Goosky S2 Ultra Review — What Changed, How It Flies, and Who This Micro Heli Is Really For

Quick answer: the Goosky S2 Ultra is more than a cosmetic update to the S2 family. It combines a carbon-fiber chassis, full-metal servos, revised direct-drive hardware, split electronics and a Rotorflight-based flight controller in a helicopter that still weighs only about 360g. The result is a highly tunable micro heli that can remain manageable for sport flying while giving experienced pilots the control authority required for aggressive 3D.

The original Goosky S2 established the basic appeal of the platform: a portable collective-pitch helicopter with direct-drive simplicity, useful durability and enough performance to remain interesting after the first few flights. The S2 Max then pushed the series toward a more accessible, simplified package. The Goosky S2 Ultra moves in the opposite direction. It restores a more premium mechanical specification and adds an electronics package that is unusually advanced for this size class.

The most important change is not one individual metal component. It is the way the entire system now works together. The stiffer structure gives the servos and flight controller a more consistent platform, the revised motors provide the necessary authority, and Rotorflight opens the door to governor control, telemetry, Blackbox analysis and much deeper tuning than a conventional preset micro-heli FBL system.

This review examines the S2 Ultra’s specifications, construction, Rotorflight system, flight performance, receiver options and practical battery requirements. It also addresses a question that matters to existing owners: does the Ultra provide a meaningful advantage over the S2 Max, or is it mainly a more sophisticated version for pilots who enjoy tuning?

Goosky S2 Ultra Specifications

The flight-time figures illustrate how much flying style matters. A pilot using lower head speed, moderate collective and smooth sport manoeuvres may approach the longer figure. Repeated tic-tocs, rapid reversals and sustained high-head-speed 3D can consume the same 750mAh pack much faster.

A Carbon-Fiber Structure Without Sacrificing Easy Battery Access

The S2 Ultra immediately looks more serious than a typical ready-to-fly micro helicopter. Its new stacked fuselage uses high-strength carbon-fiber side panels, producing a cleaner and more rigid structure around the servos, electronics and direct-drive system.

Rigidity matters because every control correction begins with the flight controller and ends as a mechanical movement at the rotor head. Flex between those points can soften stops, introduce inconsistency and make aggressive tuning more difficult. The carbon structure cannot create precision by itself, but it provides a more stable foundation for the upgraded electronics and servos to work from.

The cyclic servos now use full-metal housings. The practical benefits are improved structural support and better heat transfer from the servo assembly. It would be misleading to assume that a metal casing automatically makes every internal component indestructible, but the complete installation feels more appropriate for repeated high-load collective-pitch flying than a lightweight cost-focused layout.

Goosky also retained one of the platform’s most practical features: the battery can be changed without removing the canopy. That sounds like a small detail until several packs are being flown in one session. The open access reduces turnaround time and avoids repeatedly flexing or detaching the canopy.

Amber Orange and Green canopy versions use the newer Flow Ink Phantom finish. Visibility will still depend on sky conditions, viewing angle and pilot preference, but the contrasting graphics help distinguish the compact airframe during close sport flying.

What Rotorflight Means on the Goosky S2 Ultra

Rotorflight is open-source flight-control firmware developed specifically for collective-pitch RC helicopters. It is not simply drone firmware installed on a helicopter. Its mixer, governor, filtering, servo control and tuning tools are designed around the requirements of main-rotor cyclic control, collective pitch and tail authority.

The S2 Ultra flight controller integrates an STM32F405 processor, a CM42688P six-axis sensor and 128MB of Blackbox storage into a compact 24 × 33mm CNC aluminum enclosure weighing approximately 12g. Goosky supplies it with Rotorflight 2.2 tuning intended for the S2 Ultra hardware.

Rotorflight gives the S2 Ultra access to several tools that were previously uncommon in a production micro helicopter:

• Governor control for maintaining a target head speed as battery voltage and collective load change.
• RPM-based filtering that uses motor-speed information to target vibration frequencies from rotating components.
• ESC telemetry for data such as RPM, voltage, current, temperature and consumed capacity when supported by the installation.
• Blackbox logging for reviewing gyro response, control output, vibration and power-system behaviour after a flight.
• Multiple tuning profiles for adjusting rates, gains, response and governor behaviour to different flying styles.

This flexibility is both the Ultra’s greatest advantage and the reason it will not appeal equally to every pilot. Someone who wants to bind the helicopter, select basic rates and fly may never use most of the available data. A pilot who wants to inspect vibration, refine the governor or create separate sport and 3D profiles will find considerably more room to work.

The useful distinction is that Rotorflight does not require every owner to become a tuning specialist. The supplied configuration provides a starting point. The advanced tools become valuable when the pilot has a specific issue to solve or a clearly defined flight characteristic to pursue.

