nyoung
Pre-takeoff checklist
The GPS offers lower minimums (I do not dispute that) but the real question... How often is that valuable?
For example, I am based @ 3ck. If you can get a local altimeter setting, VOR-26 minimums are 492ft AGL. LNAV minimums are 412 feet (rwy 26) and 392 feet (rwy 08) respectively.
The number of days where a pilot can get in with the extra 80-100 feet are minimal, probably a handful of times a year. In my ~7 years of flying instruments to 3CK, I have had to divert to DPA twice. In both cases, I flew the DPA ILS to 300 feet or lower. So the GPS approach at 3CK would not have helped, I would have ended up at DPA anyway.
I have never had to divert at my destination.
Regarding GPS vs VOR. True, the GPS is more accurate. But, I have never missed a VOR because of not being aligned with the runway. Typically approaches are missed b/c of the cloud base.
Why is a GPS approach easier to fly? With a VOR/DME approach, I open an approach plate, select the VOR frequency, dial the approach course on the OBS, verify the VOR (audio panel). I bet I can do that quicker than most people can program an approach on a 430 ! And as far as the in-flight portion. What's more difficult with VOR/DME than GPS? They both involve crossing a FAF, following an approach course, descending, and waiting for the MAP. Sans-GPS, it is not hard to bracket a VOR course, and if you have a handheld, it is easy to use to zero out the cross-track without bracketing, thereby nailing the heading.
Last, regarding your direct routing comment. That's the trick and it works >90% of the time. It is pretty rare when a controller won't let you fly a requested heading.
In my experience, for the cost, IFR GPS offers minimal extra capability.
Now, if we want to talk about a WAAS approved GPS with GPSS steering coupled to an STEC-55, then that's a different story. But that is also $25k of avionics, which in no way is relevant to the original post.
For example, I am based @ 3ck. If you can get a local altimeter setting, VOR-26 minimums are 492ft AGL. LNAV minimums are 412 feet (rwy 26) and 392 feet (rwy 08) respectively.
The number of days where a pilot can get in with the extra 80-100 feet are minimal, probably a handful of times a year. In my ~7 years of flying instruments to 3CK, I have had to divert to DPA twice. In both cases, I flew the DPA ILS to 300 feet or lower. So the GPS approach at 3CK would not have helped, I would have ended up at DPA anyway.
I have never had to divert at my destination.
Regarding GPS vs VOR. True, the GPS is more accurate. But, I have never missed a VOR because of not being aligned with the runway. Typically approaches are missed b/c of the cloud base.
Why is a GPS approach easier to fly? With a VOR/DME approach, I open an approach plate, select the VOR frequency, dial the approach course on the OBS, verify the VOR (audio panel). I bet I can do that quicker than most people can program an approach on a 430 ! And as far as the in-flight portion. What's more difficult with VOR/DME than GPS? They both involve crossing a FAF, following an approach course, descending, and waiting for the MAP. Sans-GPS, it is not hard to bracket a VOR course, and if you have a handheld, it is easy to use to zero out the cross-track without bracketing, thereby nailing the heading.
Last, regarding your direct routing comment. That's the trick and it works >90% of the time. It is pretty rare when a controller won't let you fly a requested heading.
In my experience, for the cost, IFR GPS offers minimal extra capability.
Now, if we want to talk about a WAAS approved GPS with GPSS steering coupled to an STEC-55, then that's a different story. But that is also $25k of avionics, which in no way is relevant to the original post.
I beg to differ on the GPS vs VOR mins, which IME are often 100-200 ft lower. In addition a GPS is easier to fly AND more accurate plus it gives you the ability to fly VOR and LOC approaches that require DME or ADF.
And while those friendly controllers will indeed allow you to fly off airway, you are not legally entitled to accept a clearance to a distant waypoint that you cannot navigate to on your own without using your VFR GPS unless you use the subtefuge of requesting and getting a "vector".