Is there an in flight divert gadget on the market?

[Chocks Wahey]

I had to do one on Monday and found my alternate by eduacated luck. In this day and age there must be some kind of gizmo about that can aid you in planning an in flight divert.

[Timothy]

GPS

[spitfire]

The Garmin GPS Pilot III has a nice feature (other GPS units have it too) you can use if you get in trouble called "Goto Nearest" - will give you an instant distance and bearing from nearest airfield.

[Chocks Wahey]

Thanks for the replies, but I really don't want to fork out for a GPS. I am more of a traditionalist and want to resist the drive towards GPS.

[TonyR]

The day you really have to divert in bad weather you will give up being a traditionalist and wish you had a GPS

Tony

[CPilotUK]

Chocks,

I'll take a guess - based on your first pprune post - that you are either still a student or a newly qualified pilot. If you are such a traditionalist, why not use the methods that you were recently taught; as far as I know, they are simple enough.

CPilotUK

[locksmith]

the best gizmo sits 18" behind the airspeed indicator and used to be called a pilot

[spitfire]

Is this a wind-up?

[stillin1]

Please tell me this IS a wind-up. Pop back to your friendly instructor and ask him to go over the basics of nav / in-flight emergency handling you apparently slept through.:(

[BEagle]

To help folk with sorting out in-flight diversions, we produced a PA28 checklist which has a nice large laminated blank area on the back, along the edge of which is a half-mill scale. So, when planning the diversion, put checklist on map between diversion start and diversion end, draw line on map with chinagraph. I recommend a chinagraph as it doesn't have a top - if you use a lumocolour felt tip or similar, you end up with the top in one hand (or between your teeth!) and trying to hold the map/checklist still whilst drawing on it is a right $od! Once you've drawn the line, note the distance and write it on the back of the checklist. Then do the angle measuring by paralleling your track at a VOR rose (easier to do than describe), then write it on the back of the checklist. You now have something like 205/34 as your new track/distance. For speed, it's doubtful whether you'll be flying with more than a 30 kt wind, so if your IAS (OK- TAS really but IAS is good enough) is 90 kts, the groundspeed can only be between 1 and 2 miles per minute. If you've been taught 'max drift' and how to apply it, that's the next stage. Let's say IAS is 90 kt and W/V is 260/30. OK, max drift (you can work it out before you go) is 30 divided by your 1 1/2 miles per minute groundspeed, i.e. 20 degrees. The wind is 55 deg off your track, call it 60 deg. So use all of max drift for the heading, i.e. make the heading 225. For speed, use (90-55), i.e. 35 or 'half past' - your GS will be IAS minus half the wind, ie 75 knots. That's 1 1/4 miles a minute, easier to call it 5/4 miles a minute, so your 34 miles will take 4/5 of 34......well, 'seven fives are thirty five', so call it 28 minutes. Write 225 deg, 28 minutes down on the pilot log, put the checklist down, sort the aeroplane out and then set off from the diversion start point, noting the time as you do so. Recheck the DI, airspeed and that your timer/clock/watch is working OK, add 28 to the start time. Or add half an hour and knock off 2 minutes - it's easier. On the diversion, use as many ground features as you can to update position and ETA, but keep flying accurately.

To sum up:

Choose an easy start point
Draw line with topless writing instrument.
Measure distance, write it down.
Measure track from a VOR rose, write it down.
Work out the Max Drift factors to apply.
Apply to heading, write it down.
Apply to groundspeed, write it down.
Work out leg time using distance and 'miles per minute', write it down.
Sort out aeroplane.
Set off on diversion, note time.
Recheck DI, IAS and timer.
Note down ETA.
Use ground features to check your progress.


PS - With the whizz-wheel, I got a heading of 224 and a GS of 69 kts, so the 'in your head' method isn't too far out!

[Whirlybird]

Don't know about a gizmo, but I've found all the following useful:

1) Hate to say it, but get a GPS. Make sure it's accessible, but only switch it on when you need to. I rarely use mine, but I always carry it.

2) Get used to estimating distances on the chart. Practise on the ground, either using a thumb, or just eyeballing it. I spent many years using 1:50,000 OS maps for walking, and was used to estimating distances. So it wasn't too difficult for me to do the same thing on the 1:500,000 chart.

3) Similarly, get used to estimating headings. When you plan a route, estimate every heading, and see how far out you are. It really isn't that hard. Divide every 90 degrees in half, then half again, then estimate.

4) Get used to really doing VFR nav, really recognising ground features. It's much easier to do this while someone else is flying. You can practise recognising distances at different heights, looking out for useful features, etc.

