GPS - Why Not????

[Julian]

Having read a few threads on GPS it seems that we pilots in the UK are absolutely **** scared of using GPS as a means of navigation.

Having used GPS in the US for both navigation and approaches I dont really seem a problem with it. There is a current thread on GPS jamming but lets it face, choice of flying blind in IMC with GPS or GPS that could be jammed at any moment, I would take the GPS every time - if you fly an approach in the US then its integerity is certified via RAIMS so you know you arent getting false data, if it fails you go missed.

I think this is one area where the US wins hands up and we are (sadly) lagging behind.

[twistedenginestarter]

From my experience GPS is widely used in the UK both for VFR and IFR flight. I'm have been surprised several times by who just whips one out.

[GRP]

Often seems that people are a little shy of admitting they use one though!

[28thJuly2001]

They are probably the same people who wont admit they shop at Kwik Save.

I use a GPS all the time, best part is when you get home and look just how great your circuit was. <that dont read well. ho hum>
Walt,,

[A and C]

I dont know why there is so much resistance to GPS in the UK ,I suspect that most of it comes from the "old guard of navigators" in the CAA.

If the took a walk down the corridor in aviation house to the aircraft engineering people they would find that most of the airliners flying about are using GPS as the primary navigation sorce backed up by DME/DME , VOR/DME ,VOR/VOR and inertial ref.

GPS is the most widely used system to comply with the european B-RNAV requirement and when a TSO unit is fitted into the pannel of an aircraft and rigged to the proper instruments then it can be used to fly an aproach that is in the data base.

Unfortunatly no one seems to want to set up a GPS aproach in the UK.

I can see the authoritys reluctance to except hand held GPS units because the instalation is not tested can be subject to interference from the VHF com system or simply the passenger accidentily pulling the power lead out of the cigarette lighter socket.

[411A]

One very simple reason GPS is not used for approaches in the UK....not invented there. 'Tis a US system and therefore cannot be trusted.
And for those that mention jamming, these schedules are published well in advance (in the USA) so ops can be planned accordingly.
Have used GPS in my private aeroplane for the last five years and have found it dead-on, every time, approaches included.

[niknak]

I understand that CAA trials with GPS approaches are at quite an advanced stage, but it would appear the problem of ensuring that the system is free from interference has yet to be overcome.
Additionally, although improving, the coverage of sattalite reception is still not 100% throughout the UK.

Airport operators would leap at the chance of GPS approaches being approved, as long as they still had a radar back up, this would then negate the need for having and maintaining ILS systems, which are very expensive to buy and involve a lot of monitering and maintenence.
Equally, I'm sure that airline operators would be equally receptive, for much the same reasons.

It should be borne in mind that when it all does come about, as now, pilots and aircraft will be restricted to certain limitations, so it isn't necessarily the panacea that some may believe it is.

However, whilst there is no doubt that the accuracy of the system is capable of exceeding present instrument approach aids, until the provision of the service can be proved to be as reliable as current systems, AND, a suitable back up is maintained by aircraft and airport operator, it will not be approved.

[BEagle]

Although I'm a big fan of properly-used GPS (but not 'moving map' GPS as that encourages too much 'head in' time), I've noticed the odd glitch in the VFR-only GPS equipment in my 4 PA28s and also the occasional GPS wibble in the Y-code GPS element of the embedded GPS and laser INS in my 'day job' aeroplane. Which is why GPS-only is never used for navigation, GPS blended with LINS or GPS blended with a secondary INS through the Flight Management System is used for LNAV autopilot steering.

Nothing to do with 'not made here' - everything to do with safety of air navigation!

[A and C]

As I see it if you have a aproach aproved GPS fitted to your aircraft ,the aproach is in the (up to date) data base then you can make a non-precision aproach.

The CAA published an AIC on the GPS some time back and if you read deep in the small print you can find the aproval.

