I don't see why this is inherently more dangerous than, say, flying a powered parachute. It's really more in the same class as a helicopter except that engine failure risk is mitigated by the emergency parachute system. Running into stuff while flying low is probably the main mode of death.
Mainly due to the fact that a 'powered parachute' (e.g. an ultralite) undergoes essentially no mass modal volume delta in airflow when transitioning between powered and unpowered flight.
The controls, and fundamental aeronautical responses to flight inputs, remain the same in both flight regimes and, for the most part, there's a gradual and manageable amount of pilot feedback during the transition.
In fact, this lack of "gradual feedback" was the main reason that power steering took so long to be safety-approved in automobiles. It's also why, in most countries, pure 'drive-by-wire' controls are only allowed in experimental and prototype road vehicles. Despite the obvious ergonomic and cockpit layout virtues of joysticks, steering wheels and worm gears can still work without active power-assists.
The same can be said for a gliding light airplane or helicopter under auto-rotation.
Alas, the same CAN NOT be said for the Martin jetpack when deploying its ballistic parachute. Btw, aside from cost and liability issues, this is one of the reasons emergency ballistic parachutes haven't caught on in small single-engine aircraft.
I wonder how much altitude you could expect to lose from the moment the engine quits until the moment the parachute is fully deployed and slowing your descent? Surely it would be over a hundred feet - which means that any engine failure in that altitude range would result in a painful splat on the pavement. http://en.wikipedia.org/wiki/Height-velocity_diagram
This could deploy more quickly since it's actively assisted by the explosion. This shoots up, rather than floats up (admittedly "float" in this case is a pretty high wind velocity! ;)
A skydiver is transitioning (abruptly) from unpowered free-fall into unpowered, albeit greatly slowed, descent. The jetpack user is transitioning from powered, controlled horizontal flight (with its characteristic 6 degrees of freedom) into unpowered descent.
A back-up chute for the skydiver has essentially, but not quite, the same flight characteristics and initial deployment conditions as a main.
Parachutes in a stable flight configuration are incredibly safe and reliable, but it's GETTING that 6-axis dynamic flight-body INTO that stable flight configuration that's the real challenge.
It's relatively easy to design a system for even extremely large, static, dead-weights (such as cargo or even battle tanks) to be safely launched, arrested, and landed via parachute.
It's an entirely different problem when your safe chute deployment must take into account the wide variance in airspeed, pitch, yaw, altitude, and environmental influences which powered free flight allows. Imagine a worse-case scenario where all power was lost just after a major inadvertent yaw maneuver (it appears to be designed to minimize yawing). That's a sticky-wicket to solve repeatedly and reliably.
In the case of the jetpack the parachute is launched upward with rockets. This takes extra time: the time it would take for the operator or system to detect engine-out and initiate parachute launch, then the time it would take for a rocket(s) to launch the parachute up to where it could be, then the time for the uprush of air to catch the canopy.
Here's a link to an article about the ballistic parachute fitted to Cirrus SR20/22 aircraft. http://www.cirruspilots.org/content/CAPSHistory.aspx There's one mention of a low-altitude parachute deployment: "one activation occurred at too low an altitude to fully inflate the canopy (witnesses report 200 feet above ground), and another activation where the rocket took an unusual trajectory resulting in a failure to open the canopy."
I think the problem is that the airframe provides no tendency towards being aerodynamically stable, the flight stability relies on good pilot input, thus tending to be less robust and forgiving in situations involving pilot error or mechanical problems.
Seems like it'll get the same treatment as the Segway. Lots of places banned Segways from sidewalks... Jetpacks certainly need to be banned from pretty much anyplace where it would be worthwhile or incredibly fun?
If it gets certificated as something more than an experimental aircraft, you should expect to be able to fly it at least by the same rules you fly a helicopter.
What's funny is after watching the video I imagined myself flying this thing to my work, landing on the roof then taking the ladder down to our deck. After that I'll just stroll through the doors like business as usual. So basically the same thing I was dreaming of when I was in grade school.
I've seen this on a few New Zealand current affairs shows and have never seen any footage of an unassisted outdoor flight. Every time the creators have had media coverage they have insisted on doing it inside and not allowing it to go higher than a few meters off the ground.
I'd like to see them do a real test flight higher than a few meters off the ground before I'm convinced that this is the real deal.
"Martin Jetpack is currently accepting enquiries from commercial customers. Please place your initial enquiry through this site and we will contact you directly.
It is expected that early orders for sales to private individuals will commence late 2010"
EDIT: removed [sic] for "enquiries", as MW dictionary doesn't contain it but others do.
It is classed by the FAA as an ultralight aircraft. Google surely will provide full details, but in brief, that means that you cannot fly it over any inhabited area. No commuting.
It's a bit of a stretch to call it the first commercially available personal flying machine, there are plenty of single-seat aircraft and choppers that qualify for that title.
Thought their pricing was interesting, lower than I would have guessed: "Martin Aircraft has built several prototypes so we have a good idea how much they cost to manufacture. Depending on production volume, the initial cost will be about the same as a high-end motorcycle or car. As volume increases this will drop to be similar to a mid-range motorcycle or car."
Are there any videos of a full flight? I only saw an indoor test flight. Wondering what happens when you get a strong wind - a good control system is going to be needed to keep the thing from total failure.
Why are they using a 2-stroke ICE instead of a small turbine I wonder? The pack looked quite cool from the front but when the pilot spun around it looked like he had a VW beetle strapped to his back...
I can only guess fuel-consumption-to-thrust efficiencies (longer flight times) or pure cost since a pure gas turbine will always beat out a mechanically linked fan-stroke in specific power (i.e. kW/kg), but will almost always be more costly due to the extremely high manufacturing tolerances required for turbines.
