Helicopter Main Rotor Blade Patents: Who Leads, Where the Gaps Are 2026
- 70.9% concentration. the top 5 of 62 ranked assignees hold 173 of 244 records in scope — filing here means facing entrenched claim positions from the outset.
- B64C dominates, but not exclusively. 79.9% of records sit in aeroplanes-and-helicopters classification, while coating (B05D, 8.6%) and metal working (B23P, 4.1%) show smaller, separately claimable footprints.
- Filing has cooled, not stopped. the peak year was 2018 at 10 filings; recent years show fewer new filings, though publication lag means the last year or two is undercounted.
Top-5 share is the combined record count of the five largest assignees divided by all 244 records in scope (CR5), not by the ranked leaders only.
What the rotor blade patent record actually shows
Helicopter main rotor blade design sits at the intersection of aerodynamics, structural engineering and coatings chemistry. The 244 records in scope span airfoil section selection, blade twist distribution, spar construction, leading-edge erosion protection and blade tracking adjustment — a set of problems that has occupied airframe manufacturers and specialist coating suppliers alike since the earliest rotorcraft programmes. The filing record is old and settled at its core, with a small number of assignees holding the foundational airfoil and spar claims, and newer activity clustering around coatings, repair methods and secondary structural refinements.
That pattern matters for anyone assessing freedom to operate: the aerodynamic core of blade design is heavily claimed by a handful of long-standing rotorcraft manufacturers, while the coating and metal-working classes tied to the same records represent a comparatively less crowded, though still active, adjacent space.
Filing trend and technology composition
Two views of the same 244-record dataset: filing activity by year, and the IPC subclasses those records fall into. Because a single record can carry several IPC classes, the composition shares add up to more than 100% of the record total.
Filing activity, 2017-2026
Filings rose to a peak of 10 in 2018 and have since declined; the most recent year shown is partial because publication typically lags filing by around 18 months, so recent-year counts understate real activity.
Technology composition by IPC subclass
B64C (aeroplanes & helicopters) accounts for 79.9% of the 244 records in scope, confirming the aerodynamic and structural core of the field. F01D (turbines), B05D (coatings) and B23P (metal working) each cover a meaningfully smaller share, marking out adjacent claim territory rather than the field's centre of gravity.
Shares are the percentage of the 244 records in scope. A patent can carry several IPC classes, so the shares add up to more than 100%.
Go deeper on Helicopter Main Rotor Blade Design with Eureka
This page is one run against one query. Ask Eureka your own question about helicopter main rotor blade design and every answer comes back with the patent numbers behind it.
Try EurekaMost-cited records and a representative filing
Airfoil for a helicopter rotor blade (US20110010936A1)
The filing describes an airfoil family, designated SC362XX, that removes the lower-surface suction peak associated with drag creep at moderate lift coefficients while reducing peak Mach number and shock strength at high lift/Mach conditions. A second, thicker airfoil family (SC3252XX) is described for inboard rotor regions, adding thickness forward of the 30% chord location for structural rigidity. Both families are optimized around a shared lift coefficient for drag-divergence Mach number.Assignee and filing date are rendered separately above.
| # | Publication no. | Patent title | Citations |
|---|---|---|---|
| 1 | US20050045762A1 | High performance VTOL convertiplanes | 145 |
| 2 | US20050151001A1 | Compound helicopter | 119 |
| 3 | US6203269B1 | Centrifugal air flow control | 112 |
| 4 | US4524620A | In-flight monitoring of composite structural components such as helicopter rotor blades | 103 |
| 5 | US20120163981A1 | Method and coating for protecting and repairing an airfoil surface | 102 |
| 6 | US6974105B2 | High performance VTOL convertiplanes | 100 |
| 7 | US6109566A | Vibration-driven acoustic jet controlling boundary layer separation | 93 |
| 8 | US5542820A | Engineered ceramic components for the leading edge of a helicopter rotor blade | 88 |
| 9 | US20110006165A1 | Application of conformal sub boundary layer vortex generators to a foil or aero/ hydrodynamic surface | 86 |
| 10 | US20080159870A1 | Method and coating for protecting and repairing an airfoil surface using molded boots, sheet or tape | 71 |
Citation counts reflect influence within the searched corpus and favour older filings; they are not a measure of current commercial importance.
Each row carries its publication number; clicking a row searches Eureka by that number.
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Three patterns stand out once the ranking, trend and classification data are read together.
The aerodynamic core is not open territory
With 173 of 244 records held by five assignees, core airfoil and blade-twist claims sit on dense prior art built up over a long filing history. New entrants working directly on airfoil section selection or twist distribution should expect to design around, not into, this space.
Coatings and repair are a smaller, adjacent claim space
Leading-edge erosion protection and repair methods fall under B05D and appear in 8.6% of the 244 records — a meaningfully smaller footprint than the B64C core, and one where fewer of the largest airframe assignees compete directly.
Recent-year activity has gone quiet across the leaders
Every one of the leading assignees shows zero filings in the most recent year on record. Given the roughly 18-month publication lag, this likely understates true recent activity rather than signalling that rotor blade R&D has stopped.
