Landing Gear Retraction Patents: Who Leads, Where the Gaps Are 2026
- 83.9% concentration. the top 5 of 52 ranked assignees account for 375 of 447 records in scope — a field with almost no room at the top and a long tail below it.
- Filing fell 78% in three years. from 45 records in 2021 to 10 in 2024, the last year that can be read as complete; 2025-26 figures are still filling in under an 18-month publication lag.
- One subclass dominates. B64C aeroplane and helicopter structures covers 92.8% of the 447 records, while fluid-pressure actuation (F15B) and gearing (F16H) sit under 5% each — the likely site of open claim space.
Filing growth compares 2021 (45 records) with 2024 (10) — 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 447 records in scope (CR5), not by the ranked leaders only.
What this dataset covers
The corpus spans 447 published records filed between 2015 and 2026 that combine landing gear retraction or door mechanisms with a specific locking or sequencing element — uplock mechanism, downlock, sequencing valve, free fall extension, drag brace or side stay. That pairing narrows the field to the mechanical and hydraulic core of gear actuation rather than the broader landing gear literature, so the concentration figures below describe a genuinely tight subject area, not an artifact of a loose query.
Filing offices split heavily toward the United States and Europe, with Germany, Canada, Austria and the United Kingdom each contributing a secondary tier — a pattern consistent with a supply chain built around a small number of airframe and landing-gear-systems primes with manufacturing or design footprints in those jurisdictions.
Trend and classification
Two views of the same 447 records: the year-by-year filing count, and the IPC subclasses those records carry.
A sharp pull-back after 2021-22
Filings rose to a peak of 46 in 2022 and had fallen to 10 by 2024, a 78% drop from the 2021 level of 45. Treat 2025 and 2026 as incomplete rather than as a continued decline: publication lags filing by roughly 18 months, so recent-year counts will still rise as more applications publish.
Concentrated in aircraft structure, thin elsewhere
B64C (aeroplanes and helicopters) appears on 92.8% of the 447 records, confirming this is fundamentally an airframe-structures field. F16F (springs and dampers), B64D (aircraft equipment) and F15B (fluid-pressure actuators) each sit near or under 9%, and gearing (F16H), clutches and brakes (F16D), and dimensional measurement (G01B) each cover under 2% — thin enough that a well-drafted claim there has real room to stand.
Shares are the percentage of the 447 records in scope. A patent can carry several IPC classes, so the shares add up to more than 100%.
Go deeper on Landing Gear Retraction and Actuation with Eureka
This page is one run against one query. Ask Eureka your own question about landing gear retraction and actuation and every answer comes back with the patent numbers behind it.
Try EurekaThe most-cited prior art in this field
US11981447B2 — Systems for harvesting rotational wheel energy for landing gear retraction
A system for extracting energy for landing gear retraction may comprise a wheel pump rotationally coupled to a wheel via a pinion gear. A landing gear control valve assembly may be fluidly coupled to an output of the wheel pump. A secondary pump may be fluidly coupled to the landing gear control valve assembly, and an electric motor may be operationally coupled to the secondary pump.Filed by Goodrich Corporation, published 2024-05-14 — illustrates the shift toward hybrid electro-hydraulic actuation built on top of conventional wheel-pump energy harvesting.
| # | Publication no. | Patent title | Citations |
|---|---|---|---|
| 1 | US5022609A | Landing gear | 112 |
| 2 | US20100219290A1 | Electric-powered transfer cylinder for landing gear system | 89 |
| 3 | US2661171A | Up and down lock mechanism for retractable landing gear for aircraft | 66 |
| 4 | CN102020014A | 一种带偏转机轮收放机构的飞机起落架 | 60 |
| 5 | US20060102775A1 | Landing gear | 57 |
| 6 | US4155522A | Overload release apparatus for aircraft landing gear or the like | 52 |
| 7 | US20090078821A1 | Landing gear | 43 |
| 8 | WO2004039671A1 | Landing gear | 39 |
| 9 | US20090108131A1 | Retractable articulated landing gear | 38 |
| 10 | US2552843A | Sequence control for landing gears | 38 |
Citation counts reward age inside this corpus — the oldest record here, a 1953 up-and-down lock mechanism, is also the most cited. Read these as markers of foundational influence, not current commercial relevance.
Patent titles are shown in the language they were filed in, not translated, so that each record stays verifiable against the original filing — a translated title will not match in Eureka or in any national register. 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 read-outs from the concentration, trend and classification data above.
Five companies set the terms of this field
With 375 of 447 records held by the top five ranked assignees, most of the fundamental uplock, downlock and sequencing-valve mechanics are already claimed by a handful of landing-gear primes and airframers. A new entrant filing on the core mechanism is filing into occupied ground.
