flying in low visibility

MET Eish ja!
User avatar
p3tr
Signed up at flight school
Posts: 27
Joined: Thu May 07, 2009 5:31 pm

flying in low visibility

Postby p3tr » Sat Jul 06, 2013 7:34 am

Hello.

as in the title:
some technical bits (correct me if i am wrong please)
- a weight-shift aircraft's attitude (apart from the immediate short-term effect of turbulence) is uniquely defined by bar position and throttle setting
- the axial rotation can be quantified from the rate of turn, and measured on the compass.
- a weight-shift aircraft only has these 2 variables, as yaw is stabilised by the wing, therefore this summarises the aircraft's position in flight completely.

so some philosophical bits:
it would therefore follow that one could theoretically keep a weight-shift craft airborne without external reference. (this is not LANDING in IMC, but traveling through it)
one would say the problem is that nobody is used to doing that, so would not manage correctly in the moment. but nobody practices this.
it feels as if we are allowing ourselves to be stuck within a limiting feedback loop, of not having experience of something, and therefore not doing it, thereby not building experience.

so the question would be
i doubt anyone would mind putting some extra training hours down to do this, but i am not aware of any such option. why is that?
is there any technical issue i am missing?
ZU-DFM
User avatar
tka
Ready for the first flight
Posts: 46
Joined: Fri Jul 27, 2012 9:33 pm
Location: Ballito microlight field and King Shaka / Durban

Re: flying in low visibility

Postby tka » Sat Jul 06, 2013 12:33 pm

p3tr wrote: is there any technical issue i am missing?
Hi,
The short answer is that if you fly in IMC without the necessary equipment and training you will die.
Sorry to be so blunt but that is the fact of the matter. Ever heard of the grave yard spiral? It has that name for good reason.

As to the technical reasons why not, you should have been taught them when you did your licence.
And it is illegal.
Please dont even think about it.

Regards,
Trevor

ps I dont fly microlights but have been flying IFR all my career and have given myself a few frights despite having the equipment, experience and training and training and training..............
User avatar
John.com
Frequent Flyer
Frequent Flyer
Posts: 1278
Joined: Tue Nov 08, 2011 8:31 pm
Location: Broederstroom (Magaliesberg) - home airstrip Aeroden

Re: flying in low visibility

Postby John.com » Sat Jul 06, 2013 3:26 pm

p3tr wrote: . . . it would therefore follow that one could theoretically keep a weight-shift craft airborne without external reference.
NO, NO, NO!!! ## ## ##


This video might point you in the right direction!

178 Seconds to live - Spatial Disorientation
John Comley
ZU-BST (the Beautiful Seductive Temptress)
Magaliesberg, South Africa
Read my flying blog here . . . http://johncomley.blogspot.com/

"Truly superior pilots are those who use their superior judgment to avoid those situations where they might have to use their superior skills"
User avatar
p3tr
Signed up at flight school
Posts: 27
Joined: Thu May 07, 2009 5:31 pm

Re: flying in low visibility

Postby p3tr » Sat Jul 06, 2013 8:24 pm

:) thanks, i know you are meaning well.

John, i know i should leave this now, but the point is the compass did indicate a turn. it was a choice not to respond to it. the video was also done with a 3-axis aircraft, where axial orientation is independent from angular rotation. there is no way one could have a weight-shift aircraft sideways without turning.
Trevor you mentioned training. my point is maybe that there is none available for weight shift aircraft,
even though it should be possible to deal with this correctly from the available instruments.

it's not something on my to-do list, but it just feels as if everyone would be safer if we were trained to deal with this correctly?
i know convections could also be severe inside some clouds, so navigation alone may not be enough not to end up in a dacron-tangle.
ZU-DFM
justin.schoeman
Frequent Flyer
Frequent Flyer
Posts: 1231
Joined: Tue Aug 30, 2005 5:25 pm
Location: Pretoria

Re: flying in low visibility

Postby justin.schoeman » Sat Jul 06, 2013 10:41 pm

p3tr wrote:it's not something on my to-do list, but it just feels as if everyone would be safer if we were trained to deal with this correctly?
You have been trained to deal with it correctly. And that training is: Stay out of IMC!

There are two aspects to flying in IMC:

1) Keep the shiny side up. As you have pointed out, this should be quite easy. Keep the bar in the same position, and keep the compass pointing in the same direction. But it is a lot harder than it sounds. Do it in a simulator, and you will think it is easy. Do it in real life, and it is HARD. The hardest thing about instrument flying is to ignore your feelings. You will feel you are turning, even though the compass is standing still. Your inner ear will tell you you are turning. You will know you are turning. But the compass will stand still. Learning to trust that compass when everything else is telling you that you are turning is HARD.

2) Avoid flying into things. By far the biggest chunk of IFR training is procedures. Since you can't see other aircraft (or the ground, for that matter), everybody has to be precisely obeying procedures to be sure to avoid flying into other people. Navigation is also a lot trickier (although a good GPS with terrain and obstacle maps does make this a little simpler).

