Engine Bleed Air Systems Patents: Who Leads, Where Gaps Are 2026
- Top 5 filers hold 53.4% of all 826 records. and the top 10 hold 74.1% — this is a field with a short list of gatekeepers, not a fragmented one.
- Filing rose 16% from 2021 to 2024, the last year with a complete publication picture, after peaking at 111 filings in 2017.
- B64D aircraft equipment covers 63.0% of records, while F25B refrigeration and heat-pump classes touch only 4.0% — bleed air thermal management sits far behind the airframe integration claims.
Filing growth compares 2021 (19 records) with 2024 (22) — a three-year span. 2024 is the most recent year we treat as complete: publication lags filing by roughly 18 months, so 2025 onwards are still filling in and any growth rate that ends there would understate the field. Top-5 share is the combined record count of the five largest assignees divided by all 826 records in scope (CR5), not by the ranked leaders only.
What the engine bleed air patent record shows
Engine bleed air systems sit at the intersection of gas-turbine architecture and airframe environmental control: hot compressor air is tapped, cooled, regulated and routed for cabin pressurisation, anti-icing and pneumatic actuation. The patent record in scope — 826 published records from 2015 through mid-2026 — spans valve control, precooler heat exchangers, overtemperature protection and duct leak detection, the functional blocks a bleed air system must solve regardless of airframe.
Filing activity peaked in 2017 and has settled into a lower but still active band since, with 2021-to-2024 volume up 16%. Because publication trails filing by roughly 18 months, the most recent years in the trend understate real activity and should not be read as a slowdown.
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Filing trend and technology composition
Two views of the same 826 records: how filing volume has moved year over year, and how coverage splits across IPC subclasses. Because a single record can carry several IPC codes, the class shares below sum to more than 100%.
Filing trend: a 2017 peak, then a steadier plateau
Filings hit their high point in 2017 at 111 records, then declined before recovering into growth: 2021-to-2024 volume rose 16%, from 19 to 22 in-scope records. 2025 and 2026 figures will continue to rise as later publications land — read them as provisional, not as a trend reversal.
Technology composition: airframe integration dominates
B64D (aircraft equipment) touches 63.0% of the 826 records and F02C (gas-turbine plants) touches 40.7%, confirming that most claims sit at the point where bleed air meets airframe systems or the turbine core. F16K valves, F02K jet propulsion, B64C airframe, F04D pumps and F25B refrigeration each cover under 10% of records, marking narrower, more specialised filing bands rather than absent ones.
Shares are the percentage of the 826 records in scope. A patent can carry several IPC classes, so the shares add up to more than 100%.
Go deeper on Engine Bleed Air Systems with Eureka
This page is one run against one query. Ask Eureka your own question about engine bleed air systems and every answer comes back with the patent numbers behind it.
Try EurekaThe most-cited prior art in this field
Linear quadratic regulator control for bleed air system fan air valve (US8529189B2)
A system and method are provided for controlling the temperature of engine bleed air from a turbofan gas turbine engine. The system includes a fan air valve and a fan air valve controller. The fan air valve is adapted to receive a flow of fan air from a turbofan gas turbine engine intake fan. The fan air valve is coupled to receive valve position commands and is configured, in response to the valve position commands, to move to a valve position to thereby control the engine bleed air temperature. The fan air valve controller is configured to implement a linear quadratic regulator (LQR) control.Filed by Honeywell International; published 2013-09-10.
| # | Publication no. | Patent title | Citations |
|---|---|---|---|
| 1 | US7976213B2 | Arrangement for controlling fluid jets injected into a fluid stream | 1,007 |
| 2 | US5137230A | Aircraft gas turbine engine bleed air energy recovery apparatus | 218 |
| 3 | US5143329A | Gas turbine engine powered aircraft environmental control system and boundary layer bleed | 208 |
| 4 | US4262495A | Cabin-air recirculation system powered by cabin-to-ambient pressure differential | 203 |
| 5 | US5114100A | Anti-icing system for aircraft | 197 |
| 6 | US6305156B1 | Integrated bleed air and engine starting system | 195 |
| 7 | US20150275769A1 | Bleed air systems for use with aircraft and related methods | 165 |
| 8 | US20150275758A1 | Bleed air systems for use with aircraft and related methods | 158 |
| 9 | US20140250898A1 | Bleed air systems for use with aircrafts and related methods | 157 |
| 10 | US20130187007A1 | Bleed air systems for use with aircrafts and related methods | 155 |
Citation counts favour older records simply by having had longer to accumulate citations inside this corpus; treat them as a signal of influence on later filers, not as a ranking of current importance.
Each row carries its publication number; clicking a row searches Eureka by that number.
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Browse MCP servers →What the numbers mean for a filing decision
Three patterns stand out once concentration, timing and classification are read together.
A short list of gatekeepers, not a crowded field
With the top 5 assignees holding 53.4% of all 826 records and the top 10 holding 74.1%, engine bleed air system claim space is controlled by a small group of airframe and systems primes rather than spread across many independent filers.
Activity recovered after the 2017 peak
Filings peaked at 111 in 2017, cooled, then grew 16% from 2021 (19) to 2024 (22) — the last year the data can treat as complete given an 18-month publication lag.
Airframe integration dominates over thermal management
B64D aircraft equipment claims cover 63.0% of the 826 records while F25B refrigeration and heat-pump claims cover only 4.0%, showing that the bulk of protected ground is at the airframe interface rather than in the cooling and thermal-management side of bleed air handling.
Eureka can read the same corpus for gaps instead of for coverage: under-claimed branches adjacent to engine bleed air systems, with the prior art for and against each one.
