landing tops (nose heavy ?)

[mumdad696969]

Hi all . I have a rans s6 . & am struggling getting nice landings with it . I have plenty of experience on other types . Including tail draggers . But finding the rans a bit tricky . There's no gentle round out , hold off & flare , it drops rapidly on finals when I chop the power . & flare is quick & it drops quite quickly . It's a little nose heavy . Is this an issue ? I've tried flaps . No flaps . Different speeds etc . But more often than not , the landings are all the same , any advice or thoughts gratefully received

Mike

[Nick Allen]

Have you tried keeping a little power on all the way down? Or alternatively a judicious waft of power to cushion the flare? (I fly a lightweight taildragger, and both of these techniques help.)

[mikehallam]

Presume this relates to the same enquiry as on the BMAA forum ?
In which case I've just posted some gen. there, with sketches.

mike hallam.

[mumdad696969]

Hi Mike yes same issue . Still pondering on my tail incidence ? I have a lot more than 1 degree negative . But surely if I reduced this ? I'd make the problem worse ? Also . I've heard about power on landings before . I'll def try that . As someone suggested that with power of , glide approach . You have to haul the stick back at the last minute & arrive aircraft carrier style ! That's what it's like ! I've always tried to use glide approach . To help in case of engine failure . But maybe a powered approach & a trickle of power on flare is the way to go with a nose heavy rans ?

[mikehallam]

I agree you shouldn't change more than one thing at a time, but certainly the effect of too much negative incidence on the tail plane is to find at cruise speeds or faster, you have to keep pressure forwards on the stick to stop it wanting to climb all the time. Which is in a round about way what made me look at the set up.
One non invasive, thus quick to check clue is to remember where, say relative to the panel, the top of the stick is - fore/aft position - in normal S & L.
Safely on the deck tie the column in that position and see if the elevator and tail plane are more or less in a straight line. Too much one way or the other means the slightly crossed controls cause unnecessary drag and aren't (IMHO) set up correctly.
[In my case the inherited fixed elevator tab added to the mix and I realised it needed to be fairly neutral too].

Personally, at some stage this season after I sort out 'landings' I'd carefully measure the tail's A of A and put it to the Rans recommendation

I am curious about two things you indicate.

a) If it's too nose heavy with your HKS up front (why as it's lighter than the 912 - is it set a long way forward ?) you must get the C of G corrected. On the 912 the battery is mounted about 1 1/2m behind the P2, but a lump of lead - check with your inspector if need be - at the tail end is the common if disliked fix. At least you'd find out if your assumption on nose heaviness being the principal landing problem is true.

b) My ex instructor chum here tells me the normal S6 34.5 ft span wing is a bit of a floater, so I'm not sure why you find it a problem - especially as you have a wide enough experience of different similar types.
With a stall speed of (I assume) ~38 mph, finals should be done at 49/50 mph, which is stall X 1.3.
I've only flown the reduced area -116 wing and a gentle flare & holding off - with power off at the last stage of 'finals' works well enough for a decent landing most times. Speed for me is an ias 60mph,
I usually use two stages of flap, often three to get her to land shorter at my base field.
Otherwise if I rush down the final and heave back to flare hard hoping to land short she'll certainly hit the ground more heavily & one usually feels dissatisfied with the result.
The method of a using a gentle flare & holding off might take a little more runway but is a smoother and less frantic method of arriving.

mike hallam

[mumdad696969]

Mike , thanks for your help & advice . It's actually a verner engine . (later 3 bearing type) Similar in weight to a 912 I believe ? C of g is 67" aft of datum , so fairly close to front limit of c of g ? I'll definitely try the stick position idea . Great idea that . & go from there ? As for landings . I'm not getting any float at all . With power off it will drop fairly quickly .& on finals it's As if I'm experiencing sink ??But can't be every time ! Then I find I have to yank the stick back fairly rapidly for a quick flare & touchdown . Do this too high & it will drop the last couple feet, which isn't ideal ! I'll try powered approach as well . & maybe reduce the speed a bit ? I normally come in around 60 mph . Thanks again most appreciated

Mike

[Bob F]

Mike,
On your glide approach you will be coming in steeper than a powered one, try two flares, one to flatten your initial approach then a normal flare to land. I fly spam cans and it works a treat.

[mumdad696969]

Thanks Bob , few things to try now

[mikehallam]

Oh, one more, if unlikely, possibility which I guess you've already thought of.

Is the ASI reading high at landing speeds ?

In which case if you suspect that, and can't easily calibrate it, try coming in say 3 to 5 mph ASI reading higher - provided the runway allows for her floating on a bit more.

It might prevent it falling out of the sky which is exactly the trait the very much lighter single seat Rans S4 would do every time unless you kept power on till inches above the ground, for a smooth landing.

mike hallam.

[mumdad696969]

Ok Mike thanks . I'll try that as well

[mumdad696969]

Ok . Got in the air tonight . All be it with an 18 mph headwind . & landings definitely better with power . & only used 1 stage of flap . Mike , I tried that quick elevator position check . & in straight & level , I have around 1" of down elevator ! As measured from a straight edge on the top of the tailplane . Is this excessive ? Or acceptable ? Power of & full up trim , if I let the stick go . It would point straight at the ground ! So I'm thinking . If I reduce the tailplane negative incidence ? I'd make that worse engine off ? Might be ok straight & level ? But with power of . It would nose down even more ? Any thoughts ? I've got a few pics if you'd be kind enough to send your ema address ?
Mike

[mikehallam]

Thanks for the trial results.

As you have so neatly explained how things were tonight, I suggest you leave the tailplane alone. It's clearly not miles out and minor changes won't help, might even change the characteristics before you are happy to want them and/or have more experience to read them.

Please send those pic's to [email protected]

Regards,

mike