A few years ago I was reading a story about some gents flying around the world on their trikes. It was quite a while ago, so I may have the details wrong. They were both experienced trike pilots, and were both 'competent' IMC pilots - and they flew IMC during the trip, when required. Until one day only one trike made it out of IMC...
User avatar
Tumbleweed
Toooooo Thousand
Toooooo Thousand
Posts: 2348
Joined: Wed Nov 16, 2005 7:14 pm
Location: FASC

Re: flying in low visibility

Postby Tumbleweed » Sun Jul 07, 2013 2:38 pm

Besides the condensation which could delvelop on your goggles/ visor. One thing-you'll become a lot more spiritual.
Sling ZU FYE - For Your Entertainment
User avatar
p3tr
Signed up at flight school
Posts: 27
Joined: Thu May 07, 2009 5:31 pm

Re: flying in low visibility

Postby p3tr » Sun Jul 07, 2013 4:30 pm

thank you, that is interesting stuff. i would read up about them. i imagine specially at the elevations most trikes spend most their time not flying into things becomes a critical issue, even without any other aircraft around.
ZU-DFM
User avatar
Luan
First solo
Posts: 82
Joined: Mon Aug 27, 2012 11:47 am

Re: flying in low visibility

Postby Luan » Fri Jun 27, 2014 4:13 am

I was reading up on some of the limitations that delta-wing aircraft had, and found this paper by Dr. Guy Gratton, MSETP written for the BMAA. You can read the paper at http://www.hgfa.asn.au/resources/Gratto ... stance.pdf . The short and sweet of the paper is this, all/most trikes have a unrecoverable tumble mode that can be entered into in a number of ways. One of which is Spiral Instability, the paper has this to say: "Weightshift microlight aircraft are normally approved only for flight in Visual Meteorological Conditions (VMC). This implies a guaranteed visual horizon which the pilot may use as a reference when correcting small rolling departures. However, it is possible through ill-luck or poor judgement for an aircraft to enter conditions where a defined horizon cannot be guaranteed (most commonly by entering cloud). If this happens, any pilot should attempt to remove the aircraft from this condition as quickly as possible; however, if the pilot is unable to extract themselves from this situation it is almost inevitable that some cause (most likely the turbulence commonly found inside or near to most clouds) will initiate an undemanded rolling manoeuvre. Unlike most conventional fixed wing aeroplanes, many weightshift microlight aircraft are spirally unstable (particularly at higher power settings); thus, an initial small bank angle is likely to increase without (unless a horizon reference is available) the pilot’s knowledge or ability to control it. The aircraft would then enter a divergent rolling manoeuvre, potentially through 90° of bank to a condition where the pendulum stability which keeps the trike below the wing will cease to act, and the wing angle of attack will reverse sense – inevitably causing some loss of control. Some tumble accidents, for example that to G-MVEP [1] have occurred in conditions where the horizon was known to be poor, and where the subsequent damage to the aircraft showed that the basebar had fractured (in contact with the front strut) at the end. "
User avatar
Alkemac
Top Gun
Top Gun
Posts: 587
Joined: Thu Jun 18, 2009 11:05 am

Re: flying in low visibility

Postby Alkemac » Fri Jun 27, 2014 6:35 am

ZU-DODO
pit bull
Almost a pilot
Almost a pilot
Posts: 162
Joined: Mon Dec 24, 2012 11:17 pm
Location: Rwanda- Work, Grassland sports facility home base

Re: flying in low visibility

Postby pit bull » Fri Jun 27, 2014 7:55 pm

vhpy ek glo nie DIT KAN M E E R DUIDELIKER ge stel word nie. ## ## ## ##

veilig vlieg.

pit bull
Blessed By THE BEST.
User avatar
Wargames
Frequent Flyer
Frequent Flyer
Posts: 1353
Joined: Sat Jan 12, 2008 2:00 pm
Location: Morningstar, Cape Town

Re: flying in low visibility

Postby Wargames » Wed Jul 23, 2014 10:11 am

p3tr wrote: - the axial rotation can be quantified from the rate of turn, and measured on the compass.
If you knew how a compass works, you would know that it cannot be trusted in a turn as it has a lot of errors. Mine for instance is turning while taking off, and if I turn steep enough, I will stand still at certain points because it has weights inside to balance the compass for the earths magnetic flux lines.

Hope that clears it up.

Regards,
The Naked Trike
ZU-AVL
"I hate CIRCLIPS!!"
User avatar
Horse
Heard about flying
Posts: 4
Joined: Thu Aug 28, 2014 10:22 am

Re: flying in low visibility

Postby Horse » Tue Sep 16, 2014 9:10 am

Lesson understood! :shock: Sounds like a terribly terribly k@k idea.

I Flew to Beira about a year ago with SA Airlink. On the approach we went IMC for probably 2 minutes and emerged what seemed less than 330ft AGL and touched down seconds later.

I fly probably 50 to 100 hours a year for the past many years,in Sardine class so it shouldn't be a new experience in a white out but! I can confidently say, from the bottom of my heart and with tears in my baby blue eyes, even though the pilot probably has 10 000 plus hours, together with the appropriate training.
I HATED every second of it and will never get used to it!!!! (**)
Fly a trike for the same reason a dog puts its head out the window

Who is online

Users browsing this forum: No registered users and 1 guest