NDB approach without ADF

[Dollehz]

Hello,

Yesterday i had a discussion with an IR student who was training NDB approaches.
The aircraft used in training is equipped with a G1000 but not with an ADF.
The training is done using a waypoint (the NDB) in the G1000.

My question: is this legal? (EU regulations)

As far as i'm concerned one is allowed to do this providing you have the conventional navaid tuned as backup, but since there is no ADF installed, for me this aircraft is not allowed to do NDB approaches.

Is this correct or am I missing something here?

Thanks

[TwoFiftyBelowTen]

You're probably better off without the NDB! ... but I'm betting you can't do it.....

[BOAC]

I'm sure if it is 'training' only and VFR then it will be ok.

[Dollehz]

Indeed, accuracy is without a doubt better and in VMC there is no problem.
However this was in IMC :uhoh:

[flyboyike]

An En-Dee-What?

[dubbleyew eight]

NDB, non directional beacon. basically an AM (amplitude modulated) radio station transmitting continually a 3 letter morse code identification.
you tune the advertised frequency, listen for the morse ident to make sure you are receiving the intended station.
then the needle of the ADF (automatic direction finder) points to the transmitting station.

since the NDB isn't a DME (distance measuring equipment) there is no two way transmission between an aircraft and the station.
so an aircraft using the location of the antenna as a gps waypoint causes what problem??
there is no interference with the transmitter so it is basically a separation from other aircraft issue.

[Intruder]

Legally you must have the required equipment for the approach.

If it is solely an NDB approach, you need an NDB. If it is an NDB or RNAV approach, you can use the Garmin.

[flyboyike]

Thanks, dubbleyew, looks like my humor passed over you at FL390.

[mad_jock]

Its not really preparing them for the real thing due to the bearing being stable.

No dip or any of the other things which the bloody thing does to annoy you.

training in VMC isn't a problem shooting a IFR approach wouldn't be allowed or legal.

[Denti]

Yup, however regulations are sometimes somewhat funny. We do have to have an ADF for a NDB approach, however we do not need to monitor it anymore, although it is still recommended. Since in germany an ADF is minimum equipment for IFR approval we do have them of course, but only one, whereas it used to be two a few years ago.

[mad_jock]

you see through experience I don't do that I just use the needle and use the GPS as backup.

I do three NDB approaches regularly that if you set up the GPS and radial and fly it spot on you will end up over to one side with a bit of nasty get it back onto finals from mins.

Where as if I fly it on the needle I appear bang on finals.

Don't ask me why because I don't know.

[+TSRA]

I guess this could be semantics, but where in the regulations does it state that the ADF must be standalone? It says that you must have one (IFR), but as far as I'm aware (and I'm ready and willing to be corrected for my own knowledge) it does not state that it cannot be combined into another instrument. Heck, if it had to be standalone than most of the aircraft I've flown for the last couple of years have not met regulatory standards.

Not that I've ever flown a G1000, but it would be worth looking into the manual to see what it says about the ADF presentation. If it overlays on an HSI (just like any other HSI) than I don't see an issue from a regulatory perspective.

Granted, it may "wash out" all the errors inherent in using the ADF to track an NDB, but I guess that's what we call progress. :\

A very interesting discussion though. Glad to see there is instruction in minimum IFR equipment requirements.

[Intruder]

A computer generated waypoint is NOT an ADF. Only if the unit has an actual ADF radio receiver and is capable of displaying the raw data would it qualify for an NDB approach.

The lack of progress would be the airport failing to qualify an RNAV approach overlay for the NDB approach...

[+TSRA]

You're right Intruder, it's not. But I was talking about the situation where the aircraft had an ADF antenna installed (I know the OP said their aircraft did not have this ability) and that information was presented electronically, then I don't see the issue.

However, as the OP did say that an ADF was not installed but it created a waypoint from the database, this training would be considered invalid were they trying to conduct an NDB approach. Now, if we were we talking about a GNSS overlay of a traditional navigation aid...

[Intruder]

My response was presented at the OP, not your further discussion.

You are correct that you do not need an old RMI with metal needles to fly an NDB approach. "Raw data" may be displayed electronically, though I don't think the FMS can manipulate them. I've flown several NDB approaches in the 744, and it has electronic display of ADF bearing (as it does for VOR course and LOC/GS). Of course, I always create an overlay if one is not already programmed, though legally the ADF "needles" still have to be displayed on the ND, and I am required to "refer to" them.

