Importance of accurate course setting in overhead [Archive]

Chuck Ellsworth

22nd Feb 2002, 03:17

Lets try a little logic to answer your question.

We will examine two senarios when setting course and then staying on track when navigating VFR and map reading.

Senario number one:

We set course at one hundred feet above the airport runway and fly the trip at one hundred feet.

Obviously remaining right on course will be necessary as our field of view of the ground ( Your track ) will be very limited. And if we wander several miles off track getting re oriented will be a real problem.

Senario number two:

We set course at one thousand feet above the airport and fly the trip at one thousand feet. We now have a far greater field of view to map read our track and wandering a mile or so off track is easy to correct due to our increased field of view.

. .Try starting your mind picture from this simple example of map reading.

Then do not get to carried away with all the exotic problems and solutions that will be part of the training process, in other words don't let bull**** baffele brains as it really is very simple to navigate VFR with the proper map and the proper picture and understanding of what you are doing.

Here is a hint:

Note the point of departure then find the point of arrival, make a fold of your map from the start to the finish of your trip, jump in the flying machine and map read the track by following the fold crease on your map. So you don't even have to draw a line with a pencil or pen....for distance measuring use the side of your thumb to determing milaege. Anyone who trys to tell you that you must be accurate to the mile and to the minute is just missleading you.

. ...................

:) The hardest thing about flying is knowing when to say no. :)

FNG

22nd Feb 2002, 12:27

One technique that you might try is selecting an "entry point" for your nav plan, such as a clearly recognisable road junction or other prominent feature a few miles away from your departure aerodrome. You climb out of the circuit, get yourself all sorted out, then run in over the entry point at desired height, on desired heading, at desired speed, hacking your watch as you pass over the chosen feature.

Whirlybird

22nd Feb 2002, 13:50

FNG got there before I did. :)

This is not at all a stupid question, considering the way nav is usually taught to PPLs. I too was taught that everything had to be 101% accurate. But it doesn't.

If you leave the airfield and set heading immediately, you'll be circuit distance from where you want to be, at the most. And since you can see the runway from the circuit, you can see your next turning point from where that'll take you to (useful to note it though, or you'll make a heading correction you don't need). Very simple really, once you know.

On a different but related point, your compass has markings at 5 degree intervals, so can you fly to the absolute accuracy you will have worked out on your whizwheel? This is expected in ground exams and for your instructor, but in reality it doesn't matter. If you're 5 degrees out, you'll be five miles off track 60 miles away (1 in 60 rule). So as long as you fly accurately and check ground features every ten miles or so, you'll never be more than a mile off track. And if you can't see that far you should be on the ground. :)

This is not an excuse for incomplete pre-flight planning or sloppy flying. It's just that from what I've seen there tend to be two types of PPLs: those who check everything to the nth degree, and those who've given up all that as being impractical, draw a line on the map and hope for the best, or use the GPS. So I think the PPL course needs a lot more in the way of understanding of what VFR nav is really about and what is actually needed in practice. Anyone else agree?

And for those who care, I still use my whizwheel. I actually rather like it. :)

tacpot

22nd Feb 2002, 16:55

If you are monitoring your progress along your planned track, you will probably be making a heading correction at either the quarter-way ot half-way points anyway, so any error introduced by setting out from somewhere ever so slight different from where you had planned leave from should be eliminated by this course correction.

The other posts have it right, you don't have to be 100% accurate. VFR navigation is visual navigation, if you can see how far off track you are, you can make any correction you need to.

Often I will set course from a local landmark 3 or 4 miles way from the field, navigating to the landmark visually, i.e. not worrying too much about the time for that short leg. Into that leg I factor the fuel to climb to cruise altitude, I do calculate a heading to fly, as it's more efficient to take account of the wind than ignore it, but I only use this heading as a guide, as I won't necessarily know from which point in the circuit I'll be starting from, e.g. if the runway is changed between flight planning and departure.

The landmark I use is such that if I can't see it to navigate to it, I shouldn't be flying anyway. But this approach is driven to some degree by the fact that my home field has Controlled Airspace above it, so we can't set course from the overhead normally. Setting course from a nearby landmark is certainly described in the Jeremy Pratt PPL books, so it counts as a valid technique in my book.

[ 22 February 2002: Message edited by: tacpot ]

niknak

22nd Feb 2002, 17:25

A small, but VERY important point;always check before you get airborne that you can set course from the overhead.. .At our place, because of the close proximity of a H24 fast jet military airfield, overhead joins and setting course from the overhead is not permitted.. .Even though this is clearly published, and pilots are briefed if they ring up prior to departure, we still get requests from them to carry out the manouvre.

