As the flying season is winding down around here( at least for me) I've been double checking CG and lateral balance as the last few landings I've had made me think to check these parameters and was wondering if anyone has the RTF dry weight of their Hawks at hand? Thanks.

I used Spectrum A6030 servos for flaps, rudder, and steering in my Hawk. The A6030 is now discontinued but it is the same servo as the SA-1256TG. The servo is a drop in fit for the Hawk cutouts and screw holes which are sized for the DS8411/8711. I used brass eyelets from my JR spares bin as the Spectrum eyelets were too small for the CARF servo screws. The JR heavy duty servo arms fit the Spectrum/Savox servos. I used the JR servos for aileron and elevator. I believe they are more precise.

The JR heavy duty servo arms fit the Spectrum/Savox servos.

Only Spektrum...Savox are Futaba splined

Sorry about that, I was told they were the same servos, my bad.

Disregard

Hi Marty,

My Hawk when built looked great with twin pilot DerJet cockpit, smoke system, and Carf tube but……………it flew like a complete dog when below 40% throttle. Landings were pretty much uncontrolled crashes, and by some pretty competent pilots too! With just the UAT filled it weighed in at 39lbs! She had a remarkable tendency to nose into the floor at landing speeds…….ugh!

After stripping out cockpit, smoke set up and replacing the pipe with a lightweight Grumania one she now weighs 31 lbs and is transformed!! I can't really get the weight below that, but I know a couple of other Hawks in the UK are at 29lbs and they fly really well. Reducing the weight makes landings fear far easier, there is a much wider envelope of control. The C of G at the reduced weight is 195mm, and I solved the climb under power issue by moving the turbine above the rails.

Now I think I can enjoy the beast, they do look great in the air!!

Cheers
David

David -
i am in the middle of a build and need to paint her so am going to bve very careful with paint so as not to get her "plumped up "

Dave - is this the dry weight that is normal ?

thanks izzy

I have two of them. They are set up pretty much identical with full cockpits, 1pilot and large Weatronic (powerbox type)receivers. The Display team Hawk has a P-120sx, lights and a nose pitot and a Tam's pipe vs a JC Cheetah, no lights, no pitot and stock pipe on the Red Arrows. No smoke on either.

Display weighs 29lbs 6oz, Red arrows weights 27lbs 12oz dry with UAT full. I just added an additional 3.5 oz's to the back end of both of them that is not included in those weights. Wanted to move the cg back to 200-205mm as some on here have done to improve flying. Haven't had a chance to try the new CG yet though.

Mike

Hi Marty,
I might as well chime in here .
I have 15 flights on my hawk. In the air it is a pleasure to fly.
Landings can be something else.
It appears the landing envelope on mine is quite small.
I have made some greasers with mine but if you are not on the numbers it will bite you big time.
My last flight tore the nose gear, nose gear frame, right wing landing gear, the bottom skin behind the wing gear as the air cylinder being under the skin has no place to go so it takes the bottom wing skin with it.

My CG was 190-195, it weighed approx 28 lbs with the hopper tank full.

Thankfully my repair looks about normal. I have set the CG to 200 but have not flown it yet.

I also had one of the best turbine pilots Dan Avila in our area fly it and he had a problem with the landing also. His comment to me was fly's great in the air but the landing envelope on mine was very small.

I have a feeling that there are people out there for whatever reason will not comment on their landing problems.

In conclusion I am sure there are good flying CA hawks out there, but I believe based on my experience everything has to be right on or you can have landing problems.

I have lots of flights on my Flash with no landing problems what so ever.

Curious if anyone else has experienced the same landing problems as me.

Stan

Stan,
I'm a Hawk kinda guy so I watch Hawk models, especially Dave's on video. As with most Flash's mine needs a 3 degree nose high approach and flaps around 35-40mm. The Hawk appears to be quite opposite, with nose down approach, a level-off, and 3-5 degrees nose high only on touchdown.

The large Skymaster Hawk version of my buddy's was the same. Following his instruction in the pattern to a landing, I was able to grease it on with the nose down turning base, through final, then level at 3 feet, and let it settle to land nose high. Same approach in full scale Cessna.