[dubbleyew eight]

I do three NDB approaches regularly that if you set up the GPS and radial and fly it spot on you will end up over to one side with a bit of nasty get it back onto finals from mins.

Where as if I fly it on the needle I appear bang on finals.

Don't ask me why because I don't know.

I think I can answer that conundrum.
in australia at least the published gps locations are rounded off.
this reduction in the precision is supposedly to prevent people doing IFR conditions approaches to runways using the published gps location values.

what this rounding off of the gps position does is move the position to the north of, or to the west of, or to the north west of the actual full value gps location.

the NDB antenna is where it physically is and homing on it will be accurate.
homing on the published GPS value may see you homing on a location to the north west of the actual position and thus needing a last minute correction to align on the runway.

[Piltdown Man]

The aircraft used in training is equipped with a G1000 but not with an ADF.

I hope he doesn't do his test in that aircraft because that would result in a fail. To do an NDB approach, you have to have an ADF installed, tuned and identified. Failure to perform any of these items in a test (and in real life - because others are depending on you to do it properly) should be a fail and one of the main parts of an NDB approach is managing the nif-naff and trivia before you actually fly the approach. And you have to wonder about the value of learning to fly an approach using a device that removes all the "wonder" of the NDB/ADF combination such as dip, coastal effect, interference etc. and your anticipation and reaction to these effects. And just think about this. Flying a dead-pat needle is so easy the examiner will find it simple to rip into something else. But when there is only a crappy needle floating around the place he'll be looking to see how that is handled and assess accordingly.

[esreverlluf]

Surprised no one has mentioned the perfectly legal "NDB or VOR overlay" approaches. Of course certain preconditions have to be met, but it is possible to do an NDB approach with the NDB and or ADF unserviceable if you have appropriate RNAV AND approval from your regulator.

[BOAC]

Surely if the pilot is merely using the GPS 'NDB' for tracking and procedural training, and can conform to IFR rules, there is no problem? Although why not just do it on a PC Flt Sim.............................. a lot cheaper?

[172_driver]

Surprised no one has mentioned the perfectly legal "NDB or VOR overlay" approaches. Of course certain preconditions have to be met, but it is possible to do an NDB approach with the NDB and or ADF unserviceable if you have appropriate RNAV AND approval from your regulator.

I believe it's a US and Oz(?) thing only. Haven't seen any around Europe after a few years covering most corners of the continent. GPS approaches, yes! But no VOR/NDBs that's got GPS overlays. I guess it's possible they're filtered out through our approach plate provider if our authority wouldn't want us to do them.


I hope he doesn't do his test in that aircraft because that would result in a fail. To do an NDB approach, you have to have an ADF installed, tuned and identified. Failure to perform any of these items in a test (and in real life - because others are depending on you to do it properly) should be a fail and one of the main parts of an NDB approach is managing the nif-naff and trivia before you actually fly the approach.


Don't worry.. I know we are talking Europe.. but, in the US a student of mine did this very thing. Got a bit overloaded with all the tuning and button pushing in the G1000. Flew the VOR procedure turn and whole approach following the magenta line on the MFD instead. Examiner couldn't fail this person, it was a published "VOR or GPS" approach.

I guess the art of flying a NDB to minimums to see the runway at your 11 o'clock low is slowly fading.

[BOAC]

at your 11 o'clock - which time zone are you using.........? Some of us fly accurate NDB approaches on local time.........:)

[172_driver]

I can remember one peculiar NDB to KSBD where "established" meant that you were about 1,5 nm south of track, if you asked ATC … Same approach, the NDB shifted 10 deg as you passed some hills on the right side. The accumulated errors got you fairly spot on ……… :)

[+TSRA]

Surprised no one has mentioned the perfectly legal "NDB or VOR overlay" approaches. Of course certain preconditions have to be met, but it is possible to do an NDB approach with the NDB and or ADF unserviceable if you have appropriate RNAV AND approval from your regulator.

Perfectly legal here in Canada too...however, all the operators I've worked for have required you to tune in the underlying nav aid and have it presented.

[latetonite]

Operators love SOP's, the legal part is something else.