Where is my plane?
|Michael Wright||12/01/2019 21:31:09|
|64 forum posts|
Hi everybody, first off I am not a 'newbie' flyer, I have been flying for many years in many disciplines...trainers, wot4's, warbirds,gliders,EDF's, and 3D.
My question is this, how common is poor depth of field placement, ie 'am I over the boundary hedge line yet'? hitting trees when I could have sworn that my plane was between me and the tree by a good distance?
Just interested in the experience of others.
|Martin Harris||12/01/2019 21:57:29|
8219 forum posts
I doubt you'll find many regular flyers that haven't had a nasty surprise at one time or another!
|Chris Walby||12/01/2019 22:00:55|
838 forum posts
Depends of the risk you are prepared to take.
Our field has a line of trees on part of the boundary, personally I always fly with sky between the model and the tree tops. Other members fly in front of the tree line and below tree tops... sometimes they end up in the trees.
One member has two T28's that are different sizes and identical markings...clipped the hedge with the larger because he thought he was flying the smaller and it was closer.
Even if I had a model a didn't want I would still not deliberately fly under the tree line just to test my depth of field.
IMO Biggest problem is flying models very infrequently and getting used to them again in 6 minutes before landing
PS I asked a club member who flies aerobatics/3D and anything else, how he flies so low, his answer was that it does not matter if its up high or 6 inches off the ground it is where he wants it to be! Very accurate depth placement in any orientation
|Denis Watkins||12/01/2019 22:09:02|
|3455 forum posts|
Have a look here too Mike
The guys have various problems with placement
|Percy Verance||12/01/2019 22:22:59|
7511 forum posts
Improved depth perception usually comes with experience. I guess you might liken it to parking accurately at the kerbside. It's a knack you sort of acquire ( or not!).
Trees do catch many flyers out though, and I've had a total of four *tree toppers* in 45 odd years. I even won a trophy for one of them at a national event back in the early 80's.
Until a few years back I flew from a field with a stone wall on the final part of the landing approach. This stone wall was on a raised part of the field, which made it all the more tricky to judge just when you'd passed over the said wall. What made it considerably easier though was the model's shadow on a sunny day. It did get interesting on cloudy days though........
Edited By Percy Verance on 12/01/2019 22:41:03
|J D 8||12/01/2019 22:30:40|
1035 forum posts
Probably one of the most difficult things to get used to with RC flying. Us humans are just not good at depth perception, we nearly always think models are nearer than they are.
I think flying different size models does not help but most of us like to fly an assortment.
One thing you can do is place your aircraft on the ground at your boundary line and walk back to your flight box and try to memorise what it looks like at that distance.
It is possible to do on line tests to see what your depth perception is like.
One thing I like to do [ only works on a sunny day ] is glance where the models shadow is when landing, if on the strip we are good.
|Chris Bott - Moderator||12/01/2019 23:40:34|
6519 forum posts
|A good while ago we tested depth perception at our club by sending folk out with a 2 way radio so they could shout up when a model was beyond an arbitrary boundary that we'd picked. |
Many pilots were so convinced that they were well inside the boundary when the spotters said they were outside, that arguments broke out. Pilots would not have it.
The conclusion was that our depth perception at distance, more often than not, is terrible.
|Martin Harris||13/01/2019 02:14:32|
8219 forum posts
Most people's eyes are less than 4 inches apart so while stereoscopic vision helps us pick up a servo screw from the bench at arm's length, the angular variations between the eye lines at circuit distance are miniscule so I think we can say that physical depth perception has little to do with the ability to judge distance.
What, apart from ground shadows, is left? It can only be judgement of apparent size which has to be learnt by repeated experience - sometimes with expensive results! In my experience, swapping model size is the most hazardous condition.
The best defence seems to be setting up a steady approach to a preselected aiming point, carefully monitoring the relationship between the runway threshold or obstruction and the approach line to ensure that you are overshooting it slightly. Flying into a distant tree that you think you're in front of (or behind!) can only ever be avoided by an estimate born out of experience - or luck!
|Michael Wright||13/01/2019 08:09:27|
|64 forum posts|
Thanks for the replies. It seems that I am not alone in this. It is interesting that we are all suffering more away from the close up zone.
We also conducted tests with people on the boundary fence and had the same result, the plane looks closer than it is in reality.
