PPL Diversions
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Thanks for all the replies folks. I am still to cover diversions with my instructor but just wanted to be one step ahead of the game. Spent all last night with a map and a few pens and I believe I may now be a diversion God! ..
I guess we shall see.. Thanks again
MB
I guess we shall see.. Thanks again
MB
BEagle: "12. The hardest sum next! Time = Distance / Speed! Either mentally or on the back of the checklist. Write it down, then lookout."
Avoid the random number generator known as "hard sums" by simply marking the track line at intervals of 1/10 of groundspeed (equivalent to 6 minutes) and adding-up the 6s (e.g. groundspeed 140 equates to 14 miles in 6 minutes).
HFD
Avoid the random number generator known as "hard sums" by simply marking the track line at intervals of 1/10 of groundspeed (equivalent to 6 minutes) and adding-up the 6s (e.g. groundspeed 140 equates to 14 miles in 6 minutes).
HFD
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Couple of other useful tips regarding diversions: (1) Treat your current (known) position with (hopefully) a good landmmark as your 'local area' and don't set off from it until planned & ready. Once you set off, if it looks like you've made a gross error calculation then do a quick 180 and return to your known point to figure out your error.
Other tip (2) is to always note if you are north/south or east/west of good line features such as motorways/canals/railways etc. That way you will always know what 'grid sector' you are in.
Other tip (2) is to always note if you are north/south or east/west of good line features such as motorways/canals/railways etc. That way you will always know what 'grid sector' you are in.
BEagle: "12. The hardest sum next! Time = Distance / Speed! Either mentally or on the back of the checklist. Write it down, then lookout."
Avoid the random number generator known as "hard sums" by simply marking the track line at intervals of 1/10 of groundspeed (equivalent to 6 minutes) and adding-up the 6s (e.g. groundspeed 140 equates to 14 miles in 6 minutes).
HFD
Avoid the random number generator known as "hard sums" by simply marking the track line at intervals of 1/10 of groundspeed (equivalent to 6 minutes) and adding-up the 6s (e.g. groundspeed 140 equates to 14 miles in 6 minutes).
HFD
You don't care about groundspeed in knots, you just need it in minutes per mark on the chart.
I learned to navigate flexwing microlights that way, and still use the system in an open cockpit.
G
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At Sywell I was taught to use the knightson computer for diversions:
www.knightson.org.uk
Quite expensive for what it is
, but very quick and efficient 
.
Tip: Put a bit of bluetack on the back so it can be stuck to the chart. That way if you have to look out of the window whilst using it you don't have to restart from scratch.
W
www.knightson.org.uk
Quite expensive for what it is
, but very quick and efficient .Tip: Put a bit of bluetack on the back so it can be stuck to the chart. That way if you have to look out of the window whilst using it you don't have to restart from scratch.
W
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I go with the windstar method. Draw a cross somewhere on your map where you can see it easily (N,S,E,W) and then another for NE,NW,SE,SW.
You then work out the drift to apply using your CRP-1 calculator, as well as groundspeed, for each point. Write these figures against each of the points (eg. N -5/86). You can interpolate fairly accurately in the air for headings between the cardinal points.
I also had a small piece of paper with pre-defined GS and distances marked on it
e.g
Speed
5 10 15 20 25 30 (nM Distance)
80 <Fill in times prior to flight>
85
90
and fill in the times. You can then interpolate when you know the actual distance and groundspeed.
This worked for me during the PPL.
You then work out the drift to apply using your CRP-1 calculator, as well as groundspeed, for each point. Write these figures against each of the points (eg. N -5/86). You can interpolate fairly accurately in the air for headings between the cardinal points.
I also had a small piece of paper with pre-defined GS and distances marked on it
e.g
Speed
5 10 15 20 25 30 (nM Distance)
80 <Fill in times prior to flight>
85
90
and fill in the times. You can then interpolate when you know the actual distance and groundspeed.
This worked for me during the PPL.
That way if you have to look out of the window whilst using it you don't have to restart from scratch.
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Pathetic; the examiner expects you to plan a diversion with head down, doing the maths etc etc. In the real world, tell him, (or her) that would NOT be your plan. Radio OK? Ask for a vector! Say Student pilot, uncertain of position! I had to do that to find my way back to Booker from Blackbush when it all got a bit fuggy......and was located just about directly overhead RAF Benson, who were actually the kind folks advising me! Cloud base getting so low I had to creep up the motorway to clear the Chiltern ridge.
