Gullfaxi
Topic Author
Posts: 37
Joined: Sat Apr 27, 2002 7:18 am

Best Way To Find Out Your Groundspeed?

Thu May 30, 2002 10:00 pm

What is the safest and fastest way to find your ground speed ?
How can I easily find out which way the wind is blowing ??
 
saintsman
Posts: 2037
Joined: Fri Mar 15, 2002 12:34 am

RE: Best Way To Find Out Your Groundspeed?

Thu May 30, 2002 10:17 pm

Make the most of technology. A hand held GPS doesn't cost much these days and will give you most of the information you need.
 
L-188
Posts: 29874
Joined: Wed Jul 07, 1999 11:27 am

RE: Best Way To Find Out Your Groundspeed?

Thu May 30, 2002 10:21 pm

Without spending a lot of cash?

Try routing directly over a highway.

Then slow it down to pace the cars that are on it. Figure 70 mph for freeways.


Ok, you probably don't want to do this in a Citationjet but in a Supercub it workes just fine. Actually you have to speed up.
OBAMA-WORST PRESIDENT EVER....Even SKOORB would be better.
 
FredT
Posts: 2166
Joined: Thu Feb 07, 2002 9:51 pm

RE: Best Way To Find Out Your Groundspeed?

Thu May 30, 2002 11:37 pm

By using a GPS or an INS as suggested, or by taking your TAS and heading, adding the known wind and calculating the length of the resulting velocity vector.

How to find out which way the wind is blowing? By using a hight-tech gadget called a 'windsock'. Big grin

If you're up in the air, check your drift.

In the good old days they had an instrument specifically intended to check the drift angle. Checking the drift angle on two different headings would enable you to calculate the wind speed and direction.

Cheers,
Fred
I thought I was doing good trying to avoid those airport hotels... and look at me now.
 
PPGMD
Posts: 2398
Joined: Sun Sep 30, 2001 5:39 am

RE: Best Way To Find Out Your Groundspeed?

Fri May 31, 2002 1:17 am

SuperCub speeding up, how true. I was once going to fly the cub inland a little until I called for briefing, 15kts direct headwind, that would cut down my cruise speed by 25%, oh well faster to drive, but then again with Orlando Traffic, maybe that 45kt cruise ain't that bad.
At worst, you screw up and die.
 
bio15
Posts: 1048
Joined: Fri Mar 23, 2001 8:10 am

RE: Best Way To Find Out Your Groundspeed?

Fri May 31, 2002 3:24 am

1)FredT's method is a good one, not so easy as the GPS. You can calculate your drift also using a VOR. If you're heading straight to it, you take a reference distance point, and then let yourself drift for a while and then take another reference point. You will be able to calculate the ground distance flown by the change in radial from the VOR and your change in distance to the VOR (which is not always the same as the ground distance flown). You calculate the resulting vector by knowing it is the addition of your vector with respect to the air (airspeed and heading) plus the vector of the wind (speed and heading as well), and it will be headed in the direction of your drift. Therefore if you have your heading and airspeed, you can find out the windspeed.

2)Or, stick to the GPS.

-bio
 
wilcharl
Posts: 1151
Joined: Sun Jun 25, 2000 11:19 am

RE: Best Way To Find Out Your Groundspeed?

Fri May 31, 2002 7:01 am

go the handheld route... alota fun in say a cessna 150 to look and see how slow your groundspeed is when your going upwind
 
XFSUgimpLB41X
Posts: 3960
Joined: Fri Aug 25, 2000 1:18 am

RE: Best Way To Find Out Your Groundspeed?

Fri May 31, 2002 1:18 pm

Then theres the cheapest way to find your groundspeed... all you need is a watch and a map and an E6-B.


Clock yourself between two points on the map.... figure out how far it was, and plot that time/distance on the E6-B. Wherever the big black triangle is pointing at is your groundspeed.

Did that make sense?
Chicks dig winglets.
 
jkarry
Posts: 43
Joined: Fri Nov 02, 2001 11:22 pm

RE: Best Way To Find Out Your Groundspeed?

