Definition
A configuration, modification, or operating condition of an aircraft that differs from its original type-certificated design but has been formally accepted by the FAA through a documented approval process such as a Supplemental Type Certificate (STC), field approval, or other authorized means.
Plain English
Changes to an aircraft from how it was originally built or certified, which the FAA has reviewed and officially allowed.
Context Anchor
Seen in discussions of airworthiness, aircraft records, inspections, and whether an airplane is legal and safe to fly.
Derivation
In everyday speech, 'altered' simply means changed. Here it has a regulatory weight: a change that affects the aircraft's certificated configuration. 'Approved' signals that the change is not just done, but officially sanctioned by the FAA.
Why Pilots Care
Maintains continued airworthiness and legal compliance by ensuring pilots observe the new requirements created by the approved change.
Intuition Check
Do not read “approved” as “someone thought it was okay.” Here it means the change has been allowed through the proper FAA process or authority. Do not read “altered conditions” as damage or a casual modification. Here it means a changed aircraft condition that is officially acceptable.
Example Sentence 1
The mechanic confirmed that the new avionics installation qualified as approved altered conditions because it was covered by an STC.
Example Sentence 2
The aircraft flight manual supplement listed the approved altered conditions that applied after the engine upgrade.