[andrewc]

BEagle, do you really mean that you think that it is better
for a pilot to be working out lat/long coordinates rather than
have their position indicated on a moving map? That
has got to be a difficult position to justify...

If you are flying with an approved IR GPS setup in the US
you can perform the whole enroute element of the flight
on GPS, switching over to ILS for the landing phase.

Alternatively as A&C states you can make a non-precision
GPS approach to a beacon using the NDB procedure.

Having had the pleasure of recently doing a stack of NDB
tracking I am convinced that GPS approaches are far more
accurate than the NDB equivalent and less prone to systematic
errors.

-- Andrew

[411A]

BEagle states that...GPS- only is never used for navigation.
Cannot speak for the UK, but in the USA it IS perfectly legal to depart IFR with GPS only, fly enroute (below FL180), approach to and land at an airport using an approved GPS approach. The GPS installation in the aeroplane MUST be IFR approved AND be fitted with a current database.
In addition, in these days of proliferating TFR's and restricted airspace, a moving map display (which I also have incorporated in the GPS) allows a positive way to avoid these areas so that one does not get close and personal with an F-16.:eek:

[Chimbu chuckles]

Our Company Falcon has dual Universal 1D FMSs with imbedded GPSs. They are fully stand alone enroute and approach approved. They can also use rho/rho and rho/theta but our navs need an upgrade to do that, hence we are flying the length and breadth of Asia on GPS only the vast majority of the time. I've yet to see anything less than 'Approach' when conducting enroute RAIM checks. The same applies to pre departure RAIM checks using the US Coast Guard RAIM prediction software/website.

My personal A36 Bonanza has a Garmin 100(like the aircraft itself, oldy but a goody) which one of these days I'll upgrade to an IFR one now that Australia has dozens of GPS NPAs scattered all over.

In 12 years of using GPS daily I've yet to see one glitch in any way that wasn't finger trouble. The classic finger trouble is when, in the older non database ones (Garmin 100) you input an incorrect latitude, i.e. North instead of South, but easily picked up if you note the track distance and find it is several thousand nm out.

IMO GPS will never replace ILS or where it's used MLS but for enroute and NPAs it cannot be beat...the whole world relies on it nowadays...The US couldn't turn it off if it wanted to.

Chuck.

[BEagle]

andrewc - first the VFR-only use of GPS at, say, PPL level. In my opinion you should draw your route on the map and calculate track and groundspeed in the conventional manner. In the ac, enter the GPS route with turning points. Select the data fields to give DTK, GS and ETA plus have the mini-CDI bar displayed. When you are airborne, start your navigation and use the GPS to cross-check your pre-flight work. You can keep an eye on the mini-CDI from time to time, but your primary navigation is by map and time, backed up by GPS.

However, if you have an IFR-approved GPS with all the relevant requirments, things will be different. As far as I'm aware, the UK hasn't published any GPS non-precision approach procedures yet though.

The 'day job' ac uses basically twin INS, one of which is GPS blended. We do not use GPS-only for LNAV, we use the best FMS-derived steering solution to navigate between database or manual waypoints. That's because the GPS element does not have RAIM (astonishingly), nor does it have adequate stability to be coupled directly to the autopilot.

Other ac with infinitely more modern GPS/FMS would not be so hampered, but my point was that not every GPS is suitable for IFR navigation and approach - although it might seem to be very accurate, there's still a chance of it going out to lunch at an embarrassing moment unless it has the appropriate mandatory certification.

[englishal]

In the US there are ' GPS Overlay' approaches which are basically a NPA such as VOR but overlayed on top is the GPS prcedure...which is exactly the same...

So if I was shooting a NPA in the UK and I had an IFR GPS fitted I would set up the approach in the GPS, and use this alongside my conventional nav equipment. If I had a problem with the conventional equipment, I'd follow the GPS....

Cheers
EA:)

[englishal]

The other advantage with using GPS in conjunction with standard nav equipment is that any mistakes you make will become obvious.