Fri May 31, 2002 2:03 pm

just ask ATC what your groundspeed is.
 
SkyGuy11
Posts: 532
Joined: Fri Oct 26, 2001 7:09 am

RE: Best Way To Find Out Your Groundspeed?

Fri May 31, 2002 3:29 pm

Or see how far you went in a minute and multiply that by 60. This will work better in faster planes, however, because it's kind of hard to distinguish between 1.4nm and 1.6nm.

But if you see how far you go in 6 minutes and multiply it by 10 then you will get a more accurate answer. I prefer to time myself between two predetermined checkpoints, and divide the distance by the time.
.
 
Gullfaxi
Topic Author
Posts: 37
Joined: Sat Apr 27, 2002 7:18 am

RE: Best Way To Find Out Your Groundspeed?

Fri May 31, 2002 9:52 pm

That was just what I was looking for !!
 
KALB
Posts: 564
Joined: Sat Mar 11, 2000 12:33 pm

RE: Best Way To Find Out Your Groundspeed?

Fri May 31, 2002 11:38 pm

If your aircraft is equipped with DME and you are flying inbound/outbound on a VOR-DME radial, it will give you the groundspeed. However, its not accurate when close to the VOR.
 
dragogoalie
Posts: 1172
Joined: Sun Oct 14, 2001 3:58 pm

RE: Best Way To Find Out Your Groundspeed?

Sat Jun 01, 2002 9:32 pm

"Then theres the cheapest way to find your groundspeed... all you need is a watch and a map and an E6-B.


Clock yourself between two points on the map.... figure out how far it was, and plot that time/distance on the E6-B. Wherever the big black triangle is pointing at is your groundspeed.

Did that make sense? "


Thats the way I learned....

--dragogoalie-#88--
Formerly known as Jap. Srsly. AUSTRALIA: 2 days!
 
TurbineBeaver
Posts: 1511
Joined: Fri Jan 11, 2002 1:50 am

RE: Best Way To Find Out Your Groundspeed?

Sat Jun 01, 2002 10:40 pm

The first thing I learned when flying a cross country: calculate groundspeed after every checkpoint. Yeah, we've got the fancy GPSs, but there are easy ways. Find two points on your sectional, measure the distance between, and fly from them, timing it. Then, just plus it into your flight computer or whiz wheel, the distance and the time, and you get your groundspeed. Then, by referencing this to your airspeed, you can get a good sense of the wind.

TB
 
bio15
Posts: 1048
Joined: Fri Mar 23, 2001 8:10 am

RE: Best Way To Find Out Your Groundspeed?

Sun Jun 02, 2002 2:22 am

>>>Then, just plus it into your flight computer or whiz wheel, the distance and the time, and you get your groundspeed

I believe all pilots should be able to NOT use a computer on this one!!!
v*t=d
you know the distance, you know the time, so guess what! The velocity is your distance divided by the time it took you to fly it.
That, you plus it into your brain and give your maths some exercise.

It's just a shame seeing there's nothing to do about the issue of computers dominating aviation, and pilots getting dumber.

-bio
 
ThirtyEcho
Posts: 1409
Joined: Tue Jan 01, 2002 1:21 am

RE: Best Way To Find Out Your Groundspeed?

Sun Jun 02, 2002 8:20 am

The fastest way to find out groundspeed? Absent a good GPS or DME readout, you can always try "XYZ Center, can you give us a groundspeed?"
 
saxman66
Posts: 459
Joined: Sun Sep 03, 2000 7:05 pm

RE: Best Way To Find Out Your Groundspeed?

Sun Jun 02, 2002 10:15 am

As for wind ask FSS for the winds aloft. Then interpolate that for your altitude. Also the general direction that the wind is at the airport will be about the same in the air. As for WCA (wind correction angle) i use about 5 degrees of correction for every 10 knots of direct crosswind. You just kinda have to mess with it.
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