Filing has cooled from its 2022 peak
The 46-record peak in 2022 followed by a fall to 10 in 2024 suggests the last wave of retraction-mechanism innovation has largely been filed and published. Because of the roughly 18-month publication lag, 2025-26 counts are not yet a reliable read on current filing activity.
Hydraulic actuation is under-represented relative to structure
B64C airframe structure claims cover 92.8% of records, but the fluid-pressure actuation systems that drive retraction (F15B) and the gearing that transmits it (F16H, 1.8%) are comparatively lightly claimed. That gap is where mechanism-level, rather than structure-level, claims still have room.
Eureka can read the same corpus for gaps instead of for coverage: under-claimed branches adjacent to landing gear retraction and actuation, with the prior art for and against each one.
Who is filing, and who has stopped
The ranked leaders in this dataset are almost all recognisable landing-gear-systems or airframe primes, and recent-year momentum figures show most of them pulling back at the same time rather than one company overtaking another.
One company holds the largest single share
The leading assignee's 136 records sit well ahead of fifth place at 18, meaning the gap between first and second-tier filers is far wider than the gap within the second tier itself.
The pull-back is broad, not company-specific
Multiple leading assignees show zero filings in the latest year with a -100% year-on-year change. Combined with the 2021-2024 trend, this points to an industry-wide lull in new retraction-mechanism filings rather than one firm exiting the space.
Co-assignee pairs cluster around single corporate groups
Ten co-assignee pairs appear in the data, and the strongest links sit between entities that are effectively the same corporate family filing across affiliated legal entities, rather than cross-company joint development.
| Assignee | Recent year | YoY |
|---|---|---|
| Messier-Dowty Ltd. | 0 | -100% |
| Goodrich Corporation | 0 | -100% |
| Airbus Operations Ltd. | 0 | -100% |
| Safran Landing Systems Canada Inc. | 0 | -100% |
| The Boeing Company | 0 | — |
| Airbus UK Ltd. | 0 | — |
| Airbus Operations SAS | 0 | -100% |
| Airbus Operations GmbH | 0 | — |
Where to take this analysis
The concentration and classification data point to specific next steps depending on what you need to decide.
Map claim scope on the F15B and F16H gap
Fluid-pressure actuation and gearing claims are lightly filed relative to airframe structure. A claim-chart pull against the leading assignees' F15B and F16H filings would show how much of that gap is genuinely open.
Explore this technology in EurekaTrack the leaders' next filing wave
The -78% drop to 2024 combined with the publication lag means the next 12-18 months of publications will reveal whether the lull holds or the leading assignees resume filing.
Set up monitoring in EurekaCheck design-around freedom against US11981447B2
The wheel-energy-harvesting approach in the featured 2024 filing sits at the intersection of two thin subclasses. Understanding exactly what it blocks matters before building on the same architecture.
Run a freedom-to-operate check in EurekaCommon questions on this landscape
In this dataset of 447 records, the ranking is led by a single assignee with 136 records, well ahead of the fifth-ranked company at 18. The top five assignees together hold 375 records, which is 83.9% of all 447 records in scope, and the top ten reach 96.0%. That means the field is dominated by a small group of landing-gear-systems and airframe primes rather than spread across many independent filers.
Filing peaked at 46 records in 2022 and had fallen to 10 by 2024, a 78% decline from the 2021 level of 45. Because publication typically lags filing by around 18 months, the 2025-26 figures in the data are still incomplete and should not be read as proof the field has gone quiet, but the 2021-2024 trend itself is a real and complete decline. Whether filing has genuinely slowed or is simply between waves will only be clear once the more recent years finish publishing.
The overwhelming majority of records, 92.8% of the 447 in scope, carry the B64C aeroplane and helicopter structures classification, reflecting that these mechanisms are claimed as part of the aircraft structure. Secondary classes include F16F springs and dampers at 8.7%, and B64D aircraft equipment and F15B fluid-pressure actuators each around 4.9%. Because a single record can carry multiple classes, these shares add up to more than 100% and should not be summed.
The classification data shows fluid-pressure actuation (F15B, 4.9% of records), gearing and transmissions (F16H, 1.8%) and dimensional measurement for downlock sensing (G01B, 1.3%) are all thinly claimed relative to the dominant airframe-structure classification. These are mechanism-level and sensing-level branches rather than structural ones, and they are the more plausible places to find genuinely open claim space in an otherwise concentrated field.
US11981447B2 is a Goodrich Corporation filing published in 2024 covering a system that harvests rotational energy from an aircraft wheel via a pinion-coupled wheel pump, feeds it through a landing gear control valve assembly, and pairs it with a secondary pump driven by an electric motor. It sits at the intersection of the thinly-claimed F15B fluid-pressure actuation space and wheel-energy harvesting, making it a useful reference point for freedom-to-operate work on hybrid electro-hydraulic retraction systems.
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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.