Quick mental math for the cockpit

My Garmin Pilot III has a vertical nav feature which will display Glide
Rate to Target on final glide. Its more accurate than judging the glide by
the goal position on the canopy. (hard to tell between 2 degrees - in - and
1.5 degrees - land out) If it is improving I speed up.

Jim



At 15:37 28 September 2009, ZZ wrote:
Here is another...the typical human finger is approx. 5 NM wide.

Paul
ZZ


5Z wrote:
One minute of LATITUDE is approximately a nautical mile. Use your
fingers as a crude caliper to measure distances on the chart.

Double the distance and multiply by 100 for 30:1
Triple the distance for 20:1

I'd set my GPS for STATUTE miles then use the above math while flying
the club's ASK-21 for a conservative glide for home.

Use an E6-B to calculate L/D. Some high end aviator watches have one.

Distance in NM vs altitude and the pointer indicates glide ration
needed to make the goal. Update every few miles and if the L/D
remains constant, then you're on glide. If it gets smaller, then you
have it in the bag.

I recall the huge amounts of heads down time in the pre-GPS days while
on a tight final glide or over unfamiliar terrain as I tried to figure
out precisely where I was.

-Tom