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GPS in Flight

Posted: Wed Sep 19, 2018 9:45 am
by Jim Hardin
Talking about GPS in another topic got me curious. This discussion in not limited to instructors, I would like to see all of you contribute your thoughts.

My question is Do you fly a Course with the GPS or just Bird Dog it like was common with the ADF? Bird Dogging was to keep the airplane pointed at the ADF even as the wind blew you off course.

I guess that depends somewhat on your GPS. Mine (iFlyGPS) offers an HSI which gives you an added instrument like an HSI.

This is from my phone while sitting at my computer but you can see the 'airplane' as well as the HSI:
HSI.jpg
HSI.jpg (148.36 KiB) Viewed 15824 times
I did have one customer who would have flown us through that Restricted airspace if I had let him continue to Bird Dog.

Re: GPS in Flight

Posted: Wed Sep 19, 2018 9:56 am
by 3Dreaming
My thoughts, are if you are going to use a GPS, then put the airplane on the magenta line and follow it. Just like you would a line on a sectional.

My 15 year old son has more time flying cross country without a GPS than with one. He can draw a line on a sectional chart and follow it just about as close as someone can follow a line on a GPS.

Re: GPS in Flight

Posted: Wed Sep 19, 2018 12:50 pm
by TimTaylor
With GPS, I don't know why you wouldn't plot a course and follow it. That helps keep you from wandering into some place you don't belong. I use iFly GPS also. IMHO, it's the best app available for aircraft navigation

Re: GPS in Flight

Posted: Wed Sep 19, 2018 5:35 pm
by FastEddieB
TimTaylor wrote:With GPS, I don't know why you wouldn't plot a course and follow it.
Agreed.

Homing is inefficient, leading to a curved - parabolic? - path to the station/waypoint if there is any cross wind at all.

I use the “faux HSI” display on my 496 to stay on course, backed up with my iPhone running WingXPro7.

Re: GPS in Flight

Posted: Wed Sep 19, 2018 5:41 pm
by TimTaylor
FastEddieB wrote:
TimTaylor wrote:With GPS, I don't know why you wouldn't plot a course and follow it.
Agreed.

Homing is inefficient, leading to a curved - parabolic? - path to the station/waypoint if there is any cross wind at all.

I use the “faux HSI” display on my 496 to stay on course, backed up with my iPhone running WingXPro7.
I do homing in my car sometimes. Driving on the interstate, if I come upon a huge traffic jam, I take the first exit and go from there. I would rather drive out of my way on back roads than sit in a traffic jam.

Re: GPS in Flight

Posted: Wed Sep 19, 2018 8:44 pm
by Scooper
If I'm flying to a destination instead of just boring holes in the sky, I program my Aera660 with a flight plan, and include waypoints to avoid restricted airspace and active MOAs, then just follow the yellow brick road, er.. magenta line.

Re: GPS in Flight

Posted: Thu Sep 20, 2018 7:44 am
by ShawnM
Scooper wrote:If I'm flying to a destination instead of just boring holes in the sky, I program my Aera660 with a flight plan, and include waypoints to avoid restricted airspace and active MOAs, then just follow the yellow brick road, er.. magenta line.
I do exactly the same thing as Stan, if I'm flying to a destination I tell my Aera 660 where I want to go, how to get there if not direct and the autopilot flies the plane there for me. I dont even have to try to follow the magenta line, Ginger (my plane) does it perfectly all by herself. If I tried it myself I'd probably screw it up and wind up off course somewhere in the wrong state. Or worse, inside an active MOA. :mrgreen:

If I didn't have autopilot I'd also just follow the magenta brick road. :P

Re: GPS in Flight

Posted: Sun Sep 23, 2018 11:11 am
by Jim Hardin
Thanks gang!

But we are mostly old school... I wonder how low time pilots view this?

Re: GPS in Flight

Posted: Sun Sep 23, 2018 11:53 am
by TimTaylor
I don't know why it matters, but I doubt many pilots, old or young, would use GPS homing as a technique for navigating to a specific destination. Now, if they are out boring holes in the sky with no specific destination, they would probably use GPS to depict their current location.

