Southern Microlight Club of Victoria
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On a Wing and a Chair
You might think that maybe a pilot who became a quadriplegic might try to find a way to fly again but how about someone who wasn't a pilot beforehand.
In a motorcycle accident David Jacka broke the fifth vertebrae in his neck which left him as a C5/6 complete quadriplegic, with limited arm function, unable to move anything from his armpits down, with no finger function and unable to regulate his body temperature.
As David says, losing 95 percent of your body function can slow you down a bit. Life tends to change rather dramatically: all the things you once did have gone and you’re left wondering where to from here. It was a long road from the initial year of rehabilitation. He started from the basics, such as feeding himself, dressing, and picking things up, then with time re-learning how to drive, and finally building a new career.
Never one to be idle, it was only a matter of time before this adventurer was going to cast an eye skyward. Without the dexterity in his hands and fingers and with insufficient strength in his arms, it took a while before David decided to make aviation happen.
When he first saw a microlight trike at the Avalon Air Show in 2005 it sparked that distant memory of wanting to fly. What attracted him to the trike was the simplicity of its construction; being like that of a hang glider. You don’t need dexterity of the hands, which suited David, but you needed a fair bit of strength to hang onto the wing.
An initial challenge was to find an instructor that had an open mind and who was willing to give David a go at flying. Following a few disappointments, he got onto Steve Ruffels of Eagle School of Microlighting in Bright who agreed to give him a go. Within only a couple of hours of flying it became apparent that with the right aircraft and the right modifications, he would be able to fly!
The problem when you have a significant disability is there isn’t an off the shelf product you can simply buy and use. Having a drafting and engineering background was invaluable to develop the modifications for the aircraft as David could undertake and develop the functional designs and work with the fabricator to make it work. The fact that David gets a kick out of this kind of challenge made the task of R&D much easier and less expensive.
As he doesn’t have any finger function he developed a control bar that attaches to the base bar, which allows him to lock his hands in place to steer the wing but also allows him to remove them by sliding them out. To control the foot throttle he converted it to use an electric actuator to pull the cable backwards and forwards controlled via pushbuttons on the control bar.
The ground steering was achieved by using a lever connected to the front forks by a rod and by moving the lever backwards and forwards allowed the trike to steer left and right. When taxiing the trike would be steered with David’s left hand and he would hold the wing with his right, which was alright in light conditions.
After 17 hours this dedicated aviator went solo and like all of us, though probably even more so, says it was the most exhilarating experience he has had…and just a little bit frightening. It took months to build up enough strength in his arms to handle the wing effectively and develop the modifications which was a mammoth achievement in itself but, in true David Jacka style, it set in motion the idea that anything might be possible.
Trying to hold the wing with one hand and steer the trike on the ground with the other did eventually prove fallible. On the odd occasion an unexpected wind change caught him out, as David says, it was like being on the end of a very large umbrella. On one occasion he went into a ditch, steering involuntarily into an embankment and almost rolled the trike.
The solution to the problem was to develop a steering system that worked by sucking and puffing on a tube. By sucking it steered left and puffing it steered right. This worked perfectly and it allowed David to have both hands on the wing and a whole lot more scope for flying.
Ever since he soloed in 2006, David has wanted to fly around Australia, but realized that the trike would not be the aircraft for the job. It is difficult to get a wheelchair on board, plus the open cockpit makes it hard for him to regulate his body temperature: a potentially deadly problem. That’s when David had a chance meeting with a Jabiru.
After coming face to face with a friend’s J230 on a flying trip and perusing the impressive specs (120kt cruise speed and baggage space in the back for a wheelchair and gear), David started to have glimpses of moving from weight shift to the sporty side of fixed wing aircraft. The cold was just too much, as was waiting for his wheelchair to turn up on a bus when he flew cross country.
David looked at many other aircraft before deciding on the Jabiru. There were four main things the aircraft had to have: good access into the driver’s seat, a cruise speed of at least 100 knots, suitable storage for his chair, passenger and gear and, most importantly, a HEATER! The Jabiru J230 was the only aircraft he could find that would meet each item and be RAA registered.
Before jumping into the deep end, David decided to see whether the manufacturer would approve the modifications. He was pleasantly surprised when Rod Stiff from Jabiru said he couldn’t see any issues in principal. David would provide a functional design of the modifications and Rod would provide approval prior to purchasing the aircraft.
The controls on the right seat had to remain operable for the instructor and all controls had to be able to be overridden manually if necessary. They initially developed a pneumatic system that was going to operate the throttle, trim, and brake, which would disengage when the air was removed from the system. The rudder/front nose wheel was to be operated by a lever arrangement that David would use on his left hand and the pedals on the right remained operational. Having completed the functional design in consultation with Jabiru, approval in principal was provided and David ordered the aircraft in October 2008.
