pylon500 Posted May 15, 2015 Posted May 15, 2015 http://www.gizmag.com/aeromobil-flying-car-prototype-crashes/37473/ Looks like it got into a spin, and deployed the ballistic chute...
Guest ozzie Posted May 16, 2015 Posted May 16, 2015 http://www.digitaltrends.com/cars/aeromobil-flying-car-prototype-crash-lands-during-test-flight/ Some images of the remains here. Wonder if it had an airbag. Looks like it came down nose first.
Ultralights Posted May 16, 2015 Posted May 16, 2015 from what i read is it failed to recover during spin testing. hope they have another one to continue and modify to get it tested
Downunder Posted May 16, 2015 Posted May 16, 2015 Looking at the crash pictures, the front wheel looks almost pushed back to the leading edge. I wonder if the front "folded up" on impact.
dutchroll Posted May 17, 2015 Posted May 17, 2015 That's a bummer. A roadster which can bypass M1 congestion or pileups at 1000' has been my dream for a number of years!
jetjr Posted May 17, 2015 Posted May 17, 2015 dont they still have to pass road occupant safety regs? if so the deformation would be designed in and it appears to have worked.
fly_tornado Posted May 18, 2015 Posted May 18, 2015 Ballistic parachutes are designed to tip the airframe, to increase drag, to slow it down so that the aircraft makes a vertical descent. This is designed to improve accuracy of picking a landing area as well as reducing impact speed.
SDQDI Posted May 18, 2015 Posted May 18, 2015 Combine that with some decent(descent lol) crumple zones and it could make it one of the more 'comfortable'/survivable brs systems
Downunder Posted May 18, 2015 Posted May 18, 2015 dont they still have to pass road occupant safety regs?if so the deformation would be designed in and it appears to have worked. I guess pushing straight back is fine. I was worried about the "dash" folding back and sandwiching your head between it and the headrest.... I think there was a thread on here about an aircraft that did that. After folding back on impact the front flopped forward again..?
Oscar Posted May 18, 2015 Posted May 18, 2015 Ballistic parachutes are designed to tip the airframe, to increase drag, to slow it down so that the aircraft makes a vertical descent. This is designed to improve accuracy of picking a landing area as well as reducing impact speed. There is NO pilot control possible once the BRS is utilised; this comment is complete nonsense. You are at the mercy of the wind speed and direction. The descent is NOT vertical unless there is zero wind. The attitude of the aircraft has precisely zero effect on impact speed. Aircraft are designed so that the undercarriage absorbs the major part of vertical speed at the moment of contact; tipping the airframe so that the undercarriage is ineffectual reduces the energy absorption capability of the airframe, which is NOT designed to be flown into a brick wall. I guess pushing straight back is fine. I was worried about the "dash" folding back and sandwiching your head between it and the headrest....I think there was a thread on here about an aircraft that did that. After folding back on impact the front flopped forward again..? RV6. 3
Oscar Posted May 18, 2015 Posted May 18, 2015 Well, thanks, FT. I don't intend to be really 'back', the editorial direction of the site and I have issues, and it's his site - but I do have some affection for my fellow aviators and I do believe it's important that people don't get dangerous information and believe it without having the realities explained. A BRS is - quite literally - the 'last chance' option: I agree with you that it will slow down impact with the ground if that is uncontrollably INEVITABLE ( i.e. as a result of structural / control system failure / otherwise unrecoverable aerodynamic situation due to the proximity of the terrain / unlandable terrain - but to represent it as a controllable situation once deployed, is just completely wrong. Once a BRS is deployed, the aircraft becomes at zero airspeed, it is hanging under a canopy that moves with the air. Therefore, NONE of the flight controls can have any effect - unless you have engine power and can achieve a positive airspeed of sufficient velocity to make the flight controls effective - in which case, why did you pull the BRS handle? I don't know of any BRS installations that have a 'detach' mechanism, so assuming you stabilised flight under the BRS and had engine power, applying power to achieve the effective use of flight controls would result in nothing more than a huge upswing of the aircraft against the drag of the BRS chute - negating the use of flight controls. Almost by definition, you could not regain use of the flight controls with the BRS deployed but still attached. Aircraft are not designed to absorb more than a relatively low forward impact speed. They ARE designed to have a specified vertical speed resistance - i.e. a stall - smack down situation - and the undercarriage and even the tyres are all part of that. A BRS descent into water - particularly for a low-wing aircraft - is more likely to crush your spine than a BRS descent onto flat ground in a relatively fuselage-level position where the undercarriage can absorb the energy as it is designed to do. For more information, look at the FAA requirements for energy-absorbing seats. If you pull the BRS handle, you have made the call to God on the Golden Telephone, you don't get to control what happens after that. I would agree that there certainly can be situations where that is the only option - but to suggest that you have any control once you have puller the BRS, is simply wrong. 2
Guest ozzie Posted May 19, 2015 Posted May 19, 2015 Zero airspeed? about 26ft per second decent rate can be called airspeed. You will possibly have some roll control as there will be some airflow over the aircraft.
