Fri Jun 26, 2009 10:37 pm
#759822
If a very near miss of airspace counts:
1. Were you a student or qualified?
Qualified (glider XC qualified - this was in a glider, but I think that makes no difference)
2. Were you current or rusty?
Current
3. Was it in your own/group aircraft or rented/school?
Own
4. Were you familiar with the aircraft?
Yes
5. Were you using a nav aid?
Yes
6. If so which navaid (e.g. VOR, NDB, GPS)?
GPS plus PDA running XCSoar moving map
7. Were you aware of the airspace you bust?
Yes - I planned not to go too near it
8. Was it in a complex airspace area?
No
9. How close to your home airport was the airspace?
100+nm
10. Only if you wish, say which airspace you bust.
Class A airway near Bristol (from memory - might have been class D I suppose, but I don't fly in either).
11. Why do you think it happened?
Was flying from Nympsfield, my first visit to the area, and enjoying a local soaring tour. I'd decided to go as far south as Badminton, just North of the airway, and then turn back. Working height band was 3,500-5,000 ft (as I had no retrieve crew, so was making sure I didn't land in a field). The airway base is 4,500 msl.
I was using the map for primary navigation rather than the PDA, and couldn't locate Badminton. On the map it has an airfield symbol, so I was pleased to spot an airfield in the right direction, and headed for it.
As I neared it at 4,600 ft msl the PDA display flashed red all over! Quick check, 180 turn, check map and PDA - my trace is perhaps 250m from the edge of the airway. I'd overflown Badminton and was headed for some other airfield.
Had I continued I would have bust airspace by maybe only 100ft vertically, but it would still have been a bust.
12. Any other comment that might help the rest of us.
GPS + PDA made all the difference. Using map alone I'd probably have turned the airfield, maybe climbed above it to 5,000ft (i.e. into the airway by 500ft) and never realised I'd been in airspace.
Lessons learned:
a. When close to airspace, monitor the GPS/PDA more closely. It would have been indicating the airspace much earlier, as it's set up to indicate airspace as solid red when within 5k horizontal, 500ft vertical. I hadn't noticed because I'd located Badminton (I thought!) visually and from the map it's well outside the airspace, so I just continued with visual navigation. Also, if I'd looked at the PDA I'd have seen that I'd flown past Badminton.
b. Distances when navigating visually are very deceptive as height changes. I'd already been caught this way before, when I visually misidentified a combination of two towns connected by a Fenland drain as two other towns, similarly connected but a few miles further on. This is why I installed the PDA in the first place,
c. I was taught navigation with map and compass, and when I started using GPS treated it as a check on my visual navigation. I think I need to swap round - GPS as primary navigation, map as check on accuracy of GPS.
If it helps anyone flying power, the gliding software for PDAs is pretty good for basic navigation and airspace avoidance. XCSoar is Open Source, and thus free to install and use. It accepts any GPS source producing NMEA output. What I see on my moving map is very basic topography at about the 1/2 million map level - major roads and rivers, big towns, BGA turning points. Airspace appears and disappears as I get close to it - these setting are user selectable, so you could show airspace at all times. I believe more complex topography, airfields and other waypoints can be downloaded, or you can create your own files, and you can leave out things you don't want like the BGA turning points (except that gliders go near them, so might be worth keeping).
I mention this because the costs are minimal - free software, £50 or so for the PDA via eBay, £15 or so for a GPS receiver and the same for a mount with a suction cup.
1. Were you a student or qualified?
Qualified (glider XC qualified - this was in a glider, but I think that makes no difference)
2. Were you current or rusty?
Current
3. Was it in your own/group aircraft or rented/school?
Own
4. Were you familiar with the aircraft?
Yes
5. Were you using a nav aid?
Yes
6. If so which navaid (e.g. VOR, NDB, GPS)?
GPS plus PDA running XCSoar moving map
7. Were you aware of the airspace you bust?
Yes - I planned not to go too near it
8. Was it in a complex airspace area?
No
9. How close to your home airport was the airspace?
100+nm
10. Only if you wish, say which airspace you bust.
Class A airway near Bristol (from memory - might have been class D I suppose, but I don't fly in either).
11. Why do you think it happened?
Was flying from Nympsfield, my first visit to the area, and enjoying a local soaring tour. I'd decided to go as far south as Badminton, just North of the airway, and then turn back. Working height band was 3,500-5,000 ft (as I had no retrieve crew, so was making sure I didn't land in a field). The airway base is 4,500 msl.
I was using the map for primary navigation rather than the PDA, and couldn't locate Badminton. On the map it has an airfield symbol, so I was pleased to spot an airfield in the right direction, and headed for it.
As I neared it at 4,600 ft msl the PDA display flashed red all over! Quick check, 180 turn, check map and PDA - my trace is perhaps 250m from the edge of the airway. I'd overflown Badminton and was headed for some other airfield.
Had I continued I would have bust airspace by maybe only 100ft vertically, but it would still have been a bust.
12. Any other comment that might help the rest of us.
GPS + PDA made all the difference. Using map alone I'd probably have turned the airfield, maybe climbed above it to 5,000ft (i.e. into the airway by 500ft) and never realised I'd been in airspace.
Lessons learned:
a. When close to airspace, monitor the GPS/PDA more closely. It would have been indicating the airspace much earlier, as it's set up to indicate airspace as solid red when within 5k horizontal, 500ft vertical. I hadn't noticed because I'd located Badminton (I thought!) visually and from the map it's well outside the airspace, so I just continued with visual navigation. Also, if I'd looked at the PDA I'd have seen that I'd flown past Badminton.
b. Distances when navigating visually are very deceptive as height changes. I'd already been caught this way before, when I visually misidentified a combination of two towns connected by a Fenland drain as two other towns, similarly connected but a few miles further on. This is why I installed the PDA in the first place,
c. I was taught navigation with map and compass, and when I started using GPS treated it as a check on my visual navigation. I think I need to swap round - GPS as primary navigation, map as check on accuracy of GPS.
If it helps anyone flying power, the gliding software for PDAs is pretty good for basic navigation and airspace avoidance. XCSoar is Open Source, and thus free to install and use. It accepts any GPS source producing NMEA output. What I see on my moving map is very basic topography at about the 1/2 million map level - major roads and rivers, big towns, BGA turning points. Airspace appears and disappears as I get close to it - these setting are user selectable, so you could show airspace at all times. I believe more complex topography, airfields and other waypoints can be downloaded, or you can create your own files, and you can leave out things you don't want like the BGA turning points (except that gliders go near them, so might be worth keeping).
I mention this because the costs are minimal - free software, £50 or so for the PDA via eBay, £15 or so for a GPS receiver and the same for a mount with a suction cup.