CG and spins
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So, Shy Torque, you were in an inverted spin, rather than just inverted? So pulling back on the stick while in an inverted spin would be the same idea as pushing the stick forward in a non inverted spin, yes?
G:- My objections to 2 strokes are really just noise and fuel burn. The Shadow CD seems the best to me too; narrower cockpit etc so more air for the prop, longer wings than some of the others, so slower stall and better glide angle. If the little rotax is actually a good engine, all the better. I'm encouraged by your opinion of the 503; all 2 stroke engines in any form are a mystery to me, I just remember being drenched in fuel by a seagull outboard in a rubber dingy years ago;- my only experience with 2 strokes, besides falling off the back of a GT750 in my teens.
A hangar would be obligatory at my local field, and I'm up for learning new maintenance skills. Plus a long standing member of the local club has owned one for many years, and loves it.
You mentioned the CFM's being fragile; one option for me to learn to fly is to buy one, and get the local instructor to teach me on it. He flies flexwings and 3 axis, but currently only owns a flex wing. Not sure if that level of financial commitment is quite called for; what if I decide to quit and want to sell it? Are they easy to sell, or do they 'stay on the shelf' for years?
Would you say the shadow is a good option for a novice student pilot to learn on? Or would the fragility be an issue?
Thanks for tolerating me veering off topic, let me know if I should just start a new thread....
G:- My objections to 2 strokes are really just noise and fuel burn. The Shadow CD seems the best to me too; narrower cockpit etc so more air for the prop, longer wings than some of the others, so slower stall and better glide angle. If the little rotax is actually a good engine, all the better. I'm encouraged by your opinion of the 503; all 2 stroke engines in any form are a mystery to me, I just remember being drenched in fuel by a seagull outboard in a rubber dingy years ago;- my only experience with 2 strokes, besides falling off the back of a GT750 in my teens.
A hangar would be obligatory at my local field, and I'm up for learning new maintenance skills. Plus a long standing member of the local club has owned one for many years, and loves it.
You mentioned the CFM's being fragile; one option for me to learn to fly is to buy one, and get the local instructor to teach me on it. He flies flexwings and 3 axis, but currently only owns a flex wing. Not sure if that level of financial commitment is quite called for; what if I decide to quit and want to sell it? Are they easy to sell, or do they 'stay on the shelf' for years?
Would you say the shadow is a good option for a novice student pilot to learn on? Or would the fragility be an issue?
Thanks for tolerating me veering off topic, let me know if I should just start a new thread....
I'll leave current admins like DAR to worry about thread discipline.
My impression is that Shadows I see on sale don't usually stay advertised for more than a month or two, so I'd hope that you can get rid of one if you want to quite easily.
There is a Shadow CD, G-MWVG (known to one and all as George) that was used for ab-initio PPL training from the Shadow Flight Centre at Old Sarum. Looking on G-INFO it is still there, with 4000hrs on it (although I don't think they're regularly teaching on it any more). I passed my microlight GFT on it in 1993! That probably tells you all you need to know about the robustness and suitability for student pilots, if well looked after.
The main thing with the 503 is that it needs regular maintenance - plugs at 25hrs (cost of a set about a tenner), every 50 hours for minor maintenance, monitor crankshaft wear from about 250hrs, and expect to decoke about every 150hrs and rebuild (actually about a 3 day job costing a few hundred pounds in parts, £700 if you're unlucky) about every 450hrs. I'd be very happy to own a 503 engined microlight again any time, having had a couple.
G
My impression is that Shadows I see on sale don't usually stay advertised for more than a month or two, so I'd hope that you can get rid of one if you want to quite easily.
There is a Shadow CD, G-MWVG (known to one and all as George) that was used for ab-initio PPL training from the Shadow Flight Centre at Old Sarum. Looking on G-INFO it is still there, with 4000hrs on it (although I don't think they're regularly teaching on it any more). I passed my microlight GFT on it in 1993! That probably tells you all you need to know about the robustness and suitability for student pilots, if well looked after.
The main thing with the 503 is that it needs regular maintenance - plugs at 25hrs (cost of a set about a tenner), every 50 hours for minor maintenance, monitor crankshaft wear from about 250hrs, and expect to decoke about every 150hrs and rebuild (actually about a 3 day job costing a few hundred pounds in parts, £700 if you're unlucky) about every 450hrs. I'd be very happy to own a 503 engined microlight again any time, having had a couple.
G
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One of the problems in this Industry is that pilots, in general, are trained to comparatively low levels of technical understanding.
The static and dynamic stability lectures took me five hours in total and in terms of spinning I took them through the subject of B/A ratios also.