By this I mean dialing in say 123.05 instead of 123.50. I was once onboard an aircraft, the pilot was shooting an ILS (can't remember the exact frequecy) something like 123.50 and a nearby VOR had the freq 123.05. The wrong freq was dialed in, and should have been picked up when 'identifying' the navaid...but wasn't...so we had intercepted the 'localiser' which in fact was the VOR....ok there were other clues, like the inbound course, lack of GS etc...but in this situation, the pilot was under pressure and didn't pick up on these things straight away. The thing that made it obvious to me was my handheld GPS (Garmin eTrek) which I was monitoring to confirm the accuracy of the waypoints just downloaded from the web. I could see we were heading away from the airport and towards the VOR...which could have been a fatal mistake as the VOR elevation was significantly higher than the airport....when I checked the approach plate it became obvious what was going on....In this instance the error probably would have been picked up before a dangerous situation arose, even without GPS, there were 3 of us onboard and although vis was ***** it wasn't on the deck. Now imagine the pilot, on his own, in turbulent IMC, apprehensive.....

So I'm inclined to trust GPS and if not use it as a primary navigation system, to certainly use it as a secondary system. The more info you have the better...

Cheers
EA:)

[bookworm]

BEagle

Do you really mean:

"Select the data fields to give DTK, GS and ETA plus have the mini-CDI bar displayed."?

If DTK (desired track) is the same on your GPS as on mine, it's the track between the last waypoint and the next one, which is probably written on the PLOG anyway. TRK is the one you want to tell you which way you're going, and therefore whether your heading is working or not. I find that much more valuable.

[A and C]

A few people have mis-quoted me in post above so lets make this clear A GPS aproach is leagal in a UK registered aircraft ONLY if the aproach is in the data base.

This is because when the unit enters the aproach "ARM" mode the cdi scale reduces to 2.5 miles fsd at the FAF the unit goes from ARM to "ACTIVE" mode this slowly reduces the cdi scale from 2.5 mile fsd to 0.3 mile fsd by the time the aircraft reaches the MAP. the scale will also change back to 2.5 mile in the case of a missed aproach.

As you can see there is a lot more to a GPS aproach than first meets the eye and to be safe the up to date database for the aproach must be in the box.

At the moment I know of no GPS aproaches in the UK.

[BEagle]

bookworm - I do indeed mean 'DTK' and NOT 'TRK'! The idea is that you should check the GPS value against the planned value at the turning point to show any gross error. The mini-CDI will show cross-track error which can be very useful if you have to deviate from track for some reason - such as a rain shower, for example.

A very common mistake is to have 'DTK' and 'TRK' displayed. All that will do is to tell you (from a rather inaccurate GPS-calculation of track angle) that, when the values are equal, you are parallel to your desired track, not maintaining it!

[andrewc]

BEagle, yes that is in fact how I do organise myself for
flights of any significant distance. My GPS gear, a pair
of 430's is rated for IR approach use in the US when a
current database is installed.

This year I've done an IMC, the experience of which
I'm going to spend some time converting to my own
aircraft.

The plan next year is to do a US IR that will give me
full airways and approach access in the UK with
my (N-reg) plane.

-- Andrew

[BEagle]

andrewc - you lucky chap! A pair of 430s indeed! We still have GPS150s and GNC250s.

Using a US IR in your N-registered aeroplane is a very sensible thing to do. But isn't it amazing how the aeroplane's registration makes soooooo much difference to IFR/IMC flying - if it has a 'G' painted on the side you can't use your IR, but if it has a 'N' then all is fine!

[FlyingForFun]

As a pilot who flies VFR in an aircraft which is fitted with moving-map GPS, but who would rather the GPS wasn't there, I feel like I should comment on this.

There is no doubt at all that GPS can be a navigation and safety aid, providing extremely accurate positional information. The thing which concerns me about it, from first-hand experience, is that it makes the concious part of your brain less aware of your location.

