4.29m ASW-27 built by HKM

[edfmaniac]

I just picked up a 4.29m ASW-27 built by HKM and was wondering if there was any info, tips or recommendations to be had from the community. I didn't find much on it. Any known sweet spots for CG location or should I just experiment? And is this a plane that can be considered a hot rod or should I take it easy? It's already had an FES motor installed and I was hoping to be able to do some high energy but graceful aerobatics in between soaring. The wing rod is short but beefy so I'm wondering about the reputation of the wings if there is one. Nice looking kit!

Thanks

[lenb]

The HKM ASW 27 is considered a hod rod for sure. I had one of the first kits brought into the USA by John Derstine way back. It was the most beautiful fiberglass plane I had ever seen at that time. And the biggest.
I eventually assembled the plane and flew it a bunch. It flew extremely light feeling and will turn on a dime. Vert predictable, no bad habits and is very strong.
I sold the plane to Dave Harris who I believe still owes the plane.
A++++ airplane.

Len

[Soarntz]

Unfortunately, I had an electronic malfunction a couple years ago at Delaware... The ASW is no more. I did like it alot.

Burt from Chicago has one

[ARUP]

We want pictures!

[edfmaniac]

Here's a pic I grabbed from the internet. Mine is in very good shape for a kit that's been passed around and never finished.

[edfmaniac]

The HKM ASW 27 is considered a hod rod for sure. I had one of the first kits brought into the USA by John Derstine way back. It was the most beautiful fiberglass plane I had ever seen at that time. And the biggest.
I eventually assembled the plane and flew it a bunch. It flew extremely light feeling and will turn on a dime. Vert predictable, no bad habits and is very strong.
I sold the plane to Dave Harris who I believe still owes the plane.
A++++ airplane.

Len

Len

I just had my first flight and the plane seems like it's suffering at the current CG. It's located just at the back side of the wing rod. Pitch response is real slow but I also need a lot of down trim to keep the nose level. Something doesn't seem right to me. Any help in regards to desirable CG location would be greatly appreciated.

Thanks
Victor

[lenb]

Hi Victor,

Be sure to tame the elevator throw or it can seem tail heavy it not flown fast enough and with a lot of elevator throw.

Here are some specs I found for you

Modell ASW 27
　-scale 1: 3,5
　- wing in two parts, double trapeze, winglets
　- wingspan : 4,285 m
　- profile: HQW 3-12/10/12
　- tread deep: inner/middle/outer: mm 230/190/87
　- area: (dm2) : 73,5
　- winglets height: 85
　- elevator: T-tail
　- wingspan: 735 mm
　- profile : 12% symm.
　- area: (dm2) . 7,4
　- rudder height: 340 mm
　- lenght over all : 1.871 mm
　- weight ready to fly : 5500 g
　- wing loading: (g/dm2) : 74,8
　- cg behind the leading edge nearly 95 mm
　- EWD . 1° - 3 °

[edfmaniac]

Thanks. Elevator throw is probably an issue if the model likes a lot. I was close on the CG but still need to move it back 3-4mm if the specs are good.

Cheers

[edfmaniac]

Hi Victor,

Be sure to tame the elevator throw or it can seem tail heavy it not flown fast enough and with a lot of elevator throw.

Here are some specs I found for you

Modell ASW 27
　-scale 1: 3,5
　- wing in two parts, double trapeze, winglets
　- wingspan : 4,285 m
　- profile: HQW 3-12/10/12
　- tread deep: inner/middle/outer: mm 230/190/87
　- area: (dm2) : 73,5
　- winglets height: 85
　- elevator: T-tail
　- wingspan: 735 mm
　- profile : 12% symm.
　- area: (dm2) . 7,4
　- rudder height: 340 mm
　- lenght over all : 1.871 mm
　- weight ready to fly : 5500 g
　- wing loading: (g/dm2) : 74,8
　- cg behind the leading edge nearly 95 mm
　- EWD . 1° - 3 °

There's definitely a decalage issue when balanced at 95mm. I have to use an all of my available down elevator trim in thermal mode and about 25% in speed mode. But it did seem to take off earlier and I even managed to find some lift directly above the runway so was able to enjoy the flight for a little while. It should fly great once I get the incidence figured out.

