Impact Hints, Tips & Information

This page contains items that may help you whilst building and flying your Composite-ARF Impact. The items are in no particular order.


It should be noted that you will still have a 100% capable model should you choose to build your Yak exactly as per the standard instructions.


Check the gallery here and equipment list here




Item Description
Latest Instructions Click below for the new illustrated Impact instructions.

Impact Instruction Manual V1.0

Impact Instruction Manual Addendum

Impact Tail Template

Impact Fuselage Floor/Crutch Template



David Gibbs has kindly offered the following info regarding the setup of his Impact which others may find ideal for them too or at least an excellent starting point....


Model trimming is personal -- so make of the following what you may . . . .

15 flights in and I have a set up that broadly feels comfortable for me. Still tidying expos. Tight but not over controlled. I found the settings in the manual to be more 3D like -- so I am well back from there!

Model is flying with OS140; standard pipe; elevator and rudder servos at back of canopy area in fuselage; battery just in front of the wing tube.

This puts the CofG 20mm back from the front of the wing tube (about 2/3rds of the way back through it and well in front of the suggested position). Locks onto a line nicely, snaps straight and controlled (see flight mode settings below), spins tidy. Only minor elevator needed for level inverted flight. 45 degree up, roll inverted test and it slowly drops its nose into a nice arc.

Motor and stab at 0 degrees incidence; wing at +0.25 degrees. Tracks down dead straight with only very minor mix of down elevator to low throttle. No mixing required for knife-edge. 2 degrees right thrust close but not quite enough -- so a touch of right rudder mixed to higher throttle (multi point mix used to get this right from about 1/2 throttle up)

Normal flight trim:
- Elevator: Up 11 deg; Down 13 deg (approx 14 and 16 mm respectively at fuselage end)
- Aileron: Up 6 deg; Down 9 deg (approx 10 and 14 mm respectively at fuselage end)
- Rudder: 30 deg (approx 55 mm)

Snap trim:
- Elevator: Up 16 deg; Down 18 deg (approx 19 and 22 mm respectively)
- Aileron: Up 9 deg; Down 13 deg (approx 13 and 18 mm respectively)
- Rudder: 20 deg (approx 40 mm)

Less expo on down elevator than on up; quite a bit more aileron differential than in manual (30% on JR10X) to stop adverse rolling.

Necessary model maintenance -- round wing edges where they seat on fuselage and put some clear plastic (I used book covering) on fuselage to minimise eating through paint through vibration!

David Gibbs also gave an update too!....


Trimming update -- after another 5 good flights and handing it to one of the trimming gurus for an opinion the changes were:

- For normal flight trim -- about 10% more aileron throw to tighten up response.
- For snaps -- about 5% less elevator, 5% more rudder, and 15-20% more aileron.

Experimented a bit with the CofG, and happy that the 2/3 way back through wing tube works well.

Still has about 1mm of down trim on elevator, so I will now tidy up engine and wing incidence relative to stab -- maybe by lowering the back or the stab a fraction.



Kit Component Weights

I decided to weigh the kit components and list them here for those who are interested in such things!



Weight (g)











Left Wing


Right Wing


Left Stab


Right Stab


Wing Tube


U/C Legs


Wheel Pants




Total Weight

2150g or 4lbs 12oz


Construction Threads

The following link will take you to the build thread of my own ZDZ-40 petrol engine powered Impact


Impact Build


Also, the following site, whilst unfortunately in German, may prove useful to builders or potential builders of the Impact.


Jason Schulman's NATS winning Impact

The following lists Jason's set up for his Nat's winning electric powered Impact. The link at the bottom should take you to a thread Jason

himself started to show details of his own model and info on his setup


Airplane: Composite-ARF Impact
Radio: Futaba 9ZAP
Servos: Aileron: Futaba 9151, Elev: Futaba 9650, Rudder: Futaba 9151
RX: Futaba 148 DP
Motor: Hacker C-50 14XL 6.7:1 Acro
Controller: Master-90-Acro
Prop: APC-E 22x12
Batteries: Thunder Power 10S3P 6000 mAh ($325 a half-pack, $650 for the 10S3P)  Duralite 6V reg with 730 2-cell
Weight: 11lbs RTF


Jason started a thread at RCGroups which you can find here.....