Bell’s X-76 is an experimental aircraft demonstrator for DARPA’s Speed and Runway Independent Technologies (SPRINT) program. Bell said on March 9, 2026, that the aircraft had passed Critical Design Review and that construction would begin. Its central idea is to use rotors for vertical lift, then stop and fold them during flight to transition toward jet-like cruise. The program’s 400–450-knot figure is a goal—not a demonstrated X-76 speed.
What Bell’s X-76 is—and what it is not
The X-76 is being built by Bell as the demonstrator for DARPA’s SPRINT program, which is jointly funded by DARPA and U.S. Special Operations Command, according to Bell’s March 9, 2026 announcement. DARPA also described the aircraft as under construction following its Critical Design Review in its March 9, 2026 announcement.
“X-plane” here means an experimental aircraft program, not an aircraft already in operational service. The public announcements establish a design-and-build milestone; they do not establish that an X-76 has flown, entered production, or received a service-entry date.
How the rotor-folding concept is supposed to work
Bell’s High-Speed Vertical Takeoff and Landing (HSVTOL) concept combines a rotor system for vertical lift and hover with a stop-and-fold transition in flight. Once the rotor is stopped and folded, the aircraft can reconfigure toward a lower-drag, jet-like cruise mode. That is the proposed answer to a familiar compromise: fast conventional aircraft rely on runways, while helicopters can take off and land vertically but generally cruise more slowly.
What’s actually slowing this PC down?
Pick the symptom - the matching free tool is one click away.
#1 Best Overall
- Easy to Fly & Friendly Operation: This rc paper airplane kit features a user-friendly remote control system designed for beginners, pilots, and adults. Without complicated setup, both novice fliers and hobbyists can quickly master flight skills and enjoy the hands-on building fun of this diy airplane kit
- Ultra-Stable Flight & Gyro Control: Equipped with a built-in gyro stabilizer and dual propellers, this paper airplane motor unit delivers balanced and smooth aerodynamic performance. It effectively minimizes shaking and drift, dramatically improving steering accuracy for a steady flying experience
- 2 Batteries Long-Lasting Flight: Equipped with 2 upgraded rechargeable batteries, this remote control paper airplane motor module provides extended endurance flight time. Enjoy continuous flying fun without frequent charging interruptions, ensuring double the entertainment for outdoor and indoor flight practice
- Lightweight & Reusable DIY Flight Project: Crafted from premium durable materials, this lightweight rc plane kit serves as a creative alternative to complex diy drone kit builds. Simply attach the power module to your own folded paper plane designs to test folding structure, airflow, and thrust across various custom shapes
- Aviation Gift for Enthusiasts: Meeting safety standards, this motorized diy paper airplane kit brings endless creative joy. It is a tech gadget gift for model lovers, DIY hobbyists, and aviation fans on birthdays, holidays, and special celebrations. (Note: Paper body not included, prepare your own folded paper)
Bell presents HSVTOL as a scalable concept family, not a single fixed aircraft design. Its HSVTOL overview includes conventional takeoff and landing, short takeoff and landing, and vertical takeoff and landing as possible modes across that family. It cites a 200–400-foot short-takeoff distance for the concept, not as a measured X-76 performance result.
What performance Bell and DARPA are targeting
Bell describes SPRINT’s intended cruise-speed range as 400–450 knots at relevant altitudes, alongside the ability to hover in austere environments from unprepared surfaces. This is a program goal stated by Bell, not a speed or capability demonstrated by the X-76. DARPA frames the challenge as combining “the high speed of an aircraft that needs a runway” with the go-anywhere flexibility of a slower helicopter.
Rank #2
- Reissue of the classic 1/120 box scale Boeing B-29
- Measures 10 1/2 inches long with a 14 inch wingspan
- This kit comes molded in silver with clear swivel stand and another display stand option
- Updated decals for 3 versions! Built up by Bill Engar with Dauntless Dotty decals
- Skill Level 2. This 8.1x2.2x15.9 inch package contains 44 parts. Made in the USA.
| Figure | What it describes | Evidence status |
|---|---|---|
| 400–450 knots | SPRINT cruise-speed goal at relevant altitudes | Program goal stated by Bell in its March 9, 2026 announcement; not a demonstrated X-76 result. |
| 200–400 feet | Short-takeoff distance | Claim for Bell’s HSVTOL concept family on its concept overview; not identified as measured X-76 performance. |
These figures describe different things: one is a program speed target and the other a concept-family short-takeoff claim. Neither is a published X-76 test result, so they should not be treated as proof that the demonstrator has met them.
What has been tested, and what remains ahead
Bell has reported risk-reduction work on technologies relevant to the concept, including folding-rotor, integrated-propulsion, and flight-control demonstrations at Holloman Air Force Base. Bell also reported wind-tunnel testing at the National Institute for Aviation Research at Wichita State University in its July 9, 2025 announcement.