Chuck Ellsworth

22nd Feb 2002, 20:31

Setting course overhead:

Only in the goofy makebelieve world of ab-initio flight training could someone think up such a waste of time as the overhead course setting.

In the real world of flying you plan your trip so as to take off and conform to the traffic patterns of the airfield you are using to set course when safe to do so.

In IFR flying we are given SIDS ( Standard instrument departures ) in our clearances, once airborne the SIDS are usually cancelled by ATC with heading and climb instructions. Can you in your wildest thoughts imagine jets climbing for an overhead departure?

VFR map reading is straight foward, you compare what you see on the map with where you should be. If you are not on track change heading sufficient to fly yourself back to the desired track then maintain it as bset you can.

Whirley brings up a good point, the stupidity of planning for heading accuracy that is impossible to maintain. When flying you will end up averaging the compass (H.I.) readings, as you gain experience your averaging will become more precise.

Then one day you will be able to roll your cigarettes whilst holding the localizer dead center to the runway. Then you can sit at your computer making a fool of yourself because you are bored to death. I can't wait until I get back to work.

.................... . :) The hardest thing about flying is knowing when to say no. :)

Aussie Andy

22nd Feb 2002, 21:22

beammeupscottie = its not a dumb question at all mate - I remember puzzling over this as well. This is a function of the way we're taught, as everyone else has said. Everyone else has already given you the practical answers you need above.

I actually think the way we're taught is OK because it gives us a step-by-step fool-proof approach... however, the trick is to realise as time goes on and you gain experience that you can cut corners and relax a bit with it. But until you feel OK with this, definitely keep asking the "dumb" questions!

Enjoy the weekend everyone - if the bl**dy wx lets us!

Andy

twistedenginestarter

22nd Feb 2002, 22:29

My advice, particularly for any flight tests, is to climb overhead. You have to get to the right place and within 2 mins of estimate so why make things more difficult for yourself?

Beethoven

23rd Feb 2002, 03:10

Overhead to overhead is obviously the most accurate but means nothing if the destination does not allow overhead joins,which many dont.Just think of your field of vision from 2500 feet.All that matters is that you can SEE your destination at the end so that you can adjust for your join.Its no good putting yourself overhead a field only to be told to join right base!!I would say,that as long as you depart in sight of your departure field,then if your plan works out,you should arrive in sight of your arrival field and that,to me,is a good vfr nav.As for a PPL flight test,just do as your instructor says and experiment when you have your licence,as you will find,there are many ways to navigate successfully.. .Ludwig

Chuck Ellsworth

23rd Feb 2002, 04:14

Within two minutes?

Within two minutes in how many miles? Or better still exactly what is the two minutes requirement?

As to the overhead departure and overhead arrival why would anyone with half a brain require such an unorthodox procedure in 2002?

Whirlybird

23rd Feb 2002, 15:40

Cat Driver,

An overhead departure makes no sense at all usually. But it's perhaps fairly useful for student pilots who have difficulty understanding nav; I remember on my qualifying cross country getting very confused because a power station a few miles away wasn't where it should be. Just flying was enough for me at the time without working that out; I worried for several miles until I realised my heading was working, and only realised afterwards on the ground what had happened. But for anyone with even a minimal amount of experience it makes no sense at all.

Overhead joins I have mixed feelings about. It does mean you can circle around in safety and work out how to join the circuit, which can be very useful for the inexperienced, especially those of us with spatial perception difficulties. <img src="eek.gif" border="0"> I used to always do it, for that very reason. Also, there are a lot of quite busy airfields in the UK with only A/G radio. Some would say that it makes sense to have everyone joining those overhead, well out of the way, descending deadside etc, rather than having them all joining the circuit where they feel like it. I'm not sure, since it means the whole world can theoretically be flying around overhead at 2000 ft in any direction. I do remember one time when it made a lot of sense; I arrived at Shoreham at the same moment as an aircraft making an emergency (or do I mean precautionary) landing after a vibration problem mid-channel. I'd been earlier told I could join the circuit etc, but I saw what was happening, asked if I should wait as I could see all the fire engines etc and knew they wouldn't want anyone else around. I then circled overhead until the aircraft landed safely before asking if I could now descend. Probably easier for both me and ATC then anything else, under the circumstances.

