flyerme Posted June 27, 2014 Posted June 27, 2014 NAIPS first and foremost ! If cavok .then willy weather for local ground wind speed. If theses don't confirm together I just don't fly( that's the convenience of having my plane home to fly anytime , I'm not forced to fly when I GET THE CHANCE) unfortunatly most don't have the option of - cavok today with no winds? You right for hr or 2 Pa ?im out here! Not sure Anyone said it had struts! Just used struts as a reference point as to were the wing detached. That is all! Stay safe everyone and I believe this thread to be helpfull - even speculation can be helpfull! Ie.. Weather, towers!, clouds,, all can open the eyes of the new comers and the inexperienced to hazards they may not have been concerned about prior to reading this. A lot of you guys/gals don't accually realise the good in the " speculation " side of things- ok so it proberbly didn't happen like that but each theory gets you thinking about your own flying and outcomes and what one should be aware of. I say it again stay safe every one Friendly regards Tim 2 1
metalman Posted June 27, 2014 Posted June 27, 2014 Nice weather in SA today? Its sad that often the accident investigation will be done under blue skies, RIP aviators And NAIPs for me, I made the mistake of ignoring a severe tubulance SIGMET, up in Qld it would've meant it was a bit bumpy, around the ranges near Melbourne a very different problem, after a few "moments " I very slowly returned home and put it in the hangar, Matty
flyerme Posted June 27, 2014 Posted June 27, 2014 Sa the worst weather I've seen in years! Very nasty right now
flyvulcan Posted June 27, 2014 Posted June 27, 2014 This is simply an observation (which could be wrong) with no conjecture as to the cause, but if you zoom in to the alleged area of failure of the port wing on the photo at post #92, it appears that the lower wing surface shows a line of rivets running chord wise along what could be the join to the separated outer wing panel. This might suggest a lap joint of the inboard and outboard lower wing skins. However, the upper wing skin in the same area looks to be of a ragged and torn appearance. So, a clean failure point on the lower surface along possibly a skin lap joint with an apparent uneven tearing of the upper wing skin...
Admin Posted June 28, 2014 Posted June 28, 2014 A new thread was created from this one regarding what weather report do you use: http://www.recreationalflying.com/threads/what-weather-report-do-you-use.120138/
turboplanner Posted June 28, 2014 Posted June 28, 2014 The weather forecast directly relates to this accident; there's not a lot of point discussing it separately.
turboplanner Posted June 28, 2014 Posted June 28, 2014 This is simply an observation (which could be wrong) with no conjecture as to the cause, but if you zoom in to the alleged area of failure of the port wing on the photo at post #92, it appears that the lower wing surface shows a line of rivets running chord wise along what could be the join to the separated outer wing panel. This might suggest a lap joint of the inboard and outboard lower wing skins. However, the upper wing skin in the same area looks to be of a ragged and torn appearance. So, a clean failure point on the lower surface along possibly a skin lap joint with an apparent uneven tearing of the upper wing skin... I used #84 and if you do a screen capture of the section then blow it up 400% it looks as of the rivets have sheared cleanly in an upward bend of the wing tip, and there's a tube protruding which also looks as if it has bent upward and then wrenched off, hence my speculation that the forecast turbulence might have got the wing moving and overloaded the tip. I'm not familiar with the structure at that point but the rivets appear too far apart for the bottom skin to be used as a stressed part of a monococque construction
Admin Posted June 28, 2014 Posted June 28, 2014 The weather forecast directly relates to this accident; there's not a lot of point discussing it separately. Yes, but the question of what weather reports people use doesn't...its a subject worthy of its own thread 3
facthunter Posted June 28, 2014 Posted June 28, 2014 Flap extension speed might have something to do with it . It is very low on the Echo. In turbulence there is not much margin above the safe speed clean (for control). Clean in turbulence would have to be the recommended option under those conditions. Nev
turboplanner Posted June 28, 2014 Posted June 28, 2014 There doesn't seem to be much mention of where the flaps finished up, so maybe FH. From looking at past photos of aircraft which have gone in vertically the flaps/ailerons often seem to be flung off by the impact force.
turboplanner Posted June 28, 2014 Posted June 28, 2014 Ian the question of what weather reports are used is relevant since NAIPS gives moderate/severe turbulence warnings and the others don't.
