Form 337 Field Approval with
Instructions for Continued Airworthiness

Introduction

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We have created this video to provide an example of how to properly proceed with a Form 337 Field Approval with Instructions for Continued Airworthiness. While watching the video all the links for the items discussed can be found throughout this webpage.

Video Form 337 Field Approval with Instructions for Continued Airworthiness

Video Detailing how to proceed with Form 337 Field Approval with Instructions for Continued Airworthiness

Major Repair or Major Alteration ICA

One of the largest problems for FAA Inspectors and aircraft owners and their maintenance providers is the development of Instructions for Continued Airworthiness, or ICA when performing a Major Alteration in accordance with a FAA Field Approval.

In a majority of cases submitted to the FAA for approval, the ICA is not correctly developed, or is missing from the Form 337 as an Attachment. The FAA will reject the Form 337 causing operating delays for the aircraft owner, and creating, in many cases, a hostile situation which could have been avoided if done right.

Advisory Circular 43-210a covers the complete development of Major Alteration Field Approvals, including the development of ICA starting with paragraph 5. In Figure 5-1 of this AC, there is a template describing the “16” items required to be addressed on the ICA to be attached to the Form 337 for FAA approval.

The Form 337, is approved by the FAA in Block 3 while the ICA is accepted by the FAA unless another FAR is involved. If you follow the AC you’ll never get into trouble!

Developing a Project

The best course of action is to develop a Project Checklist that will detail exactly how the new panel project will proceed. This can be reviewed with the appropriate FAA person to whom you will ultimately submit the Form 337 and ICA. Getting input at the beginning will save you much heartache later! The AC will help you as well!

CESSNA INSTRUMENT PANEL PROJECT
1962 C182E

1. EXISTING INSTRUMENT PANEL(S)

The existing instrument panel actually consists of three (3) individual panels: Pilot, Co-Pilot, and Pilot-side sub-panel (“panels”). The Pilot panel is shock-mounted to protect installed gyro instruments and is attached to the two (2) upper shock mounts and attached directly to the lower structure. The Co-Pilot and Pilot sub-panels are not shock-mounted and merely attached to the sub-structure. Covering both Pilot and Co-Pilot panels are plastic overlays attached using Velcro to the underlying aluminum panels. The center structure between the Pilot and Co-Pilot panels accommodate the installation of radio and associated avionics equipment. (See photographs)

Inspection of the three (3) panels reveals they are 2024T3 Alclad aluminum .063 thick with an anodic protective coating. The panels are further described the Cessna C182E Illustrated Parts Catalog (“IPC”), Figure 53.

2.PROPOSED INSTRUMENT PANEL REVISION

A.Remove all existing overlays, instruments, and radio/avionics equipment.

B.Remove all three (3) existing panels exposing the underlying frame structure. (See photographs)

C.Overlay Plexiglas sheets over the Pilot and Co-Pilot underlying structure to indicate where instrument positions are available without any underlying interference. (See photographs)

D.Purchase an appropriate amount of 2024T3 Alclad .063 thick sheet aluminum to specification QQ-A-250/5 receiving appropriate material certifications. (Ref. Cessna Structural Repair Manual (“SRM”) ATA 51-30-00, section 2.

E.Using the completed Plexiglas overlays, fabricate each of the three (3) panels from the purchased material.

F.The completed three (3) panels will be powder-coated using Tiger Drylac Polyester TGIC, #38/30033, Boysenberry color with a matte finish, compliant with AAMA 2604. (Ref. https//www.tiger-coatings.com/us/products-specifications/tiger-drylacr-products#/show/38-30033)

G.Reattach the three (3) panels back onto the existing frame structure as were the original panels except the Pilot panel to use AN515B8R20 brass screws in the shock mounts per the IPC, Figure 53, item 44, and reinstall the instruments, radios and avionics as required per the Cessna C182E Service Manual, any revised equipment to be added through the Supplemental Type Certificate (“STC”) process, and any other components considered “Minor” as defined in Federal Aviation Regulations (“FAR”) Part 1 and Part 21.93, and Part 43, Appendix A.

