Supplemental Type Certificates and Aging Aircrafts

Whether for passenger comfort, in-flight entertainment, connectivity solutions or safety aspects, operators are continuously upgrading their fleet to their required standards. While modifying a new aircraft may present concerns, modifying an aging aircraft raises uncertainty regarding the potential impact on the aircraft life limit, approved and published by the OEM. Notably the anticipated challenge can be elevated when an aircraft modification is completed with an approved Supplemental Type Certificate, through an independent modifier.

Many aircraft flying today are being operated well beyond their original Design Service Life limits for flight cycles and flight hours. They are able to operate in this manner because aircraft OEMs recognize the benefits of continued operation of these aircraft to their extended service limit. Through approved data defining operational limits, service bulletins and changes to maintenance programs, aircraft OEMs allow aircraft to safely operate beyond these initial service limits. Maintaining the airworthiness of the aircraft and keeping up with passenger, crew and pilot requirements means new aircraft modifications may be on the horizon.

Addressing the Concerns Associated with Retrofit Modifications on Aging Aircraft

We have taken a deep dive into this issue in one of our whitepapers. Based on our extensive expertise and IAMA Rulebook, the white paper provides a detailed examination of whether endorsed IAMA member-modifier retrofit solutions have any impact on aircraft operability and continuing airworthiness when exceeding original design limits. It explains why approved design and substantiation modifications are independent of original design limits or extended service limits for aging aircraft. Additionally, it details the measures independent modifiers, particularly those endorsed by IAMA, take to ensure safe aircraft operation beyond the original design limits towards extended service limits, exploring in-service and continuing airworthiness.

When considering a modification to an aging aircraft, irrespective of the approval process, regulatory airworthiness requirements are consistent across aviation certification authorities. It is no secret that approval timelines and processes vary across jurisdictions, but we have carefully and thoroughly considered the various processes. This exercise has helped clarify the situation and although an independent aircraft modifier is unlikely to extend aircraft life, the approved modifications they complete are accepted by aviation authorities. In general, such modifications will not have a negative effect on the ODSL or ESL of the aircraft. Additional inspections may be required, but the results are approved and accepted.