Who holds the ground, and where it is still open
The ranked leaders in this dataset are large airframe and aerospace-systems suppliers; momentum in the most recent year has gone flat across nearly all of them, consistent with publication lag rather than an actual pullback.
One filer well ahead of the pack
The leading assignee holds 122 records against a fifth-place figure of 44 and a tenth-place figure of 17 — a steep drop-off that marks this as a field with one dominant filer rather than several close rivals.
Recent-year counts have gone flat industry-wide
Every one of the largest filers, including the top-ranked assignee, shows 0 filings in the latest year in this dataset, with some recording a -100% year-on-year change. This tracks with the roughly 18-month publication lag rather than a genuine stop in R&D.
Co-filing is limited and clustered
Only 10 co-assignee pairs appear in the dataset, and the strongest pairings sit within a small number of related corporate groups rather than across independent competitors.
| Assignee | Recent year | YoY |
|---|---|---|
| The Boeing Company | 0 | -100% |
| Honeywell International Inc. | 0 | — |
| Hamilton Sundstrand Corporation | 0 | — |
| United Technologies Corporation | 0 | — |
| GE Aviation Systems LLC | 0 | — |
| General Electric Company | 0 | -100% |
| Airbus Operations GmbH | 0 | — |
| Rolls-Royce plc | 0 | — |
Where to take this from here
The dataset points to a field with settled leadership at the top and open ground in the thermal-management and sensing branches.
Map freedom-to-operate against the leader's portfolio
With one assignee holding 122 records well ahead of the field, a freedom-to-operate check should start there before broadening to the rest of the top 10.
Explore assignee portfolios in EurekaWatch the under-claimed thermal and sensing branches
F25B refrigeration-cycle cooling and duct leak-detection sensing sit well below the airframe-integration classes in filing density, and are worth a closer claim-by-claim read.
Run a white space search in EurekaTrack the next publication wave before calling a trend
2025–2026 filings are still arriving; treat the 2021–2024 growth figure as the latest reliable read and revisit once later years settle.
Set up filing alerts in EurekaCommon questions about engine bleed air system patents
The dataset ranks 826 records across 100 assignees, and the leading filer holds 122 records, well ahead of the fifth-ranked assignee at 44. The top 5 assignees combined hold 53.4% of all 826 records, and the top 10 hold 74.1%, so this is a field concentrated among a small group of large aerospace systems and airframe suppliers rather than spread evenly across many filers. Anyone assessing freedom to operate should treat that leading group as the primary reference set.
Filing peaked in 2017 at 111 records and has since settled into a lower plateau, but the most reliable recent read shows growth: 2021-to-2024 filings rose 16%, from 19 to 22 records. Because publication typically lags actual filing by around 18 months, the 2025 and 2026 figures in any trend chart are still incomplete and should not be read as evidence of a slowdown. The field should be treated as active based on the last complete year, 2024.
The largest share, 63.0% of the 826 records, falls under B64D aircraft equipment, and 40.7% falls under F02C gas-turbine plants, reflecting that most claims sit at the interface between the turbine and the airframe's pneumatic and environmental control systems. Smaller but active bands include F16K valves and taps (6.1%), F02K jet propulsion (5.3%), B64C airframes (4.8%), F04D pumps (4.2%) and F25B refrigeration (4.0%). Because a record can carry multiple IPC codes, these shares add up to more than 100% and should be read as coverage density, not as mutually exclusive categories.
The classification data shows refrigeration and heat-pump-based cooling (F25B) and pump-based approaches (F04D) each cover only around 4% of the 826 records, well below the 63.0% held by airframe-integration claims under B64D. That gap suggests thermal-management approaches to bleed air cooling, alongside duct leak-detection sensing and fan air valve durability, carry lower filing density than the core valve-control and airframe-integration claims. Lower density does not guarantee an open path, but it flags where a claim-by-claim search is more likely to find room.
US8529189B2, assigned to Honeywell International, claims a fan air valve controller that uses linear quadratic regulator (LQR) control to manage engine bleed air temperature by adjusting fan air valve position based on sensor input. It matters because it sits squarely in the fan air valve control sub-area that appears repeatedly across this dataset's most active classification, B64D. Anyone designing a bleed air temperature control loop that uses closed-loop valve positioning driven by sensor feedback should review this claim scope closely before finalising a control architecture.
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Disclaimer. This page is generated from Patsnap Eureka data drawn from a limited snapshot of global patent and scientific-literature records, and is provided for general information and reference only.
Patent data carries inherent limitations: recent filings (typically the most recent 18–24 months) are under-counted due to standard publication lag; counts may be reported at either a patent-family or a patent-record basis and are not always directly comparable; classification, applicant-name, and citation data may contain errors, duplicates, or omissions; and the underlying search query defines and constrains the scope shown. As a result, the analysis may be incomplete or inaccurate and may not reflect the full technology landscape.
Nothing on this page constitutes an exhaustive prior-art, novelty, freedom-to-operate, or validity search, nor does it constitute legal, financial, investment, or professional advice, and it should not be relied upon as such. Any patent, commercial, or strategic decision should be verified independently and reviewed with qualified patent, legal, and domain professionals. Patsnap makes no warranties, express or implied, as to the accuracy, completeness, or fitness for any particular purpose of the information presented.
Machine translation. Assignee and organisation names originally recorded in Chinese, Japanese or Korean have been rendered into English by an AI translation step so that the tables stay readable. These renderings are best-effort and may not match a company’s registered English name; the original name is what the underlying patent record carries, and it is what any Eureka query launched from this page uses.