The assignee ranking in this dataset covers 54 companies and institutions across 124 records, with the leading assignee alone holding 25 records. The top 5 assignees together account for 50.0% of all records in scope, and the top 10 reach 74.2%, so filing activity is concentrated among a small group of aerospace manufacturers and research institutions rather than spread evenly. Beyond that group, most other entities appear with only one or two filings each, forming a long tail of occasional contributors.

Filings rose steadily through the late 2010s and peaked at 29 records in 2020. Comparing 2021 (3 records) to 2024 (2 records), the last window that can be treated as complete, filings fell by 33%. Data from 2025 onward is still incomplete because publication typically lags filing by about 18 months, so it is too early to call the current trajectory a continued decline.

The overwhelming majority, 83.1% of the 124 records, fall under IPC class B64C, which covers aeroplanes and helicopters, confirming this is primarily an airframe structures technology. Smaller shares extend into wind motors, turbines and solid-state devices, reflecting actuator and flexible-skin concepts shared with other machinery. Because a single record can carry multiple IPC codes, these shares add up to more than 100% of the record total and should not be summed as if they were mutually exclusive categories.