General Electric Company and its aviation systems affiliate hold several of the most-cited records in this dataset, including foundational filings on hybrid-electric propulsion systems published between 2016 and 2020. That said, their recorded filing activity in the most recent tracked year is zero, meaning their position rests on claims staked out during the 2017-2019 peak rather than ongoing filing. Newer or smaller entrants, including academic institutions, show more recent but far lower-volume activity, so leadership by citation count and leadership by current filing momentum are not the same thing here.

The dataset shows filings rising from 8 in 2017 to a peak of 17 in 2018, then falling through subsequent years to a single filing by 2022. This pattern is typical of a field where a small number of applicants claimed the core architectural concepts — turbomachine-to-propulsor coupling, electric-mode decoupling, boundary layer ingestion — early, leaving less obvious ground for follow-on filings. It is worth remembering that publication lags filing by roughly 18 months, so the apparent decline in the most recent one to two years is partly a reporting artefact rather than a real drop in activity.

In this dataset, boundary layer ingestion claims describe propulsor placement and inlet design intended to capture and re-energise the slower-moving air along the airframe surface, improving propulsive efficiency. Because these claims often combine airframe geometry with propulsor operating mode, a new design that changes either element independently may still avoid infringement — but only if that difference is checked against the specific claim language of the cited records rather than assumed from the abstract. Given how concentrated this claim area is around a small number of 2017-2019 filings, a targeted claim chart is more useful here than a general keyword search.

The United States accounts for 24 of the tracked filings, well ahead of the European Patent Office at 10 and Canada at 9, with only a single filing recorded in India. This distribution suggests that most competitive and defensive filing activity to date has focused on the US and, to a lesser extent, Europe and Canada. Applicants considering markets outside these three should treat the thin patent record as an opportunity for earlier, cleaner filing positions, not as evidence that the underlying technology is unimportant elsewhere.

Relative to the dense claim coverage on core propulsor-to-turbomachine coupling, several adjacent branches show thinner coverage: wake interaction control for distributed propulsor arrays, inlet distortion tolerance specific to boundary-layer-ingestion configurations, and aeropropulsive coupling applied to blended-wing-body airframes rather than conventional tube-and-wing layouts. Traffic-management and flight-path integration claims for distributed-propulsion aircraft also appear in a smaller share of the dataset, suggesting the operational side of these architectures is less thoroughly claimed than the propulsion hardware itself. Any of these should be validated against full claim text before treating them as genuinely open.