Kollsman confusion

[atceng]

Another lesson and set the alti incorrectly again. Right enough the Rotax was shaking it a bit or perhaps the window was steaming up but the FI had no problem so it's getting embarrassing,not to say dangerous.
I do suspect he's pretty good at mental arithmetic and can calculate in a flash what the big hands should say,as I go from NH to FE,but maybe not.
Anyone got a u/s altimeter with a working Kollsman to sell me/hire me so I can practice setting it attached to my orbital sander at increasing revs till I can do it with one eye? ( Yes, I've tried ebay.)

Myoptically,atceng

[rans6andrew]

you don't need to be good at mental arithmetic, you increase the altidude reading by the height of where you took off from, it is marked on the chart. When you get where you are going you reduce the altitude reading by the height of the destination airfield, again conveniently marked on the chart.

When you get UP there wind it UP by the height on the chart. When you want to come DOWN, wind it DOWN by the height on the chart. Works for me.

[atceng]

Thank you rans6andrew,I will give this a go. At the worst I will have to do my 30x table for the few mb regional differences thrown at me by fisbangwallop and co.:confused:
I take the point that I should be cross checking the result of twiddling the wee numbers on the big hands,so I will just set them instead as you suggest.!
The Yankee outfit that make the 'one wink' magnifiers for just a few hundred dollars just lost a potential customer'

less confused,atceng.

[scooter boy]

??????How is mental arithmetic involved in setting QNH/QFE????????????
SB

[atceng]

Well sb, some of us are 'late starters' and find difficulty reading the tiddly little numbers,so we start off to do circuits on QFE and set the big hands to zero.
The circuits kinda busy so we decide to go and do some exercises,PFLs etc.so we add our present height to the field height and set that for QNH.
Contacting thingy information,he doesn't like our QNH and gives a new one,probably a few mb different ,so you multiply the mb difference by 30 and add or subtract to the big hand reading.When we get back to the field the QFE has changed 'cos its Britain and the weather changes occasionally.So a bit more arithmetic is called for.
Anyway thats the theory and I'm going to try it tomorrow,sounds quite easy but simultaneous with rudder,elevators,ailerons,carb heat,prop pitch,ATC calls,Hassell,hastle, etc. I might not manage it and another bawling out expected.

optimistc,atceng.

[atceng]

update for rans6andrew,

Flew the Robin HR200,fairly smooth Lycoming if I avoided the red rpm sector and had no difficulty setting pressure,and fisbangwallop didn't correct my QNH. So minimum arithmetic.
However your wheezes helped cross check the settings and I'll continue to do that.

Maybe the first sign of a rough Rotax is difficulty setting the alt.:)

atceng

[Bahn-Jeaux]

Well sb, some of us are 'late starters' and find difficulty reading the tiddly little numbers

I was a late starter too and had difficulty reading the fiddly little numbers.
I found prescription bifocals did the job perfectly.

[SNS3Guppy]

Well sb, some of us are 'late starters' and find difficulty reading the tiddly little numbers,so we start off to do circuits on QFE and set the big hands to zero.
The circuits kinda busy so we decide to go and do some exercises,PFLs etc.so we add our present height to the field height and set that for QNH.


There's your problem. You're starting with a bad habit and then trying to develop a fix once underway.

Start by using your altimeter correctly, with a proper altimeter setting, or set to field elevation, before you go fly.

[GOLF_BRAVO_ZULU]

SNS3Guppy is right. Do the admin stuff on the ground where you (theoretically!) have all the time in the world.

One of the "joys" of very light aeroplanes is being bounced around by rough air. I remember re-learning that preparation on the ground point, a couple of years ago. QNH set and setting the QFE (winding off the A/D elevation) for the re-join and, part way through turning the knob, a quite lively thermal propelled me skywards and tried to roll me over. Had I remembered the QNH? No! Had I written it down? No! Anyway, from that day forth, I deliberately zero the needles and write down the QFE then wind on the A/D elevation and write down the QNH; all safely on the deck, not attempting to multi task.

[Mark1234]

Slightly intrigued (expat brit, who will be returning home in the not-too-distant) Do you really have to mess about with QFE? These parts we just set QNH the whole time and remember to add airfield elevation to the numbers for circ's and the like. Seems a whole lot simpler...

[GOLF_BRAVO_ZULU]

If it's any consolation, use of QFE isn't compulsory. Some of us are rather fond of it, though.

[Pace]

AtcEng

some of us are 'late starters' and find difficulty reading the tiddly little numbers

I think you need to invest in a good set of glasses :)

Pace

[atceng]

Pace
You do me an injustice.
I got a new eyetest and the best glass varifocals I could (suprisingly difficult, Specsavers couldn't supply and I had to go to an independent supplier who did Zeiss).
But even with them I'm just on the limit for the PPL med exam eyesight test.
The sunbeds in the Katana dont make for peering closely at the insts. I find the Robin armchairs better and I can lean forward.
So its probably a choice between the nippy Katana and the old Volvo Robin as a solution.
But applying the various tips and subterfuges kindly supplied on this thread I think I can manage either.

atceng