Odd? landing technique (PA28) wanted by school
 

Hello folks,

I am revalidating my PPL after being overseas (and flying privately) for many years. I've found a school and an instructor who seem great, the only strange thing is the touchdown technique they are telling me is their accepted technique in a PA28 Warrior - I wanted to ask if this is a countrywide phenomena or just particular to this school?

So, my tried and tested (overseas) way of landing a Warrior: Approach 65kts with full flap, roundout and power to idle (apply crosswind correction as desired), flare....keep the aeroplane flying 6 inches off the ground for as long as possible..touchdown at minimum flying speed on the mains with a squeak from the stall warner and warm applause from the passengers. This seems in line with the POH.

The technique I've been told to use is: Approach 70kts with full flap, roundout and power to idle then let it pretty much settle (or plonk) onto the deck.

This second technique seems like that used for something much bigger and faster (or for a Warrior in very exception conditions e.g. strong x-wind with turbulence). To me this is asking for trouble - 7kts over the POH speed you'll eat up kilometres of runway, risk huge bounces if the touchdown is slightly on the heavy side and puts the nosewheel at risk of becoming retractable.

I've got a remedial session of circuits because of "my" landing techinique - I'm not sure whether to be belligerent and continue land the way I normally do or not!

Maybe their experience of your landing technique, doesn't line up with yours :confused::ok:

Find another school. Your technique is fine.

As India Four Two says.

I spend most of my working life trying to undo that sort on nonsense instruction :ugh:

+1

When an instructor suggests "plonking" on, or otherwise a less than gentle touchdown, ask if they pay for the tires and brakes....

The book figure which I believe is 63kts is for maximum weight. At below maximum 70kts will be way too fast. I see this type of teaching regularly and we have the skid marks to prove it.

Get him to demonstrate his technique on a 500M runway:rolleyes:

D.O.

Odd? landing technique (PA28) wanted by school
 

...........

Oddly, I was taught both techniques at Oxford Air training School a long time ago. Your version was what they termed a "performance landing" as it resulted in a shorter roll and was useful at Oxford off a low level circuit to land.

The other method was what we were taught in the "normal" circuit. Then again the they were training us for the airlines where "plonk it on" is not surprising for anyone.

SND

Odd? landing technique (PA28) wanted by school
 

Landing technique is very simple.
Very good and safe and smooth landing can be done just by doing it opposite as you do any takeoff rotation.
Nobody ever did a hard takeoff.
):-

One really obvious point - check you haven't gone from a knots aeroplane to a mph aeroplane.

But if everything's still in knots, then yes, the correct approach speed for a -161 is 63kn, reducing with weight - so a half tank solo aeroplane, likely to be around 80% MTOW, will want about 57 knots. I can think of no good reason to fly a 70kn approach in a -161 with flaps used as per the POH.

BUT, I have also seen various instructors around the world use 70+kn flapped approaches, causing some combination of hard landing and float. It's bad practice, poor airmanship, and it's just as well that PA28s have such strong nosegear !

I think that the "going to the airlines" argument is spurious - all pilots should learn to fly the aeroplane that they're sat in, properly. Not the one after the one after that !

G

Preferably while you watch from the sidelines! :E

I once flew an ILS in a 172, flaps-up and full throttle, to accommodate an ATC request - they had jets turning final 50 miles out! I closed the throttle over the threshold. You wouldn't believe how far we floated before I could even lower the flaps, never mind touch down. Luckily, it was a 13,000' runway. ;)

Genghis,
Do you have a specific formula for reducing the approach speed from 63 kts to 57kts at 80% MTOW. Or is this just some sort of personal guesstimation?

MTOW_approach_speed x SQRT (actual_weight / MTOW).


So in this case, 63 x SQRT(0.8) = 56.3, which I rounded up to 57.


It's just an extension of L=W=½RhoV²SCl. So, as Cl is the same (and a function of AoA), the speed has to go with the square root of weight, to balance the equation.


G

I was just thinking that myself.

Agree!

Vat (Velocity at Threshold) as Genghis states. I believe performance criteria assume crossing the threshold at 50 feet.

Have not got the POH to hand for the PA28 -161 here but the (UK) CAA appendix for landing distance states "fully stalled touchdown" as one of the assumptions to achieve the scheduled landing distance.

The only reason to fly faster than the POH says is when facing severe gusts in which case it is considered wise to add half the gust factor to the POH speed. So in normal circumstances you'd approach on short final at around 60 to 65 knots and on a day of 20G40 you'd approach at around 70 to 75

?¿? half of forty makes twenty, so "approach at around 80 to 85" ?

half the gust factor , the difference between the wind and the max gust
so 20 knots in this case
so add 10 knots ( although I was taught UP TO half the gust factor) IE no more!

It might be that the instructor realises the Piper has dampers in the main LG, so maybe a bit more 'bounce-proof' than a Cessna, that is just a sprung system.
Commercial aircraft also have very heavily damped MLGs, so maybe he has been trained that way... or he could have flown RAF Fast Jets (thinking of carrier landings now...)


.

I agree with Genghis, and most of the others. Either find another school, or play along with them for the checkout, and then go back to your original way of landing.

Don't forget, though, that to achieve the POH landing performance, you will need the correct speed/height at the threshold, and the throttle at idle from there on.

If you keep any power on to the 'roundout'/'flare' you will extend the landing distance considerably.


MJ:ok: