Why this and not single-rotor collective pitch? There's no good explanation in the marketing material.
Probably to make maintenance simpler? That's the most expensive part of operating a helicopter.
SureFly – a personal helicopter designed for safe and easy flight
31–40 of 157 posts
Re: SureFly – a personal helicopter designed for safe and easy flight
#32I'm very skeptical of their claims of "unparalleled safety". Thanks to "autorotation"[1] regular helicopters can safely land in most situations even with complete power failure. The claims of safety of this craft seems to derive from N+1 battery redundancy which isn't that impressive. They say they have 8 independent motors, but don't say how many are needed to stay aloft. [1] https://en.wikipedia.org/wiki/Autorotati…
Should be four or less considering each arm has two props. (Unless the motors aren’t powerful enough)
If all four on one side went out, I assume you'd be in big trouble.
Re: SureFly – a personal helicopter designed for safe and easy flight
#33 > 1 hour of fuel
> 70 mph speed
This means that the maximum legal range with FAA-mandated fuel reserves is 46 miles (assuming no wind). Also despite shots of it on a driveway, it would most likely be impossible to actually take off or land on your driveway due to local ordinances in most cities. Oh and it doesn't appear to be properly equipped for IFR, so clear weather operation only.
Re: SureFly – a personal helicopter designed for safe and easy flight
#34Earlier quoted context omitted.
The BMI chart maxes out healthy weights at 192. So unless you have two NBA players or something, it should work well for most but perhaps not all healthy people.
Average weights (no median, sorry) from the CDC ( https://www.cdc.gov/nchs/fastats/body-measurements.htm ): >Men: 195.7 pounds >Women: 168.5 pounds So this could carry an average man, average woman, and under 36 pounds. At that point, the weight of your clothing or a bottle of wine becomes very important.
Maybe the US version should have one seat :)
Re: SureFly – a personal helicopter designed for safe and easy flight
#35A part of me thinks this is really cool tech and it would be amazing for anyone to be able to just hop aboard their personal helicopter and fly wherever they want, but then another part of me thinks of the future this would create, skies no longer clear, filled with objects buzzing around and what hell that would be, on top of the already stressful and crazy life we have now. It's the kind of situation where I think…
I empathize but I think that attitude is an artifact of the age we grew up in. I'm sure equestrians felt the same way when those rackety automobile contraptions started zooming around.
I still feel that way about cars. Those horse riders were right.
Re: SureFly – a personal helicopter designed for safe and easy flight
#36Wait: - Curb Weight: 1100lbs - Max Takeoff Weight: 1500lbs So... you, your passenger, and any cargo combined can't weigh more than 400 pounds? That's a pretty serious limit for people hoping to transport multiple adults. And "precision agriculture" or the sorts of practical uses they discuss all go right out the window.
400 lbs capacity for passengers / cargo is in line with an R22, a common 2 seater helicopter (389 lbs for Pilot, Passenger and Baggage). However the SureFly situation is likely worse than that. Typically the empty weight does not include fuel weight, which might be another 100 lbs.
It seems that SureFly has designed an aircraft with less than half the range of an R22, that can't autorotate, and costs roughly the same. The SureFly might be easier to fly though.
Re: SureFly – a personal helicopter designed for safe and easy flight
#37A part of me thinks this is really cool tech and it would be amazing for anyone to be able to just hop aboard their personal helicopter and fly wherever they want, but then another part of me thinks of the future this would create, skies no longer clear, filled with objects buzzing around and what hell that would be, on top of the already stressful and crazy life we have now. It's the kind of situation where I think…
I empathize but I think that attitude is an artifact of the age we grew up in. I'm sure equestrians felt the same way when those rackety automobile contraptions started zooming around.
I think everyone must have felt this way about automobiles. And by and large, it's worked out just as horribly as they imagined: our communities are divided by dangerous moats we call "roads" -- death traps which we must painstakingly teach our children to avoid, if we dare let our children wander outside on their own anywhere near them in the first place.
Re: SureFly – a personal helicopter designed for safe and easy flight
#38[deleted]
Re: SureFly – a personal helicopter designed for safe and easy flight
#39I'm very skeptical of their claims of "unparalleled safety". Thanks to "autorotation"[1] regular helicopters can safely land in most situations even with complete power failure. The claims of safety of this craft seems to derive from N+1 battery redundancy which isn't that impressive. They say they have 8 independent motors, but don't say how many are needed to stay aloft. [1] https://en.wikipedia.org/wiki/Autorotati…
Small "personal" helicopters like the Robinson R22 are quite difficult to autorotate safely in a real emergency, due to low rotor inertia. [0] For the SureFly, Hypothetically if loss of several motors caused the aircraft to be unable to maintain altitude, the aircraft would not suddenly drop like a brick, but drift down to a controlled landing. [0] http://philip.greenspun.com/flying/robinson-r22
No, worse. That thing would turn into the tumble dryer from hell with partial power. It has no blade pitch control (like a helicopter does), requiring power on the motors in all four corners to maintain stability.
The real emergency situation to worry about would be a total power failure. Failure of the individual electric motors will likely be extremely rare but a battery fire or controller failure could send this thing falling like a rock due to the lack of auto-rotation. It has a BRS chute but that won't do anything in the critical ~500ft band above ground level, too low to deploy normally. Additionally, I hope they've figured out how to guarantee safe chute deployment while inverted because of the tendency to tumble with no/partial power.
Re: SureFly – a personal helicopter designed for safe and easy flight
#40electric transmission vs mechanical and 8 tiny inefficient props?
1 hour flight with 30kg of fuel?
I can make something more efficient in a garage...