But do we get too hung up on overhead departures and joins? Yes, definitely. And getting asked to join overhead in a helicopter makes no sense whatsoever - and it happens! <img src="eek.gif" border="0">

Rusty Cessna

23rd Feb 2002, 16:35

My opinion:

Yes, Overhead to Overhead is the shortest route, but I have to agree with the points raised that if you are actually inbound to an aerodrome and an overhead join isnt either available or issued, then what? In the practical world I would beleive a lot of pilot's stop flying their nav route accurately when they either get visual with the field or have received the joining info,I'm talking VFR here. I don't know a lot about it but as someone said when you start doing IFR stuff SIDs start to come into play.

Everyone seems to be clear about reasons why Overhead to Overhead is or isn't practical, but something that I dont think has been mentioned yet is the actual performance issue. The approach I take now to planning routes is I start the route from either a VRP or a prominent feature, (as FNG, tacpot and whirly suggested), this enables yourself to get sorted and start the leg immediately.

The reason I take this approach is because I find it easier, I have time to get everything sorted and once I'm over the VRP all I have to do is "hack" the watch. Another reason (probably because I'm lucky to have VRPs within 3 miles North East and West of my field) is that by the time I have climbed to the overhead I could have got to my VRP, which is also a little more en route.

That's just my opinion, I prefer the VRP approach, as does my instructor, I was taught both, but decided against the overhead route. I won't bother restating the issues already raised about the approximation involved with flying routes such as compass markings and drift, but I do think they are apparent, however, adequate post PPL experience is needed before you can accruately approximate I think, so best stick to your plan and definate drift corrections.

With regards to the test, I would do what you have been taught, this will probably be what you are most comfortable with, be as precise as possible, there are limits on the test, I think its + or - 100 feet on altitude holds, + or - 10 knots on speed, and 2 mins on time, but I'm not deffinate on that. I tried to be as precise as possible, 37 mins was the calculated leg time on my test, 37 mins 13 seconds I think was the actual leg time, it works!

Of course this is totally relative, sometimes overhead to overhead may be appropriate, I woul'd be reluctant to say "i'm only going to fly this type of nav", it restricts your options.

One final point, as tacpot suggests, I'm very wary where and when I do my drift corrections, unless you have the post PPL experince to approximate accurately, which I yet don't , I would stick to correcting for apparent drift at quater or half way points, this is again my prefered method, simply because its nicely spaced intervals, that are easy to calculate using the drift angle, closing angle method, but hey, ways of correcting drift is another thread totally!

Gawd that was a long one! hope it makes sense and helps.

Rusty.

P.S as Cat river says, Height = Sight, and yes I know spelling is awfull, but I'm tired ;-)

[ 23 February 2002: Message edited by: Rusty Cessna ]

twistedenginestarter

24th Feb 2002, 15:33

Cat Driver

My point is that the only reason most people do this sort of navigation is because they are in training. Once you've got your CPL (this is in the UK) you wont bother with this again. You either become an airline pilot or use your GPS, VOR etc.

I believe for the CPL you need to arrive at your turning points within 2 mins of estimate. The legs are of the order of 50-100 miles. I guess you can correct your estimate at half way. I'm not sure at what point you can no longer adjust your eta without failing.

Clearly you would never climb in the overhead for any real-world reason.

Zlin526

24th Feb 2002, 17:05

I think Catdriver talks a lot of sense.. .Whats wrong with setting course from a point, say a mile from the airfield??? My own airfield has parachuting all day, everyday, so setting course overhead is for bozo's. Take off, fly to the selected point and then turn on track your destination - easy. . .I admit CPL and ATPL standards are higher, but why can't the ordinary PPL also have high standards too? Reminds me of the guy who mistook his destination of Compton Abbas for Bournemouth a few years ago. A large Tarmac runway 2 miles from the sea as opposed to a small grass strip 40 miles inland! Would setting course overhead the departure airfield have helped him??? Makes you think about pilots personal standards....... <img src="frown.gif" border="0">

[ 24 February 2002: Message edited by: Zlin526 ]

Chuck Ellsworth

24th Feb 2002, 21:37

Twistedenginestarter:

When I learned to fly we were taught several very important things, first and foremost was good airmanship, which simply put is common sense.

(By the way before I was allowed to fly for my first employer I was required to spend several years working as a mechanic in the hangar.)

Common sense dictates that "all" pilots conform to a safe and workable pattern of flying.

Overhead departures and arrivals are not the norm for aviation if they were everyone would be required to use that method. Just imagine the chaos that would entail.