When I fly using only a chart, I am always able to point at my location on the chart within a few seconds of being asked. In other words, I know exactly where I am, all the time. I don't often use VORs or NDBs, but the few times I have, I've still been able to pinpoint my position on the chart. A VOR radial simply isn't enough by itself - you need to be able to transfer the raw data from your VOR onto you chart in order to be able to navigate.

When I have flown with the GPS turned on, though, I can't honestly say that I've been able to pinpoint my position so easily. I've known I'm "somewhere south of Newbury", but if you wanted anything more precise than that, it would have taken me a minute to spot landmarks and locate them on the chart. Unfortunately, I can't turn my GPS off, since it doubles as a radio. However, I now switch the GPS to a mode which doesn't show me any navigational information. It's comforting to know that it's there if I manage to get myself completely lost, but I won't use it any other time, because I don't like the effect which it's having on my situational awareness.

The last time this was discussed here, someone (sorry, I forget who) suggested that it's useful to program your route onto the GPS, but then set your display so that the only thing it shows is your planned track. That way, you can't use it to get navigational information, but it serves as a nice check that you're on track. This sounds like an excellent idea, and one which I plan to try, but a combination of bad weather and non-flying commitments means I haven't had a chance to try it yet.

This is all IMHO, of course!

FFF
-------------

[bookworm]

bookworm - I do indeed mean 'DTK' and NOT 'TRK'! The idea is that you should check the GPS value against the planned value at the turning point to show any gross error. The mini-CDI will show cross-track error which can be very useful if you have to deviate from track for some reason - such as a rain shower, for example.

A very common mistake is to have 'DTK' and 'TRK' displayed. All that will do is to tell you (from a rather inaccurate GPS-calculation of track angle) that, when the values are equal, you are parallel to your desired track, not maintaining it!

Interesting. I'll extend the debate, not because I believe there's a right way and a wrong way to do it -- clearly how you use the tools at your disposal is entirely up to you -- but because we can learn from different techniques.

DTK is static. It can be checked against your PLOG before flight. There doesn't seem to be much point in displaying it. I like to have BRG (which gives the bearing to the waypoint) and TRK on display.

I find TRK the single most useful output from a GPS, as it takes away all the uncertainty of drift. As you say, DTK and TRK is not a lot of use, but BRG and TRK aligned can tell you that you're going the right way, and, if you diverge from your intended track, what you need to do to get back there sensibly.

I've never understood why anyone with the choice of a CDI or a moving map would choose the CDI, but I realise there's not the luxury of a map with all equipment.

[wet wet wet]

I don't think that the anti GPS stance of the CAA has anything to do with it being an USA system, as has been suggested, after all VORs and ILSs came from the states. There MAY be an issue that the USA can downgrade the accuracy (or even switch it off) at any moment.

However, I think that the real problem is that it is very easy to jam the very weak GPS signals over a small area, i.e. the approach path to a major airport. I guess the tests that were carried out this weekend were to access the threat.

Also I would hate to do an approach to the minima with a display that only updates once a second!

[englishal]

Its very easy to block an ILS....just park another aircraft in an ILS critical area, and there you go :D

[A and C]

If the GPS signal fails or is switched off then an aproach aproved GPS unit will put up a nav fail flag just like if the signal fails on an ILS or VOR ,this is more than we can say for the CAA aproved NDB aproach !.

[BEagle]

'BRG' and 'TRK' will get you to your turning point if you're off track - not necessarily back to your planned track. You may as well just press 'Direct to' if that's all you want to do! 'DTK' and the CDI bar remind you of the original planned track and show relevant cross-track information relative to it.

I specifically asked my radio shop to source a GPS150 and 2 GNC250s rather than something with a moving map to reduce 'head-in' time - and to stop student pilots being seduced by GPS. We train our students to be able to read off GPS range and bearing from their home aerodrome if they need it to help ATC find them quickly (the default waypoint is user-defined as our home aerodrome). We do not teach 'GPS for naviagtion' to non-licence holders

However, that was before the advent of kit like the Garmin 430 which is in a rather different league!

