DME/VOR & NDB Approaches

[Daniel Beurich]

Hi Everyone,

Im currently a student pilot with about 20 hours or so, Just was abit curious about how to do a VOR/DME and/or NDB Approach, any explanation, or a website that explains how from anyone would be great! thanks!

Daniel

[swh]

Daniel,

Your at the stage of your training where you could benifit from understanding some basics of instrument flying.

If you get a chance during one of your lessons why dont you ask one of your instructors to demostrate an instrument approach, you would learn more than anything you could read. Alternatively, try and back seat some instrument training flights out of Cooly.

Essentially any instrument approach is a combination of level and descending turns, & level and descending straight segments.

Good luck with your training.

:ok:

[helicopter-redeye]

There are a number of books available on precision and non precision approaches. Take a tour around the Transair site on similiar.

One of these would give the theory. To be able to do it you need to do the course (basically IR) to be safe and effective.

Best to get an appreciation of the concept with an instructor on your PPL (as above) then concentrate on the basic VFR flying for now, so you can do this (running & walking etc)

Gd luck,

h-r

[witchdoctor]

level and descending descents? :confused:

blimey! glad that wasn't in the ir. ;)

[Droopystop]

Very simply, you track towards the beacon (assuming of course that it is on the airfield) on a published radial that aligns with the runway. Descent is governed by published heights/altitudes at various DME from the threshold. For example the inbound QDM might be 180 degrees so you track towards the beacon on the 000 radial keeping the head of the needle on 180 (your heading might be offset to allow for any cross wind) and at 6d you should be at say 1800', 5d at 1500' etc until the minimum descent height which is again published. All the information is given in the Aerodrome section of the AIP, but Aerad or Jeppesen plates are more user friendly in the air.

[swh]

Daniel,

I cannot emphasise to talk to your instructor about this further, if you were to follow a runway aligned radial at Cooly (Gold Coast/YBCG) you will hit a hill, approaches there take you over water, or are not aligned directly with the runway to avoid hitting a hill either during the approach or go-around.

:ok:

[silverknapper]

Running before walking!!

I reckon a PC based program best illustrates it. Try RANT. I'm sure any decent flight sim would do it though.
However don't try it just yet!!!

[Big Pistons Forever]

For a 20 hr pilot I would only start studying IFR procedures if you can answer afirmative to the following questions.

- I fuly understand the aerodynamic principals affecting all flight modes

- I fully understand airlaw and know and understand all ATC phraseology aplicable to flight training

- I know how every system in my aircraft works and have a firm grasp of all memory items for every emergency procedure in the POH

If the answer is no to these questions which based on experience is highly likely, than I would suggest your efforts be concentrated on aquiring the foundation knowledge which you will use throughout your flying life

BTW I actively discouraged my PPL students from considering any IFR procedures except at the very end of the course. I also cover up the AI and DI untill the student is 100% proficent at attitude flying by looking out the windshield. Besides what is your hurry, the best part of flying is looking down on the passing country side on a sunny calm afternoon.:ok:

[Chuck Ellsworth]

"I also cover up the AI and DI untill the student is 100% proficent at attitude flying by looking out the windshield. "

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

How refreshing to see some instructors understand this very basic issue.

Now if all the rest of the instructors will follow BPF's example we will have far better PPL's flying around.


Chuck E.

[Daniel Beurich]

Guys,

thanks for the .understand what you are talking about.

SWH,

Yes, if i was to follow the radial directly in probably would hit a hill! I was booking my next lesson in with my instructor, and he said he could demonstrate a VOR/DME approach for me.

I've been an entthusiast for quite a few years, and ive gone solo, i was jsut a bit curious, because when i look at the charts, i wish i could understand it, it seems very more complicated than the SIDs or STARs!

I would never dream of trying a VOR/DME approach or even practise one, unless i had the full backup of my instructor, who would say the same as you.

Daniel

[S-Works]

wow the luxury of having an AI and DI to cover up! The aircraft I learnt in had a slip ball and an ASI and a VSI and RPM gauge.

At least it made us look out the window as there was nothing to look at inside!

[Droopystop]

With only 20hrs, I would suggest that a demo of an intrument approach is a waste of money. They can take a long time, particularly at a busy aerodrome. Save your money for now and look forward to having the demo when you have your ppl. You will learn and remember alot more then. There is a lot more to IF flying than just following the approach plate.

[drauk]

Daniel, don't be put off - if you want to learn about instrument approaches you go ahead and learn about them! I would have thought enthusiasm to embrace a subject should be encouraged, not shot down by a bunch of elitists who may be factually correct but just love to conserve their perspective. Instrument flying is quite difficult and can be dangerous, but it is also expensive and time consuming, so some people that have been trained to do it have a very high opinion of themselves. Learning about it is not dangerous or expensive (there are plenty of good books or try a PC flight sim for example, though some would say they could slow down your progression in learning to fly for real).

I don't think you'll learn anything very useful at this stage by doing one with your instructor and it might take a reasonable chunk of your one hour lesson, but it's your money and if you want to see it done, go ahead. There *are* people on this forum who would happily take you on a flight and show you one for free, though I've no idea if there any near you.