Eureka can read the same corpus for gaps instead of for coverage: under-claimed branches adjacent to helicopter main rotor blade design, with the prior art for and against each one.
| Assignee | Co-assignee | Shared families |
|---|---|---|
| Sikorsky Aircraft Corporation | BAGAI ASHISH | 4 |
| Bell Helicopter Textron Inc. | SCHILLINGS JOHN J | 3 |
| Bell Helicopter Textron Inc. | NARRAMORE JIMMY C | 3 |
| Bell Helicopter Textron Inc. | AGNIHOTRI ASHOK K | 3 |
| HONTEK CORP | HONG SHEK | 3 |
| Sikorsky Aircraft Corporation | WAKE BRIAN E | 2 |
| Sikorsky Aircraft Corporation | SUN FANPING | 2 |
| Sikorsky Aircraft Corporation | OWEN STEPHEN J | 2 |
Ten co-assignee pairs appear in the dataset, with the strongest pairings linking a manufacturer to named individual inventors rather than to other corporate assignees — consistent with in-house engineering teams driving the bulk of blade design IP.
Who holds the ground, and where it thins out
The ranked list covers 62 assignees across 244 records. Concentration is high at the top and thins quickly: fifth place holds 12 records and tenth place holds only 4, pointing to a long tail of single- or few-filing entrants below the leaders.
A single assignee anchors the field
The leading assignee's record count is more than five times that of the fifth-place holder, reflecting decades of continuous rotorcraft programme activity rather than a recent filing surge.
The drop from fifth to tenth is steep
Combined, the top 10 hold 82.8% of all 244 records, meaning the remaining 52 ranked assignees share the rest — a long tail of narrower, more specialised filings.
No leader shows fresh filings in the latest year
This is consistent with publication lag rather than a genuine stop in R&D, but it does mean the newest claim activity in this dataset is not yet visible in the ranking.
| Assignee | Recent year | YoY |
|---|---|---|
| Sikorsky Aircraft Corporation | 0 | — |
| Bell Helicopter Textron Inc. | 0 | — |
| HONTEK CORP | 0 | — |
| United Technologies Corporation | 0 | — |
| The Boeing Company | 0 | — |
| GKN Westland Helicopters Ltd | 0 | — |
| MCDONNELL HELICOPTER | 0 | — |
| HONG SHEK C | 0 | — |
Where to take this analysis
The dataset points to a crowded aerodynamic core and a thinner, more accessible periphery. Turning that into a filing or design-around decision requires going deeper than the aggregate numbers shown here.
Map claim scope on the leader's core patents
Before proposing a new airfoil or spar design, check exactly what the top-ranked assignee's claims cover and where their boundaries sit.
Explore claim charts in EurekaTrack the coatings and repair sub-space
B05D-classified filings are fewer and more scattered across assignees, making this a more tractable area to monitor for freedom to operate.
Set up monitoring in EurekaCommon questions about rotor blade patent activity
The dataset ranks 62 assignees across 244 records, and filing is heavily concentrated: the top five assignees together hold 173 records, or 70.9% of everything in scope. The leading assignee alone accounts for 68 records, more than five times the count at fifth place. This concentration reflects decades of continuous rotorcraft programme filings by major airframe manufacturers rather than a recent surge from any single company.
Filing peaked in 2018 at 10 records in this dataset and has since tapered, with every leading assignee showing zero filings in the most recent year on record. That said, publication typically lags actual filing by around 18 months, so recent years are undercounted rather than genuinely inactive. The honest read is that the field has slowed from its earlier pace, not that R&D has stopped.
Relative to the aerodynamic and structural core classified under B64C (79.9% of records), adjacent areas like coatings for erosion protection (B05D, 8.6%) and metal-working fabrication methods (B23P, 4.1%) carry a smaller filing footprint. Sub-areas such as anhedral blade tip geometry, blade tracking adjustment mechanisms and composite spar repair also show comparatively less concentrated activity, making them worth closer freedom-to-operate review before assuming they are blocked.
With the top 10 of 62 ranked assignees holding 82.8% of all 244 records, this is a highly concentrated field by any standard, though the drop from fifth place (12 records) to tenth place (4 records) shows the concentration is driven mainly by a handful of firms rather than a broad club of major players. Below the top 10, the remaining 52 assignees form a long tail of single- or few-filing entrants, typical of a mature aerospace sub-field with a small number of dominant manufacturers.
US20110010936A1 claims an airfoil family (SC362XX) that reduces lower-surface suction peaks and shock strength at high lift and Mach conditions, plus a thicker inboard airfoil family (SC3252XX) optimized around the same drag-divergence lift coefficient. It is a specific airfoil geometry claim rather than a blanket claim over rotor airfoil design generally, so it constrains designs that overlap its specific thickness and pressure-distribution parameters without necessarily blocking airfoil work outside those bounds. Anyone designing a new rotor airfoil should compare candidate geometries against its specific claimed parameters rather than assuming it forecloses the category.
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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.
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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.