[QNH 1013]

A difficulty with trying to use the built-in database in a 430 or 530 to check a procedural Instrument Approach is that the database only contains the Cat C/D procedures. The outbound track for Cat A/B is frequently different. Does anyone know if the GPS approaches in the states have the same tracks for all aircraft cats?

[411A]

In answer to your question...yes, nearly all do have the same tracks for the various aircraft catagories.

Was just quoted an install cost for a Garmin 530 of $13,200...very tempting indeed. Puts my King KLN89B to shame.

Have done over 50 GPS approaches to date...all 'spot on'. The FAA releases approximately 6 new GPS approaches per month.
And...are now considering LORAN approaches as well, as a back-up for GPS.:D

[GoneWest]

I'm not going to vote either for or against - the GPS is an amazing piece of kit if used correctly .

First scare I had with it was listening to an R22 helicopter, which was talking to London Information.

Pilot asked for weather at Gloucester, FIS read it to him - it was cr*p. Fog. When asked for his position and intentions, pilot (term used loosely) informed FIS that he would "have a go at finding Gloucester" - but was not 100% sure of his position due to being IMC (in an R22)....but the GPS was telling him that he was tracking down a valley between mountains.

Second encounter was hearing a Bonanza, talking to Miami Center. I had heard the aircraft come on frequency and declare his route as Ft. Pierce to North Palm Beach - a magnetic track of approx. 170 degrees.

Miami later called the Bonanza and asked for confirmation of destination and heading. Aircraft confirmed "North Palm Beach - heading 224 degrees". When Miami pointed out that 224 degrees would not get him to North Palm - the pilot (?) argued that the heading shown on the GPS was 224. 54 degrees of drift?

Helicopter pilot (British Army Air Corps - in the Gulf War), turned on GPS whilst aircraft was on the ground at base camp. GPS put their position as 180 kilometers further East than where they were.

Was working with the FAA at a safety meeting and heard two FAA inspectors discussing a previous flight they had taken together. GPS went blank - for forty minutes.....they were grateful it was during the cruise, not on an approach.

Last encounter worth recalling was that of John Steurnagle (Senior bunny with AOPA, USA). His passenger (also a pilot) pressed the magical "direct" button. Read off the track and distance and suggested turning that way......which would have taken them straight into a mountain.

The truly scary thing with GPS is that people simply believe it - with little or no mental picture of what it should be showing.

AOPA (USA) say their main fear is that there is no standardisation of display and controls - even on different models from the same manufacturer.

A truly magical piece of kit - if used correctly.

[A and C]

Having used the King KLN 89B and both the Garmin 430 and 530 you may well find that the 89B is a lot more practical to use in the air than the 430.

The 530 with the bigger screen is a lot better as more can be put on the screen and this saves a lot of knob twisting.

If I was re fitting an aircraft avionic stack now I think that I would go for the GNS 530 and a nav/com rather than two 430 units the main reason being that the 530 has the screen space to interface with a lot of kit such as data linked real time WX imformation ,stormscope ,TCAS and may be soon real time data linked trafic imformation.

I,m keeping my 89b in the aircraft for a year or two just to see what happens the 430 from garmin was a big step forward but was very much a MK 1 box the 530 has shown that.

New displys are on the way from King some will interface with the 89B so this may be the way for you to go rather than to rip the whole fit out .

[411A]

Many thanks A and C, I was going to keep the 89B regardless, 'tis a nice unit (and paid for). The rest of the radios are King Gold Crown and are still working fine after all these years. As you mention, some very nice units in the pipeline, especially multi-function displays.

[Julian]

Well nice to see I have got a bit of a debate going with even a few comments from the day-to-day pilots.