Do you know what the last line of the spec list is referring to?

Thanks

[Ken Kaye]

EWD is decalage. The stab saddle is moulded to 3 - 3.5 degree of decalage. Mine came with an "expert" shim which brings it down to 1 - 1.5 degrees. I was initially disappointed with the plane but after moving the cg back and installing the shim it flew quite well.

[Mark9]

Most high performance sailplanes have a horizontal incidence of 1 - 2 degrees. It allows for a wider speed range without needing to hold down stick. However, the aircraft does become more pitch sensitive, but dual rates and exponential can be used to cure that.

The Phoenix Model Ka-8 that I put together required a 5/16" shim under the LE of the horizontal to get to about 1.5 degrees and I flies great at that setting with a neutral elevator trim point. A buddy up here has one without a shim and he has a very pronounced down elevator trim position. The fact you needed a lot of down trim for your CG position indicates you may need to shim up the LE of the horizontal Victor.

[edfmaniac]

EWD is decalage. The stab saddle is moulded to 3 - 3.5 degree of decalage. Mine came with an "expert" shim which brings it down to 1 - 1.5 degrees. I was initially disappointed with the plane but after moving the cg back and installing the shim it flew quite well.

Thanks for that info. I was wondering why it was so far off. Where did you end up balancing it with the expert shim? I'll have to make something as my plane came to me second hand and doesn't have that shim.

[edfmaniac]

Most high performance sailplanes have a horizontal incidence of 1 - 2 degrees. It allows for a wider speed range without needing to hold down stick. However, the aircraft does become more pitch sensitive, but dual rates and exponential can be used to cure that.

The Phoenix Model Ka-8 that I put together required a 5/16" shim under the LE of the horizontal to get to about 1.5 degrees and I flies great at that setting with a neutral elevator trim point. A buddy up here has one without a shim and he has a very pronounced down elevator trim position. The fact you needed a lot of down trim for your CG position indicates you may need to shim up the LE of the horizontal Victor.

I already shimmed it up with about 10 layers of masking tape, staggered to make it follow the shape of the saddle as much as possible. But it wasn't nearly enough. I'll get there eventually, quicker with this new info about the decalage option shim.

[Ken Kaye]

Unfortunately that plane is long gone.

[edfmaniac]

We are getting there. I need another degree or so taken out of the decalage setting and the trimming process will be done with. Enjoyed my first thermal extended flight today. Seems to climb much better with only the flaps coming down a couple of degrees in thermal mode, as opposed to the whole trailing edge.

I love the sound of whistling glider wings from a thousand feet away!

[ARUP]

Congrats on getting the sailplane dialed to almost perfection!

[edfmaniac]

Balance and trim are where they'll likely stay. If my calculations to reach 1 degree were correct, the missing shim should have been just shy of 3.5mm thick at the leading edge of the horizontal stab, tapering back to nothing at the hinge line/trailing edge, so that's what I made. I also set the CG at 90mm back from L.E. for this flight and was very happy with the results. Elevator trim is right where it should be now. Plane flies great, climbs in weak lift and turns well without trying to tip stall too easily.

Next up is to install a pitot/static tube so I can start learning how to set up the Eagletree vario. Anything wrong with putting it in the nose? I know most people have them in the vertical stab but I'm looking for an easy install. Any objections/suggestions? Thanks

[airporter]

There were two versions of the HKM ASW 27, standard and carbon. The standard was quite strong, but the carbon one is essentially bullet proof and considerably heavier. And yes, the incidence was off and needs to be reduced to 1° or 1.5° for better performance, both in speed and thermalling.

[edfmaniac]

Thanks. I have the standard glass version and I'm glad. Every day that I've flown in the short time since finishing it lacked any strong lift, but I was still able to have fun and gain altitude. The first good day is going to be a blast.