'Dear Customer,

Your parcel has arrived at the post office at December 26.Our courier was unable to deliver the parcel to you.;

Your order from Connect Distribution Services is out for delivery today by your DPD driver and is due to be delivered between 09:29-10:29. Can you please ensure that someone will be available to sign for the parcel at:

I got these emails, the one in blue is a scam, the red one is legitimate.
How do you  tell? I cant: don't follow links on emails, look up the address and log on, scams often have good copies of ligit web sites and will steal your log on details

Also watch out for these two scammers, I wasted a fiver last year, they made a very poor job of clearing my drive of snow

Last year there was a query over the launch height of my electric thermal model, it was suspected of launching too high

I tried to check the launch height and had to give up, it was supposed to launch to 150 metres, but using any barometric device to measure height is like using an elastic rule.

Above sea level is used but where is sea level? Also it will not be in the same place after the polar ice caps have melted and the oceans expand as they warm, we also get a bulge on the equator due the earth spinning 

The barometric system for measuring height is very inaccurate, errors can be 1000 feet at high altitudes when it is very cold

The lowest pressure recorded at sea level is 26.7 HG and highest 32 hg

Any barometric altimeter needs to be corrected for temperature, local air pressure and ground height. There is also an atmospheric tide as the moon pulls and centrifugal force from the spin of the earth

As we get higher the air gets thinner and colder.

there is no fixed relationship between pressure and height, you can not calculate height from barometric pressure. Below is a graph for the standard model and  the formula used to approximate it

I took my wall Barometer for a ride,  the change in elevation is 155metres from Sainsbury's roundabout to Selsley car park, this moved the mercury 0.5 inches at 10C

My Ram3 altimeter agreed with this, see below, the two spikes are caused by me blowing on the device to mark the 45 and 200 metre points.

I will do these tests again in hot and cold weather 

You would think that we would be better off with GPS; my sat nav seems accurate with horizontal resolution to a couple of feet, (crap at picking the best route) but are subject to the errors in the chart below.
Errors in height calculation can be reduced with second ground receiving station

GPS Z axis has three times the errors of X & Y, it important that pilots all use altimeters so they will have the same errors for height separation

What all this means for esoaring I don't know, I think I will just trust the limiter to switch my motor off at the right height
If the limiters match the F1A specs they will all launch to same height

My view is the same as Elton John's "And all the science I don't understand" If you want to know read Paul's piece at

http://www.esoaring.net/forum/viewtopic.php?f=3&t=2384&hilit=&sid=540de059fc4f5ded4f54dac749faec4a 

South Cotswold Soaring Association

20th January 2013

Paper airplane contest
16th January 8.00PM
BGGC Nympsfield

Re-run of Boxing Day Open Class glider pylon race on a local slope new  date
Contact Pete Wolf on the day from 8.00 AM to find which slope is in use.

Non members welcome
10.00AM start 
Phone Pete Wolf on the day from 8.00AM 
07761 199123

Fees 2013

SCSA Senior member:-    
 £40.00 (Include BMFA membership and insurance costing £32.00)

SCSA Associate member:-  £8.00 (member needs to show proof of BMFA membership, either as an individual or as a member of another BMFA affiliated club)

SCSA Junior member:-        £17:00

Don't forget that your 3rd party insurance expires on 31st December 2012

Membership form

Download 2013 membership application form. no fee increase

new car park 

1st Prize Mike Bradbury Yak 54 ARTF
2nd Prize Mark Riley Yak 54 EP
3rd Prize Paul Williams Super 60 Kit
donated by Colin Buckle.

Indoor flying every Saturday until March 2013.
6.00pm - 8.00pm. Bentham Country Club

Cost as of 1st December 2012 £6.00 per session for seniors.
£1.00 for juniors.

Non GMFC members very welcome BMFA insurance or similar required.

Photos from Saturday

The Field is still damp at Fish meadow

Print a membership form.

Tony had a flight of 3:33 mins with the same model

Sunday

Haresfield, the fog cleared in the afternoon

Main slope at Haresfield was good this afternoon, nice even lift, we just had to fly around all the paragliders who took the slope line astern & we had to wait for a gap before making our approach ! Joined by Stuart & as I was leaving Tony turned up with a vast flying wing .

Such fun . 

Tim