I tend to file IFR for most flights now and even though I am navigating mainly via VORs or under direct vectoring from ATC I still carry a handheld GPS. This weekend was a prime case, 3-up over to France and a cloud base of 700' we were running a handheld linked to a laptop running moving map software, it is actually very accurate. It was also very useful afterwards to checkout track , alt holds, etc during the flight afterwards. It gave us a useful secondary indication especially after we lost the VOR signal and were waiting for the next to come in, we were holding a mag heading.

If a GPS was fitted in an aircraft I would have it switched on and in use, I do not see the point of disregarding a piece of kit that is there to help you. I must admit to being a bit bemused by FFF comment on wishing it wasnt there, there is nothing to stop you having it switched on and ready and waiting - you shouldn't be living on the panel as a VFR pilot anyway :D Dont forget FFF that you can use two radials from VORs to find out where you are exactly on the map also if you have DME equipped aircraft you can again find out where you sit on a particular radial.

As stated previously you should make sure you know how to use one first! I think this is pretty self explanatory though as you would not attempt to track a VOR if you had never been shown to do it first - probably a bit suicidal :rolleyes: , who knows where you would end up... Anyone who would just blindly follow a GPS heading without checking first should not really be in an aircraft, you have your charts, you have all the aids to tell you where you are on that chart - think then act !

[FlyingForFun]

Quite right, Julian, you can use two VORs, or VOR/DME, to find where you are on the map. And most pilots who use VORs do this at regular intervals, because it's necessary to have any kind of situational awareness.

With a GPS, however, it's possible to have some kind of situational awareness without attempting to transfer the data from the GPS onto a map. Therefore, the pilots I've flown with who use a GPS for navigation - and I include myself in this - tend not to bother to do so. Thus, their situational awareness is well below the standards of a pilot who uses VORs, or ded reckoning/pilotage.

As for why I'd rather it wasn't there, what I really mean is that I don't like to use it, because I notice my situational awareness decreasing when I do use it. Certainly if I was kitting out an aircraft myself, I'd save myself the money - maybe fit a VOR/DME or two instead if I really felt I had to spend some money on nav-aids. Sorry if I bemused you! :D

I should also point out (again) that the above is a generalisation, and is all IMHO. Of course there are some very good pilots out there who are using GPS, and it's possible, with a bit of discipline, to maintain situational awareness with a GPS that's as good, or better, than without. But see GoneWest's post for some excellent examples of where this hasn't been the case. I don't want to be one of the people GoneWest is writing about, which is why I don't use the GPS in my aircraft.

FFF
-------------

[Chuck Ellsworth]

Wow:

I really am begining to feel afraid to fly in British airspace knowing there are pilots who do not use every nav aid availiable to them for situational awareness.

To not use, understand and trust the information being displayed on a GPS is truly difficult for me to believe.

I will be flying from Prestwick to Iceland, Greenland and North America in a couple of weeks. If I do not use the four GPS receivers we have on board can anyone please, please explain to me what form of navigation units I should replace them with?

A.D.F.?......Yeh that is what I will do get rid of the GPS units and put in four more A.D.F.'s :) :)

Cat Driver:
...................
:D The hardest thing about flying is knowing when to say no.:D

[englishal]

Chuck,

You can just DR your way across:D

Sounds like an interesting trip, one I hope to make in the future...

Cheers
EA;)

[411A]

englishal,
Take it from one who HAS DR'ed across the North Atlantic (destination Stansted, B707-138B ferry circa 1975, LORAN & both Bendix Dopplers went kaput) it ain't fun. If it had not been for Clipper and TWA providing drift data, might have ended up in.....France.:eek:

[Chuck Ellsworth]

411A:

At least in France you can get good food.:D :D


Cat Driver:

[Julian]

Chuck - Well said mate! I think the US has a much more pragmatic approach to GPS.


