Guest disperse Posted June 18, 2007 Share Posted June 18, 2007 im not a pilot yet but ive flown rc gas helis .....after watching the footage of the crash on tele tonight.....im left wondering if it was a manouver they where trying or a failure ........."TO THE FAIMILIES" Link to comment Share on other sites More sharing options...
Ben Longden Posted June 18, 2007 Share Posted June 18, 2007 I saw the vision on NINE news.. and was bloody astounded..:;)2: That thing BOUNCED. Bloody hell. And if any friends or rellies of the families are reading this, I really do hope the inquiry can get to the bottom of this, and may those who were lost get to rest in peace. Ben Link to comment Share on other sites More sharing options...
Guest ozzie Posted June 19, 2007 Share Posted June 19, 2007 on the news tonight a trooper who was on board said that the engines started screaming but the blades were drooping. maybe with the downwind component and a rapid increase in pitch to slow up the aircraft entered the vortex ring (falling into your downwash) or stalled the blades. any experienced rotary wing pilots here.? I only have 2 hrs on a bell47. ozzie Link to comment Share on other sites More sharing options...
Dieselten Posted June 19, 2007 Share Posted June 19, 2007 Vortex Ring State is a possibility; apparently there was a tailwind component as well, which would not have helped. The rate of closure between the helo and the vessel was very high and the helo hits very hard indeed, tail-rotor unit appears to shear off, then the bouncing helo is torque-turned over the opposite side. Very dramatic and in all likelihood well outside the manoeuvring envelope of the helo. All our service personnel operate in high-risk environments, and occasionally they pay the ultimate price. Just hope we don't have a repeat. Link to comment Share on other sites More sharing options...
Guest brentc Posted June 19, 2007 Share Posted June 19, 2007 Here is the video link to the crash: http://ninemsn.video.msn.com/v/en-au/v.htm?f=39&g=128bd554-d91d-4eff-b07a-0ccc7652651f&p=aunews_aunationalninenews&t=s29&mediaid=103980" Pretty bad indeed. Link to comment Share on other sites More sharing options...
Guest Fred Bear Posted June 21, 2007 Share Posted June 21, 2007 I doubt loss of tail rotor control (until it snapped off). Media was talking about a tail rotor stall (although this was not visible). I think (personally) and I am no investigator, that there was a little bit of a tail wind component when coming in to land making him too fast on the approach. Why the vessel does not give the wind direction/strength I will not know. Anyone? Link to comment Share on other sites More sharing options...
Guest Fred Bear Posted June 21, 2007 Share Posted June 21, 2007 Some good reading (with diagrams) here: http://www.dynamicflight.com/aerodynamics/loss_tail_eff/ Link to comment Share on other sites More sharing options...
Guest angus Posted June 21, 2007 Share Posted June 21, 2007 the thing i like about flying choppers is you can slow your approach right up (to a hover if you have to) . For some reason the pilot has come in way to hot. might have had 1 motor failing. Link to comment Share on other sites More sharing options...
Guest brentc Posted June 21, 2007 Share Posted June 21, 2007 The issue was caused by a Vortex ring I believe. Those into choppers can elaborate further. It happens in a downwind landing situation. Link to comment Share on other sites More sharing options...
eastmeg2 Posted June 21, 2007 Share Posted June 21, 2007 A freind who used to fly an R22 once explained this to me. If a helicopter reduces its airspeed to zero, as would occur at some point on a downwind approach, it can set up a rotating donut shaped vortex around the rotor which escalates into faster and faster sinking air for the helicopter, requiring more and more power to maintain height until there's not enough power and the helicopter then descends. The air goes down through the rotors, out, up above the rotors, in and then down again - faster each time. My conclusion from this is that rotor wing aircraft develop lift best when the rotor blades keep moving translationally into fresh air. Best angle of attack for the least induced drag. Rgds, Glen Link to comment Share on other sites More sharing options...
Guest disperse Posted June 21, 2007 Share Posted June 21, 2007 they have now said there was a equipment faillier .....but that helli looked to be hooking in as it came down alongside the boat with a quick turn to land on the pad...also the ship was rising on a wave when it hit but i doubt this would make much diff......the rest of the footage would say a lot i think Link to comment Share on other sites More sharing options...
Guest brentc Posted June 21, 2007 Share Posted June 21, 2007 No equipment failure on the Blackhawk - you're referring to the SeaKing investigation which was also re-visited yesterday. In that one, the appropriate lock nut wasn't used on a control arm. They are also bringing charges upon an individual who loaded the chopper with butane gas bottles. Link to comment Share on other sites More sharing options...
