JP256 wrote:So that pilot who flies downwind at 90, base at 80, and final at 70 (very commonly heard numbers amongst C172 pilots) has a whole lot of energy to dissipate in the final 10 feet above the runway...
Flying that same airplane in the pattern, using a much tighter pattern than most current flight schools teach (so you're not having to drag it in on a long final approach leg, well behind the power curve), AND using the FAA-recommended speeds for base and final approaches would result in a LOT less energy to be dissipated. But logic dictates that you also have less margin for error... So I suspect that the flight schools – out of self-preservation, and making allowances for rookie pilots – teach faster and faster speeds. If you were taught the 90/80/70 speeds, and then encounter gusty winds, and add 1/2 the gust spread to those speeds, you could easily arrive in ground effect at nearly twice the stall speed... That's a lot of energy to dissipate in that last 10 feet!
Actually, what happens at schools is we have the lowest time commercial pilots in the industry generally occupying the flight instructor's seat in those planes. Those kids are still kinda scared of the whole notion of flying in the first place, and now they don't even get to fly.....they're watching some other kid try to kill them in an airplane.
So, those CFIs read the checklist or POH and then add five knots to all speeds for Mom. And, some of the slightly more paranoid CFIs add another five knots for Grandma.
Now, the brand new solo student knows that his/her flight instructor added five/ten knots for Mom/Grandma, so he/she adds ANOTHER five knots for his/her Mom.
Etc. Trust me, that's the way it works. And, as a consequence, as noted earlier in this thread by several folks, most pilots fly too fast on final.
We had this at a school I was affiliated with. Big come to Jesus meeting of all check airmen and Chief instructors. It seems that they were having 172s flown by solo students running off the end of 4000 plus foot runways, and regularly removing nose gears from same.
I pointed out to management that their checklists were really bad, as in stupid fast on approach speeds, as you noted. The solution was to reduce the approach speeds on the checklists and to start holding students (and CFIs) TO those approach speeds on checkrides, as in nothing OVER those speeds.
But, I totally agree, and have said forever it seems that far too many pilots fly the approaches too fast.
MTV