M-SAT Spec Installations Monitors Literature Field Installs Partnerships FAQ's Contact Us
Field Approval Process Page
for guidance in obtaining a Field Approval.
Data Package Page
supporting documentation for data package
Drawings Page
 detailed drawings for mounting configs
Field Approval Process  

Note: The developed mounting point on the aircraft is a major/minor alteration requiring a field approval and the camera assembly is an STC product. Typical of a one-time approval, however, installation on identical make and model aircraft can be granted if the FAA inspector is satisfied and signs Block 3 that grants duplication of data for the original Form 337.

Excerpt from: FAA Order 8900.1 CHG 24, Vol 4, Chapter 9 Section 1, dated 07/03/2008 - full text on FAA site is here.

Figure 4-68, Major Alterations Job Aid

Note: An ASI will seek guidance in Figure 4-68 to determine when additional coordination with a DER or the ACO may be necessary.

Items with the letters STC require an STC.

Items with the letters EVL may be eligible for approval by means other than an STC, depending on the scope and complexity of the alteration. These items will not automatically qualify for a field approval; they require evaluation and review of guidance to determine if the field approval process may be used.

Items with the letters ENG may be eligible for approval by means other than an STC, but require either supporting DER engineering data or concurrence from the ACO for field approval.

Figure 4-68 below is just a snip of a very long list of criteria, the section below applies for exterior mounted FLIR systems.

click on numebrs to view procedures

Excerpts from: AC 43-210A dated 08/17/2016.  For full text reference AC 43-210A Chapter 3.

This reference material describes a standardized procedure for requesting
approval of technical data associated with major repairs/major alterations.

General Information. An applicant must use approved technical data to accomplish a major alteration or repair on a product and approve the product for return to service. An applicant must perform three major steps when performing a major repair or major alteration: (1) conduct research, (2) evaluate the data, and (3) perform the repair or alteration.

Plan the Repair or Alteration. You should review the repair or alteration to be performed to determine the effects to the proposed change as to whether certain aspects of the alteration or repair can be accomplished using "acceptable data" and/or whether other aspects of the alteration or repair require "approved data". See field approval intro page (1) for the difference.

[1] Determine the Repair or Alteration Classification. Determine if the repair/alteration is a minor change in type design (as defined in 14 CFR part 21, § 21.93) to the product’s type design; and if so, is it a major or a minor repair/alteration. fig 3-1

[2] Minor Repair or Minor Alteration. If you are properly authorized, you may perform a minor repair/alteration using "acceptable data", and without "approved data". fig 3-1

[3] Major Repair or Major Alteration. You must perform a major repair or major alteration using "approved data". fig 3-1

[4] Major Changes to Type Design. Major repairs/major alterations that are major changes to type design require an STC or an amended type certificate (TC). The field approval process is not available in these cases. fig 3-1

Gather Data. Gather and organize data describing and substantiating the proposed repair/alteration.
The Data Package Page contains supporting documents and data for a complete package.
The Drawings Page supports previously approved installations on both "honeycomb" and "skin & rib" structures.

[5] Prepare the Data Package. To organize project data and standardize the field approval process, we recommend using a data package. A typical data package should include the following items contained in the Data Package Page  fig 3-1

[6] Provide Data Package to the ASI. Send a complete data package to the ASI. Using the checklist is one way to organize data and may help prevent omissions.  fig 3-1

[7] When the ASI receives the package, the ASI will review it to determine if the field approval request is appropriate. fig 3-1

1. Minor alterations/repairs do not require approved data.
2. The Major Repair and Alteration Data Approval Job Aid describes repairs and alterations within the scope of a field approval (fig 4-68).
3. The ASI will examine the data to see if it has been approved. If all the required data is approved, then further approval is not required.
     If any required technical data is not approved, then you can obtain approval from a DER, an ODA, or by requesting a field approval. fig 3-1

[8] After the ASI has reviewed the data package and/or inspected the aircraft, and can approve the repair/alteration, the ASI may (1) approve the data package only, or (2) approve the repair/alteration on FAA Form 337 by physical inspection. The ASI will sign and date block 3 indicating approval. The ASI enters one of two statements: fig 3-1

1. First statement: “The data identified herein complies with the applicable airworthiness requirements and is approved for the above described aircraft, subject to conformity inspection by a person authorized in § 43.7.”

Note: This statement is entered on block 3 of FAA Form 337 when the ASI reviews a data package and completes data approval.

2. Second statement: “Approval by Physical Inspection, Demonstration, Testing, etc. One Aircraft: The repair or alteration identified herein complies with the applicable airworthiness requirements and is approved for the above described aircraft, subject to conformity inspection by a person authorized in § 43.7.”