Guest pelorus32 Posted June 22, 2007 Share Posted June 22, 2007 It's a pity that we can't see the approach as the helicopter comes in. From the video I've seen it would appear that he was not undertaking a controlled landing but "throwing himself" - intentionally or otherwise at the deck. Vortex ring state - as others have said - arises when the aircraft is not in effective translational flight. That is the a/c is not moving relative to the airmass. In certain high power situations a strong downward airflow is created which is the equivalent of a phyxed wing aircraft flying through downflowing air that is moving down faster than the a/c can climb. Loss of Tailrotor Effectiveness (LTE) is different. It arises in a complex set of airspeed and wind azimuth circumstances and results in the aircraft yawing uncontrollably. I understand that without rapid response the a/c enters an almost self sustaining LTE state. There is a recent ATSB report on a LTE event at St Kilda. In any event one of the recovery actions from both states is rapid a large reduction of collective - thus the a/c descends quickly. Given what little we can see idle speculation would suggest that it is a little more likely to be LTE than vortex ring - we don't ever see him in a high power hover situation. But who am I to know? Maybe some of the rotary wing guys can tell us more. I've just put my life in their hands more often than I care to remember ;-) Regards Mike See page 4 of the attached file for some discussion of causes and recovery. The 1989 file gives a really good rundown on both states - LTE and VRS. hs_jan-feb05.pdf hs_mar-apr89.pdf hs_jan-feb05.pdf hs_mar-apr89.pdf hs_jan-feb05.pdfhs_mar-apr89.pdf Link to comment Share on other sites More sharing options...
Captain Posted June 22, 2007 Share Posted June 22, 2007 Brent Is it clear that there was no failure on the Blackhawk, or is it too early to discount that? Have they recovered it yet? And if so has the investigation of the aircraft been completed? Regards Geoff Link to comment Share on other sites More sharing options...
Guest brentc Posted June 22, 2007 Share Posted June 22, 2007 Pretty sure there was no equipment failure. My earlier post was highlighting that both crashes came into the spotlight on the same day and there were different reasons for both (apparently). (The Blackhawk versus the SeaKing) They suggested pilot error very early on. Perhaps there was a co-pilot? They blamed the strong tailwinds and poor briefing as contributing to the crash. Link to comment Share on other sites More sharing options...
Guest Fred Bear Posted June 22, 2007 Share Posted June 22, 2007 Mike: From the video I've seen it would appear that he was not undertaking a controlled landing but "throwing himself" - intentionally or otherwise at the deck. Mate, you really disappointed me with this comment this time. You have not made one like it before. Intentionally? Unlikely mate. A very experienced pilot you are talking about here. I don't think he would 'intentionally' throw himself at the deck with all of those soldiers knowing that he would kill them/himself unless he was suicidal which clearly he was not. If he was, why would he attempt a landing on the carrier and not crash into the sea killing all onboard? It's clear it was an approach, even by watching the footage and something has clearly gone wrong. He has come in too fast, attempted to arrest the descent and had a tail strike at this time. Without the tail rotor (as we all know) the bird becomes a massive 'ceiling fan'. Unlikely it's intentional. Link to comment Share on other sites More sharing options...
Guest pelorus32 Posted June 22, 2007 Share Posted June 22, 2007 Sorry Darren I have obviously not communicated clearly. I was not casting any aspersions on his skill or his intentions. What I was trying to say (obviously not well) was this: We don't get to see his approach at least on the video I have seen. We get to see an initial shot and then a very tight shot of the a/c arriving very forcibly on the deck. What I saw was not a landing that was "overhot" or something - in other words I don't think it's a misjudgement or something like that. The little I saw made me think that he had serious control problems of some sort or another and that he had probably made an attempt to try to just get the aircraft on the deck (intentionally throwing it at the deck). He may have made a judgement that that was better than ditching. Or it may be that his control problems were so serious that the deck literally got in the way of where the a/c was going (unintentionally throwing himself at the deck). I didn't think that what I saw in the video I saw was a controlled approach and landing - and I've seen a few. But the video I saw was very limited - I don't know if there is more extensive video as I can't play the link earlier in this thread. I suspect that the miscommunication is partly because of my shorthand thinking. So let me be clear. Just idly speculate for a moment that he had LTE. Now we have no evidence of that really but if we just speculate. The recovery is down collective (among other things). So you end up with an a/c going down fast and yawing uncontrollably. Now apply that scenario to what we see briefly in the video. My apologies for any angst caused - that wasn't the intention - quite the reverse. Regards Mike Link to comment Share on other sites More sharing options...