3.ADVISORY CIRCULAR REFERENCES

AC 23-27 - Parts and Materials Substitution for Vintage Aircraft

AC 43-210A - Standardized Procedures for Obtaining Approval of Data Used in the Performance of Major Repairs and Major Alterations - Change 1

AC 20-62E - Eligibility, Quality, & Identification of Aeronautical Replacement Parts

AC 43-18 - Fabrication of Aircraft parts by Maintenance Personnel

AC 43.13-1B (par. 4-22 pars a&b) Acceptable Methods, Techniques, and Practices - Aircraft Inspection and Repair [Large AC. This includes Change 1.]

AC 43.13-2B (pars. 106, 113, 114, 201, 202, 203, 1100, 1103) Acceptable Methods, Techniques, and Practices - Aircraft Alterations

Completing the Project

In this training block is an example of a proper ICA and Form 337. You will see how the Form 337 is approved by the FAA in Block 3, and how the alteration is described in Block 8. Then view the Instructions for Continued Airworthiness and you will see why the ICA was necessary for continued maintenance and inspection.

NOTE 1:

Instructions for Continued Airworthiness is usually only required when an alteration is not already covered by FAA-approved data. An STC does not require any additional FAA approval if the STC directly applies to the specific aircraft involved list on the STC. STCs are required to contain ICA so a separate ICA is not required. In this case the Form 337 need only reference the STC.

Block 8 Form 337 Major Alteration

8. Description of Work Accomplished

(If more space is required, attach additional sheets. Identify with aircraft nationality and registration mark and date work completed.)

CESSNA 182E 182XXXXX

N12345 03/15/2021

Nationality and Registration Date

1.EXISTING INSTRUMENT PANEL(S)

The existing instrument panel actually consists of three (3) individual panels: Pilot, Co-Pilot, and Pilot-side sub-panel (panels). The Pilot panel is shock-mounted to protect installed gyro instruments and is attached to the two (2) upper shock mounts and attached directly to the lower structure. The Co-Pilot and Pilot sub-panels are not shock-mounted and merely attached to the

sub-structure. Covering both Pilot and Co-Pilot panels are plastic overlays attached using Velcro to the underlying aluminum panels. The center structure between the Pilot and Co-Pilot panels accommodate the installation of radio and associated avionics equipment.(See photographs)

2.PROPOSED INSTRUMENT PANEL REVISION

A.Remove all existing overlays, instruments, and radio/avionics equipment.

B.Remove all three (3) existing panels exposing the underlying frame structure. (See photographs)

C.Overlay Plexiglas sheets over the Pilot and Co-Pilot underlying structure to indicate where instrument positions are available without any underlying interference. (See photographs)

D.Obtain 2024T3 Alclad .063 thick sheet aluminum to specification QQ-A-250/5 with appropriate material certifications. (Ref. Cessna Structural Repair Manual (SRM) ATA 51-30-00, section 2.

E.Using the completed Plexiglas overlays, fabricate each of the three (3) panels from the material in D.

F.The completed three (3) panels to be powder-coated using Tiger Drylac Polyester TGIC, #38/30033, Boysenberry color with a matte finish, compliant with AAMA 2604. (Ref. https//www.tiger-coatings.com/us/products-specifications/tiger-drylacr-products#/show/38-30033)

G.Reattach the three (3) panels back onto the existing frame structure as were the original panels, except the Pilot panel to use AN515B8R20 brass screws in the shock mounts per the IPC, Figure 53, item 44, and reinstall the instruments, radios and avionics as required per the Cessna C182E Service Manual, any revised equipment to be added through the Supplemental Type Certificate

(STC) process, and any other components consideredMinoras defined in Federal Aviation Regulations (FAR) Part 1 and Part 21.93, and Part 43, Appendix A.