Split ESC Architecture, AM32 and the Direct-Drive Power System

The S2 Ultra separates its flight controller and ESCs rather than combining everything into one board. This layout gives each part a clearer role and can make fault diagnosis or component replacement more manageable than an all-in-one assembly.

The ESC system uses AM32 firmware and provides the speed information required for closer integration with Rotorflight. Accurate RPM feedback is especially valuable on a direct-drive helicopter because the controller can relate motor speed directly to rotor speed without calculating through a conventional main-gear reduction.

Both the main and tail drive systems have been revised. In practice, the important result is not simply a higher peak-power claim. A useful micro-heli power system must deliver repeated torque changes without excessive temperature rise or a weak tail response when collective load suddenly increases.

The upgraded motors, metal servos, carbon structure and Rotorflight electronics should therefore be viewed as one system. A stronger motor would have limited value if the frame flexed, the servos lagged or the flight controller could not use the available RPM data.

How the Goosky S2 Ultra Flies in Sport and Aggressive 3D

In our own testing, the Goosky S2 Ultra could be pushed substantially harder than most micro helicopters without immediately losing its composed feel. Fast circuits, high-energy tic-tocs, rapid flips and inverted transitions remained connected rather than breaking down into a series of nervous corrections.

The closest large-heli comparison is not based on physical size or stored energy. It is the way the helicopter accepts a command, stops and then settles into the next line. At an appropriate tune, the Ultra displays less of the loose, over-reactive character often associated with very small collective-pitch models.

Rotorflight’s filtering and governor tools contribute to that consistency, but the mechanical upgrades remain equally important. Software cannot compensate indefinitely for structural movement, weak servo response or an underpowered tail.

Sport pilots can reduce head speed and rates to make the helicopter calmer, while experienced 3D pilots can explore more aggressive collective and cyclic settings. That range is a major part of the S2 Ultra’s appeal: the same airframe can be configured to feel relatively smooth or extremely fast without replacing the core electronics.

The Ultra is still a small collective-pitch helicopter, however. Its low mass makes it portable and reduces the energy involved compared with a large model, but its rotor blades can still cause injury. Proper spool-up distance, throttle-hold discipline and a suitable flying area remain essential.

Goosky S2 Ultra vs S2 Max: What Actually Changed?

The S2 Max does not become obsolete simply because the Ultra exists. Skilled pilots have already demonstrated that the Max is capable of advanced manoeuvres. The Ultra’s value is not that it suddenly makes difficult flying automatic. It gives the pilot a stiffer platform, more sophisticated electronics and far greater control over how the helicopter responds.

An S2 Max owner who is satisfied with the current setup and does not want Rotorflight may gain little from changing models. A pilot who enjoys analysing logs, refining head-speed behaviour or building several tuned profiles will see a much clearer reason to upgrade.

Receiver Compatibility: ELRS, SBUS, DSMX and Futaba

The BNF package includes a compact external ELRS receiver, and the flight controller supports ELRS, SBUS and DSMX receiver options through its plug-in interface. This gives the Ultra more radio flexibility than a model tied to a single integrated protocol.

• ELRS: the included micro receiver provides a direct route for pilots already using an ELRS radio system.
• SBUS: suitable for compatible receivers that provide an SBUS output.
• DSMX: supported through a suitable Spektrum-compatible satellite or receiver arrangement.

Futaba pilots are not restricted to a dedicated “Rotorflight transmitter.” They need a compatible receiver that can provide one of the supported signals, together with the correct micro connector or adapter wiring. Depending on the transmitter and receiver combination, this may involve a compact Futaba S-FHSS or SBUS-capable receiver.

A receiver with sufficient usable channels is preferable because Rotorflight may use separate channels for arming, throttle, profile switching, rescue and other auxiliary functions. Confirm the channel map, voltage requirement and plug orientation before powering the helicopter.

What Battery Does the Goosky S2 Ultra Use?

The Goosky S2 Ultra is designed around an 11.1V 3S 750mAh LiPo battery. This is the correct reference point when comparing normal flying weight, energy capacity and expected runtime.

Smaller 350mAh and 450mAh batteries can be useful alternatives when their dimensions, connector and retention method are suitable, but they should not be described as equivalent replacements for the stock pack. They contain substantially less energy and will produce shorter flight times.

The correct way to compare the three capacities is by intended use:

A high discharge rating can improve voltage stability under load, but it cannot replace missing capacity. A strong 450mAh pack may feel responsive during a short flight, yet it cannot reasonably be expected to match the runtime of a healthy 750mAh battery.

Can the New 78 × 21 × 22mm CNHL 750mAh Battery Fit?

The new CNHL 750mAh 3S battery is approximately 78 × 21 × 22mm, weighs about 61g, uses 16AWG wire and is fitted with an XT30 connector. Its capacity and weight are much closer to the factory Goosky setup than the smaller 350mAh and 450mAh packs.

