PDA

View Full Version : Seriously Navigation


Cirrusly
2nd Aug 2010, 10:30
How many of you out there do some really serious navs? Has anyone ever done a 1 in 60 in the real world? Or even calculated a ROD/ROC in flight? I know it's a different ball game for us rotary pilots but has anyone actually used anything from what you learn in basic navigation? Any interesting nav related stories out there?

spinwing
2nd Aug 2010, 11:27
Mmmmm ...

Of course we use it ..... thats WHY we had to learn all about it ...

Having said that .... after awhile it (basic Nav) becomes second nature and you start to make instinctive decisions ....

I learnt a lot during the early days of my career flying across the great antipodes with nowt more than mag compass and a WAC (not forgetting the chinagraph pencils melting somewhere on the cockpit floor) ..... Oh what fun it was ... :eek:

:}




God bless GPS and all who use it ! :D

Fareastdriver
2nd Aug 2010, 11:28
In March 1973 I was called on to do a 'lone ranger' from Odiham to Practica (Rome) via Cognac and Istres. All the RAF Pumas had as a nav aid at the time was Decca Mk8: 3 dials plus a master and a roller map that was initiated manually. Like all hyperbolic nav systems the accuracy deteriorates the further you get from the transmitters and Decca effectively ground to a halt half way down France.
After that we had two problems; one was transiting all the controlled airspace on the French Riviera and the sea crossing from Nice to Cape Corse in Sardinier.
Not having even an NDB when we were asked to report over a beacon we would look up the beacon; plot it from its Lat/Long on our 1/4 million; DR towards it and call overhead when we got there. We did this fast and accurately enough for nobody to raise any comment.
For the sea crossing we borrowed a drift sight. This had a plumb edge to it and on the Puma you could raise the centre panel to mount the load pole. The back of the was perpendicular to the aircraft's centreline so by mounting it against this and looking through it at the sea you could ascertain your drift. An accurate calculation of TAS plus three timed changes of heading and with a whizz of the Dalton you had your track and groundspeed.
IIRC we put in three corrections of heading and we hit Cape Corse on track within 45 seconds of the last ETA.

pasptoo
2nd Aug 2010, 11:38
I Follow Roads, Rivers and Railways ! makes the "nav" a lot easier.

Seriously though, too many newbies rely on GPS/FMS and not enough emphasis on basic nav when it all goes PeteTong. Nav is the best skill you will ever learn to get you out of soooo much trouble.

Pas

Earl of Rochester
2nd Aug 2010, 11:49
- FarEast D

That's a brilliant story. :D

Those were indeed the days!

EoR

John Eacott
2nd Aug 2010, 11:51
How many of you out there do some really serious navs?

Most navs are serious! Rig support 350nm overwater, north of WA (pre GPS) single pilot in a Wessex 60 on a regular basis. Trips across the outback (in a fixed wing: helicopter was too slow) with 400nm legs, no navaids, were nearly as challenging. Even a couple of hundred nm up into NSW at night was a serious nav!

Has anyone ever done a 1 in 60 in the real world?

See all the above.

Or even calculated a ROD/ROC in flight?

Just about every IFR flight would need that, too. Part of normal IF skills, and needed to advise area control of ETA to TOD.

All basic skills, IMO :ok:

As for fareastdriver: that's why we had a looker in the back with a doppler plot and lots of nav skills ;)

SASless
2nd Aug 2010, 13:04
In my early days flying in Africa (Ghana, Mali, Ivory Coast and The Republic of Upper Volta....now Burkina Faso) we used three types of maps....Rand McNally , US Government, and hand drawn. The bought maps were at a minimum twenty years out of date thus not much use re roads (what few there were) and far too many areas of the US map showed blank white areas annotated with the statement "Reported hills, streams, and mountains".

It was not unusual to have two hour transits with no usable nav features and DR techniques were necessary....also learning to make nav decisions without any met information whatsoever beyond the MK I eyeball. Add in Harmataan when the Sahara Desert dust moved south really made it interesting.

I have been so lost I did not know which country I was in.....much less where the next fuel stop was.

An old offshore trick came in handy on some legs.

That being flying the plotted heading to the rig without compensating for wind drift....then upon reaching your ETA....turn into wind and start looking for the rig. The key was to have enough visibility so you could have hope of seeing the rig as you flew up wind.

In Upper Volta it was fly to the escarpment that rose up just before Bobo-Dioulasso and the point where a dirt track cut through it which in turn would lead to Bobo.

Fareastdriver
2nd Aug 2010, 13:14
In Borneo in the 60s we were issued with maps that were the result of aerial survey. Where there was cloud when the picture was taken, quite often, the blank space would be labelled ‘Relief Data Incomplete’. The middle of this is where you usually wanted to go. You would blunder off the printed bit of paper DR-ing to a cross that somebody else had marked on blank bit of your map. There would be the occasional surprise like a river or a mountain range but the most important thing was to know the way home. The trick here was to do periodic 360 turns so that that you had an idea of what the scenery looked like when you coming back.