Regarding throttle, with the Skymaster it needed some power all the way around base through final to just before level, then power to idle in the level-off. Does the CARF need this also? Dave?

Can't believe we are back to this. I would say I have flown 20-25 CARF Hawks, all the same. Flew DJR's for the test flight and although it was defo heavier than most I don't remember an issue. Post rebuild after a whoopsy I'm sure it gained a lot of "flab"! The Graupner Hawk is the same (OK except Flap set-up) and they weigh way more than a CARF Hawk. I test flew and have flown a Graupner Hawk out of our 90ish meter (270-300') grass strip with no issues.
Its a Hawk. Not a Boomerang, a Classic Flash or anything else lacking drag. Only reason in my mind to "drag" an aeroplane in nose high is to add aerodynamic drag. Hawk has a tonne of drag set up as intended. It lands a bit like an Ultra Flash, You have to keep the nose down to keep the speed constant without a LOAD of power on and a swept back LE wing like a Hawk breaks away really quickly if you miss handle it. Treat it right and its easy going, easy to land and just no issue.
I have some pictures somewhere doing low passes, gear up, full flap. Over grass I can get the nose on the grass and the fuse strakes clear! It naturally sits slightly nose down full drag, read that and let it fly in, I find the Hawk easy to land, hardly any elevator work needed. I have a lot of friends who would class themselves "average" pilots, they all fly their Hawks without an issue. The balance range...read back a few pages, I test flew Matt's Hawk as built for him and it was way nose heavy, new it was but decided to fly it as it was to see (we were at the field and no way of changing much around) after the first flight which landed fine we ended up with more than 1Lb of lead on the rear most flat surface on the fuselage over the next two flights...it was then a "porker" (was not light to start with-full of unnecessary "bling" ali ball valve mounts and double fuel filler lock/stop stuff, smoke pumps and tanks, cockpit and and...all flown at our 300' patch...

My Hawk is super light,no full cockpit, but it has 280g of nose lead to allow for the difference (I installed it with a Derjet cockpit in mind, just never fitted it) No flannel or bling, it was 27.5lb when built. I'd say 28.5lb is about normal and right. BUT flown as a scale model, 30-32lb no problem. Think about the big 1:2.9 scale Hawk I flew...203lb at take-off...work out that wing loading!!!!!

Model is fine...

Thanks for the replies guys. I weighed mine last night on a digital scale and she was 31+ lbs. with a full UAT. I have a Skymaster cockpit with one pilot. The cockpit/canopy weighs in at 2 lbs 5 oz. I'm sure when I initially set the plane up, I set it at the 190mm mark. It landed fine and inspired confidence. After that, I added lights, lighting board, and a 4cell Ni-Cd for the lights. I took out a little lead in the nose to compensate for the equipment but never re-balanced it.

Flew it at the First in Flight rally in NC at the end of May and had very good landings with it. At the beginning of July at Kentucky Jets I decided to pull out a little more nose weight as I thought It might have been nose heavy due to the amount of down elevator needed for inverted flight. It wasn't much weight but that's when I had a few not so pretty landings and one came to a stop sideways which caused the tire on one of the mains to come off the rim. After getting the tire back on, I didn't check the gear for proper operation on the ground and the next flight I was only able to get the nose and one main down. Couldn't get them to go back up and try a belly landing. That ended with a skid off the runway with the wing impaling itself on a landing light. That repair added some weight in front of the CG.

I've since flown it on two outings for a total of maybe six flights and still don't feel it's as good as it was when I first maidened it. I think some of this problem may be mental. Are most of you balancing the plane upright or inverted? I'm asking because my pal was pointing out today that it's more accurate to get the measurement on the bottom of the wing than the top as the curved intakes can throw it off. I'm putting the CG back to 190 and hopefully will get to fly it before the cold weather comes.

Mine was the same with the CG forward. I moved it back as mentioned in the earlier posts and the landing window was greatly improved.

Thanks Chris, and Gary.

Gary I had read your post about moving your CG back, plus a few others on this thread with similar problems.

Hopefully this will help.

Stan

Ok! Game on! I'm in! 2010 Display Scheme sitting in my living room. Thanks for the phone consult tonight Marty and thanks to Andy Kane for the quickest best customer service I've ever seen!