FFF - I see where you are coming from and I agree that when VFR its only right to be fully aware of where you are. There are going to be occasions as stated where you cant judge where you are by DR so GPS is the only way really - even if the dreaded 'Men In Black' are out with jammers! I just think we are a bit backward when it comes to GPS, I think it is a very interesting debate though.

Julian.

[Sdn Ldr Handlebar]

Chuck my man

GPS.....pish and tish

I've said it before and I'll say it again....small HB with a pink rubber on the end...... a note pad.......and a sextant.......saved me on more than one occasion.....can't patch flack holes at 12,000ft with a GPS system.

Must Fly.....TTFN

Sdn Ldr Handlebar

[Chuck Ellsworth]

S.L.H.:

Great, how about flying the ferry trip with us and we will let you navigate with your equipment.

However what do I do if there is no way to see the sky? ( you know about cloud cover I presume? )
:) :)

Cat Driver:

[QDMQDMQDM]

I will be flying from Prestwick to Iceland, Greenland and North America in a couple of weeks. If I do not use the four GPS receivers we have on board can anyone please, please explain to me what form of navigation units I should replace them with?

Me. I'll use ESP to get us across if it means coming along in a Catalina. ;)

QDM

[Chuck Ellsworth]

QDM:

Great reply, but all kidding aside I sometimes believe that only ESP can account for some of the luck we have had on some of our trips.

All the planning, care and experience on earth sometimes will not keep us from fuc.ing up when making decisions.

Staying alive is part training, part experience, part planning part caution and blind luck.... and possibly ESP.

Just imagine the money I could make if I offered seats for sale on some of these flights. ;) ;)
Cat Driver:

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

[FlyingForFun]

Chuck, that sounsd like a fun trip!

No doubt at all that GPS is extremely valuable for that kind of flight. I certainly wouldn't want to ded reckon over any large stretch of water - I've done it over the Channel, which was ok, but that's the furthest.

I have flown over the desert of eastern California, in an aircraft without GPS - not much on the ground to navigate by there, especially when vis was reduced to about 10 miles by a dust storm (although still more on the ground than when you're over the sea!) I made far more use of the VORs on that flight than I have on any other VFR flight (which accounts for almost all the flying I've done, since I don't have an IR or IMC rating yet). I'm pretty sure I'd have found a GPS very useful for that flight, too, if I'd had one.

Question - and I'm not trying to provoke an argument here, I genuinely don't know the answer. If you are navigating a long way over water, using GPS, how do you know where you are? I presume a moving map GPS will simply show a large area of sea, with a line showing your track. Would you zoom out enough to see the land too? Or would you get your distance to go off the GPS and use that to find your location on the chart? The only thing which would worry me is if you haven't thought about that, if you were just planning on flying the line the GPS tells you to fly until you reach the land. I'm certainly not suggesting that you'd do that, Chuck - in fact, I don't know of many pilots who would. I can think of one, maybe - I only flew with him once, and never again.

FFF
-------------

[QDMQDMQDM]

If you are navigating a long way over water, using GPS, how do you know where you are? I presume a moving map GPS will simply show a large area of sea, with a line showing your track. Would you zoom out enough to see the land too? Or would you get your distance to go off the GPS and use that to find your location on the chart?

Wouldn't you just read off the lat / long every half hour or so and then put a cross on your paper map to maintain situational awareness?

QDM

[FlyingForFun]

Good point QDM - thanks.

FFF
---------------

[QDMQDMQDM]

Just imagine the money I could make if I offered seats for sale on some of these flights.

Chuck,

You definitely would have thought so, but that French guy went bust, didn't he? The chap who was taking tourists on the old Empire Boat route to Lake Tanganyika in the eighties?

Maybe if you were going that way in any case, though, it might be worth it.

Anyway, I've got my thinking cap on and am concentrating reeeal hard. ;)

QDM

[Vortex what...ouch!]

I use GPS to assist with my navigation every time I take off.