Just before Christmas 2008 David received his new toy and got to work on the mods. The rudder steering was started first as it was the easiest. The functionality of the existing rudder and front wheel steering was not modified and the pedals on the right side remain fully functional.
On the left side however, where David would fly, the pedals were removed and the rear rudder pedal assembly shaft was extended closer to the left side wall of the aircraft with a connection lever to allow for feet positioning. From the connection lever a rod connects to a hand lever mounted to the side wall of the aircraft. By pushing the lever the aircraft will turn right and by pulling the lever the aircraft will turn left.
The control column consists of three upright posts. The wrist is supported between the two end posts with the hand and fingers wrapping around the centre post. The wrist is then held in an extended position, which securely locks the hand in place to allow movements in all directions. The hand can be removed easily and quickly by sliding it out in an upward direction as necessary.
The existing brake system has not been modified and can be operated manually as intended. A pneumatic brake actuation system was installed to allow David to control the brake via a toggle switch. The system comprises mainly of a compressor, air receiver, linear actuator and air regulating components.
The pneumatic linear actuator is mounted on the fire wall and an extension rod is connected to the output shaft of the actuator, with the other attached to the brake lever below the handle. When the actuator extends the brake is applied. The actuator shaft travels approximately 10 – 15mm per second therefore by flicking the toggle switch quickly on/off the speed and position of the brake application can be controlled easily. If the brake needs to be held on then the toggle switch is held in the on position thereby locking the brakes. Once the switch is disengaged the brake lever returns to its neutral position.
The throttle is then controlled by a Sip & Puff system comprising of two pneumatic switches and relays housed in a box. From the Sip & Puff box a plastic tube is used to either sip or puff air through it, activating either of the pneumatic switches driving the motor forward or reverse. The system is configured so if you puff on the tube the engine will throttle up and if you sip on the tube it will throttle down. When you stop the input, the system stops immediately allowing incremental adjustments to the throttle. The sip & puff tube is attached to the mike boom to allow quick and easy access when needed. When the motorised system is not activated or power fails, the clutch is not engaged and the throttle input shaft can be used manually without resistance.
Due to having no finger function to hold the yoke, hand supports are required which consist of three upright posts. The wrist is supported between the two end posts with the hand and fingers wrapping around the centre post. The wrist is then held in an extended position, which securely locks the hand in place to allow movements in all directions. The hand can be removed easily and quickly by sliding it out in an upward direction as necessary.
Other minor modifications were done to make it easier to access vital items, including relocation of some of the switches, moving the carburetor heat, additional pushbuttons on the rudder lever to operate the flaps changed the location of the PTT switch and a footplate to hold David’s feet in position. The mods were finished and the approvals were finally completed last June, when David undertook his 3 axis conversion with Tooridan Flying school CFI, Ian Loveridge.
In the air David found that in the Jabiru things happen a lot faster than the trike. So much so that he initially had trouble completing all the tasks required in the circuit. Having all the extra controls made it both possible, and nearly impossible, to fly at the same time. The hardest part was trying to use the yoke with the right hand and rudder with the left - like trying to tap your head and rub your stomach at the same time.
After 24 hours and plenty of unavoidable crosswind practice thanks to Tooradin’s weather, David was finally reward for all his hard work with the issue of his 3-axis recreational license. For someone once told his life would forever be limited, he suddenly felt freer than ever before.
Apart from trying to get away as much as possible for weekend flying, David has his sights set on one of his biggest challenges to date: to be the first quadriplegic to fly solo around Australia - crossing the four most Southern, Northern, Eastern and Westerly points of the country. These being South East Cape Tasmania, Cape York QLD, Cape Byron NSW and Steep Point WA. The trip is anticipated to take approximately six weeks, depending upon weather, and a support aircraft will be used to carry equipment and carers for assistance.
There are two main areas of focus for the trip. The first is to promote a not-for-profit charity. The second to raise public awareness, demonstrating that people who are disadvantaged can achieve much more than what most people would realize. Through this journey, David hopes to inspire others, with or without a disability, to push their personal boundaries and not see the limitations, but the possibilities of what they can achieve.
David is seeking sponsorship to enable the vision of inspiring others to follow their dreams, promoting awareness to the general community and assisting in raising funds for a not-for-profit charity, become a reality. For David Jacka it is challenges like these that helped him develop an attitude of looking for a solution to every problem and by just giving things a go, look at what can be achieved!
This article is excerpts taken from an article written by David Jacka and Kristy How.