Question #1: Anyone see any problems using 8411's on the ailerons and 8711's on all the other surfaces? Do the ailerons need 8711's or are 8411's plenty?

#2: What servo for a JR guy to use on nosewheel steering? I will be running 2 x 6.6 2500 A123's unregulated.

#3: For air system I'm planning on an UP3 for gear and doors, UP6 for brakes. Any issues there?

#4: Tailormade Decals, what's the best way to "fake" the fin? Not interested in repainting anything.

#5: Dave, you mentioned waxing it... is that before beginning work on it or after applying decals?

Here's my understanding so far....
8411s for ailerons are fine
Up3 good, up6 also good.
dont know about Taylor made yet
wax it before however I have a question about that as well. What's the best way to remove the wax, IE to glue a part or apply a decal?

Joseph

Glad you received your probe ok, yes 8411 fine in ailerons and flaps also have 8911 in elevator and rudder (what I already had)

if you mean to glue on the outside of the skin, I use Dremel to roughen through paint etc and also when gluing inside and clean with pure alcohol before using 9461 Hysol

Alan

Servos exactly how i would do it. I use JR 579 (non Digi) on nose steering.

Have a few guys using the UP3 set up and UP 6 Best brake valve made....

Taylor Made stickers come with sticker sheet to get the fin better.

I wax before starting build, but like Alan says for the strakes, i use a dremel disc to rough the surface, clean with alcohol, stick 9462. The Taylor made decals go onto and stock on a waxed aeroplane just fine

Dave

Just going back to when weights were being discussed, I had a chance to weigh my Hawk and after having painted the fuz and tail plane and wing as original (but will be painted). Now this does have Der jet cockpit with one pilot, my light set with 4.7 Li-Ion etc and it weighs just under 29.4lbs so for all the 2k primer and paint pretty happy with this weight probably around 300g for wing when painted as estimate


Also has any one got advise on how to paint over the live hinge as masking the thin line would not be easy unless using PCB track tape, never have painted over a live hinge! Noticed on ailerons and flap there looks like 0.5mm gap....don't fancy running a blade down the line after painting for obvious reasons!
One way way is to mask and spray either side of hinge line separately?

Alan


really have to watch the spell/grammar on this iPad it has a nasty habit of changing text without you noticing!

This is a nice landing and flying airplane :-) The scale l. gear is a bit heavy but my all up w. is 12,7 kg, UAT full. So all in all a leight Hawk for that size. I use a bit crow with the flaps and i guess I have only a little over idle when it comes in. Just lets it come down, nose down by itself... Mine will be 4 years in january :-) http://www.youtube.com/watch?v=P36IB7r15ws
And ofcourse no gyros. That's for helicopters! He he.

Happy landings everyone.

Alan

Only way I have done it is to prepare the wing, mask either side, rub 2 coats of wax polish over the gap left. peel of the tape and paint. I does not stick or penetrate the hinge

D

Dave

Thanks, I only just thought about it the other day and suddenly realised I did not want 2k paint bending over the hinge!

Just got a small job to complete before I carry on with the wing...

Replacing the roof on my workshop! This PVC coat galvanised steel is really good stuff to work with and is quoted to last 40yrs plus so I will not be doing it again!

Alan

Now finished!

Good thing it's just a small job Alan. Done yet?

Marty

Just got the roof finished and heavens opened right on que, someone must have ordered the rain to test for leaks!
Started this job last Saturday and spent Sat and Sun drilling around 100 holes to fix wooden purlins to the angle iron framework then Mon to Wed to fit panels and tomorrow will be sealing day and clear up day back to work on Fri for a rest!
Looking forward to get back to the models!

Alan

smitty1001, careful with the alcohol! The exterior finish will come right off with it so only use it inside or on a roughened up area. Use Ronsonol lighter fluid to clean painted surfaces. You can use the Tailormade Decals on the fin without repainting. I just skipped the lettering and stuck the crown sticker on. It looks great and scale enough for this bird. I like the CARF color scheme as it is, more color but less scale than than the real thing.But Tailormade gave me two sets of lettering for the fin. One scale size if it is repainted and another small size if not. I just didn't like the little letters crammed into the small black area.