5) BEagle might disagree but...
Your diversion airfield is unlikely to be too far away, so timing probably isn't crucial, except approximately. In the same way, in light winds, you probably hardly need to correct for drift. In stronger winds, do what my instructor taught me, which I haven't heard from anyone else. If the wind is at right angles to your track, correct by 3/4 of the windspeed, at 45 degrees to your track, correct by half. It works well enough for shortish distances, and is easy to do even when you're overloaded, as will probably happen in a real diversion. When there's too much to do, complicated mental arithmatic can go out the window, and can having three hands to draw lines, measure them etc.

6) The best gizmo, if needed, is ATC or D & D on 121.5 :ok:

[Timothy]

So, when planning the diversion, put checklist on map between diversion start and diversion end, draw line on map with chinagraph. I recommend a chinagraph as it doesn't have a top - if you use a lumocolour felt tip or similar, you end up with the top in one hand (or between your teeth!) and trying to hold the map/checklist still whilst drawing on it is a right $od! Once you've drawn the line, note the distance and write it on the back of the checklist. Then do the angle measuring by paralleling your track at a VOR rose (easier to do than describe), then write it on the back of the checklist. You now have something like 205/34 as your new track/distance. For speed, it's doubtful whether you'll be flying with more than a 30 kt wind, so if your IAS (OK- TAS really but IAS is good enough) is 90 kts, the groundspeed can only be between 1 and 2 miles per minute. If you've been taught 'max drift' and how to apply it, that's the next stage. Let's say IAS is 90 kt and W/V is 260/30. OK, max drift (you can work it out before you go) is 30 divided by your 1 1/2 miles per minute groundspeed, i.e. 20 degrees. The wind is 55 deg off your track, call it 60 deg. So use all of max drift for the heading, i.e. make the heading 225. For speed, use (90-55), i.e. 35 or 'half past' - your GS will be IAS minus half the wind, ie 75 knots. That's 1 1/4 miles a minute, easier to call it 5/4 miles a minute, so your 34 miles will take 4/5 of 34......well, 'seven fives are thirty five', so call it 28 minutes. Write 225 deg, 28 minutes down on the pilot log, put the checklist down, sort the aeroplane out and then set off from the diversion start point, noting the time as you do so. Recheck the DI, airspeed and that your timer/clock/watch is working OK, add 28 to the start time. Or add half an hour and knock off 2 minutes - it's easier. On the diversion, use as many ground features as you can to update position and ETA, but keep flying accurately....or press NRST, DCT on the GPS ;-)

[BEagle]

..after you've first drawn a line on a chart to make sure that 'DCT' doesn't take you through any restricted or regulated airpsace!

And I'm all in favour of correctly used GPS to back up your estimates. Always ask yourself what you'd do if the GPS died at the critical moment!

[Timothy]

Restricted and regulated airspace is usually shown on the GPS.

No, as you know, I am teasing.:}

The real answer to the whole question is situational awareness backed up by whatever you have at your disposal.

Even though I carry three GPSs and three moving maps I always know where I am on the paper map (which I hold) always have VOR/ADF tuned in, always know where the nearest airfields and CA is. If any of the systems broke I would fall back on what remained, from traditional radio aids to DR to pilotage as required.

[Miserlou]

If you really need a gizmo, then an ADF is what you need. Once you've tuned it to the correct frequency it just points at it. All you do is keep the needle pointing up and you'll get there!

Otherwise, your brain is the best thing. GOTO Nearest on a GPS may point you in the direction that you want to turn away from. Then you have to press buttons and think.

Thinks: Surely if you know where you are, and you know where you can't go, and you know where you shouldn't go, you're already close to the solution. Look on the map!

[Evo]

If you really need a gizmo, then an ADF is what you need. Once you've tuned it to the correct frequency it just points at it.


... or the nearest thunderstorm... :*

[Final 3 Greens]

Listen to Timothy, listen to BEagle :O

[ThePirateKing]

When I was training, I had a thing called a Knightson, or Nightson, or somesuch. It's a little disc which you mark the wind velocity onto before flight. During a divert, you draw a line from the start of your divert (remembering to make this a visible feature a couple of minutes up-track), to your divert destination, and then use the Knightson to measure the heading (i.e. wind-corrected), and to make 6-minute marks alone the track. In essence, this little beauty is like a pre-programmed whizz-wheel which calculates the wind-drift, and ground speed for you.

The only minor annoyance is, they only work for a given air speed. So, you need to buy a 100kt one for use in the Warrior, and a 140kt one for use in the Arrow, etc. (And remember to mark up and take the right one with you!)