To suggest that a student pilot cannot start a x/country from any portion of an aerodrome traffic circuit is just plain stupid. I defy anyone to convince me that you cannot see the airport from any portion of the circuit pattern unless you are in cloud.

Now to examine this mindless notion that a student must start from overhead so as to be able to get an accurate fix for time and course corrections that is just not intelligent thinking. Because once on route there is no guarantee you will have check points that are as positive as the airport you just left. So common sense dictates the student should start the x/country navigation from any point and fly to any other point by "map reading" and accurate heading and time management.

Remember the bureaucrats who dream up all these exotic requirements for flight training and written exams are not necessarily the brightest and most gifted among us.

Flight instructors are victims of the system.

................

. . :) The hardest thing about flying is knowing when to say no. :)

FNG

24th Feb 2002, 22:18

Twisty, forgive me if I am misreading your post, but are you implying that primary navigation skills are just for studes, and that, once licensed, you can just switch on the GPS, dial up the VOR, and have a snooze?

twistedenginestarter

25th Feb 2002, 13:17

FNG

Exactly that.

You really must embrace technology when it provides a clear-cut advantage.

I learned to fly using visual navigation because they didn't put radio aids in any of my FTO's singles and I couldn't afford a Decca at the time.

Nowadays everyone can have gps and I haven't been in a plane for 30 years that didn't have VOR and ADF. So if you want to fly from Newcastle to Lands End it would surely make sense to use radio aids and gps as your prime navigation. If the GPS/DME says you are two miles from controlled airspace then most likely you are. What's the point in trying to work out which dual carriageway that is crossing which railway line?

Unfortunately there is no promulgated Modern VFR Navigation Method. Perhaps we should develop one on a thread here?

[ 25 February 2002: Message edited by: twistedenginestarter ]

Chilli Monster

25th Feb 2002, 13:33

Twisted

I thought there was now by the introduction of the JAA PPL which includes the use of radio aids in the syllabus.

Of course,what happens when the alternator/battery fails <img src="wink.gif" border="0">

But to get back to the original thread: +/- 5 degrees is normally a good enough accuracy for PPL flying - but don't expect to do it from the overhead - pick a start point on track. It's a lot tidier form of nav.

CM

FNG

25th Feb 2002, 13:37

I am not suggesting a luddite approach to new technology, and integrating the GPS into pilot training might well be a good idea, but what happens to average plonker pilot when his GPS suffers a fault? Most flying skills seem to be use-or-lose skills. Is navigation an exception?

Whirlybird

25th Feb 2002, 16:38

FNG,

He dials up 121.5 and calls; "Mayday, Mayday, Mayday, my GPS has stopped functioning". Honestly, that was told at a CAA safety evening a few years ago; it happened!!! <img src="eek.gif" border="0"> <img src="eek.gif" border="0"> <img src="eek.gif" border="0">

FNG

25th Feb 2002, 16:50

!!!!!!!!!. .Picture that same guy with a radio failure (not altogether unlikely if the GPS has conked because the electrics have fried). I know that no one should ever be discouraged from calling D&D, and ordinarily there should be no recriminations for doing so, but I wonder if this person was given any, er, counselling after landing?

twistedenginestarter

26th Feb 2002, 12:48

Whirly

Excellent first contribution to The New Method.

Navigate using the GPS, checking periodically against ground features and ADF/VOR if fitted. Periodically also check the GPS is functioning ie picking up a useful enough signal to display meaningful groundspeed and track. Do not rely on map displays.

In the event GPS malfunction is detected and map orientation has been lost, transmit a Practice Pan - request position confirmation

Whirlybird

26th Feb 2002, 13:58

twisty,

The problem with calling a Practice Pan if you have a real problem is that you're gonna feel a right idiot when they tell you they can't do it as they're dealing with a real emergency, and you have to confess. <img src="eek.gif" border="0">

Aside from that, has it occurred to ANYONE that visual nav can be FUN. <img src="confused.gif" border="0"> When a friend and I did the Dawn to Dusk competition last year (in a C152, not my favoured whirly things), our whole 8-9 hours flying was a figure-of-eight course round Wales, looking for everything from small towns to single buildings to an isolated rock, in connection with our theme. GPS would have been little use, and radio navaids not much more use as there aren't any VORs etc round there. But we had a wonderful time (and won, incidentally). And the nav I did for the CPL(H) - finding isolated buildings on OS maps; horrendous under exam conditions, but great to be able to do. And necessary if you're on the London or Paris heli-routes or similar too.

