Primarily for general aviation discussion, but other aviation topics are also welcome.
User avatar
By Danny
#1870139
Gosh, bit of a humbling experience today. Part way through my CPL and did my first 2 hour long navigation, old school style. Chart, stopwatch and compass. Having passed my PPL 20 years ago I, can hand on heart, say that I last navigated like this on my PPL skills test and have since then "enjoyed" the advances in affordable moving map technology. Evidently allowing my map reading and cockpit management skills to deteriorate in the process.

First leg was a bit chaotic at the start but I soon ended up pointing in the vaguely correct direction and the timing and headings seemed to work OK. I remembered to rely on the times and headings and was pleased with the result. However the next leg was planned to cross Birmingham airspace on a West to East track. Called up in good time e to be informed that my planned track would be inconvenient, to say the least, to the departures. The superb controller suggested an overhead the field transit which I accepted. This is where I really started to feel the pressure as I had to work out how to get to the Western edge of the airport perimeter, with said Birmingham International right on the chart fold. I have to admit the I ended up track crawling somewhat and best guestimates, without redrawing a new track. In hindsight I think this was a mistake and I should have replanned properly. Having been cleared into the Class D I felt a bit compelled to "get on with it". I have to say that this was only coming from me and there was no such pressure from the excellent ATC. I eventually spotted the airfield and routed to the Western perimeter where I got an ace view of the goings on underneath. Cleared straight across then back to the chaos of trying to exit the zone with my huge unfolded chart with no lines of any use on it!

Once I spotted coventry I was then able to exit the zone and find my turning point.

I must admit I didn't really mind the Class G navigation leg as it was pretty much as I remembered it however the Class D transit with the change of transit route and resultant dealing with a half mil chart that seemed to be alive and determined to get me in trouble (legal or otherwise) AND having no gadgets or navaids to assist made me wonder if everyone was like this back in the day, and whether Ded Reckoning in or close to controlled airspace can be made easier. Of course I was under radar control and could have asked but the spirit of the exercise was DR nav to the fullest extent possible.

It was a great flight but did get me wondering if there is a CRM issue that I need to resolve.

Also does anyone have any interesting ways of regaining track other than the usual Closing Angle etc techniques taught at PPL level?
User avatar
By foxmoth
FLYER Club Member  FLYER Club Member
#1870148
[url][/url]
Also does anyone have any interesting ways of regaining track other than the usual Closing Angle etc techniques taught at PPL level?


Try Standard Closing angle (or Modified SCA if under 120kts)

The SCA (standard closing angle) gives you an intercept angle to fly, for 1 minute for each nm you are off track. SCA is calculated as 60 divided by TAS in nm per minute. So if we are flying at 120 kts on a heading of 100 and find we are 3 miles left of track, we fly a heading of 130 for 3 minutes.

For modified SCA divide SCA by 2 and double the time, so in the above example you would fly 120 for 6 minutes.

Its sounds a bit complicated with the formula but once you have worked out the angle for your cruise speed then that angle stays the same every time.
Danny, StratoTramp liked this
User avatar
By StratoTramp
FLYER Club Member  FLYER Club Member
#1870157
Did my first nav the other day on charts. :thumleft:

Sackville > Leicester > Fenland and back. Was really cool. Didn't go wrong once. (Ok it's a big triangle). And instructor was there with Skydemon but didn't have to intervene. But extra confidence I suppose.

That said was heavily reliant on tick off features. Didn't use a lot of timing, though I had the stopwatch going as backup I just wasn't cross referencing a lot.

Is pretty satisfying when you spot the thing you are looking for and you can reset your certainty.

Though apparently my instructor said you can use Skydemon in exams now? Which was news to me.

I am pretty good at navigation on the ground. Did my lowland leader in may. Had to do 20 x 4-5 hour hikes towards it before you could claim a pass.

At the end of the day I think people should be able to do both. But is nice to have Skydemon.

One key thing I think Id struggle with is absolute precision. So I'd know ok I'm in this 1 mile circle. But that isn't necessarily accurate enough for a avoiding airspace. Say if going in between two areas and there aren't any really clear features just a blank hill side.