The Tool Desk
Outbyte Driver Updater FREEFix the driver behind crashes, sound loss and screen glitchesFind Drivers →Outbyte PC Repair FREERepair Windows errors before they cause bigger problemsFix Now →Rank #3
- Revell Model Kit #85-5810, Skill Level 4, Contains 66-Parts, Recommended for ages 12 and up
- Accurate surface details
- Includes GTD-21 surveillance drone with cart
- Decals with authentic U.S. Air Force markings
- Molded in black and clear. Paint and glue required(not included).
In December 2024, Bell said it had completed wind-tunnel tests intended to validate the stop/fold jet-transition capability, following earlier sled testing at Holloman. Those are technology-development and validation activities; Bell’s announcement does not establish that an X-76 demonstrator has completed a flight. See Bell’s December 4, 2024 update.
Phase 2 covers detailed design, construction, and ground testing. Bell says flight testing is expected in Phase 3, but its March 2026 announcement gives no date for that phase and no cost, production plan, or service-entry schedule.
Rank #4
- 【Newly designed assembly model】The F-35 fighter jet assembly model kit is based on the real F-35 fighter jet, and the appearance carefully restores the classic features of the F35 fighter jet, such as the unique aircraft shape, exquisite spraying details and airplane model wheels, etc. The fighter jet model perfectly demonstrates the modern technology of the military aircraft. And the texture is very good, making the model look more refined.
- 【Easy-to-use assembly experience】The parts of the F-35 fighter jet model kit are carefully designed and made with good compatibility and fit, and can be assembled without special tools. It comes with an assembly step-by-step diagram, so even beginners can easily get started. At the same time, the assembled F35 fighter jet model is also movable, the cabin can be opened, and the fighter wheels can also move, bringing you a more vivid display effect.
- 【Product size and painting】The F-35 fighter model kit is restored according to the prototype ratio of 1:72, with specific dimensions of 24.5*17.5*5 and a weight of 0.175 pounds. The F35 fighter jet model is made of high-quality plastic material, which is not only sturdy and durable, but also not easy to oxidize and fade. The material is exquisite and lightweight, it has no sharp edges, and can effectively prevent the model from being damaged during assembly and play, which is safer.
- 【Unique decoration and gift】The F-35 fighter model is not only a beautiful handicraft, but also can be used as a decoration and collection. It is very suitable for military enthusiasts and model collectors to collect or give as gifts. For teenagers and children, the assembly process of this 1/72 F35 airplane model can exercise hands-on ability. Whether you collect it yourself or share it with like-minded people, this F35 military aircraft model can bring you endless fun and satisfaction.
- 【Worry-free Purchase】The product contains tiny parts, be careful not to let children swallow them by mistake. The fighter model kit uses a hard carton as the outer packaging to better protect the helicopter from damage during transportation. We insist on strict production requirements to control the quality of this F35 military fighter jet model to ensure that every customer is satisfied with the high-quality product. If you encounter any problems, please feel free to contact us!
How the idea compares with today’s aircraft
The intended distinction is operational rather than a published head-to-head performance comparison. The sources describe the broad tradeoff, but do not provide comparable measured X-76 and in-service aircraft figures.
| Aircraft type | Runway access | Vertical lift or hover | Speed and maturity in this comparison |
|---|---|---|---|
| Conventional fast aircraft | Runway-dependent, as characterized by DARPA | Not the runway-independent vertical-lift capability sought by SPRINT | DARPA identifies high speed as the advantage; no comparable numeric benchmark is provided. |
| Helicopters | Can operate without conventional runways | Vertical operation and hover | DARPA describes helicopters as slower than runway-dependent fast aircraft; no comparable numeric benchmark is provided. |
| Bell X-76 / SPRINT demonstrator | Program aims for runway-independent operation | Program aims for vertical lift and hover, then rotor stop/fold transition | Still an experimental demonstrator under construction after Critical Design Review; the 400–450-knot figure is a goal, not a demonstrated result. |
What is known about the X-76 timeline
The latest milestone established by the cited announcements is the March 9, 2026 completion of Critical Design Review and start of construction. Bell identifies detailed design, build, and ground testing as Phase 2 work, with flight test expected in Phase 3. The announcements do not establish when flight testing will begin or whether a production aircraft will follow.
Quick wins for a faster PC:
Clear out junk files and repair common Windows errorsFree Scan →Fix the driver behind crashes, sound loss and screen glitchesFind Drivers →Quick Recap
Best Value
- Revell Plastic Model Airplane Kit #85-5512 is skill level 4 and contains 147 parts. Recommended for ages 12 and up.
- 1:48 scale model, Length 14-1/4", Wingspan 16.75"
- Crew figures and weighted tires. Machine guns mounted in glass nose.
- Decals included to build one of two variants from the 345th Bomb Group, the Air Apaches.
- Molded in light gray and clear. Paint and glue not included.
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
