Re: [aus-soaring] Tow height when launching

[Ian K McPhee]

My two bobs worth on Harry's retrieve is there were two heavy weights in the tug (crazy) and the Pawnee 235 had 800 tyres not balloon 850s which really make a difference in some paddocks (and ware over twice as long).  I seem to remember something about riding the brakes or was it a fouled up plug or did they find a cracked barrel or a combination of same - I just can't remember.  I have flown over 2000hrs of tugging with close to 2000 paddock tows from both ends.  I do not say all trouble free.eg a supercub took off on one magneto on me once out of a paddock (I have never trusted a tug pilot since! - If they do not discus with me then I discuss with them) and I have spent up to an hour preparing for a paddock tow just so as to give us both extra safety margin to us both. My only knock backs were a ex F27 pilot and a helicopter pilot both too long grass/stubble for the glider they were flying.   When I do a retrieve I always discuss the options in the event of a problem on take off with the glider pilot and then say I am responsible for fuel on, both magnetos on and checked and window locked and you are responsible for airbrakes locked, canopy locked and I may ask them for one radio call to say they are AIRBORNE as this gives me a better idea of how I am going and what I can achieve.  I always go out with a moderate amount of fuel for the job and never a passenger (except possibly airport retrieve) and always know last light to the minute and I have my own quick mental arithmetic calculation as to if I have time for the retrieve or not.  The Pawnee never ceases to amaze me and I still ask myself how could anybody come to grief in a Pawnee.  More recently I have been flying a 250HP Pawnee and that is even better and well worth the extra when engine rebuild time comes around. Apart from the 850 tyres and 250HP the only other worth while Pawnee mod  would the bigger C185 tail wheel tyres like they have on Swedish Pawnees.         Ian Mc Phee Box 657  Byron Bay  NSW 2481  Australia Tel (61) 266 847 642 (Fax  942) [EMAIL PROTECTED] (alt [EMAIL PROTECTED]) www.mrsoaring.com   ----- Original Message ----- From: Christopher H Thorpe To: [EMAIL PROTECTED] Sent: Monday, April 30, 2001 7:33 PM Subject: RE: [aus-soaring] Tow height when launching Harry   There is a period during most aerotows where the option of landing within the confines of the site are not available, that’s why pilots are trained to identify suitable off-field emergency landing areas during the early stage of the tow.  However, our training system also recognises that if the launch is not proceeding well it should be abandoned.  While the tug pilot is in command of the combination, the glider pilot also has some responsibility for the safety of the flight and should not rely on the tug pilot releasing (e.g. the tuggie could have his hands full).    All I can say is that it must have been a marginal paddock for there to be merit in persisting with an unsatisfactory tow until the tug went through the fence.   Christopher Thorpe   -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On Behalf Of Harry Medlicott Sent: Monday, 30 April 2001 16:25 To: aus Soaring Subject: [aus-soaring] Tow height when launching   I am somewhat disappointed, but not surprised that my effort( 24th April ) to contribute to safety by reporting an accident resulted in more nitpicking comments than useful discussion.  It is not pleasant referring back to incidents involving oneself but it is only by analysing accidents that we can learn from them.  A few comments on my original notes and associated replies;   I was in high tow, which for me meant just above the slip stream, but then went about 1 or 2 metres higher.  Perhaps the height above the ground was as much as 5 metres but as I did not have a leadline to measure the height and am relying on a memory of eight years ago cannot be precise.   Comments re entry of the non-manoeuvring area are either an example of ignorance of wishful thinking.  When winch launching, respect and avoidance of the n.m.a. are both possible and highly desirable, but on aerotow it is a different kettle of fish.  Probably at lease 10% of aerotows spend time in an n.m.a. and on some airfields every flight is in the n.m.a. for from a few seconds to upwards of a minute.  If we were to release when we anticipated entering the n.m.a., (not much use releasing when we are in it!) then imagine the consequences, not least for those who had already entered to n.m.a.  Except in obvious cases I believe that not many pilots are aware of when they are approaching a marginal situation.  Surely it is primarily the tug pilots responsibility to release us, depending on his evaluation of power available and conditions ahead.  He must have a very good idea of his ability to safely clear obstacles and usually has many times the experience of the pilot he is towing.   Fortunately the GFA by setting standards and providing release testers has largely eliminated part of the problem of premature releases.  A new 60m length of 12mm 1400kg breaking strain poly. rope costs  $25.00 so please scrap and cut up tow ropes when they become frayed.   There are also situations when it is most prudent to stay close to the ground until a speed of 10 or 15kts above stall speed has been reached.  Certainly under windy and turbulent conditions this applies, unless you wish to be unceremoniously dumped back on the ground, and also with heavily ballasted gliders.  A tug will almost always be airborne well before a standard class glider ballasted to 50kg wing loading.  At this weight severe damage will result in stalling from 1metre.  I have seen it happen twice.  A heavily ballasted glider must exercise extreme care when launching, the tug has less acceleration, and any idea about transiting immediately to high tow after lift off may well have a disastrous result.