I program it with all the waypoints I have planned on my map. I then use it as my primary navigation instrument and cross reference it every few minutes against what is written on my paper chart. It is much simpler and easier to navigate this way. My SA remains high and I can spend more time looking out the window than at my map. This has to be a good thing.

Have had 2 GPS “failures” in the cockpit. I have used it in and out of the cockpit for over 6 years and these were the only 2 times it dropped out. One was batteries (I had the screen contrast on full instead of half and it drained the power and as a heli pilot I only have one spare hand to change them, which is not possible) the second it just dropped out. On both occasions I knew where I was and simply carried on and navigated using my map. I don’t see what the problem is here.

I really have difficulty in seeing how using a GPS is a bad thing. If people are not planning the route using a GPS with the same diligence as they do on paper and fully understand how that GPS works then they should not be in the cockpit in the first place.

It is simply another “tool” to assist you in getting safely from A to B. Understand it’s benefits but also it’s limitations and you will be fine.

[Chuck Ellsworth]

QDM:

Yes the French guy quit, but not for lack of customers, rather it was the mind boggling bureaucracy and corruption that is prevelant throughout Africa and especially Egypt.

The PBY I am flying to the U.S.A. was in Africa with the idea of using it for Safari trips, it also was given up as a bad idea so I went back to Africa and moved it to London.

Now back to GPS and navagation.

When flying over the Ocean or large desert areas such as the Saharah we " ALWAYS " keep an ongoing written record of lat and long for situational awareness, as well I " ALWAYS " keep a updated list of nearest airports to divert to in the event of an emergency.

In fact over the Ocean I have my Anywheremap cones of safety set for drift down in the event of an engine failure to show what airports would be in range if I canno't maintain altitude due to long range fuel overweight conditions.

The Airmap 300 can be set to a scale from 1 to 4000 miles, so looking ahead for the coastlines on the moving map is a no brainer.

I strongly suggest that all pilots learn all about the use of GPS as it is without doubt the most accurate and dependable form of navigation avaliable at a price the adverage pilot can afford.

The comments by the helicopter pilot explains everything you need to know about how to use it and the added safety of using it correctly.

So do not listen to all the naysayers about GPS not being the best nav aid availabel. Anyone with that attitude couldnt pour pi.s out of their boots if the instructions were written on the soles. :D :D

Cat Driver:

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

[Sdn Ldr Handlebar]

Chuck my man

Great, how about flying the ferry trip with us and we will let you navigate with your equipment. However what do I do if there is no way to see the sky? ( you know about cloud cover I presume? )

Good point well made.......must say that I find a lot of you techy types fall for this one......over reliance on technology, that's what it is.......in my day we were taught to use the signs that nature puts up.......or even road signs if we could get low enough to read them without crashing........

The ancient Incas were great travellers and navigators........most people don't realise that they traversed great distances with only the stars to guide them.....didn't have road signs apparently......damn shoddy of them if you ask me......well the secrets of how the Incas navigated at night in cloudy weather was thought to be lost.........not so.......on one of my expeditions to the Andes I discovered the secret of navigating in cloudy weather..........

All one needs is a Howler Monkey........simple isn't it.............as we all know the Howler Monkey always howls facing the North Star.......by some sixth sense the Howler Monkey can sense which direction the North Star is in to great accuracy.....even in total cloud.......so knowing which direction the North Star is in should enable you to navigate quite safely on your modest little jaunt........

Don't forget to pack at least 10cwt of monkey nuts and two or three bunches of bananas.......nothing more morose than a sulking Howler Monkey....

Well must fly.......TTFN

Sdn Ldr Handlebar

[Flyplan]

A few eons ago I was fortunate to get involved with the Red Arrows. On a visit to Scampton and whilst sitting in a hawk I asked the question on Nav as their equipment seemed 'limited'

I was shown a large patch of velcro. 'That's where we put the GPS' came the reply.

Good enough for the Reds, good enough for me!!!