Martin Hollmann is a past Federal Aviation Administration (FAA), Consultant Designated Engineering Representative (DER) who was authorized to approve specific certification processes such as approving modifications in design, by flutter and stress analysis and parts for 14 CFR Part 23 General Aviation Aircraft. He works closely with other DERs who are approved to perform electrical, engine, noise and flight modifications. Following are steps and sources for documents needed for certification.

To upload FAA forms and get information on how to certify aircraft or obtain Supplemental Type Certification (STCs) go to www.faa.gov/aircraft/air-cert/

To find Type Certification Data Sheets (TCDS), select LICENSER & CERTIFICATION. Then select Aircraft and then Technical Information, Then Type Certification Data Sheets. Select By Make.

The certification process is  summarized in the following steps.

1. A letter of application (FAA Form 8110-12) is sent into the Aircraft Certification Office (ACO) close to the applicant by the applicant.

2. After no more than 90 days, the ACO assigns a project number and FAA project manager.

3. With the applicant selected DER, a Project Specific Certification Plan (PSCP) is sent to the FAA project manager. This includes a TC Compliance Checklist. See AC 23-25 App. 1 for an example.

4. The DER prepares test plans needed to show conformity to the FAA regulations. These are approved by the ACO.

5. Drawings are made for parts that are to be fabricated for the aircraft or modification. The DER approves these drawings with FAA Form 8110-3.

6. A Request for Conformity (RFC) and Conformity Inspection Plane (CFP Form 8120-10) for the fabricated parts is submitted electronically through the ASIP program by the DER.

7. A Designated Airworthiness Representative (DER) conforms the parts by inspecting them.

8. The tests and stuctural analysis necessary to show that the parts will meet the regulations (14 CFR Part 23 for General Aviation Aircraft) are prepared by the DERs. The tests are conformed by a DAR and witnessed by a DER.

9. The test reports and drawings are submitted to the FAA and about 4 weeks later, an STC is issued.

Simple modifications such as fatigue cracks, stress corrosion in main wing spars, repairs can be corrected and approved by a DER who fills out a Form 8110-3 in support of a FAA Form 337. An authorized Aircraft Repairman, a Inspector for Airworthiness (IA) puts the aircraft back into service.

FAA Flutter Certification can be performed by analysis only. Flight testing is dangerous and not required to meet the flutter criteria of paragraph p.23.629 Amdt 23-459a)(2), (b).

Congratulations! on your simplification of information so we may all soar! Great stuff. Professor Martin Graydon. Canada.

SAVE LIVES, Aircraft Certification and Modifications by Martin Hollmann is a brand new book available now!

The beginning tells in flight aircraft wings coming off. Hollmann could have easily helped all of these aircraft if the pilots had listened. With these stories in mind we look at how the FAA certifies aircraft and aircraft modifications. Hollmann, a FAA DER, goes through the step by step processes with examples for increasing gross weight of a Cessna 337 by performing landing gear drop tests. How to fix a major structural failure on an all composite, certified Cessna LC350 aircraft. Limit load and ultimate load analysis. Drawing formats and drafting practices. Noise compliance calculations or flight testing. Reinforcing Seneca 1 landing gear attachments and landing gear loads program. Fire Resistant testing. Electronic testing for EMI and electronic loads analysis. Motor mount stress and fatigue analysis. Continued airworthiness and much more. Showing methods of compliance is especially important to the new Light Sport Aircraft of which over 100 different models have been certified in the past 5 years. The unbelievable truth about LSA today which the public does not know. World’s first and only book on FAA certification. 110 pages and 75 figures. Introductory price $59.00

Below is a landing gear drop test performed to show that the gross weight of a Cessna 337 can be increased from 4,700 lbs to 5,120 lbs. Also see Landing Gear Load Programs by downloading free pdf file. Click here.

Also shown below is a burn test to show Fire Resistance per RTCA/DO-160E, Section 26. An engine cowl, composite coupon, is subjected to a 1,100 deg C flame. It must show no burn through for a 5 minutes flame. For Fire Proof, this test time is extended to 15 minutes.