I think being able to fly without the ASI is a good skill for a pilot to have. It proves they understand something about the relationship between pitch, power and performance. But as a test of airman competency? Not so much unless it is just one of a great many other tests of ability and cognitive function as a pilot. Training and checking every pilot on that single skill, while valuable, cannot reveal their overall competency as a pilot any more than having them demonstrate any number of other skills.
However I personally find that the covered instrument drills are a good workout for any pilot under instruction or checking and demonstrate their ability to to understand the relationship between attitude and indicated performance. If this translates to more cross checking and correlation, then we've done some good as instructors.
As an aside, a quick story: I started covering the ASI with all my flight students after witnessing a rather extreme looking landing. I was particularly interested in this one because it was one of our club aircraft and I was one of several club instructors in our 60 member club!
The guy comes ripping in for landing doing at least 100kts in one of our 172s with what appears to be about 20 deg. flaps. The inevitable porpoise cycles occur as he forces it on at about the midpoint of the 5,000' runway. Finally running out of energy after 5 or 6 cycles, he skids the tires and turns off the runway with several feet to spare.
A friend and I get in my car and head down to the parking area, arriving just before the airplane. He's been taxiing the airplane up there with about 2,000 rpm due to the rolling drag of the flat nose tire. My friend gets his attention and waves him off from attempting to power into the parking spot and gives him a cutoff signal.
After shutting down the guy gets out and I approach him to gently ask him what happened. He replies that he ASI didn't appear to be working... Before I could say anything else, my friend blurts out "SO?" The guy says he didn't have any airspeed. My friend replies "well it sure looked to us like you had way more than enough speed !"
Anyway, the nose tire was flat and the nose fairing was broken. The paint on the lower cowling didn't look right but no other visible damage was apparent. I could barely believe the prop was pristine after all that porpoise bouncing. When I looked at the pitot tube, the back half of a honey bee was noted sticking out! The tweezers on my Swiss Army knife duly removed said insect intact and still alive! (temporarily....)
We saw to it that the airplane was inspected by our maintenance shop. The firewall, engine mount and isolators were all inspected along with the nose strut with no damage found. The nosewheel had to be replaced and a new tires all around. (Stomping the brakes and taxiing on a flat nose tire can get expensive) If the C-172 isn't about the most forgiving airplane ever built, than I'm sure I don't know what is!
A willingness to pay for the trip to the mx shop and to undertake some supplemental training kept the errant member from being banished from the club. ALL the club instructors adopted the ASI drill and put increased emphasis on preflight inspection during checkouts and annual check flights. As a relatively new CFI at the time, maybe I was just lucky I didn't train him. The cheapest lessons are learned from the mistakes of others...
westhawk