Slip to landing on PPG practical test

On Sun, 31 Oct 2004 20:52:15 +0100, CV wrote:

But even with an L/D of 1:80, if you sideslip to 1 m off the
ground you'll only float 80 m, about 260ft, from there, and
quite a bit less with a headwind.

You are correct, but the problem is not the L/D in ground effect, but
the speed. Minimum safe approach speed is about 50 kts, touchdown with
the tail wheel first in ground effect will happen at maximum at 35 kts
- to bleed off 15 kts in ground effect takes amazingly long - I'd
estimate about 3.000 ft for the ASK-21.

Of course you can put her down with force onto the nose wheel at
higher speeds, but this is probably going to result in an PIO.


Agreed that the precision needed to slip it down that low
is probably too much to ask of someone just about to get their
licence, but it does not sound too crazy as an exercise at
a more experienced level. In case you get it wrong you should
of course be ready to abort and pull the brakes well before
there is any danger of going off the far end.

Been there, done that, using Ka-8 (landing with sideslip only is
possble if the speed is correct), DG-300 and ASK-21. Neither the 300
nor the 21 could be brought down without flaps on our 1800 ft runway,
altough I was low (3 ft) and slow (50 kts) at the beginning of the
runway.

Sideslipping below 50 ft is hazardous - the slightest mistake while
pulling out of the sideslip might result in an unwanted and hard
impact, not to mention the fact that it's hard to judge the ground
clearance of the lower wing tip. And a final glide from 50 ft with a
fictious L/D of 45 will eat up 2250 ft of the runway, even not
counting the fact that you still have to bleed off your speed.


Sorry - landing with sideslip only is an interesting stunt, but
doesn't have a lot to do with safe flying.


I think it's percetly sufficient to ask for a sideslip down to 150 ft
and then a normal landing with flaps.


Or does the FAA guy in question also demand to fly without another
primary flight control, say, the elevator, if you want to pass his
test?






Bye
Andreas