fly_tornado Posted October 10, 2015 Share Posted October 10, 2015 http://www.dailymail.co.uk/news/article-3265175/Small-plane-PARACHUTES-safely-earth-pilot-dives-quickly-wings-ripped-Slovenia.html 2 Link to comment Share on other sites More sharing options...
Guernsey Posted October 10, 2015 Share Posted October 10, 2015 Good post FT. Thanks. Alan. Link to comment Share on other sites More sharing options...
Ultralights Posted October 10, 2015 Share Posted October 10, 2015 flew to fast through a cloud bank... to me, i understand it as, got into cloud, not IMC trained, entered spiral dive of death, pulled ever increasing G forces at sppeds accelerating past VNe, wings failed. 1 Link to comment Share on other sites More sharing options...
Downunder Posted October 10, 2015 Share Posted October 10, 2015 flew to fast through a cloud bank... to me, i understand it as, got into cloud, not IMC trained, entered spiral dive of death, pulled ever increasing G forces at sppeds accelerating past VNe, wings failed. Either that, or over did it avoiding getting into IMC. From the web site: (I'm just guessing it was the 100hp version) At 75% cruise-power-setting the 100 HP version speeds over the skies at 273 km/h (147 kts)! SAFETY, ENGINEERING AND WORLDWIDE CERTIFICATIONS Virus SW 80/100 can be called the 300 km/h (160 kts) ultralight/microlight/LSA, but it is much more than that! With a turbulence penetration speed (green arc) of 250 km/h (135 kts) and the VNE of 302 km/h (163 kts), you can take advantage of high-speed cruise even in strong turbulence. The cockpit remains quiet and comfortable throughout the flight! The Virus SW 80/100 has the largest flight safety margins in its category and can be equipped with the total rescue system, deployable even at maximum speeds and close to the terrain. 4 Link to comment Share on other sites More sharing options...
Phil Perry Posted October 10, 2015 Share Posted October 10, 2015 They ARE a bit quick actually,. . . be interesting to look at the ultimate airframe design airspeed in "Non-turbulent air" calculations at which the wings could not sensibly remain attached though, . . . as you blokes say, it sounds like a loss of control in IMC, resulting in the classic graveyard spiral routine to me also, although we are speculating again. Could have been due to a very sudden severe turbulence event. . . .what was the terrain like in the area,. . ? we don't know. . . ( Are they subjected to wind tunnel tests any more ? or just have a crapload of sandbags on the wings ? ) I dunno about doing it AVOIDING IMC, this would smack of leaving things a little late, before taking cloud avoidance action ? More than a little likely would be a VNE+ dive, then overcontrolling the pullup / combination of both. . . It's nice to speculate where nobody got dedded isn't it, well,. . .a little less crass anyhow. I'll bet the owner is really annoyed, . . .since his aircraft is buggered, and so is his BRS. . . .( ! ) ( do they repack those I wonder [ he said doubtfully ] ) Good result anyway. Walk away and have a cry and a beer or three. Link to comment Share on other sites More sharing options...
Marty_d Posted October 10, 2015 Share Posted October 10, 2015 Wings ripped off... probably the best example of where to pull the red lever. Yes it shouldn't have happened in the first place, he shouldn't have been in IMC, he shouldn't have oversped and stressed the airframe, but unfortunately sh*t does happen and at least he's alive. 1 4 Link to comment Share on other sites More sharing options...
Phil Perry Posted October 11, 2015 Share Posted October 11, 2015 Wings ripped off... probably the best example of where to pull the red lever. Yes it shouldn't have happened in the first place, he shouldn't have been in IMC, he shouldn't have oversped and stressed the airframe, but unfortunately sh*t does happen and at least he's alive. Yep. . . speculative but quite possibly right. Don't suppose we'll ever know the full story. . . . . . 1 Link to comment Share on other sites More sharing options...
DrZoos Posted October 11, 2015 Share Posted October 11, 2015 Another chute saves another life....give me 14kg and i will put one in tomorrow..but id like it to be CO2 deployed not a firework. Link to comment Share on other sites More sharing options...
Guernsey Posted October 11, 2015 Share Posted October 11, 2015 Will he have to do another flight test to earn his wings back?? Alan. 6 1 Link to comment Share on other sites More sharing options...