I'm not suggesting everyone navigate like this all the time; it would be slightly pointless. But it's useful - and enjoyable - to be able to do it. IMHO, to suggest it's an outdated skill is to take half the fun out of flying.

FNG

26th Feb 2002, 14:11

I entirely agree Whirly. One of the many pleasures involved in taking my wife to Burgundy by Bulldog last year was that which I experienced when I found the tiny airstrip on a hill which was our destination, in the right place, at the right time, having got there by DR navigation alone. It was an equivalent, almost tactile, pleasure to that I experienced some years ago when sighting the harbour lights after a night crossing under sail of the Straits of Gibraltar. These old fashioned skills possess a virtue of their own. Crikey, next thing I know I'll be joining CAMRA and going Morris dancing.

As for tying up the resources of D&D because your kit has packed up and you can't be bothered to find yourself, well.... A wind up, perhaps?

FlyingForFun

26th Feb 2002, 19:10

Totally agree with FNG, Whirly and others on this one!

The plane I fly most often at the moment doesn't have any nav-aids at all. But, to tell the truth, when I fly a plane which does have nav-aids, I very rarely use them.

I did make a lot of use of VORs in the USA, that's mainly because the FAA very kindly do all the hard work of drawing lines and figuring out the VOR radials for you! Even then, I always have the map next to me, and I can always point out on the map exactly where I am, by reference to features on the ground.

Plus, as Whirly says, it's fun!

As for an emergency because your nav-aids stop working, we'll leave that to the IFR guys I think!

FFF. .---------

twistedenginestarter

27th Feb 2002, 02:43

[quote] As for tying up the resources of D&D because your kit has packed up and you can't be bothered to find yourself, well.... A wind up, perhaps? <hr></blockquote>

D&D is funded by the state. What the state wants is to retrieve military jets with engine failure, stop you and the missus ploughing in to a hill side fair enough, but that's not the end of it. A big cost to keeping the whole show running is a PA28 flyer struggling with his map around his neck meanwhile sailing through Heathrow, Gatwick, Manchester etc.

Assume GPS etc (and you would have two obviously!)fail very rarely. When they do, just ring up D&D and ask them whether they want you to keep off their wavelength or they would like you to stay until you are out of harm's (ie other people's) way. I'd wager they'd be only too pleased to help avoid an incident.

I'm not saying The New Method is mandatory. Just don't feel guilty if you don't want to do DR after your PPL/CPL, particularly in poor visibility.

FlyingForFun

27th Feb 2002, 16:51

twistedenginestarter,

You're right, GPSs don't stop working very often, except for electrical failure, in which case carrying two would avoid the problem (which everyone does, of course!)

However, the US government reserve the right to turn off, or reduce the accuracy, of GPS, whenever they want, for whatever reason they want! Now I don't know very much about modern warfare, but with military action in the Middle East, I'd say it's not completely inconceivable that Bin Laden builds some kind of GPS-guided missile, and the US government turn GPS off completely to avoid having Washington or New York or some other big target blown up. Not likely, admitedly, but not completely inconceivable.

Sure, D&D are there to help - but can you imagine the carnage if every single PPL who happens to be flying at the time is suddenly declaring Mayday because their GPS has stopped working <img src="eek.gif" border="0">

I agree that nav-aids are there to be used, if you choose to use them. But please, whatever navaids you use, carry an up-to-date chart, make sure it's accessible, and make sure you can always point your finger at where you are on that chart within a few seconds of being asked!

FFF. .---------

[ 27 February 2002: Message edited by: FlyingForFun ]

FNG

27th Feb 2002, 17:39

Depressing how often you hear this on London Info:-

"G-XX, what is your present position?". .or

"G-XX, what is your estimate for XXXX?"

and the answer is "er, stand by"