Guest Fred Bear Posted June 22, 2007 Share Posted June 22, 2007 Mike, I was waiting for you to reply. Just happened to be on here when you did. No angst mate. Was more of a tongue in cheek comment I made to you. You know the old ;);). Now hope you did not take it the wrong way. There is heaps more that 'could' be seen in that video and it will be interesting to see just what the investigation will find. Anyway, off to do some flying. Enjoy youyr day! Link to comment Share on other sites More sharing options...
Admin Posted June 25, 2007 Share Posted June 25, 2007 Guys I was going to PM you both on this but thought that I would post it as it is really a message for all and not specific to you so please don't take it the wrong way - it is made with a :big_grin: There is always the possibility where two (or even more) may disagree on a point or even one (or more) people may get offended by a post - that's the nature of the "forum" beast. But may I suggest that if a situation like this rises for anyone perhaps it may be a "nicer" solution to use the PM system, discuss it between yourselves and then edit a post if needed rather then publicly voice something that may cause a problem, force someone to publicly eat humble pie or show to everyone else a friction that may exist. In this case both of you Mike and Darren and like everyone else here are valued members of these forums and Mike is a respected enough person to rise to Darren's point like a gentleman but not everyone is as much of a professional and that's how problems start. It is always great to challenge each other as that is how we can learn more but all I am saying is that there is a PM system that can be used rather then publicly force a situation. I hope no-one takes offence with what I have said as it is really just a "Hey Guys, have you thought about this" or "is this a good idea or not" type of post - that's all! Remember - always post with and read with a :big_grin: Link to comment Share on other sites More sharing options...
Guest Fred Bear Posted June 25, 2007 Share Posted June 25, 2007 Point taken Ian. I had this discussion with Ross last night. I get too fired up sometimes and I do think the PM system in this case might be a litter better but this comment in particular that I made was a little light-hearted to Mike. None the less, you are doing a massive job here and not having to further moderate some of the 'garbage' would be a lot easier for yourself so I will keep the 'firing back' comments on the board to a minimum. I have been trying to do that for some time now and no doubt you should have noticed an improvement over previous posts. I find that I am not even posting as often due night shifts. I still look forward to sharing my stories/ideas/pictures etc when I can. Link to comment Share on other sites More sharing options...
Admin Posted June 25, 2007 Share Posted June 25, 2007 - as always Darren, you always do add a lot of shall I say "Flavor" to the forums which is great ;) - the post was really just a statement to all that the PM system is there - missed your "Flavor" at the Flyin ;) - perhaps the next one you can make it with bells on Link to comment Share on other sites More sharing options...
Guest Fred Bear Posted June 25, 2007 Share Posted June 25, 2007 Well I am still angry at not making this one and still miserable about it (especially when I smelled the camp sire on Ross' clothing) ...as sick as that sounds. Woof woof. Next time mate, next time. I will fly a rag and tube there if I have to. Link to comment Share on other sites More sharing options...
Guest pelorus32 Posted June 25, 2007 Share Posted June 25, 2007 Point taken Ian, I wasn't that offended, in fact not offended at all. It's difficult communicating subtlety on a forum and as my wife will tell you I have none of that anyway. This next one is toooo good for a PM though: Well I am still angry at not making this one and still miserable about it (especially when I smelled the camp sire on Ross' clothing) ...as sick as that sounds. Woof woof. Next time mate, next time. I will fly a rag and tube there if I have to. Darren and Ian, you have to explain to me what the "...camp sire.." is (and what he had been doing on Ross's clothing). Darren it certainly has the potential to be "...as sick as it sounds". I am quite fearful that there was a secret here - that this was in fact the northern Recreational Swingers Flyin. The question remains though: Who was the Camp Sire and was he any good:cool: Swingingly yours...... Mike Link to comment Share on other sites More sharing options...
Guest Fred Bear Posted June 25, 2007 Share Posted June 25, 2007 Laughter is one of the best medicines they reckon Mike and you have sure made me do that sire. The mystery remains though as to who exactly this sire was... See, I really did miss out didn't I? Link to comment Share on other sites More sharing options...
Guest David C Posted June 25, 2007 Share Posted June 25, 2007 w Next time mate, next time. I will fly a rag and tube there if I have to. Are you suggesting we take the Bantam .. Dave C Link to comment Share on other sites More sharing options...
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