facthunter Posted June 28, 2014 Posted June 28, 2014 Re Flaps, and Vfe..They don't have to detach fully to be a problem, in flight. As you point out they could move post impact Nev
Teckair Posted June 28, 2014 Posted June 28, 2014 Sa the worst weather I've seen in years! Very nasty right now Yeah damn climate change. 2
alf jessup Posted June 28, 2014 Posted June 28, 2014 Flap extension speed might have something to do with it . It is very low on the Echo. In turbulence there is not much margin above the safe speed clean (for control). Clean in turbulence would have to be the recommended option under those conditions. Nev FH Flap extension speed on my Sierra used to be 70kts before the 600kg upgrade and the vne 152kts, now 67kts & 138 kts From memory the vfe in the manual was for full flaps not so much for partial flap extension but don,t quote me on that or shoot me down as I am current going through a tough time with an ill daughter. Alf
alf jessup Posted June 28, 2014 Posted June 28, 2014 Whether or not the weather had something do do with it a lesson for us all, if it looks crappy with low cloud and fog it probably is not the place to start playing Russian Roulette, we all have to sit and think is it really that important I have to fly today. Good old saying in aviation, if you have time to spare go by air, if you have to get there, drive Alf 4
Mick Posted June 28, 2014 Posted June 28, 2014 Good old saying in aviation, if you have time to spare go by air, if you have to get there, drive Time to spare, go by air. If you must arrive, you had better drive. 4
alf jessup Posted June 28, 2014 Posted June 28, 2014 Time to spare, go by air. If you must arrive, you had better drive. Thanks for the correction Mick, got a lot on my plate with my daughter in ICU at the moment, I knew it was something like that Alf
biggles Posted June 28, 2014 Posted June 28, 2014 Thanks for the correction Mick, got a lot on my plate with my daughter in ICU at the moment, I knew it was something like thatAlf Alf , Many of us here are parents also and have some idea of what you're going through . I'm sure that I speak for all in wishing her a speedy recovery . Bob 14
poteroo Posted June 28, 2014 Posted June 28, 2014 With many aircraft, the book load limits are halved with full flap. As a general rule, don't extend any flap is mod to severe turbulence. Va is usually about 2x the Vs (clean stall speed). In turbulence, I use a mid-point IAS - eg, C172 Va=96 (88-103 range), Vs = 52 so, use 74 IAS to get through the really rough stuff. Where you have difficulty is with aircraft which cruise well above Va, (eg, C182RG with cruise IAS more like 140, but Va = 116). Hitting severe turbulence at normal cruise is very likely to break the elevators or tailpane if you can't decelerate quickly enough. Fair warning to those speed merchants who push up into the yellow arc on descent. NB you RV drivers who descend at 160IAS and wonder why instructors go white with fear!! Once again we're talking about handling bad weather, and once again I'm advocating much more training emphasis on all these important aspects of aircraft handling. 1 3 1
turboplanner Posted June 28, 2014 Posted June 28, 2014 Fair warning to those speed merchants who push up into the yellow arc on descent. Good little warning to me Poteroo! 1
motzartmerv Posted June 28, 2014 Posted June 28, 2014 True that pots. I think VA is little understood. For instance, VA actually increases as weight is increased, contrary to popular belief. 2
acro Posted June 28, 2014 Posted June 28, 2014 True that pots. I think VA is little understood.For instance, VA actually increases as weight is increased, contrary to popular belief. ive never heard that one... Va should be specified at mtow, are you saying if you fly over weight the Va is increased? that doesnt make sense
acro Posted June 28, 2014 Posted June 28, 2014 so if a plane with a mtow of 600kg is is taking off at 900kg then it has a smaller lift factor, so the Va is just like saying you cant do more than xx G's, where as a lighter plane would at full deflection exceed that at a lower speed.
poteroo Posted June 28, 2014 Posted June 28, 2014 ive never heard that one... Va should be specified at mtow, are you saying if you fly over weight the Va is increased? that doesnt make sense Usually a range of IAS is given for Va , (certainly for most Cessnas) -starting at MTOW and going back down to BEW + jockey pilot + 1 hrs fuel. Because you have a range of clean stall speeds - so too do you have a range of Va. As Merv said, it's counter-intuitive because you have the highest = safest Va when you are at highest weight. You can work out the range by way of testing the Vs for a range of weights for your aircraft - if you've the time & patience. Where an aircraft has a permitted overload, eg for a ferry flight (15%), or for ag work, (C180 by 180 kg) - then the Va does indeed increase. However, so does the stalling speed, so using a mid point for rough air manoeuvring is still valid. happy days, 2
facthunter Posted June 28, 2014 Posted June 28, 2014 You have two considerations in turbulence. Not losing control and not breaking the airframe. If proximity to the stall is your main concern you fly a bit faster . Doing that can cause extra load to the airframe as extra lift is available. There is a speed where the aircraft can have full control deflection and it won't break. What you do with this information is a bit of a mystery to me. Why would you give it full control deflection? Nev
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