Windy Militant

27th Feb 2002, 18:12

How Sad to see everyone getting so het up about things. A number of good points made but sadly a lack of knowledge about aviation history on show. A few points of my own they may not be entirely accurate but here goes.. .Firstly the reason that overhead to overhead is used in flight training is historical it goes back to the halcyon days when aeroplanes, even commercial flights were non radio. In the good old days you took off into wind and to avoid crashing into the other people in the circuit you climbed to the overhead to depart. On arrival you flew overhead to check the signals square and wind tee before joining the circuit.. .Secondly the reason that VFR navigation is still taught by the good old fashion book is that it works. Properly taught it gives a solid grounding in the basic principles.. .Thirdly whilst GPS and radio nav aids are fine in their place, remember that the CAA have to consider all possibilities. Imagine as a worst case scenario you have an electrical failure, smoke in the cabin. However as you have dilligenty read the Manuals you are able to shut down the electrics before it starts a fire. You need to get down sharpish! Wouldn't you prefer to be able to divert to an aerodrome with emergency services and good runways rather than just pick a field and hope.. .If you are following your track on the map you are more aware of what's around you than just following the bug on the GPS.. .Technology is a good slave but a bad master to misquote the old saw.. .The standards that are set when you're under instruction are done to start you off as you should try to go on. . .As for departing and joining its good airmanship and just plain self preservation to get briefed on local procedure. I found that one out the hard way myself , though fortunately the only thing damaged was my pride.. .The only way to learn aerial navigation is to do it. The more you do the easier it becomes. A few more hours under your belt and you'll be departing ahead and joining cross wind with the best of them <img src="wink.gif" border="0">

[ 27 February 2002: Message edited by: Windy Militant ]

The Nr Fairy

27th Feb 2002, 18:41

I've just spent 3 weeks in the US, flying a Robbie around Southern California. I used charts ( quarter and half-mill ), a ruler and a pencil to mark the lines - nothing else. I felt since I was hour building towards the CPL(H) I may as well make it useful.

To some extent, VFR nav in the US with a map and a basic log is dead easy the ground features are so immense - only once did I get unsure of my position enough to ask the controller I was speaking to where I was, and that's because it was marginal VFR ( and that's in a helicopter, 10 minutes after I'd gone down to 500' AGL to read a roadsign ). I did use VORs for position confirmation.

On one leg, having found ( to my amazement ) that I'd held height and speed and heading reasonably well, worked out a rough groundspeed, calculated an estimate for the place I was going, I wasn't worried when I couldn't find the airfield because I knew I was a bit left of track, a bit past estimate and therefore too far, and "shouldn't the airfield be over there in relation to that lake and that road ?".

In the UK, I find nav tends to be a bit more difficult I think because there are too many features, but if you keep your eyes open, keep track of where you were and the direction you're pointing in, it's not difficult. Even if you're on a heading you can normally spot features well in advance to confirm you're on track, and that helps with the heading as well if you fly towards a handy reference point.

And as for overhead course-setting, it's not something which adds to the flexibility of a helicopter !

twistedenginestarter

28th Feb 2002, 13:17

FlyingforFun

It is indeed unlikely that GPS will be switched off or degraded by the Americans. Receivers are limited to 999 mph/kts to stop them being used by missiles and our transatlantic friends actually recently removed the deliberate error (SA was it called?) that was originally there to stop Mr Binladen.

You are right however to address risk. Because that what flying - and life - is all about.

The risk of unaided pilotage/map reading is you become lost. If you have ever been lost - I have - it is not easy to get un-lost. In the meantime you can look down and see a large airport. I looked down and saw a smallish one - fortunately I was above its control zone.

The other risk is you spend more time looking on the ground to locate yourself or gain reassurance. Using radio aids as the primary navigation method gives you more time to look out for other aircraft.

With GPS the greatest risk as far as I can discern is that people use map displays so they are not thinking about speed and track nor are they bothered about looking at a proper map. The displays do not show controlled airspace reliably (nothing to do with GPS of course) so people bowl into a zone and give this method of navigation a bad name.

FlyingForFun

28th Feb 2002, 18:08

twistedenginestarter,

Thanks, didn't know about that speed limit on GPS. Everything else you say in your last post I agree with 100%, by the way. Except maybe spending too much time looking at the ground - that's debatable. I think I was probably guilty of that when I first got my PPL. Now I do it much less - I pick a distant object and fly towards it, and as long as I'm flying towards my object I don't need to look directly below me very often. But I can see your point.

Windy Militant,

Joining overhead is still used for exactly the same reason by non-radio airfraft - yes there are plenty of them out there! But I have to admit I can't see the point of departing from the overhead "to avoid crashing into other people in the circuit" - surely you follow the other people in the circuit, until you're pointing roughly the direction you want to go, then you leave the circuit? As for mid-airs, I'd have thought they're more likely when departing from the overhead, because then you're in the same place as the joining traffic?

Nr Fairy,

It's great flying in the US, isn't it? But I assume you didn't go too far east - because once you do, there are no immense ground features any more - except for the dessert, and that's too immense to navigate by!!! The only time I was really glad to have a VOR on board was flying from Phoenix to LA, across western Arizona and south-eastern California - there are just enough mountains to be able to navigate using pilotage, but I was glad to have a VOR to confirm my position.

FFF. .---------