Alas, you should continue to be wary of what you read on a forum like this. At the least the fact that someone who criticized someone else for careless writing (about how an instrument approach is following a published radial that aligns with the runway when in fact it isn't always the case) that says "I cannot emphasise to talk to your instructor about this further" should bring a smile to your face. He seemed concerned you might try and do one without any further training and so you should talk to your instructor about it, yet through careless writing states the opposite!!!

[IO540]

I am with drauk 100%.

No harm in being curious. This keen pilot might, just possibly, be one of the very small percentage that don't pack in flying a few airborne hours after they get their PPL.

After all, VFR flight in European weather is very limiting if one is actually going to go places. (That will really get some people here going :O )

Where on earth is YBCG??

[drauk]

IO540: YBCG (http://fly.dsc.net/u/Info?id=16489).

[IO540]

Well no wonder it isn't in my Navbox database :O

In Australia, and asking about instrument approaches? He must be planning to come to the UK :O

[Chuck Ellsworth]

" Instrument flying is quite difficult and can be dangerous, "

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

On the other hand if you were to start your training with all flying being done on instruments except the take off and landings using the IFR minimums of 200 foot ceiling and one half mile visibility as your base line. Instrument flying would be normal for you and all you would need after getting your PPL would be getting a VFR endorsement added to your license.

So conversley for a pilot having only IFR training and skills it would stand to reason that flying VFR would be difficult and could be dangerous. :E

Chuck E

[Say again s l o w l y]

Take BPF's advice. Don't worry too much about instrument procedures yet. Concentrate on what you are doing at the moment. It will all help you in the end.

I found that when a low hours student started asking lots of questions about stuff they hadn't got to yet, it just confused things and made everything more complex that it was required to be.

With anything in flying, learn the basic skills first and you'll find the more advanced stuff comes far more easily.

It's a real pain trying to teach instrument flying to someone who hasn't got the basics of attitude flying down properly yet. A waste of my time and their money.......

BPF, in relation to the AI and DI. Amen to that!!

[FlyingForFun]

Very good point, Chuck!

Instrument flying is not dangerous, but it is dangerous if you haven't had the correct training, and it also requires more effort to remain current than VFR flying. I think we can probably all agree on that.

So, with all the also provisos of making sure that Daniel understands that his PPL will not train or qualify him for doing instrument approaches, and he would be extremely foolhardy to try to do so without having the proper training first, here goes.....

Daniel, you said that "when i look at the charts, i wish i could understand it". Different charts are laid out in different ways, but whatever type of chart (or "approach plate") you look at, there will be similar information.

Somewhere near the top of the chart will be a plan view of the approach. For a VOR/DME or an NDB/DME approach, this will, in most cases, show the beacon on the airfield. You will track towards the beacon, and then turn outbound on a specific track (a "radial" for a VOR, or a "QDR" for an NDB). Depending on the approach, there may be different tracks given for different categories of aircraft speed - Category A is the slowest, and so that's the one you will be most interested in.

You will follow this track for a set number of miles, as indicated by the DME. At the end of this, you will turn around. There are a few different ways of turning, and the plate will show a pretty good graphic representation of the type of turn which is called for. If you describe to us what it looks like, someone will tell you exactly how many seconds to fly each part of the turn for.

As you make your turn, the aim is to finish the turn lined up for the inbound part of the procedure. A bit of practice is required to be able to judge what the instruments are telling you, and either increase or reduce the rate of turn very slightly to make it work out as planned. But, by the end of the turn, you should be nicely lined up for the inbound leg, which will again be expressed as a radial to a VOR, or a QDM to an NDB. Now, it's simply a case of flying a wind-corrected heading to follow this track (with some guidance from the instruments) until you break out of the cloud. In most cases, you will be lined up with the runway - if you are not, the approach plate should describe where you will be relative to the runway.

That's the plan view of the approach. Just below this will be a side view, showing the descent profile. Generally, you will fly to the beacon at or above some set altitude or height. Ideally, you want to be there at the lowest possible altitude, but if ATC refuse this (e.g. because someone else is already there at that altitude), you may have to "hold" (i.e. fly a race-track type of pattern) over the beacon, and descend to the lower altitude in the hold. (Holds are whole other subject themselves, but are represented on the approach plate by a racetrack symbol). The descent profile will show a descent during the outbound leg of the procedure, with a minimum altitdue/height to which you should descent. Then you make the turn (see above), and you typically continue the descent once the DME shows you being a certain distance from the field on the inbound leg. In many cases, that's it - now you just set up an appropriate rate of descent for your groundspeed, and continue descending until you break out of cloud. There will, somewhere on the chart, be indications of how high you should be at certain DME distances, so that you can measure your progress and adjust the rate of descent if you are coming down either too fast or too slow. In some cases, you will have to be not below a certain altitude at some distance on the inbound leg, and then after that distance you may continue the descent - this is typically because of terrain or restricted areas on the approach, and this will be indicated by a horizontal line on the descent profile.

