EVOLUTION OF THE JB-9 JETPACK

Brought to you by the creators of the world’s first civilian RocketBelt, as flown at the Los Angeles Olympic Games opening ceremony and in countless films and shows – JetPack Aviation has developed the world’s only true JetPack. Powered by two state of the art turbine jet engines that have been specially adapted to our requirements after many years of development and testing, the JB-9 is the smallest and lightest JetPack ever created. It is certainly the only JetPack ever built that can be carried on the pilot’s back with relative ease – even when fully fuelled.

We have been quietly working on perfecting a JetPack for over 40 years – yes that’s right, since the early 1970s! During this time we have tested all manner of propulsion systems including pulse jets, pressure jets, micro turbines, ducted fans etc and only recently has turbine technology improved to the point that we have been able to build a stable and reliable craft, the JB-9 JetPack.

Our team includes Nelson Tyler who is arguably the most experienced engineer in the personal VTOL industry and who has a long list of related inventions to his name. The whole team is dedicated to bringing a real JetPack to market and to us this means a JetPack that is powered by jet engines, can easily be carried on the pilot’s back, is VTOL capable and that can fly for an extended period – anything else cannot be considered a true JetPack.

The process of developing JB-9 has been one many years of design, testing and redesign – it has certainly not been an overnight process. A JetPack, by its nature, needs to be very light and compact, have crisp handling but also be stable in all three axes of flight. Engines need to be small, light, powerful and reliable. We have used many different engine types over the years and it has always been a trade off between weight and performance. In many respects the ideal engine would be a twin spool bypass turbofan engine, something similar to the Williams WR19 engine and the modern equivalents that are typically used to power cruise missiles – see these links for more information about turbofan technology: Nasa, Wikipedia – Turbofan, but while turbofan engines provide for great specific fuel consumption and low exhaust gas temperatures they are significantly larger and heavier than turbojet engines see Wikipedia – Turbojet.

Our goal has always been the produce the lightest and smallest jetpack possible, so while we could have achieved longer flight times by using turbofan engines we opted instead for twin turbojets. We have worked with a number of engine manufacturers over the years and have needed to make many modifications to their engines and engine control units to perform as required for use in a jetpack.

The design of the airframe was helped by our earlier experience with rocketbelts but there were many changes needed related to the size, weight and shape of the engines as well as control systems and engine management systems. A rocketbelt is incredibly simple, it catalyses hydrogen peroxide fed under pressure into a silver screen catalyst pack, not a single piece of electronics is needed (the downside is extremely short flight times – the world record flight time is only 30 odd seconds!). A jetpack on the other hand requires systems to start and cool engines, to manage fuel flow and to capture operating information for display to the pilot. Significant electrical energy is also required, with the start process often drawing more than 50 amps and ongoing draw of 15 amps or more, so battery technology becomes important.

While a lot of our development work has been via testing and redesign we have also been lucky enough to work with some very talented engineers and they have helped with stress modelling for engine mounts and the airframe and with airflow analysis for engine positioning and inlet cowling design.

Nelson has been designing aviation components for fifty years and still makes the mechanical drawings by hand, working most days in his design studio in Van Nuys, CA. These drawings depict every detail of the parts to be machined or fabricated and in some cases are digitized into our CAD/CAM package. The drawings are as required by our machine shop partners for the parts we send out for machining or for our internal shop where manufactured in house.

Most of our testing has been carried out in Van Nuys, CA – including the early static engine tests and initial on-tether flight tests. We subsequently moved to a rural location as the confined environment in Van Nuys was leading to recirculation of exhaust gases and the associated problems with engine exhaust gas temperatures not to mention extremely high ambient temperatures for our team to deal with!

We also used a variety of tether systems including one that operated both laterally and longitudinally. The main tether cable runs at between 25-28ft above the ground and then can be move laterally 10ft either side of centre and a pulley rolls the full length of approximately 100ft. The Jetpack and test pilot is suspended under the tether via a cable running through an inertia descender reel. The cable length is adjusted so even if the descender reel doesn’t lock, the pilot cannot strike their knees on the ground.

After so many years we are proud to have developed and refined the JB-9, but the future is even more exciting and we have lots of work to get on with. We will continue to improve the engine technology, we will develop a parachute safety system capable of very rapid, low height deployment and of course, in this day of accelerometers and 3 axis gyros the size of coins, we are working on auto stability systems.