I’m under the impression that the ILS approach and landing is superior to other systems.

 

If that’s the case why don’t all those that cater to “heavies” offer that facility?

 

On several occasions I’ve built PfPx Flight Plans based on STARS that I later learn (when entering landing information into the FMC at the Top Of Descent) don’t offer ILS runways. 

 

Cliff

Which airports are you trying to land at?  As you've noticed, ILS isn't universal, reasons for this include:

• Surrounding terrain doesn't allow it (e.g. KPSP, surrounded by mountains, KSAN 27 surrounded by rising terrain)
• Noise abatement procedures require short/non standard approaches (e.g. KLGA 13)
• It's not always worth the investment, particularly if the weather is generally good or the airport is low traffic (generally small regional airports)

 

ILS is great, but it's expensive, requires specific terrain/approach factors and isn't always worth the money to move away from older LOC/VOR/NDB approaches.

 

Anyway, non precision approaches are more fun 

Reasons for that :

 

1.)Topographic circumstances,obstacles in the glide slope line.

2.)Economically aspects

3.)Airport is not significant for the region

4.)Military facilities and installations,risc of interferences(airport radar and other transmitters

5.) excellent climate (visibility,no fog, no dust and broad runways ,e.g  60 m,and 4000 m long Rw.

 

You can extend that list.

 

 

I’m under the impression that the ILS approach and landing is superior to other systems.

 

The best landing system of all is the two blobs of flesh sat in the very front seats

Indeed it's superior to anything else if we disregard MLS and other experimental stuff that have no real impact as of today. It's been the "de facto" standard of precission approaches for over half a century.

 

The main reason for an airport not to install an ILS is an economical one. A small regional airport that receives a couple jets a day and maybe a heavy once a week, might not justify the investment. ILS is all "fixed costs", that is, independent of usage. If you have one ILS user a day or 1000, the ILS cost is the same. With 1000 users however, there's more spreading of the maintenance costs in the form of airport charges.

 

Another reason nobody mentioned might be the current expectancy of moving over to GNS based precision approaches which I believe are becoming a reality already in the US. So why invest in an ILS today if a couple years from now everybody will be flying GNS approaches?

I believe any plane with as TOW of 255,000 lbs. is considered a heavy. Certain 752 versions fit into this category. So it starts with certain 757-200 versions and goes up from there. A lot of planes.

I couldn't have hoped for better answers.

 

It all makes sense.

 

Thank you all.

 

Cliff

Because on a general day to day usage, nobody uses them.  ILS is only used when the weather is pretty bad.  If the weather is VFR, almost everything gets cleared onto a visual approach.  They may LOAD the ILS into the airplane, but that's not the same as shooting the ILS to minimums with your eyes down.  I can't even count the last time I've been bombing around VFR in a Cessna and have heard an airliner cleared on an ILS around here.  They're all either visual or the RNAVs.