Assuming you break out of cloud in time, that's it - you then look out of the window and continue the approach visually. But a key part of any instrument approach is what to do if you don't break out of the cloud in time - you can't just carry on going until you hit the ground! Near the bottom of the plate will be a table showing the MDA - Minimum Descent Altitude - or MDH - Minimum Descent Height - for different categories of aircraft. You must not descend below this altitude/height, under any circumstances, unless you have the surface in sight. If you reach that altitude, you are allowed to level out, and continue to a point known as the "missed approach point" in the hope of seeing the ground. (The missed approach point will be shown on both the plan view and the descent profile.) If you get to there, and you still haven't seen the ground, then you must follow the missed approach procedure. This is usually shown by a dotted line, and is often described textually as well. It will usually consist of climbing on the runway heading until reaching a certain height, and then turning either left or right to track back to the beacon, but the exact procedure is different for every approach.

Hope that helps you make sense of all those marks and lines!

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

[Chequeredflag]

This may be 'de rigeur' to you guys, but before I commenced my PPL course, I spent (literally) hundreds of hours on the Microsoft flight sim, flying Cessnas, Baron's, King Air's, 737's and the like all over the country "blind", only using VOR/NDB's etc, and then capturing the glideslope for an ILS landing in 1/2 - 3/4 mile viz. It was basically self taught, with help from the F/S handbook, but I've got pretty good at it (from the safety and comfort of my study - I DO know the real thing is a LOT different!). Don't shoot me down, I know it's not the same thing, but I'm sure it has given me a head start from the 'understanding' point of view.

I love all the navigation aspects when sailing our boat, and am "comfortable" with crossing the Channel shipping lanes in fog, our colour chartplotter with radar overlay and MARPA (think TCAS) is a brilliant bit of kit. Yes, I have had the training, and can plot it all manually if I have to.

The problem with all these hours "flying" IFR is that I am constantly being hammered by my instructor for looking at the instruments rather than out of the window.

Nevertheless, I still think a flight sim with a decent joystick is an excellent learning tool. OK, start firing!!!

[boomerangben]

FFF, and then the wind blows and makes all those neat loops and straight tracks go all wonky!!! Not to mention do strange things with timings.....

Chequeredflag. I never got the hang of FSim - I kept crashing so it was never very beneficial to my training! As for keeping eyes out, get your instructor to cover up instruments and see how you get on. I found it helped students maintain speeds and headings better which will make any subsequent IF training much easier.

[Big Pistons Forever]

I just re-read my earlier post in this thread and on further reflection, think it is a bit too strident. The one thing flying has tought me is the more you know the more you realize what you don't know. I hope you are enjoying your flight training and wish you every success. I started my PPL course almost 30 yrs ago but I still have many vivid memories of my training. I answered your post because the the most profound lesson I learned as a flying instructor was the importance of foundation skills. The ability to accurately control the aircraft by visual reference is the cornerstone of good flying. In a perfect world the airplane should be doing exactly what you want it to be doing for the entire flight. So for example if you want it to climb at 75 knots than that should be the number on the ASI, not 71 or 78 or any other number. The effort spent on the basics now will pay off later in many unexpected ways.

[Chequeredflag]

Yep! He's already covering up the instruments! I've got 4 lessons this week, 3 next, and 3 more the week after that. By mid Feb, weather permitting I'll be up to around 16 hours. I'm fighting my way through the Air Law syllabus at the moment. At 61 years of age, it's a long time since I've had to revise for an exam, and it's come as a bit of a jolt!

[Global Pilot]

Now VFR from Europe to YBCG is to be left to the likes of Amy Johnson [RIP]!

Your PPL course will cover IF [Instrument Flying] in good time.
Satisfy your curiosity for instrument approaches with some computer software. Flight Sim for example will talk you thru the basics. I would also recommend using RANT.

I don't wish to dampen your spirits in any way and wish you the very best in getting your PPL . Enjoy it and see you up there!

[boomerangben]

Chequeredflag

Brings back memories of my flying training. Happy days (apart from those days spent doing autorotations!). Best of luck with your ppl and of course your exams. Fly safe.

[Chequeredflag]

Thanks Boomerangben. Pal of mine's got a Jet Ranger, and he took great delight in demonstrating autorotation one day. It was nowhere near as dramatic as I'd expected, but scary to a novice nevertheless!!

[englishal]

So conversley for a pilot having only IFR training and skills it would stand to reason that flying VFR would be difficult and could be dangerous
I quite agree....Whenever I negotiate complicated or very busy airspace in the USA, I always go IFR:E

Its so much easier to let air traffic tell you where to go, than to have to work it out for yourself;) (just be aware of where the hills are in case they decide to descend you into a mountain)

[Kyprianos Biris]

Hi Everyone,

Im currently a student pilot with about 20 hours or so, Just was abit curious about how to do a VOR/DME and/or NDB Approach, any explanation, or a website that explains how from anyone would be great! thanks!

Daniel


To answer the original post; try these Daniel :

http://www.navfltsm.addr.com/

http://www.fergworld.com/

http://www.whittsflying.com/

http://www.stoenworks.com/