INSTRUCTIONS FOR CONTINUED AIRWORTHINESS

A/C Make: Cessna Model: 182 S/N: 182XXXXX Reg.#: N12345 Revision: O Date: 03/15/2021.

This sixteen-item checklist of Instructions for Continued Airworthiness (ICA), to comply with FAA Handbook Bulletin for Airworthiness (HBAW 98-18 Dated October 7, 1998), are applicable to the aircraft listed above.

1.Introduction

Fabricate each of the three (3) cockpit instrument panels to replace the original panels to accommodate the installation of modern radio and avionics equipment.

2.Description:

Remove all existing overlays, instruments, and radio/avionics equipment. Remove all three (3) existing panels exposing the underlying frame structure. Inspect the Pilot and Co-Pilot underlying structure to indicate where instrument positions are available without any underlying interference. Use 2024T3 Alclad .063 thick sheet aluminum to specification QQ-A-250/5. (Ref. Cessna Structural Repair Manual (“SRM”) ATA 51-30-00, section 2. The completed three (3) panels will be powder-coated after laser hole cutting using Tiger Drylac Polyester TGIC, #38/30033, Boysenberry color with a matte finish, compliant with AAMA 2604. (Ref. https//www.tiger-coatings.com/us/products-specifications/tiger-drylacr- products#/show/38-30033) Using the original fasteners, reattach the three (3) panels back onto the existing frame structure as were the original panels except the Pilot panel to use AN515B8R20 brass screws in the shock mounts per the IPC, Figure 53, item 44, and reinstall the instruments, radios and avionics as required per the Cessna C182E Service Manual D138-1-13, any revised equipment to be added through the Supplemental Type Certificate (“STC”) process, and any other components considered “Minor” as defined in Federal Aviation Regulations (“FAR”) Part 1 and Part 21.93, and Part 43, Appendix A.

3.Control:

No special controls.

4.Servicing information:

No special servicing required.

5.Maintenance Instructions:

Scratches in the panels may be brush-repaired with Tiger Drylac Polyester TGIC, #38/30033, Boysenberry color with a matte finish, compliant with AAMA 2604

6.Trouble shooting information:

No special troubleshooting required.

7.Removal and replacement information:

The Cessna C182E Service Manual D138-1-13 of the latest revision, sections 16 and 17.

8.Diagrams:

The Cessna C182E Service Manual D138-1-13 of the latest revision, sections 16 and 17.

9.Special inspection requirements:

Insure that panel attachments are secure during any required inspection.

10.Application of protective treatments:

Scratches in the panels may be brush-repaired with Tiger Drylac Polyester TGIC, #38/30033, Boysenberry color with a matte finish, compliant with AAMA 2604

11.Data:

2024T3 Alclad .063 thick sheet aluminum to specification QQ-A-250/5 (Ref. Cessna Structural Repair Manual (“SRM”) ATA 51-30-00, section 2. Tiger Drylac Polyester TGIC, #38/30033, Boysenberry color with a matte finish, compliant with AAMA 2604. (Ref. https//www.tiger-coatings.com/us/products- specifications/tiger-drylacr-products#/show/38-30033). AN515B8R20 brass screws in the shock mounts per the IPC, Figure 53, item 44. Refer to specific STC equipment installation data as required. AC 23-27, AC 43-210A, AC 20-62, AC 43-18, (to the current revisions), AC 43.13-1B (par. 4-22 pars a&b), AC 43.13- 2B (pars. 106, 113, 114, 201, 202, 203, 1100, 1103).

12.List of special tools:

No special tools required.

13.For commuter category aircraft:

Not applicable.

14.Recommended overhaul periods:

No recommended overhaul periods.

15.Airworthiness Limitation Section:

No airworthiness limitations.

16.Revision:

A letter will be submitted to the local FSDO with a copy of the revised FAA Form 337 and revised ICA. The FAA inspector accepts the change by signing Block 3 and including the following statement: “The attached revised/new Instructions for Continued Airworthiness (date) for the above aircraft or component major alteration have been accepted by the FAA, superseding the Instructions for Continued Airworthiness (date). “ Once the revision has been accepted, a maintenance record entry will be made, identifying the revision, its location, date of the Form 337.