Ada Elle Posted October 11, 2015 Share Posted October 11, 2015 They're supremely slippery, and very easy to go close to Vne on. Also, Pipistrel expresses Vne as a TAS, not as an IAS; the incident was in the vicinity of Mt Kanin (8500ft) and there may have been some mountain wave in play as well (I know that the Pipistrel I fly experiences lift like the gliders I fly). So any power on maneuvering could easily have exceeded Vne. (consider that the 147kt IAS is above Vne at 8500ft.) I suspect you could easily hit 200kt TAS in any sort of dive, not necessarily a spiral one. Even if you only did a dive at 150IAS (ie above Vne at 8500ft) to get out of cloud, the pullup out of the dive would be well and truly above Va or Vb. They're a delightful aircraft to fly, but energy management is necessary, especially in the circuit. I wonder if the pilot deployed the airbrakes in the dive. 1 Link to comment Share on other sites More sharing options...
eightyknots Posted October 12, 2015 Share Posted October 12, 2015 Another chute saves another life....give me 14kg and i will put one in tomorrow..but id like it to be CO2 deployed not a firework. Whatever happened to the mechanical spring powered chute that was being developed by someone in Victoria? Has anyone ever heard what has become of this BRS-style safety chute system? 1 Link to comment Share on other sites More sharing options...
jon123 Posted October 12, 2015 Share Posted October 12, 2015 This is an interesting video of Pipistrel's wing test (for the 15 metre span Sinus - the wing is shortened for other models). 1 Link to comment Share on other sites More sharing options...
Dieselten Posted October 12, 2015 Share Posted October 12, 2015 The pilot failed well before the airframe did. Nice save though. Now he can do it so someone else's aeroplane. Link to comment Share on other sites More sharing options...
eightyknots Posted October 12, 2015 Share Posted October 12, 2015 This is an interesting video of Pipistrel's wing test (for the 15 metre span Sinus - the wing is shortened for other models). impressive! Link to comment Share on other sites More sharing options...
kasper Posted October 12, 2015 Share Posted October 12, 2015 Impressive though the test video is it is not a valid load test that would satisfy something like BCAR Section S and would give me no actual comfort as a pilot. 1. no attempt to load the wing by reference to span load or chord load - single pull from the end of the wing is a horrendous point bend load at the wing root but without span loading or chord loading the load/twist characteristics are unknown 2. no control fitted to the wing - you can't pass a load test on a wing without showing the control runs and surfaces are operable within the permitted load range of the wing ... otherwise a very 'strong' wing that is very bendy faces the problem of locking the control surface in a set position within the flight envelope .. and if that occurs in flight you are no longer the pilot but a passenger along for the ride hoping the aircraft comes out of the locked position before either the G builds and takes off a wing or you run into something hard and earthlike ... And if you throw both 1 and 2 together you may find that controls lock AND you end up with a twist in the wing differential both sides ... because in a serious 'unfun' flight upset nothing ever goes easy, Murphy is alive and waiting to throw everything at you. But as I said, nice video showing a wing failure in bending - but not a comfort to me as pilot 1 Link to comment Share on other sites More sharing options...
eightyknots Posted October 13, 2015 Share Posted October 13, 2015 Impressive though the test video is it is not a valid load test that would satisfy something like BCAR Section S and would give me no actual comfort as a pilot.1. no attempt to load the wing by reference to span load or chord load - single pull from the end of the wing is a horrendous point bend load at the wing root but without span loading or chord loading the load/twist characteristics are unknown 2. no control fitted to the wing - you can't pass a load test on a wing without showing the control runs and surfaces are operable within the permitted load range of the wing ... otherwise a very 'strong' wing that is very bendy faces the problem of locking the control surface in a set position within the flight envelope .. and if that occurs in flight you are no longer the pilot but a passenger along for the ride hoping the aircraft comes out of the locked position before either the G builds and takes off a wing or you run into something hard and earthlike ... And if you throw both 1 and 2 together you may find that controls lock AND you end up with a twist in the wing differential both sides ... because in a serious 'unfun' flight upset nothing ever goes easy, Murphy is alive and waiting to throw everything at you. But as I said, nice video showing a wing failure in bending - but not a comfort to me as pilot I was wondering the same thing, i.e., how well will the ailerons continue to work with such a massive bend in the wing? As you pointed out, if they no longer work, the strength of the wing beyond that point is just an academic matter only. Link to comment Share on other sites More sharing options...
facthunter Posted October 13, 2015 Share Posted October 13, 2015 A wing is never loaded like that is in the test. (as has already been pointed out). I can't work out what they were achieving except to see how far it bent for "show" reasons. Nev 2 Link to comment Share on other sites More sharing options...