Fareastdriver
2nd Aug 2010, 17:05
In the early 90s one could do a grounspeed check enroute from Aberdeen to the Basin using Consol. The first people to use that were U boats.

heloguy412
2nd Aug 2010, 18:55
SASless wrote "That being flying the plotted heading to the rig without compensating for wind drift....then upon reaching your ETA....turn into wind and start looking for the rig. The key was to have enough visibility so you could have hope of seeing the rig as you flew up wind.

This is brilliant in its simplicity:D.

Cheers

SASless
2nd Aug 2010, 21:36
CONSOL worked great when leaving the Ekofisk headed back to Teeside....put the tail of the needle on the bottom of the dial...and off you went. Was it Stavanger where that station was? I forget now....but it was very helpful when getting going in the murk.

I also found using the sea bouys with their radar reflectors for the Newcastle shipping channel to be a nice way of finding the beach.....or by holding just north of track for Teeside one could do a straight-in ILS. The Sea Bouys worked a treat for locating one's location when the Decca had turned into a whirling dervish when it was queered by static electricity in a snow storm.

delta3
2nd Aug 2010, 22:18
Sasless

Stavanger went offline in 1991 (was the last operational consol)

I used Lugo a lot (NW Spain) in the 70' for Gulf of Biskay crossing, but that was in a sailing boat...

Not always very precise for triangularisation but OK for homing.

d3

ShyTorque
2nd Aug 2010, 22:26
This modern nav stuff and coupled autopilot is far too difficult.

I find I can never quite turn the aircraft accurately enough using the heading bug to get the projected track line exactly over the planned track line on the moving map display. :(

I prefer the old navigation ways. The chinagraph lines were much thicker... ;)

Whirlygig
2nd Aug 2010, 22:27
How many of you out there do some really serious navs?Some of my nav-exes have been hilarious ... :}

Cheers

Whirls

ShyTorque
2nd Aug 2010, 22:29
Some of my ex-navs were really serious.....

Juan Smore
3rd Aug 2010, 06:50
It is the 1:60 rule which explains why VORs are not more than 120 miles apart in airways that are 10 miles wide. I think.

Fareastdriver
3rd Aug 2010, 07:13
CONSOL worked great when leaving the Ekofisk headed back to Teeside....put the tail of the needle on the bottom of the dial...and off you went. Was it Stavanger where that station was? I forget now....but it was very helpful when getting going in the murk.

That's ruddy cheating! When you use Consol you are supposed to count the dots to find your bearing from the station. Just because the Germans made it powerful enough to be picked up in mid Atlantic doesn't mean use you can use it like an NDB.

delta 3 Bushmills, the Consol station built by the British to fill a gap in the Atlantic coverage was eventually blown up by the IRA as a military target during the troubles.

Devil 49
3rd Aug 2010, 18:16
If you're asking "have I ever"? Yes, but it was exceptional. I use that stuff for writing spreadsheets to do the routine nav guessing.
I'm very relieved to have dual gps moving map data-link etc., but I'm sad to see that the basic understanding of what one is actually doing in real world nav isn't being developed in crew who're routinely using only the new kit. I know pros who think VFR XC is impossible without GPS...

SASless- I think that technique was called 'off course navigation', used in Vietnam and mentioned in "Chickenhawk". Another nugget is to intentionally allow oneself to hit a limit on a predetermined side of the destination so you didn't have to decide which way to turn to it.

ShyTorque
3rd Aug 2010, 19:06
Devil49, I think you will find that SASless probably used the technique in Vietnam, he is a veteran of that same conflict.

Agaricus bisporus
3rd Aug 2010, 21:02
After that we had two problems; one was transitting all the controlled airspace on the French Riviera and the sea crossing from Nice to Cape Corse in Sardinier.
And even resorted to using a drift sight.Bloody hell!


Last time I flew from the Riviera to Corsia (and back) I did it without any navaids beyond a 500,000 chart, compass, whizzwheel and Mk1 eyeball. Don't think I was more than a few hundred yards off track or a minute off estimate.

Problems?? How????? What's the beef?

SASless
4th Aug 2010, 00:27
49....it was the way early Gulf of Mexico flights were done when the only nav gear was a field map, compass, and watch/clock.

The technique is as you describe....eliminates guessing which way to turn for the search if your destination does not show up on the "corrected" track. If one holds the corrected track and the rig doesn't show....how do you know which way to turn to look for it?

Fareastdriver
4th Aug 2010, 05:26
Problems?? How????? What's the beef?
The beef is to justify the existance of the crew who had a better sense of humour.

Cirrusly
4th Aug 2010, 07:19
I didn't really expect to get much feedback. By "serious navs" I was just generalising for "crazy, out there, extreme" navs. But thanks for the stories! I must say that I have run into a few pilots (FW and RW) these days who really don't appreciate true navigation. I think having a GPS is a great thing but I think people's reliance on modern tech is diminishing the aviators list of skills. Mind you most of those pilots were still in their 20s. Not saying gen Y is lazy or anything as i'm still in my 20s :}

Fareastdriver
4th Aug 2010, 09:46
Years ago when I was a V Bomber pilot I would condescend to enter the dungeon where the navigators used to grovel. Once there I would demonstrate my skill by doing a three star astro fix.

A week later we would fly my cocked hat as a long range navex.