boingk Posted June 13, 2012 Author Share Posted June 13, 2012 Righteo mate, shoot me a message with your whereabouts and number and I'll try and get in touch tomorrow lunch time - hell might even be able to fly in! Cheers - boingk Link to comment Share on other sites More sharing options...
eightyknots Posted June 13, 2012 Share Posted June 13, 2012 I joined the groundloop club infront of the entire gliding club. OuCh G'day All, Hard for me to write this post but - yesterday took a friend for a flight in the local area. Wind was S/E and strip is 090/270 and flat to the West but into wooded terrain and ridge to East. We took off into the East and turned at 50kts and 150 ft t0 stay clear of trees. Flew for 25 mins then approached from the West. All was normal, approaching at 50 and descending at 500fpm. We touched down in 3 point and as I planted the tail the upwind wing lifted and we ground looped! I have about 1500 hrs acquired over more years than I wish to reflect on. Almost all in tail wheel a/c. I am very current in Thruster and this has me worried. I suppose that we got a strong gust from the S/E just as the stall occurred, lifting the wing. Only damage is a bent u/c spring so very lucky there. Don't ever get complacent, especially in a t/w aircraft. Don OuCh again. You better not do that too often if you want to live as long as Methusalah I. Link to comment Share on other sites More sharing options...
pudestcon Posted June 13, 2012 Share Posted June 13, 2012 Slightly off-topic but have you thruster boys read a book called "Propellerhead" by Anthony Woodward? My instructor has a copy and lends it out to students. It's a very enteraining tale of the aviation adventures of a man and his learning to fly and then owning a thruster in the UK. Yep, read it, and found it an entertaining read. Wouldn't want to make a practise of some of the actions described in the book though. Pud Link to comment Share on other sites More sharing options...
Louis Moore Posted June 13, 2012 Share Posted June 13, 2012 Thanks for the advice, guys, and the story Kaz!All up right now I don't think I can do my training for taildragger locally, but would certainly be up for it sometime in the future. I am reasonably familiar with the operation of a taildragger on takeoff and landing as I'm a bit of a nut for flight sims and also RC models. Thanks again - boingk Be careful with the flight sim and RC models, is fairly different sitting behind the beast pumping those pedals and praying it's gunna stay straight than playing it on flight sim!!! That being said I actually did not find the step from nose to tailwheel all that bad, but I had been flying a while by then and had a good number of hours and LOTS of respect for aircraft! As of yet I myself have not been bitten or had a situation where I have had to put on more deodorant after landing! But I have watched a few aircraft try to barrel roll on landing and so I never feel the need to relax at the controls of the Auster! When I doubt I always watch this video to remind me of the dangers! https://www.youtube.com/watch?v=gGOwcnGts4s Link to comment Share on other sites More sharing options...
facthunter Posted June 14, 2012 Share Posted June 14, 2012 Did that strip have a slope to the pilot's right? Pretty violent pivot at times. The Texan is a fairly basic trainer and the pilot would feel pretty embarrassed and a big damage bill even though he had washed quite a lot of speed off. Plenty of RAAus planes would ground loop easier than a T6. The cause is the positioning of the mainwheels forward of the CofG. As soon as there is a side load on the wheels it wants to yaw and that causes more sideload making it yaw more, and so on, as you saw there.. Once you have gotten to a certain point you can't stop it. Nev Link to comment Share on other sites More sharing options...
boingk Posted June 14, 2012 Author Share Posted June 14, 2012 Be careful with the flight sim and RC models, is fairly different sitting behind the beast pumping those pedals and praying it's gunna stay straight than playing it on flight sim!!!That being said I actually did not find the step from nose to tailwheel all that bad, but I had been flying a while by then and had a good number of hours and LOTS of respect for aircraft! As of yet I myself have not been bitten or had a situation where I have had to put on more deodorant after landing! But I have watched a few aircraft try to barrel roll on landing and so I never feel the need to relax at the controls of the Auster! It sure it a lot different - what I'm angling at was that they do give you a good theoretical perspective on things. Aside from that I would not rely on anything other than the real thing. On respect for aircraft, yeah definitely have that! Have had a few close calls with instructors piloting and although there was no damage there certainly could have been a less than optimal outcome had sub-par pilot skill or cocksureness come into play. Luckily both times the instructors knew exactly what to do to get us out of the situation. Cheers - boingk Link to comment Share on other sites More sharing options...
Chrism Posted June 14, 2012 Share Posted June 14, 2012 Did that strip have a slope to the pilot's right? Pretty violent pivot at times. The Texan is a fairly basic trainer and the pilot would feel pretty embarrassed and a big damage bill even though he had washed quite a lot of speed off. Plenty of RAAus planes would ground loop easier than a T6.The cause is the positioning of the mainwheels forward of the CofG. As soon as there is a side load on the wheels it wants to yaw and that causes more sideload making it yaw more, and so on, as you saw there.. Once you have gotten to a certain point you can't stop it. Nev I've read a couple of books about WW2 pilots training on T-6/Harvards etc and all the ground loop problems they had with them, only to convert to an operational type like a P40 or P51 and find them far more forgiving. Their comments were along the lines of they whished they'd trained on a p51 first in order to land a T6! Link to comment Share on other sites More sharing options...
eightyknots Posted June 14, 2012 Share Posted June 14, 2012 I wonder if I should continue with my ab initio training with a taildragger/conventional gear?? After watching this, I am tempted to swap to tricycle/unconventional gear: Link to comment Share on other sites More sharing options...
