Height?

[Monz]

Flying my NXT today and caught a monster ride upwards.  

If the glider has a span of 1500mm and it was 2mm wide directly above me, how high was it?

I chickened out as it was still going up and I was losing orientation of the speck so dropped the brakes to bring it down and even that took a while. 

[Guest]

Jeez that’s small?! I’ve never gone that high or far away, pretty much the next field I’ve been and I thought I was pushing it haha.

Got proper nervous too, my hands were shaking and heart pounding, especially when I pulled brakes and it stil didn’t seem like it was coming down haha. I need to get over my fear. 

Although I had a detached retina last year and even though I got sight pretty much fully back in the eye, my depth perception is shot and it’s goes a bit weird sometimes, like watery and I still have a lot of rubbish floating about in my right eyes vision. 

[MikeDLG]

I’m curious, how do you know it was 2mm wide above you?  Apparent height usually depends on the clarity/visibility  of the air. On a bad visibility day, you could be at 800ft and it’s hard to see and appears much higher. On a very clear day, you could be way higher.  I have flown to over 2400ft on a good visibility day. A certain Martin Godden did over 3000ft many years back.  You need the right conditions for that.  I find the glider disappears more easily against a blue sky, so ideally need high consistent cloud cover for very high flights. 

[Monz]

2 hours ago, i_am_mark_evans said:

Jeez that’s small?! I’ve never gone that high or far away, pretty much the next field I’ve been and I thought I was pushing it haha.

Got proper nervous too, my hands were shaking and heart pounding, especially when I pulled brakes and it stil didn’t seem like it was coming down haha. I need to get over my fear. 

Although I had a detached retina last year and even though I got sight pretty much fully back in the eye, my depth perception is shot and it’s goes a bit weird sometimes, like watery and I still have a lot of rubbish floating about in my right eyes vision. 

Ja, I also got quite nervous with the hands and heart both doing their thing till I could make it out properly again. Still, good fun! I'm still chicken when it comes to flying far horizontally. Don't know the glider well enough or have the skills yet for that.

A couple years ago I went for my first eye test for my PPL medical and discovered I needed glasses. I didn't realise how blind I was till I had them. Everything is like 4K x 10 now!

[Monz]

2 hours ago, MikeDLG said:

I’m curious, how do you know it was 2mm wide above you?  Apparent height usually depends on the clarity/visibility  of the air. On a bad visibility day, you could be at 800ft and it’s hard to see and appears much higher. On a very clear day, you could be way higher.  I have flown to over 2400ft on a good visibility day. A certain Martin Godden did over 3000ft many years back.  You need the right conditions for that.  I find the glider disappears more easily against a blue sky, so ideally need high consistent cloud cover for very high flights. 

Referencing what it looked like I'd say it's about right. It was a clear day where I was, mostly blue sky. 

Flying full size I have a pretty good idea of distance horizontally in differing visibility. I just don't know how to calculate how high I was today. It did give me confidence in the Taranis' range though!

2400ft? That is some serious height! I know what it looks like from up there so can hardly imagine how you kept orientation of the glider.

[mikef]

If you held up a scale and measured 2 mm. span, and the glider is 1500mm.  span,  the distance to the glider is

(Span/apparent span) x (the  distance between your eye and the scale).

As an example calculation, if I hold the scale at 675 mm, the "2mm." glider is at

(1500/2) x 675 mm.    That's 506250 mm. or 1661 feet.

 

[MikeDLG]

I totally agree with this and as I said previously, the clarity of the air makes a big difference to the apparent height.  I have often been surprised at how much lower I was when reviewing my altitude logs after a session.  Anything over 1200-1500ft with a DLG requires the right conditions., imho. 

[Martin O]

When I'm practicing and get good air I make use of vario announcements to see what height I'm at. For me 250m is usually comfortable but when getting near 300m I start thinking about chickening  out. As Mike has said, colour of the sky makes a difference. Using the vario has got me used to approximation of height but doesn't help all that much in a comp. I have never tried to visualise height by scaling the see able size, something I shall look at when I'm out tommorow! 

[Simon B]

Agreed, I'm happy up to about 1000ft in reasonably clear air based on altimeter readings, but have learned visibility can change fast and a lot lower than that, much higher can get hard to judge and sketchy for both visual and radio contact, I don't think its ever been an issue at a comp, hard to find a thermal that strong in a ten minute window with limited flight times.

[mikef]

8 hours ago, Martin O said:

...... Using the vario has got me used to approximation of height but doesn't help all that much in a comp. .......

To be clear, in case Martin's post in mis-understood, a vario is not allowed in competition flying.

[Simon B]

There are no prizes for altitude in F3K, but it's hard to resist good air sometimes when sport flying, especially now we have telemetry to play with.

[Monz]

Thanks for all the comments guys. I was just interested to see how high I'd roughly got. It was a first for me working a thermal that high and although fun at the time is definitely beyond my comfort zone! I spent this evening working on flying between thermals and consistently staying a bit higher than my launch height. Much more comfortable on the neck and good fun!

I'm still very much a beginner with this type of flying and learning how to read the air and use it. When I hit that monster and seemed to centre in it, it was unreal how quickly the glider climbed. I seem to be developing my own style of flying the NXT too to keep it in lift. It's the only glider like this I've flown so I don't really have anything to compare against, but my flight times are going up and the launches are becoming less

What I need to start working on, and this is where the DLG come and try will help immensely, is to begin flying to the events, paying attention to the stopwatch, practising quick turnarounds, those sorts of things.  I've been doing an hour and a half every day for the past week. It's like I can't wait to get home from work and go throw the thing for a while. 

[Richard Swindells]

I really would not worry about turn around time yet. It only gains a small advantage in perfect conditions where you are battling for the lead.

There is much more advantage taking a few seconds to compose yourself and maximise the launch height.

A 3 mins timer + 10 second turnaround window on repeat is about the best practice there is. If you find good lift, landing immediately and relaunching to find the same lift, will be much more valuable than riding out a long flight. (It will help build your understanding of how lift moves and passing the point where you can turn round and get home, when you know there is lift a few meters further away.)

Once you are comfortable getting a good string of flights then reduce the turn around window by a couple of seconds