The full article can be found at http://www.aviatormag.com.au/stories/Jan10_Re_Built.html
You might think that maybe a pilot who became a quadriplegic might try to find a way to fly again but how about someone who wasn't a pilot beforehand.
In a motorcycle accident David Jacka broke the fifth vertebrae in his neck which left him as a C5/6 complete quadriplegic, with limited arm function, unable to move anything from his armpits down, with no finger function and unable to regulate his body temperature.
As David says, losing 95 percent of your body function can slow you down a bit. Life tends to change rather dramatically: all the things you once did have gone and you’re left wondering where to from here. It was a long road from the initial year of rehabilitation. He started from the basics, such as feeding himself, dressing, and picking things up, then with time re-learning how to drive, and finally building a new career.
Never one to be idle, it was only a matter of time before this adventurer was going to cast an eye skyward. Without the dexterity in his hands and fingers and with insufficient strength in his arms, it took a while before David decided to make aviation happen.
When he first saw a microlight trike at the Avalon Air Show in 2005 it sparked that distant memory of wanting to fly. What attracted him to the trike was the simplicity of its construction; being like that of a hang glider. You don’t need dexterity of the hands, which suited David, but you needed a fair bit of strength to hang onto the wing.
An initial challenge was to find an instructor that had an open mind and who was willing to give David a go at flying. Following a few disappointments, he got onto Steve Ruffels of Eagle School of Microlighting in Bright who agreed to give him a go. Within only a couple of hours of flying it became apparent that with the right aircraft and the right modifications, he would be able to fly!
The problem when you have a significant disability is there isn’t an off the shelf product you can simply buy and use. Having a drafting and engineering background was invaluable to develop the modifications for the aircraft as David could undertake and develop the functional designs and work with the fabricator to make it work. The fact that David gets a kick out of this kind of challenge made the task of R&D much easier and less expensive.
As he doesn’t have any finger function he developed a control bar that attaches to the base bar, which allows him to lock his hands in place to steer the wing but also allows him to remove them by sliding them out. To control the foot throttle he converted it to use an electric actuator to pull the cable backwards and forwards controlled via pushbuttons on the control bar.
The ground steering was achieved by using a lever connected to the front forks by a rod and by moving the lever backwards and forwards allowed the trike to steer left and right. When taxiing the trike would be steered with David’s left hand and he would hold the wing with his right, which was alright in light conditions.
After 17 hours this dedicated aviator went solo and like all of us, though probably even more so, says it was the most exhilarating experience he has had…and just a little bit frightening. It took months to build up enough strength in his arms to handle the wing effectively and develop the modifications which was a mammoth achievement in itself but, in true David Jacka style, it set in motion the idea that anything might be possible.
Trying to hold the wing with one hand and steer the trike on the ground with the other did eventually prove fallible. On the odd occasion an unexpected wind change caught him out, as David says, it was like being on the end of a very large umbrella. On one occasion he went into a ditch, steering involuntarily into an embankment and almost rolled the trike.
The solution to the problem was to develop a steering system that worked by sucking and puffing on a tube. By sucking it steered left and puffing it steered right. This worked perfectly and it allowed David to have both hands on the wing and a whole lot more scope for flying.
Ever since he soloed in 2006, David has wanted to fly around Australia, but realized that the trike would not be the aircraft for the job. It is difficult to get a wheelchair on board, plus the open cockpit makes it hard for him to regulate his body temperature: a potentially deadly problem. That’s when David had a chance meeting with a Jabiru.
After coming face to face with a friend’s J230 on a flying trip and perusing the impressive specs (120kt cruise speed and baggage space in the back for a wheelchair and gear), David started to have glimpses of moving from weight shift to the sporty side of fixed wing aircraft. The cold was just too much, as was waiting for his wheelchair to turn up on a bus when he flew cross country.
David looked at many other aircraft before deciding on the Jabiru. There were four main things the aircraft had to have: good access into the driver’s seat, a cruise speed of at least 100 knots, suitable storage for his chair, passenger and gear and, most importantly, a HEATER! The Jabiru J230 was the only aircraft he could find that would meet each item and be RAA registered.
Before jumping into the deep end, David decided to see whether the manufacturer would approve the modifications. He was pleasantly surprised when Rod Stiff from Jabiru said he couldn’t see any issues in principal. David would provide a functional design of the modifications and Rod would provide approval prior to purchasing the aircraft.
The controls on the right seat had to remain operable for the instructor and all controls had to be able to be overridden manually if necessary. They initially developed a pneumatic system that was going to operate the throttle, trim, and brake, which would disengage when the air was removed from the system. The rudder/front nose wheel was to be operated by a lever arrangement that David would use on his left hand and the pedals on the right remained operational. Having completed the functional design in consultation with Jabiru, approval in principal was provided and David ordered the aircraft in October 2008.
