Jump to content

gliders full size


fly boy3
 Share

Recommended Posts

Advert


We used to use a plastic "wheel" calculator known as a "John Willy" after its designer, John Williamson (son of Henry, author of Tarka the Otter if you want some trivia) and a very nice gent to boot. This primarily gave you the most efficient speed to fly and height required to get to your goal and factored in the head or tailwind component. You'd normally mark off the distance from the goal along the expected track on your map before taking off so that it was easy to judge how far away you were. It also gave you the best speed to fly for maximum distance if you simply wanted to get home!

Bear in mind that although the best lift /drag ratio might occur at say 55 knots, this wouldn't get you far in (an extreme example) a 55 knot headwind, hence the need to be able to calculate an appropriate efficient speed which could be considerably faster than the most efficient still air speed.

Nowadays, as far as I can see, GPS and electronic navigation computers have largely replaced this technology but the principles would remain the same.

Just saw your extra questions, Plummet - the lever is the flap control - you use negative settings for higher speeds and positive when thermalling and very much more for the approach.

The clanger is the audio output from the variometer - high pitched happy sound brings a smile to the pilot's face as he climbs - low pitched melancholy one means sink and a less happy one!

P.S. Great video but could one of the Mods sort that video size and get rid of the overlapping adverts?

Edited By Martin Harris on 28/02/2012 22:28:25

Link to comment
Share on other sites

Posted by Martin Harris on 28/02/2012 22:38:19:

It's the size of Steve's video that's causing it - hopefully the mods will sort it soon...

I'm fairly sure it's filmed near Bath in Avon (Somerset really!) and you can see one glider landed at what I think is probably Lansdowne race course at around 14 minutes...

During one or the R/T conversations I'm pretty sure I heard a voice say 'I'm going back to Nympsfield' which puts it in that area ...

Probably quite a hi tech machine and had plenty of toys on board ... but still had the tell tale piece of red string on the canopy to help confirm airflow !

Link to comment
Share on other sites

Flyboy - the simple answer is we dont know.

Normal gliding day will start off with checking weather maps and deciding what the thermal strenght is likely to be, when they will start forming and what time they will die out. From this info we would plan a cross country flight. on a really good day that would be around 500km to 750km. less exciting days it may only be 200km -300km. This is just a plan though.

Glider gets rigged, flight plan entered in palm type device and then we wait for thermals to start popping, once they do its a mad scramble to the flight line.

Often the first leg of the flight will be downwind. This is because at the start of the flight the thermals will be weaker so fighting in to any head wind is not a good idea. Does make it interesting if the lift is not as expected on track. All through the flight the pilot will be evaluating the strength of the last thermal and what the weather looks like ahead on track. Strength of thermals dictates how fast we fly between thermals. It also dictates when we stop to thermal. If the average for the day is say 5m/s then stopping to top up height in a thermal only producing 2m/s is a waste of time which might cost you dearly towards the end of the day.

The height you fly at during the day will again be determined by thermal strength and frequency. A good lift day with lots of thermals about you tend to fly lower leaving thermals as soon as the lift decreases, a poor day you sometimes have to take every bit of lift just to stay in the air. Often on these poor days a climb in to the cloud can be necessary.

So basically the day goes on. At some point the software on the palm device will tell you that you are now within straight gliding range of home. Thats when you start t relax but not too much.

I remember a fligght a few years ago. I had borrowed a friends ASW28 for the clubs comp week.

Task for the day was Husbos, aylsbury, newmarket, husbos. Just over 200km iirc.

All started great with an easy run to the first turn point. Aylsbury to newmarket the clouds were lining up nicely (streeting) so no need to stop and turn, just bumble along at 100kph pulling up when lift was encountered. 10km from newmaket the shy went blue. managed to turn newmarket the started the limp home. Average height the whole way was less than 1500feet scratching in any lift I could find. About 26km from home the computer gizzmo said I within glide range with 100feet height to spare. Not a lot but owner of the glider had assured me the gizmo was acurate to around 50 feet. So off I head flying at best glide (55kts), as the kms ticked of the ground was starting to look very close indeed. 10km out it all look a bit marginal so I hung left of track knowing there were a couple of really nice fields I could land in before I got to the airfield.

2km from home it was all looking good so I swung right and lined up for a straight in approach to hus bos having called on the radio and advised 2km out and marginal.

Just as I crossed the willage on approach the glider dropped suddenly, sink of the scale on the vario. Now my marginal approach was a serious problem. I had 4 fields left before the boundry of the airfield, none of these were big enough to land in. there were trees on my left side which were now higher than my wing would have been had I banked to turn back to the safe fields.

Seemed like an eternity but in reality these option probably went through my head in less than 2 seconds

1) make a very gentle tuen left and hope I clear the trees (no way)

2) Stick the glider down hard in the field ahead of me aiming between the trees at the end know I would rip the wings off but probably survive (an option but not one I liked)

3) I remembered the owner (internation glider pilot) saying the sink stops at ground level. So option of pushing nose down, gaining all the speed I could and running in ground effect (3feet up) all the way home.

That was the one I went for. So there I am 120kts, 3 feet off the deck with 3 feilds to cover, all of which have high hedges at the ends. Final hedge also has power lines over it.

Lets just say the adrenalin was pumping on that run. Final hedge I didn't have the speed left to clear the power lines so it was over the hedge and under the lines. Wheel still retracted as I started to flair for landing, cross the threshold, pop wheel down and land.

Hopped out of glider and relieved myself. Freind of mine wandered over and remarked "If I'd just done that approach I's be peeing myself aswell"

Yep some days it can be fun!

Link to comment
Share on other sites

Best tip is relax and enjoy. Not sure you would get your CC endorsment as this requires you to have your bonze C before hand. Possible but some serious revising for the exam required.

If the club has a motor glider try and get some time in that practicing field landings. Trust me, the first time you have to land out you will be glad you did.

What club are you doing your course at?

Link to comment
Share on other sites

200km is an easy flight.

Current solo UK record is over 1000km set by Russel Cheetham in an ASW22 about 5 years ago.

As far as I know he is still the only person to have flown a 1000km in the UK. Trouble is we run out of island. It took him over 12 hours.

BTW it was his ASW 28 I was flying. I used to crew for him at comps and he let me play with it as a thankyou.

Link to comment
Share on other sites

My gliding experience was as a 16 yr old ATC Cadet. Kirkby Cadet Glider, single seater, no Instructor by your side, just verbal insruction on the ground before being launched by Winch. Can't remember how high I had been but you had to release the towline and perform a stall and recover before landing. Not even a hard hat !!

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...