Fwd: Tesa Tape

[j...@oxaero.com]

Begin forwarded message:

From: "j...@oxaero.com" <j...@oxaero.com>
Date: November 25, 2011 5:55:36 PM EST
To: Tony Lintott <derby...@yahoo.co.uk>
Subject: Re: Tesa Tape

Tony,

I saved the IGC file on my computer, but did not check it out before traveling for the Thanksgiving holidays.  Will look it over Tuesday.

I believe that you only dropped some of the speed runs that you thought were bad, as you said in your prior message.  You can judge quality best by the straightness of the points.  This is calculated as the average deviation of the points from the line fit expressed as a % of the altitude loss.  One or two % is a great quality indication.  Values up to say five % are useable.  You can see this visually in Cambridge Aero Explorer when you zoom in in a speed run.

The other problem is that you might fly a knot or do off the correct speed.  But that is not likely.  More likely, you will drift off the speed and correct it.  That will show up as a curvy data sequence and a larger % value.  

Your flying was very good for your first flight, even at the high speeds where I have trouble.  So, the only problem you should have is picking good weather conditions.  Look for a low inversion level and low winds or practically no shear.

If the sink rate variations from a 2nd degree polynomial fit to the sink rate polar are no more than 20 fpm, you are doing as well as Johnson did.  30 fpm is ok but may require more than three flights to average out the scatter.

Jim

On Nov 25, 2011, at 5:11 PM, Tony Lintott <derby...@yahoo.co.uk> wrote:

Hi Jim, The second delivery has arrived safely. Thank-you. Have you been able to assess the .igc file I sent, for acceptability of data logging? Rgds, Tony

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From: j...@oxaero.com <j...@oxaero.com>;
To: Tony Lintott <derby...@yahoo.co.uk>;
Subject: Re: Tesa Tape
Sent: Sat, Nov 19, 2011 1:09:59 AM

Tony, I'll try very hard not to send a third order. Jim On Nov 18, 2011, at 4:42 PM, Tony Lintott <derby...@yahoo.co.uk> wrote: Hi Jim, I've paid for the tape by credit card, via your link.  This is the acknowledgement I've received.  Hope I now don't get a third delivery.  Rgds, TonyL Oxford Aero Equipment Thank you. Your order has been successfully processed.  Order number : 4251555 Your payment has been approved. Please contact us if you have any questions Return to: Return to OxAero