My university ATPL students were trained and tested to very high levels of technical understanding. I accept this thread is at PPL level.
The static and dynamic stability lectures took me five hours in total and in terms of spinning I took them through the subject of B/A ratios also.
The static and dynamic stability lectures took me five hours in total and in terms of spinning I took them through the subject of B/A ratios also.
0/0....
There's always an issue that all of the professional licences train and educate people for a plethora of professional pilot roles, not just any single one. Having recently added a US CP to my EASA CPL I was struck by the very different emphasis each places on different aspects of both theory and practice - yet in theory each qualifies me to do (almost) exactly the same things, just with a different registration painted on the side.
For me, working in the technical side of aviation, the theoretical aspects of my EASA CPL are vastly more useful than the extremely minimal and light-GA centric FAA CPL written syllabus. On the other hand the greater emphasis on handling in the FAA CPL checkride is more useful to me as a test pilot than the "let's pretend we're 1960s airline pilots" content of the EASA skill test: but having done that I've found myself very well equipped to do bits of ferrying around Europe in minimally equipped aeroplanes.
Basically, I am saying that any licence course, or education course (and these combined ATPL degree programmes are both) should NOT be really narrowly focused one specific job is. That is, in my opinion, a deeply flawed view.
G
For me, working in the technical side of aviation, the theoretical aspects of my EASA CPL are vastly more useful than the extremely minimal and light-GA centric FAA CPL written syllabus. On the other hand the greater emphasis on handling in the FAA CPL checkride is more useful to me as a test pilot than the "let's pretend we're 1960s airline pilots" content of the EASA skill test: but having done that I've found myself very well equipped to do bits of ferrying around Europe in minimally equipped aeroplanes.
Basically, I am saying that any licence course, or education course (and these combined ATPL degree programmes are both) should NOT be really narrowly focused one specific job is. That is, in my opinion, a deeply flawed view.
G
Last edited by Genghis the Engineer; 15th Jul 2019 at 10:15.
Knowledge base
Having done 3 atpls, plus light aircraft, microlight,glider and paraglider qualifications on four continents, the knowledge base is impossible for one small brain to comprehend. It stems from old systems, accidents and the flying environment modified to the lowest common denominator by those who lack the ability of sky gods. There will never be a consenus even in a relatively small gliding club in one of the british isles and especially in a frog one. Add regulators, many of which dream of flying a jet, and the system is well and truely up the creek.
The best one can hope for is to write,read and talk then disagree.
From someone who nearly didn't get out of a spin, whose pupil then didn't 30 years later, and did his first open cockpit spin of a single seat vintage glider 2 years ago..when the CFI wouldn't. In the right aircraft, with a proper preflight check..great fun!
The best one can hope for is to write,read and talk then disagree.
From someone who nearly didn't get out of a spin, whose pupil then didn't 30 years later, and did his first open cockpit spin of a single seat vintage glider 2 years ago..when the CFI wouldn't. In the right aircraft, with a proper preflight check..great fun!
I've been told that spin characteristics are defined not just by CofG location, but by weight distribution, such as a lump of lead added in the tail. Is there any validity in this comment, or is weight distribution totally taken into account by knowing CofG location?
Some years ago I did a gliding instructor course here in Germany which involved a lot of spinning. It was interesting that with a rather large instructor trainer in the front that one of the two types of gliders would not stay in a spin, we were using K13 and K21s. We did days and days of spinning and the result was always the same on the K13 half a turn and despite full crossed controls it was out. So my practical experience backs up the CG theory at least on some machines. With light trainees I have found the K13 spins to your heart’s content.
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Correct. C of G is a very important factor, and spin recovery characteristics will drive C of G limits. But the moment of inertia can have an effect too. If you put a small mass wayyyy back, yet remain within C of G limits overall, the spin recovery could be affected, as there was more inertia to overcome for recovery. I think of a few engine change STC's which include a few pounds of lead in the tail to balance a heavier engine. That said, I expect that for spin approved GA types, you couldn't get enough mass far enough back, yet within C of G limits, to become a problem, but I would be considering it during flight testing. Happily (for maintaining spin recovery characteristics, most of the things I've tested hanging off the back of a GA plane were also big enough to have aerodynamic stabilizing characteristics to overcome any mass destabilizing characteristics.
