# STC SR01591NY-D

- Type: Supplemental type certificate
- Status: Current, Reissued
- Holder: Diagnostic Solution International LLC, United States
- Description: Installation of a Chadwick-Helmuth Vibration Monitoring System, VXP.
- Applied: June 13, 2003
- Status date: December 14, 2020
- Product: Aircraft, Rotorcraft
- Certification basis: Part 21, Part 29
- Data sheets: [TCDS H4SW](https://openairdocs.org/tcds/H4SW)
- Certificate PDF: https://openairdocs.org/files/sha256/a8/60/a8606f139c0da5e92925642531731f33bc6b8233c7a5d52b605589eb9c6c0ed5
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/C531FC74647C4D47862586CB004F50B4.0001
- DRS record last changed: December 6, 2025
- Page: https://openairdocs.org/stc/SR01591NY-D

## ADs that name it (0)

None.

## Approved models (3)

- Bell Helicopter Textron 412 ([TCDS H4SW](https://openairdocs.org/tcds/H4SW))
- Bell Helicopter Textron 412CF ([TCDS H4SW](https://openairdocs.org/tcds/H4SW))
- Bell Helicopter Textron 412EP ([TCDS H4SW](https://openairdocs.org/tcds/H4SW))

## 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 2 Number: SR01591NY-D This certificate issued to: Diagnostic Solutions International LLC 2580 East Philadelphia, Unit C Ontario, CA 91761 Part 29 of the Federal Aviation Regulations.

Original Product – Type Certificate Number: Make: BELL H4SW Model: 412, 412EP and 412CF Description of Type Design Change:

Configuration 1:

Installation of a Chadwick-Helmuth Vibration Monitoring System, VXP, installed in accordance with Keystone Installation Drawing List IDL00654 Rev. -, dated07/17/03.

Configuration 2:

Installation of a Honeywell Chadwick Model 15175 VXP System in accordance with Honeywell Master Drawing List 159-08344-0001 Rev. B dated July 24, 2013 or later FAA approved revision.

1) Keystone Helicopter Maintenance Man ual for Chadwick-Helmuth Model 15175 VXP System on a Bell 412 Aircraft, document number MM00654 Rev. – dated 7/15/03 or later FAA accepted revision is required for aircraft modified in accordance with Configuration 1; Instructions for Continued Airworthiness, Honeywell document number 71000028, Revision C, dated 6/2013 or later FAA accepted revision is required for aircraft modified in accordance with Configuration 2.

2) The installation should not be incorporated in any aircraft unless it is determined that the interrelationship between this installation and any previously approved configuration will not introduce any adverse effect on the airworthiness of the aircraft.

3) If the holder agrees to permit another person to use this ce rtificate to alter the product, the holder shall give the other person written evidence of that permission.

Date of Application: June 13, 2003 Date Reissued: June 5, 2009; March 24, 2020, December 14, 2020 Date of Issuance: July 18, 2003 Date Amended: August 6, 2013 By Direction of the Administrator Signature Original signed by Tina Miller for Charlene Combs Title Program Manager, Wichita ACO Branch

FAA Form 8110-2 (5/14) Page 2 of 2

Transfer Endorsement Transfer the ownership of Supplemental Type Certificate Number: SR01591NY-D To (Name and address of transferee) From (Name and address of grantor) Extent of Authority (if licensing agreement):

## Every issue (3)

- December 14, 2020: Reissued, Current. [certificate](https://openairdocs.org/files/sha256/a8/60/a8606f139c0da5e92925642531731f33bc6b8233c7a5d52b605589eb9c6c0ed5)
- April 24, 2020: Reissued, Historical. [certificate](https://openairdocs.org/files/sha256/88/a5/88a5400edceb8c1bb209a526fbb21150185fba5f9035ee803f950394fe072744)
- June 5, 2009: Reissued, Historical. [certificate](https://openairdocs.org/files/sha256/be/a8/bea8fefed430d57caf79565e5fbb9a8474a6fbdbac82e5c1f72ab35224b36760)

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