Oscar Posted May 19, 2015 Posted May 19, 2015 Ya got me there... yep, you could possibly turn the thing to look at the ground you're going to hit, or the ground that you weren't going to hit...
winsor68 Posted May 19, 2015 Posted May 19, 2015 Zero airspeed? about 26ft per second decent rate can be called airspeed. You will possibly have some roll control as there will be some airflow over the aircraft. I thought you would be travelling in the surrounding air mass...so no forward speed as such...despite ground speed. Unless the recovery canopy is set up to be steered as in square chutes? 1
facthunter Posted May 19, 2015 Posted May 19, 2015 You only have downwards velocity as far as the airmass is concerned. Nev
Guest ozzie Posted May 20, 2015 Posted May 20, 2015 Relative wind it is. doesn't matter what direction it is coming from. the aircraft hanging under the canopy is in a nose down attitude and the aircraft is descending downward direction so there must be some wind moving over the wings. Probably getting a bit of forward drive from the bit of lift being generated. deflect the ailerons and it will turn.
facthunter Posted May 20, 2015 Posted May 20, 2015 No argument with that. It's not much wind though. What is the ROD with chute extended? 1800 fpm max? Nev
rick-p Posted May 20, 2015 Posted May 20, 2015 I thought you would be travelling in the surrounding air mass...so no forward speed as such...despite ground speed. Unless the recovery canopy is set up to be steered as in square chutes? Come on where did 26ft per second come from? That would be a non survival decent. 1,560 feet per minute. That is approximately 32 k's per hour or nearly 20 miles per hour. That is very fast to run into a brick wall. The correct survival speed is about 1 metre per second or less if you hit in a certain position, you are saying that the let down rate of a BRS is 26ft per second. Someone tell me am I wrong or right. Nev where are you, please do some sums.
Marty_d Posted May 20, 2015 Posted May 20, 2015 From the BRS Aviation website: Q. What is the descent rate? A. Once under canopy and descending in a stable condition, the rate of descent will be about 15 - 28 feet per second (fps) at 5,000 feet density altitude under rated weight capacity of canopy. They give the descent speed for a C172 as 21 fps. 1
SDQDI Posted May 20, 2015 Posted May 20, 2015 Come on where did 26ft per second come from?That would be a non survival decent. 1,560 feet per minute. That is approximately 32 k's per hour or nearly 20 miles per hour. That is very fast to run into a brick wall. The correct survival speed is about 1 metre per second or less if you hit in a certain position, you are saying that the let down rate of a BRS is 26ft per second. Someone tell me am I wrong or right. Nev where are you, please do some sums. Most brs suppliers quote around 21- 26 fps. It has been mentioned before that pulling the lever for a chute doesn't give you a soft landing and anyone thinking it does will be in for a 'shock' Yes somewhere around 15 knots (I think that is what 26fps is doing a rough calculation in my head, maybe I should google it) will be your vertical descent speed, it should be survivable but it won't be comfortable! 1
Guest ozzie Posted May 20, 2015 Posted May 20, 2015 26ft per second i gave was just an educated guess from all the round canopies i jumped years ago. The 35ft dia T10s were around 22 to 24 fps, the smaller 24ft reserves were a little quicker depending on the suspended weight. 28fps was considered bone breaking rate.
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