I have spun these, they all remained compliant:
The booms are light
And:
Ugly at aft C of G, but compliant, there's quite a stabilizing effect from the stowed towed survey bird. Video here:
I have spun these, they all remained compliant:
The booms are light
And:
Ugly at aft C of G, but compliant, there's quite a stabilizing effect from the stowed towed survey bird. Video here:
The Cessna 150 with the Lycoming 150 hp engine mod is not certified for spinning. The heavier engine required the battery to be moved to the tail. The heavier bits at both ends created addition polar inertia such that the airplane no longer had acceptable spin recovery characteristics
in any case spin training has no place in ab initio flight training. Instead all of the emphasis should be on spin recognition and recovery. A deliberately entered spin with pro spin controls maintained after the aircraft departs is an aerobatic maneuver and should be thought by an aerobatic instructor as part of a basic aerobatic course.
in any case spin training has no place in ab initio flight training. Instead all of the emphasis should be on spin recognition and recovery. A deliberately entered spin with pro spin controls maintained after the aircraft departs is an aerobatic maneuver and should be thought by an aerobatic instructor as part of a basic aerobatic course.
Some years ago I did a gliding instructor course here in Germany which involved a lot of spinning. It was interesting that with a rather large instructor trainer in the front that one of the two types of gliders would not stay in a spin, we were using K13 and K21s. We did days and days of spinning and the result was always the same on the K13 half a turn and despite full crossed controls it was out. So my practical experience backs up the CG theory at least on some machines. With light trainees I have found the K13 spins to your heart’s content.
I think fairly obviously that is what we were using. I agree with a previous post that more than incipient spin recognition training on light powered aircraft is overkill (excuse the pun). On the other hand after nearly half a century of gliding, and an initial instructor course under the tutelage of Andy Gough, I believe there is definitely a place for spin training in flying sailplanes. Not least we spend a lot of time in tight turns, low and slow when thermalling down in the weeds.
I agree.
Best not to trim into the turn pressure on the stick.
Be aware of the first signs of buffet, and release some back pressure.
Best not to trim into the turn pressure on the stick.
Be aware of the first signs of buffet, and release some back pressure.
Avoid imitations
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The RAF’s Bulldogs always had a reputation for being tricky with regard to spin recovery. During my time instructing on them I did a little research into weight and balance, which wasn’t routinely calculated in detail for every flight. It appeared that with two average to heavy occupants the fuel level needed to be watched because many airframes were right on the aft C of G limit and they could be put outside. Which of course might explain the very rapid roll rate that could be experienced. Being built like racing snake back then had its advantage.
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“in any case spin training has no place in ab initio flight training.”
Try telling that to the family of the 26 year old who crashed a C150 out of Jerez in Feb.
Looking at the video, he was in a fully developed spin and there was no attempt to recover. Did he know how to?
Like ShyT, I did a 35hr PPL where spinning was taught, the to the Bulldog where it was taught and repeated constantly. A career in the RAF and airlines and a private Bulldog and now gliders. I have never accidentally spun, but I sure know how to get out of one if I have a bad day.
Me
Try telling that to the family of the 26 year old who crashed a C150 out of Jerez in Feb.
Looking at the video, he was in a fully developed spin and there was no attempt to recover. Did he know how to?
Like ShyT, I did a 35hr PPL where spinning was taught, the to the Bulldog where it was taught and repeated constantly. A career in the RAF and airlines and a private Bulldog and now gliders. I have never accidentally spun, but I sure know how to get out of one if I have a bad day.
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Spin training is a compromise.
Records show that more people have died during spin training than from accidental spins so the decision was made to limit PPL training to incipient spins. This leads us to the effectiveness of the training which IMHO is probably inadequate.
We all (hopefully) occasionally practice engine failures and emergency landings but how many practice recovery from incipient spins with any regularity ?.
Records show that more people have died during spin training than from accidental spins so the decision was made to limit PPL training to incipient spins. This leads us to the effectiveness of the training which IMHO is probably inadequate.
We all (hopefully) occasionally practice engine failures and emergency landings but how many practice recovery from incipient spins with any regularity ?.
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I’m sure that after so many decades of “spin awareness/avoidance” training, many civilian flying instructors now have far less spin experience than the majority of those in the job years ago. It’s understandable that some might actually even shy away from the subject as much as possible.
Being RAF BFTS jet trained, I’m grateful that spinning was seen as nothing unusual. We needed that experience because we were expected to fly to the limits of the airframe (and aerobatics put students potentially closer to spinning when we reached the limits of our ability). Without that ingrained early full spin recovery training I certainly would have accidentally killed myself, at least on one occasion in a JP3A that I’ll never forget.
Being RAF BFTS jet trained, I’m grateful that spinning was seen as nothing unusual. We needed that experience because we were expected to fly to the limits of the airframe (and aerobatics put students potentially closer to spinning when we reached the limits of our ability). Without that ingrained early full spin recovery training I certainly would have accidentally killed myself, at least on one occasion in a JP3A that I’ll never forget.