Example of a Panel Project

This example relates to fabricating a new instrument panel to install the latest Garmin avionics equipment and other items not referenced in the original Equipment List. You must do proper research before any alteration actually takes place – “measure twice, cut once!”

Aircraft instrument panels are not all the same. Some are structural, some are not. Those that are structural take more research such as specific material, thickness, attach points, etc. On many aircraft, especially CAR3, the instrument panels overlay the fuselage structure and attach to it. Our example will be a 1962 Cessna 182E model. You can see in the picture that the underlying structure has not been touched. The newly fabricated panel will merely attach to the structure using the original fasteners.

Repair Schemes

Do Your Research

There are numerous details you will need to research. The first will be the Aircraft Maintenance Manual or Structural Repair Manual (SRM) if available. In there you should find various repair schemes that should disclose the type and thickness of the panel material. A major concern will be the weight of what you intend to install. Obviously, the newer radios and instruments weigh far less than the older ones. A new Garmin™ 430/530 weighs far less than the older King™, Collins™, and NARCO™ units. Also, if you are removing such items as an ADF, etc., there is a lot of weight saving. This can be used to convince the FAA that the original type and thickness will certainly support the new installation, but you will need to show some calculations to them.

Garmin™ 430/530

Cessna 182E Maintenance Manual

Locating the Data Needed to Fabricate

If you refer to the Cessna 182E Maintenance Manual you will locate the data needed to fabricate the new panel. The Maintenance Manual states, “2024T3” and AlClad™”, and a thickness equal to the original. You can always go thicker, but you will have a hard time convincing the FAA to go thinner. If the original thickness is not available, just measure it with a micrometer or verniers. When you purchase the new panel material, buy it from a reputable company, and always get material certifications attesting to what it really is.

Material Certification

Creating a Template

Using Plexiglas™, cut a piece the size of the new panel and lay it over the revealed panel structure attaching it with the original fasteners. Looking now through the Plexiglas you can see where the structure is relative to where you want to install the new instruments to assure they will not interfere with either the structure or perhaps the yoke. Using a Sharpie™, carefully outline where the new instruments will be installed. Now cut the holes in the Plexiglas.

Lay the Plexiglas™ over the new panel and scribe the hole outlines. You are now ready to get the panel holes cut. They can be laser-cut, hand-cut, or any other method that will be appropriate. After the panel holes are cut, attach the new panel to the structure just to assure everything is correct. Remember, “Measure twice, cut once!”

Plexiglas™ Overlay & Color Coating

If the new panel checks out, apply whatever color coating you want assuring that coating complies with a published specification. Don’t “rattle-can” paint the panel! There are numerous coatings available such as Powder Coating, etc. Once the panel is properly coated, you will need to address any placards required by the Certification Basis of the aircraft (CAR3/FAR23), the Aircraft Flight Manual, any Ads, etc. These can be applied by various methods such as Silk Screen, Dymotape™, or any other method as long as they are in the correct location according to CAR3/FAR23, legible, and cannot be “…easily erased or become illegible.”

NOTE 2:

Do not try to put everything on this Form 337, which is just for the new panel. This example only addresses the fabrication of the new panel, not what instruments will be installed. (That should take another Form 337). Any original instruments reinstalled will not require FAA approval. You can reference the FAA AC43.13-2B chapter on relocating instruments. The installation of Garmin™ instruments are all covered by STCs. (See Note 1)

Completed Project

Lastly, you may have to obtain specific structural data from the aircraft manufacturer. In many cases you may have to have input from a DER. Make sure you research everything and develop a Project Checklist.

Use AC 43-210a as a guide.

When your project is completed it can look like this and will be FAA approved!

Form 337 Field Approval withInstructions for Continued Airworthiness