"Udo Rumpf" wrote in message
...
Why is it not possible to refine the process that is being used by
Dick Johnson by using the gadgets that are available.
That would refine the data acquisition and would make the
resolution much finer. The work load is very high during the process.
Dick invited me to a test flight from 12000ft and not much useable
data was obtained from my only attempt. It sure takes practice.

One certainly has to chew gum, use a stop watch, make notes of time,
speed and temperature and flap settings, maintain speeds, change
speed and stabilize it.

This every 500ft, At the same time Fly a big circle around the airport,
so you have a place to land when finished. I may have left things out.

What electronic aids could be used that would help in this matter?
Udo


A data logger (could be a PDA) attached to a differential carrier phase GPS
It should also be able to record accurate airspeed indicator and
temperature, or a true-airspeed reading device like the laser anemometer .
The GPS data can then be post-processed to give altitude information down to
10-15 cm or so.
The airspeed data can be be used post-flight to see just how steady-state
the data collection was.
With increased accuracy in the vertical measurement, it might be possible to
get sufficiently accurate data in say, 300 feet of altitude, allowing more
data points on a single flight.

That will make the flight card a little busier, perhaps, but fewer tows
should make the testing cheaper.

With samples every second, or even every tenth of a second, the additional
data should make it possible to improve the repeatability.

The hardware isn't cheap, but it's getting cheaper, and the data reduction
post-flight isn't a trivial problem, either, but it's doable.

Tim Ward