shorty55

Well yesterday was the maiden day. All the usuall nerves. Range check done, everything double checked, again.
1 final cigarette for the nerves then fired up the engine and taxied out, turned my beauty into the light headwind then, deep breath, power to 80% to get her rolling then 100%.Away she went perfect tracking, applied gentle up elevator,just enough to raise just the nose then let airspeed increase to make her unstick from terraferma. Heart banging away, still just a tad of elevator she lifted beautifully, scale like. I held the elevator, only a very small amount until i thought, yes the negative stuff starts her, the rate of climb would be perfect to let the speed increase just right, no more than 10-15 degrees. At this point i released the back pressure on the elevator, as soon as i did this she dropped suddenly and fast, thankfully i must of ony been 5-10 feet off the ground, she slammed her belly hard back to earth, instantly the gear ripped off and she came to a stop in just a couple to yards. My heart dived,(sad hey its a model plane but i love them even after 20yrs of it). When i arrived at the plane the under side of the wing was ripped to shreds with both gear understandedly torn away and the nose gear likewise,a real mess. Packed up my stuff with my dad and a silent drive home.
Initially because of alot a problems with my other jet with glitching, a put it down to this but now ive pondered over the dew seconds of time numerous time i put it down to the neutral positioning of the elevator. I recently read the review of the new turbine version in jet magazine and i remember to author having to hold elevator nearly full for his maiden, the trailing edge level with the flat area on the top of the fuselage. Looking back if id only kept pressure on the elevator, mmmmmmmmmm. Anyway the planes hidden away in the garage so i cant look at it for now,maybe il dig her out in a day to have a proper look at the damage.
My final thought here is I suppose where in elevator neutral position on the amd hawk, not for my knowledge but for others, being a little odd in charactor I probably wont touch her again for months. Anyway, out with the notepad and coffee, time to ponder on the next project.
Signing off,
Gutted Nick.

john agnew

Nick

Where was your elevator set at the neutral point? I.e. was it level with the top of the fuselage? Mine flew perfectly at that setting.

John

shorty55

Yes level with the top of the fus, and the c of g was dead on.
Still gutted
Nick.
Digging out the boomerang till i win the lottery.

shorty55

Im that gutted that last night i was thinking of selling my jet engines and boomer.(ps mw54 is a beauty) cany stand the stress of having all that money on the end of my thumb but having slept on it id would regret selling them.

E.Banner

Hi Nick,

Sorry to hear about your mishap with the Hawk. I hope the damage dosent look so bad in a day or two!

As you said my maiden with the AMD Hawk necessitated full up elevator.

The main reason for this being there was too much free play in the elevator linkage. Full up elevator stick was not giving full up elevator control surface movement.
I moved the rudder servo up into the fin and changed the elevator servo location to give a short stiff control rod and improved the servo arm/ control surface horn mechanical relationship.

Dave Wilde, the importer, changed the kit instructions to reflect the changes following the review.

I believe the three criteria for success are:

1/ Minimal free play in the elevator linkage, must be a lot less than 1/8th inch.
2/ C of G as specified in the instructions.
3/ Elevator neutral is trailing edge level with or just higher than the “corner� of the fuselage. I’m at work at the moment (!) but can post a photo later if it would help.

My Hawk is a delight to fly powered by an Autostart MW44 gold which is giving 10.5 lbs thrust (measured).

If I can be of any help please ask…

Eric Banner

shorty55

Eric,
The photos would be much appreciated.
Many thanks and keep up the great indepth reviews in the mag.
Many thanks,
Nick.

ravill

My Feedback: (11)

Condolences from accross the pond. Hurting our planes hurts us something awful. Hang in there, and try to recall all the fun flights you've had in this hobby. It helps me when I'm down.

Take care,

Rafael

Eric Banner

Hi Nick,

Photo's. Max up settled at 20mm

Eric Banner

Reflex on ailerons is worth including.
I'm using only 5mm take off flap, increasing to 10 mm for landing. Not alot, but it works fine!

HTH

Thanks for the kind words...

Eric

mikedenilin

My Feedback: (67)

Hi All,

Sorry to hear the loss. Personally I learned to dislike the AMD or JHH Hawks. I had 2 of them before. They never lived long enough. Many people who had this hawk also met the same fate. It's a poorly made airplane and aerodynamically unsuitable for turbine, period. It's aerodynamically unstable at low speed. A sudden flow separation at the wing tip will occur at low speed because it does not have the vortex generators on the leading edges. The full scale one have these features. Airworld Hawk has these feature and flies well at extreme low speed. On top of that, the hardware package is not good either. The fuselage (at least the old one) was made of polyester resin instead of epoxy. etc.

I really recommend anyone who has small engines try the more stable JHH F86, Savex L39 or the new JHI A7, Cermark Fun Scale F16, SM F16 (1/8) are good too, if you want to fly scale-looking airplane at bargin prices. Anyway, I have not seen many succesfful Hawks out there except the Airworld. Of course it comes with a steep price tag.

Mike

Eric Banner

Maybe.

But if you don’t know much about aerodynamics as I don’t, they fly just dandy.