A lot of we problem is having to land in fields that are a little small for the size of plane we fly here.
|Peter Miller||13/01/2019 08:29:37|
9700 forum posts
The ONLY way to be sure how far away your model is, is to fly Control LIne
337 forum posts
I think one reason why the depth perception problem is worse for novice flyers (and for more experienced pilots flying an unfamiliar model) is that the greater the level of concentration needed to fly it, the greater the tunnel vision effect. As a result less attention is available to assess the model's position relative to its surroundings.
Even so, I do agree that at distance, our depth perception is generally awful - witness the fact that when going to help retrieve a wayward model, we sometimes can't even agree which field it might be in!
|Engine Doctor||13/01/2019 08:56:17|
2164 forum posts
I find wearing a pair of glasses with a tint that enhances colour contrast helps for me although we all have different sight problems. I generally don't have a problem but I make sure that I fly keeping well clear or above obstacles that can literally catch you out , like trees in winter! I wear specs all the time but like an orangy brown tint that works well both in sunny and cloudy condition. Silver aircraft however are a different animal an I tend to only fly them in brighter conditions. One of our club members has only one good eye and he amazes me how he gets so low over trees .........most of the time .
|Jonathan M||13/01/2019 09:21:53|
604 forum posts
Interesting discussion - and I'm normally guilty of turning onto base-leg much further away than necessary.
But surely its not just a question of visual reckoning - what about instinctively knowing how far away your model should be after a few minutes' flying both upwind and down on any given day?
If the boundary of your patch is say three runway lengths beyond it at either end, and it takes say 5 seconds to overfly the runway downwind at half-throttle, then its going to take 15 seconds before you're at the boundary.
|Martin Harris||13/01/2019 12:14:20|
8219 forum posts
That wouldn't be much use at our fairly compact field where the runways starts at the boundaries - on the most commonly used one, complete with a low hedge and Armco barrier (to discourage our travelling friends). On a light wind day with a largish or fast model, flare needs to be commenced within 10 to 15 yards of the boundary so timing methods would be very hard to use.
Triangulation helps - standing back from the runway as far as practical allows a perspective view but as I mentioned before, a well set up and monitored approach is your best friend.
Edited By Martin Harris on 13/01/2019 12:17:10
1839 forum posts
I'm glad I am not the only one with this problem, a short while ago we had our club bomb drop competition and all my bombs fell long of the target. I need more practice or try flying at 45degs across the target. Maybe I could fit a laser targeting light pointing down on the field that should do it.
|alex nicol||13/01/2019 14:01:48|
|237 forum posts|
A couple of points worth noting, when learning it's not unusual for a novice pilot to complete his last turn and runway line up to early. in fact sometimes it can seem as if you need to resist the natural urge to turn by a couple of seconds to ensure proper line up.
The other point is landing a model you are unsure of or haven't flown for a bit, so much extra concentration goes in to line up, keeping wings level and reducing height and speed it's easy to overlook the fact you might be a little bit short of where you need to be and perhaps not a depth of perception issue.
|Paul Marsh||13/01/2019 14:38:39|
3497 forum posts
I have no trouble at all, having perfect eyesight. I do bomb drops and can get they in the middle of the strip.
Also, practice makes perfect. One chap at our club flew his Extrawot into a tree last year, I did remind him that he was behind the tree and going to fly into it - and he did!
1681 forum posts
The only problem you have is your modesty (or Lack thereof)
Edited By Ultymate on 13/01/2019 15:18:42
|alex nicol||13/01/2019 16:52:31|
|237 forum posts|
Actually that's just brought another factor to mind, the magnetic draw that solitary inanimate objects have on our aircraft. by that I mean things like Trees, Fence posts and the solitary rock in the middle of a grassy field. How many times has somebody hit one of these when it would be so much easier to miss. I know I have
|Josip Vrandecic -Mes||13/01/2019 18:24:42|
2939 forum posts
Hi Michael , the only real remedy, for this unpleasant anomaly is permanent flying in a familiar environment ..... Exercise is all we need.
Note:if memory does not spare ... this phenomenon is called : '' Microscopic view '' ...if I made a mistake ... Martin Harris would pull my skin off....
Edited By Josip Vrandecic -Mes on 13/01/2019 18:28:22
Edited By Josip Vrandecic -Mes on 13/01/2019 18:32:19
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