Obsolete: revised on 11/7/04
for archive only
West Coast Challenge
The Longest Flights
On Short Days
Original posting 11/3/04
Updated 11/4/04 Rev A
superseded by
Updated 11/6/04
This is obsolete Rev B, superseded by Rev C
Dated 11/7/04
Our South Coast Flying is some of the best to be had on short days. To
demonstrate, we offer a challenge to all unpowered foot launched aircraft on the West
Coast. The winner will be determined by the formula:
miles times x
- Where
- Miles = Total straight line miles between two points over-flown by an
unpowered aircraft that was foot launched from anywhere in one of the USA states that borders the
pacific ocean (California, Oregon, and Washington)
- x = (cos(d/2)2
- where d is calculated by subtracting 15 from the calendar day of the year
and clamping d so that d is not less than zero or more than 360.
- Rules:
- Aircraft: any unpowered aircraft, but the launch method for the flight
must be unassisted foot launch (no wheeled launches or towing, but you may
use a people to assist without the aid of mechanical devices)
- Entry Fee: None
- Registration or prior declaration: None Required
- Documentation: A reasonably descriptive article must be posted to
the SCPA flight discussion forum under the thread titled Challenge (thread
date:11/3/04). Flight articles must be posted by the end of January,
2005.
- Contest Period: From Jan 1st 2004 through Dec 31st, 2004
- Prizes: To be awarded by The Sundowner at
the February SCPA general membership meeting (attendance not required)
- 1st place flight $100
- 2nd place flight $50
- 3rd place flight $25
- The formula is not as bad as it looks
- Calculate "d" by taking the day of the year (counting up from Jan
1) and
subtracting an offset of 15 (to stretch the middle and account for
seasonal lag). Clamp the calculation so that d is not less that zero
or more than 360.
- Divide "d" by 2 and take the cosine of that number (in degrees)
- Squaring the cosine causes the curve to fall off more aggressively in
the midrange and then curve again the other direction toward an asymptote
rather than a cusp. It also forces the result to be positive
Examples
- a 50 mile flight on Jan 1st
- d computes to 0
- x computes to 1
- 50 times x = 50 points
- a 100 mile flight on May 1st
- d computes to 107
- x computes to 0.3538
- 100 times x = 35 points
- 50 mile flight on Dec 21st
- d computes to 360
- x computes to 0
- 50 miles times x = 50 points
- a 50 mile flight on Feb 15th
- d = 31
- x computes to .9286
- 50 miles times x = 46 points
- a 75 mile flight on April 1st
- d = 77
- x computes to .6125
- 75 miles times x = 46 points
Auto Calculator Pending
Formula Adjustment Notes: We may need to increase the exponent in
future years if late spring and early fall flight scores are better than those
in the middle of the year. We can also tune the offset if deemed
necessary. We'll see what happens for 2004 and likely run again in 2005.