Oscar Posted October 13, 2015 Share Posted October 13, 2015 Video posted by Michael Coates - little more needs to be said. 2 1 Link to comment Share on other sites More sharing options...
jon123 Posted October 13, 2015 Share Posted October 13, 2015 I am a Pipistrel Sinus pilot but I'm not Michael Coates. The technology for smooth controls in bendy wings is well and truly solved in sailplanes. Browse "ETA sailplane" 30.9m span Open class or "Concordia sailplane" for extreme examples. There is some technical discussion regards solving the control route in Dick Butler's discussion on how he designed the Concordia (sorry can't find the link atm). Link to comment Share on other sites More sharing options...
kasper Posted October 13, 2015 Share Posted October 13, 2015 I am a Pipistrel Sinus pilot but I'm not Michael Coates.The technology for smooth controls in bendy wings is well and truly solved in sailplanes. Browse "ETA sailplane" 30.9m span Open class or "Concordia sailplane" for extreme examples. There is some technical discussion regards solving the control route in Dick Butler's discussion on how he designed the Concordia (sorry can't find the link atm). You overlook that that it was Michael Coates posting the video onto youtube And the fact that bendy wings CAN have control surface work in bending makes nothing of the fact that the video as posted does absolutely nothing to cover a true test of either load test on the wing or control surface use withion the design loads for the wing - its pure advertising garbage ... and I have done proper test schedules on approved aircraft and it is never as 'spectacular' as that (they should be absolutely boring) and they are much more involced that that. 1 Link to comment Share on other sites More sharing options...
jon123 Posted October 13, 2015 Share Posted October 13, 2015 I have been advised that the test in the video was skin to spar bond test. See attached photos and videos of other tests. Much more involved than the bond test (and sandbagged wings) by the looks of it. Link to comment Share on other sites More sharing options...
kasper Posted October 13, 2015 Share Posted October 13, 2015 That's nice - and the second video you post does show that the other wing was loaded through beams so it is clear that a span load test was done though not shown ... and still it appears without control surfaces fitted and demo free and clear. I didn't and do not say that the aircraft is not compliant with the design standard ... but you have to appreciate that video is by its nature spectacular ... and the reality of a test that is designed to prove and document compliance is much less spectacular ... even the second video has three drop tests - 1 is 'boring' because its a low drop onto sloped boards ... that is the ACTUAL test that is a compliance test ... dropping the plane under a 'simulated 11G' (garbage - at that height even a 14yo with basic physics ability can tell calculate the force and it aint 11G) is not a certification test but one that the salesman like because it has 'showman' or 'spectacular' factor - the WOW! factor The spectacular and WOW bits of that video have nothing to do with testing to the design standard and are entirely to do with salesman spectacular. I ask you, would you 'feel' safer in this aircraft over a high winged metal airframe (eg CH701) that if dropped under the same 'spectacular' and WOW height because the Pipistrel just has a broken nose leg while the metal plane is all crumpled up for the front 2ft of aircraft? The salesman says - "Composites - look at how 'strong' it is, just watch this video" The engineer says "Well... it aint that simple ... look at all the energy absorbed into airframe through the crushing of the metal that was NOT transmitted into the people through their seatbelts ..." Its not a simple question. Some composites are TOO strong ... and design standards actually work against composites because they require much larger design factors than metal or wood ... result is a heaver than engineering would require for a composite airframe that MAY or MAYNOT be too stiff and not absorb as much energy as an alternate construction may have. I think having seen several Jabiru airframes after accidents and in my opinion they have got the balance right - the wings and tail group come away from the central people cell to absorb energy and even the lower firewall will crumple and collapse BUT the composite spaceframe around the people remains intact ... that in my opinion is a very good design ... one where everything basically stays attached and looks like it would be an easy repair is a composite airframe I would worry about because unless the entire airframe was, in engineering speak, very plastic, the energy has not been absorbed and the people have done all the negative accelerating in the accident ... and I know I have a low G limit in acceleration terms before bits of me start breaking and rupturing so an airframe that gives of itself to lower my impacts is one I prefer ... and lets face it, in cars the crash tests are all about energy absorption not how strong and stiff the car is to 'win' in any accident which is effectively what the Spectacular and WOW videos do for aircraft 1 1 1 1 Link to comment Share on other sites More sharing options...