Its shape is different from the shorter, wider format commonly seen in S2-compatible batteries. The new pack is longer but also relatively narrow and low. The S2 Ultra’s forward-facing, open-access battery arrangement makes that long, narrow shape a promising candidate rather than an automatic rejection.

However, it should not be advertised as a confirmed drop-in fit until a physical installation test has been completed. Before flying, verify all of the following:

• The complete 78mm battery body can move into its operating position without forcing the canopy or carbon frame.
• The XT30 connector and main wires have enough space to bend naturally without being pinched.
• The battery can be retained securely during inverted flight and rapid pitch reversals.
• The balance lead cannot reach the rotor, motor, servos or other moving components.
• The installed battery does not move the center of gravity outside the acceptable range.

Until that test is complete, the most accurate description is: a 750mAh capacity-and-weight match with promising dimensions, subject to final physical fit verification.

Recommended CNHL Battery Options for Goosky S2 and S2 Ultra

Pilots should choose by flight objective rather than assuming that every physically compatible pack serves the same purpose.

• CNHL MiniStar 350mAh 11.1V 3S 70C with XT30 — a lightweight option for brief practice flights where minimum mass matters more than duration.
• CNHL MiniStar 450mAh 11.1V 3S 70C with XT30 — a middle lightweight option that provides more energy than the 350mAh pack while remaining well below stock capacity.
• CNHL 750mAh 11.1V 3S battery option — the closest choice in this collection to the factory capacity and flying-weight class; confirm the long, narrow case fit before flight.

View the complete and most recently updated selection in the Goosky S2 and S2 Ultra Battery Collection.

Who Should Buy the Goosky S2 Ultra?

The S2 Ultra serves several pilot groups, but the reasons for buying it are different.

Developing collective-pitch pilots can use the supplied setup and moderate rates to build orientation, circuit and basic aerobatic skills. The compact size is convenient, but beginners still need simulator practice, throttle-hold discipline and enough space to fly safely.

Intermediate pilots may gain the most immediate value. The airframe is small enough for frequent practice, while Rotorflight profiles allow the helicopter to evolve as confidence and control improve.

Experienced 3D pilots receive the strongest argument for choosing the Ultra. They are more likely to notice the cleaner stops, tail authority, governor behaviour and freedom to tune the helicopter around a specific head speed and manoeuvre style.

Existing S2 Max owners should upgrade only when the premium structure or Rotorflight platform solves a real need. Buying the Ultra will not automatically improve pilot skill, and the S2 Max remains capable in experienced hands. The Ultra is more compelling when the owner wants deeper control, data analysis and a more premium mechanical package.

Goosky S2 Ultra FAQ

What battery does the Goosky S2 Ultra use?
It uses an 11.1V 3S LiPo battery, with 750mAh being the factory capacity reference.

Can a 350mAh or 450mAh battery be used?
A correctly sized 3S pack with the right connector can power the helicopter, but these capacities provide much shorter flight time than the stock 750mAh battery. They should be treated as lightweight alternatives rather than equivalent replacements.

Will a 78 × 21 × 22mm 750mAh battery fit?
Its narrow cross-section, 61g weight and XT30 connector make it a promising candidate, but the 78mm length requires an actual installation test. Confirm canopy clearance, connector routing, battery retention and center of gravity before flight.

Does the S2 Ultra require an ELRS transmitter?
No. The package includes an ELRS receiver, but the flight controller also supports compatible SBUS and DSMX receiver arrangements.

Can the Goosky S2 Ultra be flown with Futaba?
Yes, when using a suitable Futaba-compatible receiver that outputs a supported signal such as SBUS, together with the correct connector or adapter wiring.

Is Rotorflight difficult to use?
The supplied configuration provides a practical starting point, so every pilot does not need to tune from zero. Its complexity becomes more relevant when changing governor behaviour, filters, gains, rates or receiver functions.

Final Verdict: A Micro Helicopter Built for Pilots Who Want More Control

The Goosky S2 Ultra is not simply a faster S2 Max. Its real upgrade is the combination of a stiffer carbon structure, metal servos, revised direct-drive hardware, split AM32 electronics and a Rotorflight flight controller capable of logging and responding to detailed flight data.

Pilots who want the simplest possible micro-heli experience may not use enough of those capabilities to justify changing from an S2 or S2 Max. Pilots who want to adjust head speed, examine Blackbox logs, refine control response and carry a serious 3D practice helicopter in a compact case will understand the Ultra’s purpose immediately.

Battery choice should follow the same practical logic. The factory 750mAh capacity remains the correct benchmark for normal duration and flying weight. Smaller 350mAh and 450mAh packs trade endurance for lower mass, while the new CNHL 750mAh option moves much closer to the intended energy and weight class but still requires final verification of its long, narrow case.

Compare all currently available options in the Goosky S2 and S2 Ultra Battery Collection, browse more compact packs in the Micro Helicopter Batteries Collection, or explore the wider CNHL Helicopter Batteries Collection.