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NASA Designs All-Electric Personal Flight Vehicle
MikeChino writes "NASA is currently working on a personal aircraft that will put jet packs to shame. The Puffin is an all-electric one-man airplane that could be the start of some new and amazing air travel technology. With two prop electric engines, lithium phosphate batteries and a top speed of almost 300 mph, the vertical take off and landing vehicle was originally designed for covert military insertions because it has a lower heat signature than combustion engines. The Puffin would also be super quiet – 10 times quieter than current low-noise helicopters, and since the engine is electric it has no flight ceiling and can fly up to 9,150 meters high, uninhibited by thin air."
"since the engine is electric it has no flight ceiling and can fly up to 9,150 meters high, uninhibited by thin air." I presume they mean in this context no substantial flight ceiling where the engine gives out from lack of oxygen and you have a very bad day. That's backed up by the original article which says that "It has no flight ceiling--it is not air-breathing like gas engines are, and thus is not limited by thin air--so it could go up to about 9,150 meters before its energy runs low enough to drive it to descend." So in fact you could fly this much higher than 9,150 meters if you started out high up (from say a larger aircraft) or had a parachute. This leads to a question: How high up could it go before the air becomes too thin to generate enough lift to continue ascending?
how quickly will it hit the ground if it runs out of power.
You should be able to auto-rotate like you can with a helicopter. Also, there's always the parachute option.
The only title of honor that a tyrant can grant is "Enemy of the State."
Note well that the highest flying prop plane ever, the Aerovironment Helios, flew to 96,000 ft -- far higher than almost any other plane (probably the only one that could sustain that altitude was the SR-71). The Helios was powered completely by solar cells and electric motors.
I love Mondays. On a Monday, anything is possible.
From TFA:
electric aircraft are much quieter than regular planes—at some 150 meters, it is as loud as 50 decibels, or roughly the volume of a conversation, making it roughly 10 times quieter than current low-noise helicopters.
I admit that I never have gotten a handle on math beyond algebra but am I wrong by being bothered by statements like 10 times quieter? Wouldn't be better to say "makes only one-tenth the noise?" Or am I being pedantic?
This ain't rocket surgery.
Li-ion-anything has an energy density equaling 1% of gasoline. Lithium phosphate batteries are worse than others in energy density, but safer.
So for the same fuel weight, instead of a 2 hour flight reserve, you would have 72 seconds.
Until there is a radically different battery, this is unrealistic.
don't cut it off www.mgmbill.org
Wow! And I thought I was nuts for loving HALO[High Altitude, Low Opening] jumps!
[With full equipment/kit load+body wt. @ around 275 lb./125 Kg] I was told that the max. velocity was around 130 mph/209 kph...compared to 714 mph, I guess I was a piker!
Offtopic side note:The highest we ever jumped from was around 17,000 feet altitude; I found my minimum altitude for releasing my chute was approximately 385 feet, but it hurt!
(we were advised that the minimum altitude was 500 feet...I had to test this)
[using the US Army version of the Ram Air-square type 'chute]
That was also where I got over my fear of heights, once I was thrown out of a perfectly good airplane!
Down With Slashdot BETA!!! I've been around the corner and seen the oliphant; you can only abuse me from your perspecti
The politicians would never allow common people to have that much freedom. No borders, no passports, no way of stopping people from going where they wanted, when they wanted. And that's without assuming any purpose more nefarious than a cheap weekend in Amsterdam.
I wonder if there was someone a hundret years ago, who said something like this about cars.... I think, if you put some technology into those thing - most of the problems you adress could be solved. Could be some kind of electronically "check-in" when entering special areas or such... come on... I realy _want_ this :-)
It would if the charge logic had additional data lines to communicate if some of the lithium cells had been disabled.
This is the current problem with consumer electronics, is that the charge logic does not convey to the device that it has disabled some of the cells for safety reasons, and that thus, your 5000mAh battery is really only a 3200mAh battery. Thus, the device presumes it has more power remaining than it actually has.
If the charge logic properly reported what kind of cell it was attached to, how many cells were functional, and what the charge states were of those cells, it would result in a more or less accurate (to within a minute or so) of the actual charge time remaining.
The problem is that charge logic of that kind would increase the weight of the battery, increase the complexity of the battery, and increase the cost of the battery. All three things are subjects that consumer electronics bean counters dont want to even consider doing unless absolutely necessary.
Considering that this is being engineered for military purposes, I'd expect much better charge logic to be installed, and for the battery meter to be more accurate than the one for your 3oz cellphone.