Hope that helps,

TPK.:ok:

[Ludwig]

Whirlybird said:

Hate to say it, but get a GPS. Make sure it's accessible, but only switch it on when you need to. I rarely use mine, but I always carry it

I'm intriguedby this. Can I ask Whirly, why you don't switch it on until you have problem/need? I would have thought that, as nothing is cheating if it helps, it would be more useful being used. I'm not suggesting instead of all the other stuff, but as well.
:confused:

[IO540]

GPS.......................

[140cherokee]

Get a GPS and keep in switched-on. Why make things difficult for yourself when you're in a stressful situation?

Next best is to get an IMC rating and request a SRA (assuming the diversion aerodrome has full ATC, etc.). You'll be less worried by weather, diversions, etc. with an IMC rating anyway.

Else an ADF is useful provided the divertion has an NDB (better still with a DME).

140

[Whirlybird]

Ludwig,

It eats huge amounts of batteries, and I can't be bothered - I enjoy VFR nav and find it fairly easy...because I keep in practice. But it's very useful if the vis gets worse, or I can't find the airfield, or for some other good reason.

The real trouble with GPS is that if you use it all the time you start to rely on it - I know where I am, but I'll just take a quick look at the GPS to make sure. Then if you don't have the GPS, you feel lost. Been there, done that. But each to his own. I'm in no way anti-GPS. I was just saying that even if you don't want to use one, they're a useful back-up.

[Ludwig]

Whirly

Fair enough, good answer:cool:

[IO540]

Unfortunately these anti-GPS sentiments always get me going :O

But let's keep it very brief.

If you are a plain VFR PPL pilot, the proper way to use a GPS is to use it concurrently with map navigation.

Plan the flight with a chart and produce a plog. You've got to do that anyway, no matter what gizmos you have, because as of 2004 the only official terrain/CAS reference is the paper charts.

As you fly along, it (assuming it is a moving map type, anything less is a waste of money) tells you where you should be, and you are looking out of the window anyway so you can look over there and say to yourself "yes, that looks like the M25" etc etc. So you are checking the two all the way along. It's a really easy, low stress way to fly, and it is awfully hard to get lost.

I don't see why people get so hung up over sole use of GPS, using GPS for "primary" navigation and so on.

[ThePirateKing]

How has this turned into another pointless religious GPS war? For :mad: sake, can't one single thread directly answer the poster's original question without getting drawn into some holy war?

Why can't people with strong views (on GPS in this instance) accept that there are other people with opposite views, and let sleeping dogs lie?

:*

So... anybody got any good techniques for doing en-route diverts?

[IO540]

ThePirateKing

Apologies for "pointless religious GPS war"

If you know your position then a diversion is obvious. You get your chart, put a cross where you are now, draw a line to where you want to go, estimate the track angle, do a wind adjustment (max drift is half the wind, and you've got Form 214 haven't you) and fly that as the new heading. Regarding how long for, the distance between the end of one's thumb fingernail and the first joint is about 5 mins (on a 500k chart) :O Or you can measure it with a ruler. This is taught to everybody in the PPL.

A GPS is a far easier way to do it because it shows your position and shows your ground track.

Is there meant to be some clever trick for doing diversions? I've never come across one.

I have read of tricks for doing box diversions around an en-route obstacle; diverting around controlled airspace (which you originally planned to transit through but can't get clearance) can be a real challenge if navigating conventionally.

[ThePirateKing]

IO540,

I'm happy with my diverts. :D I was just trying to return this thread to the original topic. Radical, eh? :)

Returning to my earlier post - Cabair flogged me my "Knightson" during my training. However, I can't any more details about them. Cabair seem to source most of their supplies (Cabair branded, or otherwise) from AFE, but AFE don't seem to have an online catalogue. Transair don't have them listed anywhere obvious on their site.

So, does anyone have any more info on these devices? In fact, has anybody else even heard of them??? :confused:

TPK:ok:

[drauk]

(Personally I'd say GPS too, but for those that don't want to...)

ThePirateKing gave what I consider to be the best answer. These days various pilot kit shops sell a thing called The Wind Protractor. One pencil dot on it with the forecase wind, drop it on your map with the dot where you are now and read off the TIME and BEARING to where you want to go. It really is amazingly easy. No WCA, no in-the-head maths, no sliding a ruler over from a VOR rose.

Mind you, £8.75 (http://shop.pilotwarehouse.co.uk/category76023.html?page=2) for a bit of plastic.

You can also use it on the ground for creating your PLOG.

[140cherokee]

Try ... http://www.afeonline.com

140