Eric

JONATHAN G

hi mike try going to some off the jet meeting and you will see the amd hawk fly i am building one now, every one i have seen fly, flys round like its on rails, looks smart to regards jetman

shorty55

Im confident that the amd hawk would fly great, and they do look the part. Now ive come to terms with the maiden, and ive gone through the take off so many times in my mind, its, so dissappointing for me but we brits never give in. Tomorrow i will venture into the garage and start my investigations.
First thing i must say and forgot originally was that mine is the original ducted fan version, with just allen keys screws in the elevator linkage, I was never happy with the whole elevator set up from day 1. Many reasons, roughing up the ali rod and glueing it into the stabiliser, no "solid" connection, I ground flats on the other end of the rods fitting inside the elevator linkage, but again, being a safety minded person,from the position of other people and of course the plane, i just was happy. I tightened the allen keys then used my mothers nail varnish, a tip a learnt from the cool wren guys, to "lock" the screws, but I knew in my mind I was not happy with the setup.
The free play or "slop" as I called it was noticeable, not alot mind you but it was there, a millimetre or so each way. The other concern as ive mentioned before was the neutral position of the elevators, the manual said +3 degrees, from where exactly, lined up with what? I read the review by Eric Banner in jet magazine, can i say how i was so suprised when the man himself appeared on my thread, wow, he had "concerns" and struggled with the elevator setup on his maiden. All these doughts before my maiden the other day, it all started so beautifully, Oh no im off again, dont set me off, she looked the part, ive always been hooked on hawks since i had the old lmc hawk years ago, but anyway, Ive had hours now to analyse everything, lessons to be learnt, I know that it was I releasing the pressure on the stick after the lift off that caused the accident, knock, slight mishap, cockup, whatever you call it but it could off be worse.
After all of my witterings, reading the advise from Eric Banner, I like says that, what caused the first failure?
Here's my humble opinion:-
1. The C of G was dead on, as per the manual so i can scrub that off the list.
2. Has to be the stabiliser/elevator setup
3. My main concern (ignoring the hardware setup) was the neutral position the the elevator, reading the thread, trailing edge inline with the top of the rear fuselage. The thing is thats how mine was setup, so ,,,, what caused it. From that i go back to the C of G being too far forward but it wasnt so, is it the "slop" in the elevator??
The fraction of a second that I released pressure on the stick, nose down hard, in my case from about 5 ft up which meant a very hard belly connection with terraferma. I know the gear tore off big time and I know there was damage to the wings, like i said before im checking this tomorrow afternoon as im going fishing with my dad first thing.
This sudden nose down pitching has to be elevator related but i cant quite figure out exactly where/how/why.
I know ive been woffling on, but I keep going over and over the whole scenario in a complete circle, c of g, neutral position, stabiliser flutter, give me a valium.
What do you conclude from this, honestly, dont hold back. (dont be nasty )
I wait in anticipation,
Nick
ps im off to tesco for a bottle of vino to calm the brain. I hate winter dark evenings, instead of stuck in here we should be down the field in the sun.

shorty55

Oh yes a quick question, whats the best way of repairing foam damage on the wing, ie filling in holes etc, and repairing cracks/chips on the fuselage, imsure there will be a few?
Thanks again,
Nick.

Edgar Perez

My Feedback: (13)

I have one with a .46VX. With a .46VX its underpowered at 11 pounds dry. Takeoff are interesting..[X(]
However once it gets up to speed, it flies well. Landings are easy.
I learned not to use flaps. My 1st takeoff was with about 20 degrees flaps. It barely got enough push for the takeoff. Once i took out the flaps, it raised sightly and increases speed. I believe the flaps put too much drag for my underpowered setup.

I saw some of the reflex, but with aileron down[X(].. May try that later.

A turbine will be great, but must be a wren gold category AND I wouldn't trust the original elevator setup. That probably the main reason why I'm not motivated to buy a turbine for it..

Good luck,
Edgar

jason

My Feedback: (1)

Sorry mike I don't quite agree,

theres nothing wrong with the AMD hawk if you build it right and pay special attention to the elevator servo and linkage. I have seen a few of these models go in because the elevators never worked on a dive and its because the threaded rod that is used as a horn is too short so when people set them up they find that they have way too much travel so they then wind the ATV down to about 35% then there is only 35% of the power from that 9kg servo (if they used a 9kg servo that is)and that not enough on this all moving tail.

I have bottom hinged the flaps using Tams hinges and the difference is massive, no more super fast landings and the slow flight is sower than walking pace.

I think the AMD hawk is the best value for money jet made today.

Jason

The Bush

Hi Jason
I am intrested in getting one .
Can you give details of your setup?
servos etc
control throws etc

Regards
Neil

Big Tony

Jason how can we credit your opinion if we don't know your experience level is the amd hawk your first ever jet or are you comparing it to other models you have??



All the best

Ant

Fortune7

I was privileged to witness Jason, Colin and Steve last weekend put some 80 litres (over 21 gallons!) of kero thro' their 3 'Red Sparrows' at FIJR Lake Wales. I can't guess at how many flights they did but the Wren 44s weren't drinking the same as the bigger engines. These guys flew all-day-every-day in crosswinds which kept a lot of others on the ground. Their AMD Hawks flew extremely well throughout (no maintenance needed from what I could see), so I find it difficult to believe there's much wrong with the AMD Hawk, if built properly.

The Lads won a special prize for their efforts and the formation flying from these 3 was superb!

Andy

Big Tony

Jason,

WOW your an international jet super star.

my bandit this my bandit that!

See you soon dude when I maiden my viperjet

All the best


Ant

JONATHAN G

hi nick will you please send me some pics on my pm you have got, i might be able to help regards jetman.

shorty55

Will do, just got out of bed so give me a while, much appreciated.

shorty55

Here,s the damage to the wings and fus!