I could do it on the OS as I could do contouring for a fix. I think it's funny that on the ground your tickoff feature might be something small like a pylon. In the air it's something like rutland water. :lol:

Can't wait to combine the two hobbies. Fly off somewhere then hike!
Last edited by StratoTramp on Mon Sep 13, 2021 10:24 pm, edited 2 times in total.
Sooty25 liked this
By TopCat
FLYER Club Member  FLYER Club Member
#1870158
Having only started using moving map 4 years ago, I navigated like this for 22 years.

Sort of, anyway.

From about two years after getting my PPL to 4 years ago, I never used closing angles or drew lines on charts. Or even calculated headings, in fact.
StratoTramp liked this
By johnm
FLYER Club Member  FLYER Club Member
#1870160
I don’t have any of the kit anymore and I wouldn’t remember how to use it if I had......I’m a bit surprised to find that it’s used in CPL
User avatar
By James Chan
FLYER Club Member  FLYER Club Member
#1870165
s I remembered it however the Class D transit with the change of transit route


When I did my PPL training many years ago I had a similar problem as yourself with a change of transit route.

My instructor said I could "request vectors to xyz" where xyz is a VRP near the edge of the CTR/CTA on the chart.

This was granted and from that point, I resumed navigation in accordance with my PLOG - by dead-reckoning and pilotage. GPS was also banned in my day.
#1870172
I remember navigating without any gps.
There are days when the weather forecast is spot on and there are days when it is more variable so having the formula for the simple heading correction wont always work IMO - linear maths are great in linear circumstances.
When the weather is more changeable I would go for shorter leg lengths without a moving map to reduce gross errors.

Navigating the old skool way does create some natural variability of TMG compared to following a magenta line on the nav kit. Why does this make a difference? Well in Class G airspace the variability probably helps reduce MAC compared with some people that track the magenta line exactly between database waypoints. Or put to put it another way, if following a magenta line directly between database waypoints in Class G learn how to do offset routes to keep the line feature on the left and might avoid a head on collision. Similarly VOR tracking in Class G.
By patowalker
FLYER Club Member  FLYER Club Member
#1870228
GAFlyer4Fun wrote: Well in Class G airspace the variability probably helps reduce MAC compared with some people that track the magenta line exactly between database waypoints.


Database waypoints are so last century. We create our own waypoints on SkyDemon nowadays. :)
User avatar
By PeteSpencer
FLYER Club Member  FLYER Club Member
#1870241
I used to navigate the length and breadth of France using VOR/DME generated pseudo waypoints created on the trusty 8-place Narco NS800 RNAV.

Took a bit of effort as many Fr VORs had no DME....

Narco still in use (we kept it for its DME) as NAV2 and I occasionally do an RNAV route for old times' sake.

Have used VOR PAR once or twice too for 'honeypots'.

In fact WP # 8 is permanently set as our airstrip off the CLN: a throwback to the days even before we were an ink blob on Lakenheath's radar screen.....

They (literally) don't make 'em like that any more..... :wink:
#1870298
Danny wrote:... However the next leg was planned to cross Birmingham airspace on a West to East track. Called up in good time to be informed that my planned track would be inconvenient, to say the least, to the departures. The superb controller suggested an overhead the field transit which I accepted...

But this hasn't changed, has it? Surely it has always been best to plann (whether on SD or old style) to go overhead in Class D and have an alternative (such as low level under the ILS), knowing that the direct route is often inconvenient for ATC.
Danny liked this
#1870314
Please, I'm confused. What is a M A G E N T A line ? Is this yet another mysterious acronym? Intricate Navigation demands a ruler and map, the only problem to arise, is the frequent breaking of pencil tips having chewed the wrong end.

My one concession is to use two elastic bands to secure my rather old but still working bedroom alarm clock to some of the ironwork inside my cockpit rather like the early HUD images. It does tend to raise the pulse rate a bit when the alarm goes off unexpectedly.
#1870339
Time was, the last sole owner of the Shiny Colt (or first member of the group, both are true) used to navigate it across Europe using a Decca Navigator mounted on a plywood board resting on the passenger's knee.

This would have been late 20th Century

Rob P
Flyin'Dutch' liked this