Re: GPS in Flight

Posted: Sun Sep 23, 2018 4:54 pm
by 3Dreaming
I have seen pilots when they get blown off course hit the direct to button and hit enter, instead of turning to get back on course. Essentially they were homing instead of flying a course. Kind of like turning the OBS selector to center the needle when you get blown off course.

Re: GPS in Flight

Posted: Sun Sep 23, 2018 5:28 pm
by HAPPYDAN
As I recall, one of my last flights was extended cross country training. A 3 leg triangular course, somewhere around 2 hours and 150 nautical miles. The first two legs were pilotage and ded reckoning. Find the waypoint, update the nav log, correct the course. Leg 3 was using the Garmin G-300. Enter Direct To, use the HSI, keep the arrow at 12 o'clock. I learned that, by following the prescribed heading in a cross wind, lateral drift would cause that "parabolic" course. So, minor heading corrections have to be made as the Course Deviation Indicator (the Broken Arrow) drifts left or right. Get the nose pointed in just the right direction, and it stays right there. Overall, a very good lesson.

Re: GPS in Flight

Posted: Fri Sep 28, 2018 8:54 am
by foresterpoole
With GPS it's simple, you can even set it up on a computer before hand and then load it into a tablet. Just follow the thin pink line! The tricky part is when you live near a military installation that will conduct "GPS Interference Testing" on a regular interval. I live near Fort Polk, and within the last two years this has happened more and more frequently, during daylight hours and in large areas (24-75 NM radii around the base). So on more than one occasion the G430 and the tablet become heavy weights, not usable or spotty for navigation. In that case you need to know how to use a sectional and navigate via heading with adjustments for drift. If your like me, I like to use a combination of techniques in those situations: pick a known landmark on a relatively correct heading and keep the aircraft heading towards it (lake, city, water tower), then pick another and so on until the destination comes into sight, good luck doing that in Arizona or Texas though. The other option which I have tried and like even more is the IFR technique, I fly roads, works well in my area and you can tell if your drifting. Technology is great, when it works, if not your going to have to improvise, adapt and overcome. on the fly, literally.

Re: GPS in Flight

Posted: Fri Sep 28, 2018 9:32 am
by rsteele
foresterpoole wrote:With GPS it's simple, you can even set it up on a computer before hand and then load it into a tablet. Just follow the thin pink line! The tricky part is when you live near a military installation that will conduct "GPS Interference Testing" on a regular interval. I live near Fort Polk, and within the last two years this has happened more and more frequently, during daylight hours and in large areas (24-75 NM radii around the base). So on more than one occasion the G430 and the tablet become heavy weights, not usable or spotty for navigation. In that case you need to know how to use a sectional and navigate via heading with adjustments for drift. If your like me, I like to use a combination of techniques in those situations: pick a known landmark on a relatively correct heading and keep the aircraft heading towards it (lake, city, water tower), then pick another and so on until the destination comes into sight, good luck doing that in Arizona or Texas though. The other option which I have tried and like even more is the IFR technique, I fly roads, works well in my area and you can tell if your drifting. Technology is great, when it works, if not your going to have to improvise, adapt and overcome. on the fly, literally.
I've heard about these tests but I've never seen a pirep from anyone effected by them. Interesting, thanks.

Re: GPS in Flight

Posted: Fri Sep 28, 2018 12:48 pm
by Scooper
rsteele wrote:I've heard about these tests but I've never seen a pirep from anyone effected by them. Interesting, thanks.
In California, we often get notification of GPS testing around Barstow, and Thanksgiving week last year I drove to Albuquerque to spend the holiday with family. My route took me through Barstow, and my Garmin Nuvi GPS in the car went bonkers in both directions (S.F. to Albuquerque and return) for about an hour driving through Barstow. I had planned to fly, but the weather forecast nixed that idea. If I had been flying, I probably would have used VORs during that part of the flight when GPS was unreliable.

Re: GPS in Flight

Posted: Fri Sep 28, 2018 1:16 pm
by TimTaylor
Any licensed pilot should be able to navigate using pilotage and/or dead reckoning in VFR weather conditions. Loss of GPS reception should be an inconvenience at most. You don't need a sectional if you have a device that displays the sectional in graphic form. If you doubt your abilities to do this, turn off you gps next time you fly and look out the window. Of course, without the display, you will need a paper chart.