Note: This statement is entered on block 3 of FAA Form 337 when the ASI makes a physical inspection of the aircraft, or the applicant satisfactorily performs a demonstration or other type of test and the ASI completes an installation or repair approval.

DER Data Approval. A properly authorized DER is a designee of the FAA whom an applicant may employ to provide approved technical data to support a major repair/major alteration. If a DER has, or multiple DERs have, provided necessary approved data for the repair/alteration before involving the ASI, then no field approval is required.

ODA Data Approval. You may employ an ODA holder to provide approved technical data to support a major repair/major alteration. If the applicant employs a DER or ODA to provide approved technical data to support a major repair or major alteration, then the applicant is responsible for ensuring that the DER or ODA is authorized to approve such technical data, as applicable to the repair or alteration. If the data, as approved, addresses the entire repair or alteration, and all of the requirements of parts 21 and 43 are met, there is no requirement for any further approval by the ASI. If the repair or alteration data is approved solely by the DER, ODA, or DAR, but necessitates maintenance instructions, the maintenance instructions should be prepared by the applicant and recorded in block 8 of FAA Form 337. Maintenance instructions are in the form of flight manual supplements and instructions for continued airworthiness, guides and templates are included in the data package page specific for the installation of this FLIR camera system.

Note: The person performing the alteration, not the ODA, must conform and approve the installation from ODA-approved data. ODA data does not constitute a field approval, but is approved data that, like other approved data, can be used for major repairs/major alterations without further approval if the data addresses the entire repair/alteration. In this case, the applicant does not need to request a field approval.

[9] Perform Repair or Alteration. After the repair or alteration data is approved, an applicant can alter or repair the aircraft or one of its components. When the work is complete, you should review the requirements of 14 CFR part 91, § 91.407, and determine if a flight check is required. Complete FAA Form 337 and follow procedures in part 43 appendix B. fig 3-1

There Are Three Types of Field Approvals

What is a Field Approval?

A Field Approval is the granting, by an FAA airworthiness inspector, of FAA “approval” for a major repair or major alteration. The approval is given only after conducting a physical inspection and/or after reviewing data. There are three different kinds of Field Approvals for which the local FAA inspector can sign off:

1- EXAMINATION of data only:

This is the most common form of Field Approval. The mechanic or repairman submits “acceptable” data to the local FAA office for approval. The “approved data” can be used to perform a major repair or major alteration. Once the data has been approved under this procedure it can be used only for that one aircraft (described in Block 1 of FAA Form 337). However, if you want to do the exact same repair or alteration to another like make or model aircraft you can use the original Form 337 as the basis for obtaining a new Field Approval for the second aircraft.

2- PHYSICAL INSPECTION, demonstration or testing of the repair or alteration:

This is rarely done except in cases where technicians find unapproved engine or components installed on aircraft, which apparently have been installed for some time. Since the aircraft has flown successfully for many hours, an FAA inspector can, if satisfied with the installation, approve the installation. He does so by signing a new Form 337.

3- EXAMINATION of data only for duplication on identical make and model aircraft by the original modifier:

This is a procedure that saves the maintenance technician and the FAA a lot of time. For example, one technician wants to install duplicate cameras on as many identical make and model aircraft as possible. The technician can submit the data to be approved along with a request that the data approval be extended to other identical aircraft. The FAA inspector, if satisfied, signs Block 3 that grants duplication of the data for the original Form 337. When the technician finishes a duplicate alteration on other aircraft, he sends the FAA a regular Form 337, properly filled out listing the “approved data” on the back and making references to the Field Approval. To avoid problems, attach a duplicate copy of the original Field Approval Form 337.


1- First, do not make any changes to the aircraft until you receive the approval. The only thing worse than not getting a Field  Approval is
    telling your customer the expensive equipment you installed in his aircraft has to be removed.

2- Determine if the repair or alteration is minor or major.

3- Research all sources for "acceptable data" (minor) or “approved data” (major) to make the repair or alterations.

4- Find out what kind of data the inspector wants to see, then assemble it in a reasonable and understandable format. The data must be
    current, accurate and must support as well as describe the alteration or repair. Data can be in the form of drawings, sketches or
    photographs and assembled into a data package for presentation.

5- A cover letter for the Form 337 describing in detail how you are going to accomplish the repair or alteration is also helpful. With your
    research completed, send the FAA inspector duplicate copies of the Form 337 along with the data you want approved.

Ultimately, even if the alteration to mount the camera is considered to be minor, the installation of the FLIR camera will need approval from a  DER, ASI and/or concurrence from the ACO for installation. A telephone conversation with your local ASI wouldn't hurt.

     TrueView EVS  LLC 2014                   High Performance  -  High Reliability  - Proven Airworthiness                              Support  |  Warranty