Going faster(er) in my trike is quite exhausting

[Splinter]

Install a actuator and you can shift the hangpoint in flight electronicaly and change the bar position aswell .
Shift the wing to the rear , lower stall speed and flight speed , visw virsa to the front.
Contact Clive and Ivan Loubser in Stellenbosch , they imported sume of these actuators a wile back.
No effort is needed to pull in bar , it changes when hangpoint is changed.

Klaas

Please not that this will only work if your wing is in a slow position now! If the wing is set to the fastest position already the actuator will only be able to make you slower! In SA this needs a mod application and loads of paperwork at CAA. GOOD LUCK ON THAT ONE

RED

[Arnulf]

Hi!

.....Or that these wings are only made for real men with really big arms...

Regelmaessig die Mukkibutze besuchen

Gruss aus Namibia,

Arnulf

[nickjaxe]

Thanks Splinter I will look forwards to it.

Nick.

[powerfly]

Drop the washout in 5mm increments, tighten bungees

[neandertaler]

Hi!

I tried the bungee idea last Saturday during 300 Km of my 470 Km trip, as long as the air was calm - I absolutely loved it! I was cruising at about 100 Km/h instead of the 77 Km/h trim speed without any efforts.
The only downside was the high fuel consumption of my 582 of almost 18 l/h
For the next accelerated trip I however need to get stronger bungees, as the two I had were already fully stretched out due to the bar pressure.

Cheers,

Oliver

[kill_devil]

Wargames suggested "Attach a bungee to nose plate of the wing, and then with a pulley type system, pull bungee taught to achieve higher speed, and fasten bungee to boom tube."

No, don't do it, this is outright dangerous, as I will explain later below.

Conrad suggested "Check the weight distribution of your trike" or "Drill another hole and move the hang-point." No! Even worse. Either this suggestion is a joke in bad taste or reveals a total utter lack of aeronautical knowledge.

Neandertaler replies "I tried the bungee idea last Saturday during 300 Km of my 470 Km trip, as long as the air was calm - I absolutely loved it! I was cruising at about 100 Km/h instead of the 77 Km/h trim speed without any efforts."

Whoa! If it had been really thermic or bumpy he might have not lived to tell the tale.

Then he writes "For the next accelerated trip I however need to get stronger bungees, as the two I had were already fully stretched out due to the bar pressure."

Oh No. He's still determined to make a contract with the grim reaper.

Why?

The difference is that, in contrast to the motorised pulley-bungee system on the new P&M Aviation Quik range which effectively starts with the wing trimmed in fast position and then slows it down by pulling the boom down at the back, so increasing angle of attack and increasing drag, the system 'neanderaler' (means primitive man doesn't it?) proposes does the opposite, he starts with a slow wing and the pulls the bar back/nose down to decrease angle of attack and decrease drag and so speed up the trike.

The danger of the second method is that the "gust alleviation" response is amplified, not damped, and forms a positive feedback loop resulting in catastrophic depature from controlled flight if a critical gust is encountered (say every 1 in a 1000).

Read SACAA Accident Report Ref 7476 to see what happened to ZU-AVT on 15 March 2002 killing father and son.

And as for drilling another hole and moving the hang-point, I am speechless. Be sure to go through an engineering approval process before making any modifications. It might just save your life.

And oh, before I forget, flattening the battens and changing the reflex outside the tolerances laid down in the aircraft supplied batten plan and maintenance manual is also inadvisable without the manufacturer's approval.

Come on guys, this is serious shit.

[Conrad]

My apologies on the drilling another hole issue, and yes that was a bit drastic, although I have seen it before, again, I will never say this again or suggest it to anyone else.
But: still ,
check the weight distribution on the trike, it is as important as moving the hang-point. If the hang-point is already adjusted, then be happy and safe with what you have or get another trike.

[neandertaler]

Hi kill_devil,

thanks a bunch for your reply.
Let me first explain my nickname - I used to live in Mettmann / Germany which is located in the "Neandertal" where the early human "Neanderthal" was discovered and after which he was named.

http://en.wikipedia.org/wiki/Neanderthal

I just read the report of the trike accident - are you sure that this is the one to which you you wanted to refer to?

This is what it says about the probable cause:

Due to the fact that the accident occurred at 1200Z in the afternoon it is believed that the aircraft had
encountered a sudden updraft or severe turbulence, which resulted in the partial separation of the Left-Hand
leading edge from it’s excessively worn nose attachment. This rendered the aircraft uncontrollable and
resulted in a collision with the ground.

During my trip I removed the bungee when the first thermals occurred, as it was too weak and for this reason all he time fully extended which would have made it impossible for me to push the bar forward without removing the bungee.

I also don't think that it is a too good of an idea to drill other holes in the hang point, as this will weaken the structure of it and as this modification can't be changed during the flight. This would especially worry me in case if I would encounter turbulent conditions with a modification which hasn't been tested before by a professional test pilot. Nevertheless I know that at least some Air Creation wings are equipped with various holes in the hang point as standard.

Cheers,

Oliver

[kill_devil]

That's the best advice of all, Conrad - "be happy and safe with what you have or get another trike".

Redistributing the weight in the trike does affect the 'hands off' trim distance of the bar from your belly, and therefore indirectly gives you more or less pitch authority, but that effect is somewhat cancelled out by the increased/decreased gravity moment about the centre of lift. The maths is quite complicated but I might have a go at working it out sometime.

I have to say I don't like to modify anything on my GT450 without forcing myself to think it through, do the calculations, draw an engineering schematic, write a proposal, submit it to an aeronautical engineer for independent scrutiny and finally receiving written approval from the appropriate authority - this should be the big noise RAASA in my opinion.

Following this process slows everything down so that you don't end up making rash hurried changes that you you'll regret for the rest of your (short) life.

[kill_devil]

Hi Oliver,

Thanks for explaining the origins of your username - I was sort of pulling your leg. Even I understood very little about flexwing design when I first started flying weightshift controlled microlights.

As you point out, the stated probable cause of ZU-AVT's loss focuses on the resulting structural failure (exacerbated by poor maintenence) and does mention it happened in the middle of the day after encountering a sudden updraft or severe turbulence (i.e. a gust impulse). All trikes suffer partial or total structural failure when they tumble or tuck.

But it doesn't mention that the pilot was using a bungee to pull the bar back to increase hands-off speed. The bungee was allegedly found some days later nearby after the investigators had left, though my information is second hand and probably not admissible in a court of law. I won't reveal who told me this but I can assure you it was by someone who knows what he is talking about.