 2850 rpm – maximum Fuel Flow: Green Arc 7 to 17 gph – normal operating range Red Line 25 gph maximum at sea level Cylinder Head Temperature: Green Arc 200º to 460ºF – normal operating range Red Line 460º - maximum C.G. Range: Landplane – (See Data Sheet 3A24) Floatplane – EDO 249A-2870 and 628-2960 (See Data Sheet 2A24) Floatplane - (with EDO 582-3430 floats per STC SA526NW as follows:) (+41.9) to (+46.5) at 3350 pounds (+35.1) to (+46.5) at 2200 pounds or less Maximum Weight: Landplane – 3200 lbs. – 3300 lbs. (See Data Sheet 3A24) Floatplane – with EDO 249A-2870 and 628-2960 floats, see Data Sheet 3A24. Floatplane – with EDO 582-3430 floats, see STC SA526NW - END - **FAA FORM 8110-2 (5/14) PAGE 4 OF 4 PAGES** ## Every issue (1) - April 5, 2019: Reissued, Current. [certificate](https://openairdocs.org/files/sha256/03/85/0385397210cdf7e7978889da069da06646b5f9c306740b3f37483599c81a205f) --- 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.