Microlighters

I was driving past Brits yesterday afternoon when I saw what I thought were two trikes taking off a couple of kilos ahead of me. As we neared them my wife commented that the trike at the back looked rather strange. Looking again I noticed that it had no undercarridge. Turns out it was not a trike but a hang glider being towed by the front trike.
Has anyone ever seen this before??
Where does the cable get attached to the trike and how does it avoid being wound up in the prop once it is disconnected from the hang glider?

I'm not too sure of all the detail but I know there's a hole in the center of the propeller shaft. They mount 2 bearings in that hole and pull the cable through those bearings and tighten it with a clamp on the opposite side. Now when the propeller is turning, the cable just turns on the bearing, no problem!!

FF can enlighten us more on this They use a dragonfly to tow those undercarriageless people with!

See the post about it's construction here! http://microlighters.co.za/viewtopic.ph ... +dragonfly

I have to admit, once the cable is release does it just drag behind? I would like to see this in action myself.

I would imagine that the "wind" from the prop would blast the rope away? Do they actually use a rope?

Too many questions!

I got that info from Fred Blokland a while back. That's the way they constructed their system to tow somebody on "ski's" around the dam!!

They use a dragonfly to tow those undercarriageless people with

Yes but on the dragonfly the prop is reasonably out of the way. Wouldnt feel safe with 50m of rope hanging out from the centre of the prop just waiting for an oppertunity to be wound up, not to mention what would happen if you came in for a landing and it got snagged on something. Or would there be a way of retracting it in flight??

We experimented a bit with it a few years ago. We were taught by an active bunch of aerotowers in CTN.

With the hollow shafts on some gearboxes it is possible to mount a hollow tube through the centre of the prop. This is the release mechanism and extends some way out the back of the prop, ie there is no rope through the centre of the prop.

There is a quick release mechanism at the end of the hollow tube operated by a rope through the hollow tube. This allows the pilot in the tug craft to 'dump' the rope and hang glider if circumstances dictate it. Ordanarily the HG pilot will release himself at his end of the tow rope.

After releasing, the tug will do a low level fly past to dump the rope before landing. (Not a good idea to land with the rope still attached)

We found to make take off easier for the HG pilot, we constructed a dolly for the HG to be mounted on. As soon as the HG got airborne it would leave the dolly behind. This way the HG pilot could already be in flying position before the roll even started.

Have some pics, but no digital in those days. Will see if I can find them and scan them.

Thanks , it would be interesting to see how it is done

You guys have got it all wrong.
What you saw was a very rare instance on the birth of a baby trike, umbilical cord still attached. Normally this happens in the quiet dark recesses of a hangar, far away from prying eyes but obviously ZU-MUM got spooked and felt it would be better to get herself and her fledgling ZU-SON, away and to safety. Isn't nature a wonderful thing

Sorry, it's been a long day and the old grey matter is overactive again

Morph


Larry E at Bapsfontein also did a tow for Grand Rand Flying Extravaganza last couple years as demo.

Thanks for setting the record straight Morpheus.

Demon , saw a fixed wing ML over the dam but not you guys. Weather looked great for flying!!

On the topic of towing - banner towing - how does a banner stay upright and readable when towed?

how does a banner stay upright and readable when towed?

Something I have always pondered

Darkhelmet

Must be honest, in a ML, I am not sure how you would do the 'pick up' or the deployment of a banner. We use the system in the pic below (this is Mark Horning from Skydive Durban) and the helicopter towers use a variation, the difference being the way it is deployed - we drop, they lift. Fixed wing towers snatch from the ground - there are several ways for that as well. The trick is to get the weight pulling the front of the banner tight compatible with forward movement, drag on the banner blah blah - also safety considerations as your weight shouldn't be allowed to make contact with anything / anybody should it needs to be jettisoned / landed somewhere - sandbags that open on cutaways / lead pellets and not chunks of lead... , drogue parachutes on the weight etc have all been used with success and some are part of our MOPS required to be able to obtain permits.



Would like to see how the towing system and banner towing is done on a ML

Cheers
Graham

The trike you saw belongs to Thermal Riders Aerotow syndicate which operates out of Aviators Paradise – a field just to the north west of Harties dam wall. The trike is an AirBorne Edge X 582 coupled with AirBornes Wizard wing and their certified aerotow system. The tow point is just behind the prop centre and attaches to a hollow shaft passing through both the prop and gearbox. A cable release lever is situated just above the brake pedal. The towrope is not usually released and the trike lands with the towrope. If the field is very short or has high obstacles on the approach or if the hangglider pilot stuffs up then the tug pilot will drop the line. The drag of the towline ensures it stays well clear of the prop even without a drag chute that some operators put on their line. The only time you have to be aware of this danger is turning and backtracking after landing. The tug has completed thousands of tows since 2001 and unlike most trikes CKL comes out to play when the thermals are ripping.

This tow system operates equally well for banner towing. The pic shows CKL in the Free State where we towed the Dutch National Hanggliding team in preparation for the Worlds.

Hmm Airbornex2001, landing with towrope. Don't think that is a good idea. What if you snag a bush or something - there goes your gearbox, engine, and back of trike.

You will also see the sailplane tug operators, that have more experience than us, also dropping the line before landing.