ILS/NDB

[darkkk]

What is the difference between ILS and NDB?

[HEATHROW DIRECTOR]

ILS is a landing aid which enables an aircraft to fly towards a runway with a high degree of accuracy. It provides azimuth and vertical information for the the aircraft to follow. An NDB is a basic radio beacon, often used as a "marker" for en route flying and also as a beacon to home onto to reach an airfield and from which to commence an instrument approach. ILS operates on high frequency and is largely interference free whereas NDB operates on medium frequency and is subject to interference and various propagation effects.

That's very basic information. Do a Google search for a great more detail.

[Wojtus]

ILS and NDB have nothing in common except both being a radio navaid.

[eckhard]

Hi darkkk,

Maybe you are refering to an approach plate? The name of the approach can be confusing at some airports:

1. ILS/NDB RWY24 means that the same horizontal and vertical profile is followed for both the ILS approach or the NDB approach (down to different minima of course).

2. NDB ILS RWY24 means that the NDB is used to establish on to the ILS. If this title is used, there is usually another ILS approach to the same runway but using a different way of establishing, e.g. VOR ILS RWY24.

Note that in (2) above, there may or not be another non-ILS approach to runway24. This would be titled 'NDB RWY24' or 'VOR RWY24'.

Clear as mud? I have seen some occasions where I and fellow crew members were confused by multiple approaches published for the same runway, all with subtly differing titles. I was once supernumerary crew into Lagos and watched as the crew started to fly an approach to the wrong parallel runway. As I had been flicking through the charts some hours earlier, during the cruise, I recognised their confusion and asked them to turn to the correct page in the approach chart booklet. Unfortunately, I had been distracted by a passenger visit to the flightdeck while they were briefing, so only picked it up at this late stage. They were embarrassed but when we looked at the various chart titles after we had parked, it was easy to see why they may have picked the wrong one.

[darkkk]

Ahh cheers for that. Its a bit hard for me to get my head around all these different approach charts and the titles. :confused:
But there you've provided a better explanation than my lecturer. http://images.ibsrv.net/ibsrv/res/src:www.pprune.org/get/images/smilies/thumbs.gif