Flight Data Recording Requirements for Part 91 and 135 Aircraft

March 18th, 2021

This guide is to help where Flight Data Recording Regulations, come into question for domestic aircraft transitioning to FAR Part 91 and 135 Operations, or a foreign aircraft imported into operations, under FAA registration.

Below is a High-Level view of both FAR Part 91 and Part 135 Operational requirements as it relates to FDR/DFDR requirements.

Reference Regulations

FAR 91.609 – Part 91 Operational Specifications
FAR 135.152 – Part 135 Operational Specifications
FAR 135 App E – Specific details FDR/DFDR conformity
FAR 25.1459 – Part 25 Installation Requirements
AC 20-141B – DFDR Advisory Circular

FAA Part 91 Operations or N Registered Aircraft Qualifiers:

Greater than 10 Seats excluding Required Crew
Multi Engine Turbine Powered
Domestic Registered Aircraft
• FAR 91.609 applies by date of issuance of Initial Certificate of Airworthiness
Foreign Registered Aircraft
• FAR 91.609 applies by date of issuance of Initial FAA Import Certificate of Airworthiness
– Not aircraft’s initial date of Airworthiness Certificate

FAR 91.609 FDR/DFDR Requirements - Certificate of Airworthiness issue date:

Before Oct 1991
• No requirement
Oct 1991 – Apr 2010
• 17 Parameter DFDR
• 8 Hour record time

After Apr 2010
• 17 Parameter DFDR
• 25 Hour record time
• Underwater Locator Beacon
• TSO-124

FAA Part 135 Operations of N Registered Aircraft Qualifiers:

10 – 19 Seats excluding Required Crew
Multi Engine Turbine Powered
Domestic Registered Aircraft
• FAR 135.152 applies by date of issuance of Initial FAA Airworthiness Certificate
• Never under foreign registry
Foreign Registered Aircraft
• FAR 135.152 requirements applies by date of issuance of Initial FAA Import Certificate of Airworthiness
– Not aircraft’s initial date of Airworthiness Certificate
• Can receive FAA Import Certificate of Airworthiness under Part 91 as long as
FDR system complies with FAR 91.609
• Must be in conformity with 135.152 prior to Part 135 Certificate of Conformity

FAR Part 135.152 FDR/DFDR Requirements - Certificate of Airworthiness issue date:

Prior to Oct 1969
• 11 Parameter FDR
• 8 Hours record time
Oct 1969 – Oct 1991
• 17 Parameter
• 8 Hours record time
Oct 1991 – Aug 2000
• 17 Parameter DFDR
• 25 Hour record time
• Underwater Locator Beacon
Aug 2000 – Aug 2002
• 57 Parameter DFDR
• 25 Hour record time
• Underwater Locator Beacon
After Aug 2002
• 88 Parameter DFDR
• 25 Hour record time
• Underwater Locator Beacon