acquilinus wrote:
Well I was exposed to such practice as well during lessons along with different variations of flap settings. However in the exam the usual landing without flaps was checked…which was accomplished by flying with slightly higher speed and doing a touch down much further afield.
Ok, maybe it is a thing in Germany to practice fast approaches. We should not mix it up with flapless landings, then it is of course completely normal to have a slightly higher approach and touch down speed, usually around 5 knots or so for the regulars.
Cobalt wrote:
Does being so fast really help?Quick back of the envelope calculation for a runway that has a mile after the touchdown point, wherever you choose to put it:
It depends on the runway and the turnoff. That assumes that a fast approach is going to miss a taxiway, often that is not the case.
I fly into EGNS quite a lot, and when using 26, I’ll keep my speed up and do a flapless wheel landing (the touchdown speed can be considerably higher in a wheel landing vs 3 point), timing it such that I’ll be able to turn off on taxiway F (to go to area M). If I’m using 21 though, I’ll be doing about 45 mph on final so I can turn off on taxiway E to go to area M. Both approaches keep down the time I’m occupying final and the runway (on 21 there won’t be an airliner following me) and at the same time giving me the shortest taxi route.
Fly310 wrote:
Why learn to fly in at a much higher speed than normal? That is called an unstabilized approach and should always be followed by a go-around
Well I was exposed to such practice as well during lessons along with different variations of flap settings. However in the exam the usual landing without flaps was checked…which was accomplished by flying with slightly higher speed and doing a touch down much further afield.
Pilot_DAR wrote:
It’s true that pax may not like being slipped, so yes, consider that. But that is not an excuse for a pilot to not be proficient at it, practice with no, or understanding pax.
Capitaine wrote:
Does anyone know why it’s called a porpoise landing or porpoising? Dolphins are more widely known.
’Cause errantly flown flying boats are notorious for setting up a “porpoise” on landing if not held in the correct attitude when contacting the water, or hitting swells. Probably in long ago flying history a flying boat captain applied the term to landplanes as well.
Does anyone know why it’s called a porpoise landing or porpoising? Dolphins are more widely known.
Probably, you did not check well where it does idle when doing power checks Quote
Still puzzled face….
A C 172 will not fly in stable flight in ground effect at 1200RPM with any flap setting, it’ll settle. A landing with zero flaps, and no sideslip will work fine, though will be best with a more shallow approach, slightly faster speeds, and take more ground run. No problem, if you plan for it.
A 172 engine turning at 1000 RPM in flight is not producing any appreciable power, so it’ll be about the same as having the engine not running.
Ibra wrote:
You mean “the right mix at that point”, the total should be roughly the same,
During an approach, I would rather that the total energy would be deceasing at a rate I intend, terminating in it being insufficient for sustained flight, a couple of inches above the ground, at my intended touchdown zone. If the total energy were to be the same during the approach the plane will only touch down too fast, and forced on. Doing that is the main cause of bounces.
Maoraigh wrote:
“A stable approach is when the aircraft energy (kinetic, gravitational potential, with chemical/electrical available) at any point is what the pilot planned at that point.”
You mean “the right mix at that point”, the total should be roughly the same, if you mix/transfer too much you may need to add a bit of luck as well 
I was just referring to the case where you find it hard to land without flaps/side-slipping?
Probably, you did not check well where it does idle when doing power checks 
Ibra wrote:
On a flapless C172, you only need 1200rpm to maintain level flight in ground effect while you will probably need 2/3 of max power to maintain S&L in cruise, so if your aircraft idles at 1000rpm you probably need to shutdown the engine to land flapless/sideslipping
Puzzled look on my face….
“demonstration of an unstable approach”
“A stable approach is when the aircraft energy (kinetic, gravitational potential, with chemical/electrical available) at any point is what the pilot planned at that point.”
Discuss