Guest asmol Posted October 18, 2015 Share Posted October 18, 2015 Found this in my inbox this morning. Official Statement Related to accident of Virus SW 100, I-B939 on 3 October 2015 at Bovec, Slovenia Reference is made to Preliminary report issued by Aircraft Accident and Incident Investigation Branch, Ministry of Transport of Republic of Slovenia: http://www.mzi.gov.si/fileadmin/mzi.gov.si/pageuploads/SPLNI/Porocila/15_10_14-Uvodno_porocilo_I-B939.pdf Pipistrel has been cooperating closely with the Authorities to determine the circumstances of the accident and was able to obtain data from the on-board-flight/engine-data recorder. The following information are factual and derived solely from the recorded data of the flight. The aircraft Virus SW 100 I-B939, occupied by a crew of 2, departed from Caorle, Italy and flew in a north-easterly course according to Visual Flight Rules (VFR). After flying at low level the aircraft initiated a climb to from 300 m (1000 ft) AGL. At the time of flight, the cloud base was overcast between (1000-1300 m) 3000-4000 ft. In Instrumental Meteorological Conditions (IMC) and reaching approximately (3000 m) 9800 ft inside clouds where the temperature was 2 degrees Celsius, the aircraft stalled, departed controlled flight and entered a steep dive. The aircraft surpassed its maximum permitted operating speed of 163 kts (302 km/h) and reached 240 kts (445 km/h) indicated airspeed when the crew began to recover the extreme nose-down inverted attitude. During this action, the aircraft decelerated to 220 kts (405 km/h) and reached 6 G of load. Next, the load suddenly increased to over 10 G (flight data recorder senses a maximum of 10 G load, then becomes saturated) – at this conditions, 220 kts (405 km/h) and over 10 G, load the aircraft wings structures separated from the airframe. This was followed by an inverted steep dive with 105-120 m/s (21-24.000 fpm) sink rate. The crew activated the ballistic rescue system on board the aircraft a mere 515 m (1700 ft) above the ground when the speed of the aircraft was over 450 km/h (245 kts) flying at an almost vertical flight path referenced to the ground . The sink rate was stabilized as the parachute was fully opened approximately 150 m (500 ft) above the ground. Judging by the above facts, the crew activated the parachute rescue system 3-4 seconds before imminent impact with the ground and 1-2 seconds before it would be too late for the parachute rescue system to be deployed successfully. The accident occurred after the aircraft, which is not approved for flying in Instrumental Flight Rules and/or Instrumental Meteorological Conditions, stalled inside clouds, departed controlled flight, surpassed the maximum permitted operating speed by a factor of 1.47 and the permitted G-load by a factor of more than 2.5. The parachute rescue system, which is designed by Galaxy GRS to be used up to speed of 315 km/h (170 kts) was activated successfully at over 450 km/h (240 kts) after major airframe components ultimately separated from the vehicle; a testament to aircraft and systems' design. Link to comment Share on other sites More sharing options...
facthunter Posted October 18, 2015 Share Posted October 18, 2015 Good material for study. Lucky in so many ways.... Over a valley and everything above what you would ever expect it to work at. Nev 5 Link to comment Share on other sites More sharing options...
SDQDI Posted October 18, 2015 Share Posted October 18, 2015 I don't think there is any room to be criticising the structural integrity of this pipistrel after reading that! 240knots and at least 10 g. As Nev said so lucky in so many ways. Chute fully opened and stabilised at 500ft, wouldn't have had to be far to either side to have a different result. Another good reminder of the dangers of inadvertent flight into IMC. 8 Link to comment Share on other sites More sharing options...
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