Zenith 601HDS (Tapered Wing)

[Allen B]

Good morning/afternoon. I own and fly a 601HDS. Has anyone successfully designed and built flaps for the Zenith 601HDS. I find my HDS has a reasonably high stall speed and as such is not a pussycat to land.  Regards Allen B.

[facthunter]

I can't imagine that would be a simple Mod. There are all sorts of structural implications. Are you doing powered approaches with accurate speed control?   Do you regularly sideslip? Nev

[dlegg]

You could make/acquire HD wings and swap out the speed wings for slower stall speed. No flaps as far as I know.

[Allen B]

Hi Nev and thank you for your prompt reply. Regarding the approach, I have tried various approaches and despite having a couple of thousand hours and flown a number of different aircraft, I find this small aircraft more challenging than any other that I have previously flown. I suspect the rather high stall speed (a bit tricky to replicate and pinpoint the exact stall speed) of anywhere from mid to late 40's knots, requires a fairly flat approach over the fence when landing. I feel if it had flaps, it would allow for the nose of the aircraft to maintain a higher attitude while the airspeed could be a bit less over the fence. I acknowledge the full length ailerons would create a challenge to convert, to shorten the ailerons and utilise the inboard section/length of the existing ailerons to become flaps. So I just thought I would ask if this mod has already been done somewhere out there in Zenith land ?.  Allen B.

[Allen B]

7 minutes ago, dlegg said:

You could make/acquire HD wings and swap out the speed wings for slower stall speed. No flaps as far as I know.

Thanks for this suggestion Diegg, however I do like the Tapered HDS wing, but less of a challenge for the landing would be nice... (just wishful thinking I suppose)  Allen B

[RossK]

16 minutes ago, Allen B said:

Thanks for this suggestion Diegg, however I do like the Tapered HDS wing, but less of a challenge for the landing would be nice... (just wishful thinking I suppose)  Allen B

Could you convert the airlerons into flaperons like the RV-12? 

 

[Kiwi]

In my Drifter if you adjust the airlerons down a few degrees it lowers the stall speed (and the cruise speed) on your aircraft are Ailerons set correctly?

Have you thought about adding VG's ?

[facthunter]

Flaperons Have their Own control aspects/problems. You need more drag to come in steeper. Flaps of the Lifting kind will give you a  Lower nose attitude on approach AND Lower the stall speed. What do you consider a SAFE approach speed in normal conditions? Is your engine's idle speed a bit high? Get it too slow, and you introduce another Problem. Does it  drop a wing when stalling? Nev

[cherk]

My 2cents .............Stolspeed vortex generators and  Gurney flaps !  ☺️

[Allen B]

4 hours ago, RossK said:

Could you convert the airlerons into flaperons like the RV-12? 

 

Thanks for this suggestion however from my small experience with flying the RV-12 shows (at least to me) Flaperons isn't the way to go either. But thank you for your suggestion. Allen B

[cherk]

On the Stolspeed site , there is a swiss CH601 HDS with details of his VG instillation , in the instal section. Worth a check . 🙂 

[Allen B]

1 hour ago, facthunter said:

Flaperons Have their Own control aspects/problems. You need more drag to come in steeper. Flaps of the Lifting kind will give you a  Lower nose attitude on approach AND Lower the stall speed. What do you consider a SAFE approach speed in normal conditions? Is your engine's idle speed a bit high? Get it too slow, and you introduce another Problem. Does it  drop a wing when stalling? Nev

Hi Nev. I agree that Flaperons is not the way to go. Idle RPM (Rotax 914) is around 1,700, so all good there. I have tested with many stalls (at between 2,000 to 3,000 feet) and the actual stall is quite gentle, with considerable buffeting but doesn't really drop a wing of a serious nature.

[Allen B]

2 minutes ago, cherk said:

On the Stolspeed site , there is a swiss CH601 HDS with details of his VG instillation , in the instal section. Worth a check . 🙂 

I have bought the VG which I will attach soon and see what difference they make. I know about the Swiss pilot (Victor) and will follow his suggestion re placement of the VG's. I suspect the VG's may help a touch but I also suspect VG's wont perform as well as a decent set of flaps. Again, maybe it's just wishful thinking by me ?. Allen B

[Allen B]

Just now, Allen B said:

I have bought the VG's (enough for the wings and the underside of the stabiliser) which I will attach soon and see what difference they make. I know about the Swiss pilot (Victor) and will follow his suggestion re placement of the VG's. I suspect the VG's may help a touch but I also suspect VG's wont perform as well as a decent set of flaps. Again, maybe it's just wishful thinking by me ?. Allen B

 

[Allen B]

23 minutes ago, cherk said:

My 2cents .............Stolspeed vortex generators and  Gurney flaps !  ☺️

Sorry for my ignorance but what is/are "Gurney Flaps" ? Allen B

[cherk]

Dan Gurney of Indi 500 fame came up with the concept !  On the HDS wing it would be a 20mm x20mm angle on the trailing edge of the ailerons  .

Lots of references via our friend GOOGLE .  😆