Never never hesitate to ask for help.
But you won't need help if you follow motorways or coastlines. Or use your GPS. Or get your instrument rating and the enroute controller will TELL you where to go!
All the other advice given in this thread is why glider pilots don't trust power pilots to be keeping a decent lookout. The emphasis is on the gadgets rather than the mark one eyeball.
Never never hesitate to ask for help.
But you won't need help if you follow motorways or coastlines. Or use your GPS. Or get your instrument rating and the enroute controller will TELL you where to go!
All the other advice given in this thread is why glider pilots don't trust power pilots to be keeping a decent lookout. The emphasis is on the gadgets rather than the mark one eyeball.
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All the other advice given in this thread is why glider pilots don't trust power pilots to be keeping a decent lookout. The emphasis is on the gadgets rather than the mark one eyeball.
Faff around with CRP-1 and rulers and pens and arithmetic in the air? No ta, I'd rather do my spiral dive recoveries when I'm expecting them. Besides, there's too many gliders around to spend that much time not looking out the window.
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Quite right, Gertrude. There's a glider pilot in Coroner's court in Oxford this week giving evidence; he was able to parachute to safety when hit from behind.....the occupants of the power plane not so fortunate.
A unique case, but then every case is. Please maintain a good lookout, as Gertrude sensibly recommended..
A unique case, but then every case is. Please maintain a good lookout, as Gertrude sensibly recommended..
Irrespective of the gliders, I go flying because the view is good. Why should I want to spend any more time looking inside the cockpit than absolutely essential to safety?
G
G
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Irrespective of the gliders, I go flying because the view is good. Why should I want to spend any more time looking inside the cockpit than absolutely essential to safety?
(Hat, coat, and I'll have another glass of wine...
)
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All the other advice given in this thread is why glider pilots don't trust power pilots to be keeping a decent lookout. The emphasis is on the gadgets rather than the mark one eyeball.
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I'm not surprised glider pilots don't trust power pilots when you see the number of threads asking about GPS, IPADS, Mobile fone apps etc. When does flying the bloody aircraft fit in??
Though I have to say that flying a GPS approach on a G1000 is a good computer game to play in the air
(Mind you, I feel the same way about aerobatics - you can buy sick-making G forces far cheaper at a fairground - and I'm sure there are those here who would disagree with me on that one.)
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Helicopter PPLs seem to manage diversions OK without writing or marking anything at all on the chart while flying. A bent thumb is a convenient ruler.
Pre-flight planning also helps...
PS hugh flung-dung you have a PM from a while back.
Pre-flight planning also helps...
PS hugh flung-dung you have a PM from a while back.
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Silvaire's comment seems quite sensible. Except that when I did my PPL last March the documentation stated that I mustn't feature crawl, and had to work out a course to fly. And specify an arrival time +/- a couple of minutes.
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Most things covered already, personally I use clock method applied to max drift for heading and thumb for distance/time. Agree that there are some that have you with head down too much, and for those with GPS - not all of us have one and, IMHO, even if you use one you should still know the basic techniques.
A couple of other tips :-
if you are diverting for weather you might want to do a 180 - to do this just look at the bottom of the DI - that is your reciprocal heading, turn onto this then adjust by DOUBLE the drift you had on the original heading - look at the wind arrow you have drawn on the chart to confirm which direction to apply it, you already have waypoints you have seen and head/tailwind will be the same as outbound but in the reverse sense.
To draw a line on the chart, put your pencil at one end of the line, lookout, look back in at the point you want to draw to and looking at that point draw your line - might not be perfect, but close enough and takes no time at all.
A couple of other tips :-
if you are diverting for weather you might want to do a 180 - to do this just look at the bottom of the DI - that is your reciprocal heading, turn onto this then adjust by DOUBLE the drift you had on the original heading - look at the wind arrow you have drawn on the chart to confirm which direction to apply it, you already have waypoints you have seen and head/tailwind will be the same as outbound but in the reverse sense.
To draw a line on the chart, put your pencil at one end of the line, lookout, look back in at the point you want to draw to and looking at that point draw your line - might not be perfect, but close enough and takes no time at all.
Last edited by foxmoth; 19th Feb 2012 at 16:21.