boingk Posted June 14, 2012 Author Share Posted June 14, 2012 Nice video... although at 4:20 it explains that a tricycle gear aeroplane needs 'little to no rudder input for a safe landing', then promptly shows a C-150ish type plane landing in a crowsswind. I tell you what, if I'd have been advised of that 'fact' my first solo (10kt crosswinds) would have been a lot less satisfactory! Otherwise, spot on :D - boingk Link to comment Share on other sites More sharing options...
facthunter Posted June 15, 2012 Share Posted June 15, 2012 That's a good little vid. The DC-3 was a "perler". I have had students who refuse to believe you should land on one wheel in a crosswind. . I had to take-off on one wheel at Avalon because of the crosswind, in the Citabria. You have to prevent the upwind wing lifting on both landing and taking off. Nev Link to comment Share on other sites More sharing options...
Louis Moore Posted June 15, 2012 Share Posted June 15, 2012 That last guy really nailed the whole STOL effect! Bet he pulled up quicker than most other people on the day Link to comment Share on other sites More sharing options...
kiwicrusader Posted July 2, 2012 Share Posted July 2, 2012 Not really a groundloop, more a torque induced roll from the bounce recovery. Still a good example of how not to do it tho. 1 Link to comment Share on other sites More sharing options...
Tomo Posted July 2, 2012 Share Posted July 2, 2012 Ouch! Pretty good example of the torque involved when that power pulls in! Link to comment Share on other sites More sharing options...
Guest nunans Posted July 2, 2012 Share Posted July 2, 2012 So what made the nose drop so quick at :08? did the tail wheel touch first and hit a big bump or something? I'd like to see it at normal speed. Link to comment Share on other sites More sharing options...
kiwicrusader Posted July 2, 2012 Share Posted July 2, 2012 It's a bit hard to tell but I reckon he stalled on very short finals. I have quite a bit of time in 802's including dual cabs, and having someone in the back seat changes the C of G quite significantly. 802u's as shown have a pt6-67f engine which are limited to 1600hp, however you are allowed to pull 1800hp for 30 seconds. Depending on density altitude, if you open the throttle fully, like I am guessing this bloke did, you are more likely to get close to 2000hp. Far too much to control at such a slow airspeed. Link to comment Share on other sites More sharing options...
Guest nunans Posted July 2, 2012 Share Posted July 2, 2012 So the time you've spent in them have you been firefighting, spraying chemical or spreading fert? Also i'm interested in how these engines are controlled/limited, does throttle control turbine RPM or compressor pressure? I'm just trying to work out the "depending of density altitude" bit. Do they need to spin at a higher rpm to achieve the same HP in less dense air? How quickly does the throttle respond in these? ie turbine lag i guess, that video looked like slow mo I wasn't sure if he applied throttle shen it rolled if it was more stalling, there was no sound. Link to comment Share on other sites More sharing options...
Guest nunans Posted July 2, 2012 Share Posted July 2, 2012 .. Link to comment Share on other sites More sharing options...
kaz3g Posted July 2, 2012 Share Posted July 2, 2012 Ouch! Pretty good example of the torque involved when that power pulls in! Not a big problem in the Auster, I find :-) Kaz 1 Link to comment Share on other sites More sharing options...
kiwicrusader Posted July 2, 2012 Share Posted July 2, 2012 Hey nunans, 'D' all of the above. With a PT6, when you open the throttle you are putting more air into the engine. There is a signal line called the P3 line, to the fuel control unit (FCU). When the FCU realises there is more air going in, it then puts more fuel in, because of this there is a lag with these engines. These engines have limits but they are limited by the pilot, to a red line on a gauge, once you reach that red line, you stop opening the throttle. With a 67f engine the red line or 1600hp mark is at 4400ft/lbs of torque. There is also a red line on the ITT gauge (turbine temp) and the compresor has a redline also. You stop opening the throttle when you reach one of these limits. If the engine is in good condition it is usually the torque limit you reach first, however during firebombing operations on a hot day, mid 40's, you may reach ITT max before reaching full torque. You can open the throttle further however you will be doing damage to the engine. At a high density altitude, say 10,000ft you could push the throttle to the stop and not reach any red lines, however at sea level if you push the throttle to the stops, you will over torque the engine very easily thus pulling way more horsepower than you should. Hope this answers your questions, I am not an engineer and dont fully understand how all aspects of the engine works myself. I know a little bit about this part of the engine, because I know someone whos P3 line broke. i.e. the FCU thought there was no air going in so it went to idle fuel setting. Not very handy just after takeoff with 3000ltrs of chemical onboard. Sorry for the thread drift. 1 Link to comment Share on other sites More sharing options...
facthunter Posted July 3, 2012 Share Posted July 3, 2012 There is the reaction to the prop torque ( which has more relevance than HP although they are related directly), to consider, and there is an assymetrical thrust effect at high body/wing angle of attack. (Angle between thrust line and airflow direction). so one side of the prop produces much more thrust than the other due to the angle of the blade to the relative airflow. This makes the plane yaw and therefore want to roll also. You can end up with not enough aileron or rudder to oppose it at low speeds. This is where most high powered aircraft get into strife going round or doing a bounce recovery, especially if a lot of power is used. A landing duster would be empty and unlikely to need a lot of power. The brakes may have locked and there are gyroscopic effects to consider too when the plane yaws or pitches suddenly. With a large prop those forces are high. Nev Link to comment Share on other sites More sharing options...
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