Just before Christmas 2008 David received his new toy and got to work on the mods. The rudder steering was started first as it was the easiest. The functionality of the existing rudder and front wheel steering was not modified and the pedals on the right side remain fully functional.
On the left side however, where David would fly, the pedals were removed and the rear rudder pedal assembly shaft was extended closer to the left side wall of the aircraft with a connection lever to allow for feet positioning. From the connection lever a rod connects to a hand lever mounted to the side wall of the aircraft. By pushing the lever the aircraft will turn right and by pulling the lever the aircraft will turn left.
The control column consists of three upright posts. The wrist is supported between the two end posts with the hand and fingers wrapping around the centre post. The wrist is then held in an extended position, which securely locks the hand in place to allow movements in all directions. The hand can be removed easily and quickly by sliding it out in an upward direction as necessary.
The existing brake system has not been modified and can be operated manually as intended. A pneumatic brake actuation system was installed to allow David to control the brake via a toggle switch. The system comprises mainly of a compressor, air receiver, linear actuator and air regulating components.
The pneumatic linear actuator is mounted on the fire wall and an extension rod is connected to the output shaft of the actuator, with the other attached to the brake lever below the handle. When the actuator extends the brake is applied. The actuator shaft travels approximately 10 – 15mm per second therefore by flicking the toggle switch quickly on/off the speed and position of the brake application can be controlled easily. If the brake needs to be held on then the toggle switch is held in the on position thereby locking the brakes. Once the switch is disengaged the brake lever returns to its neutral position.
The throttle is then controlled by a Sip & Puff system comprising of two pneumatic switches and relays housed in a box. From the Sip & Puff box a plastic tube is used to either sip or puff air through it, activating either of the pneumatic switches driving the motor forward or reverse. The system is configured so if you puff on the tube the engine will throttle up and if you sip on the tube it will throttle down. When you stop the input, the system stops immediately allowing incremental adjustments to the throttle. The sip & puff tube is attached to the mike boom to allow quick and easy access when needed. When the motorised system is not activated or power fails, the clutch is not engaged and the throttle input shaft can be used manually without resistance.
Due to having no finger function to hold the yoke, hand supports are required which consist of three upright posts. The wrist is supported between the two end posts with the hand and fingers wrapping around the centre post. The wrist is then held in an extended position, which securely locks the hand in place to allow movements in all directions. The hand can be removed easily and quickly by sliding it out in an upward direction as necessary.
Other minor modifications were done to make it easier to access vital items, including relocation of some of the switches, moving the carburetor heat, additional pushbuttons on the rudder lever to operate the flaps changed the location of the PTT switch and a footplate to hold David’s feet in position. The mods were finished and the approvals were finally completed last June, when David undertook his 3 axis conversion with Tooridan Flying school CFI, Ian Loveridge.
In the air David found that in the Jabiru things happen a lot faster than the trike. So much so that he initially had trouble completing all the tasks required in the circuit. Having all the extra controls made it both possible, and nearly impossible, to fly at the same time. The hardest part was trying to use the yoke with the right hand and rudder with the left - like trying to tap your head and rub your stomach at the same time.
After 24 hours and plenty of unavoidable crosswind practice thanks to Tooradin’s weather, David was finally reward for all his hard work with the issue of his 3-axis recreational license. For someone once told his life would forever be limited, he suddenly felt freer than ever before.
Apart from trying to get away as much as possible for weekend flying, David has his sights set on one of his biggest challenges to date: to be the first quadriplegic to fly solo around Australia - crossing the four most Southern, Northern, Eastern and Westerly points of the country. These being South East Cape Tasmania, Cape York QLD, Cape Byron NSW and Steep Point WA. The trip is anticipated to take approximately six weeks, depending upon weather, and a support aircraft will be used to carry equipment and carers for assistance.
There are two main areas of focus for the trip. The first is to promote a not-for-profit charity. The second to raise public awareness, demonstrating that people who are disadvantaged can achieve much more than what most people would realize. Through this journey, David hopes to inspire others, with or without a disability, to push their personal boundaries and not see the limitations, but the possibilities of what they can achieve.
David is seeking sponsorship to enable the vision of inspiring others to follow their dreams, promoting awareness to the general community and assisting in raising funds for a not-for-profit charity, become a reality. For David Jacka it is challenges like these that helped him develop an attitude of looking for a solution to every problem and by just giving things a go, look at what can be achieved!
This article is excerpts taken from an article written by David Jacka and Kristy How.
The full article can be found at http://www.aviatormag.com.au/stories/Jan10_Re_Built.html