Thread Tools
Nov 20, 2011, 06:50 PM
Registered User
Gaz-b's Avatar
Was this with CG as per instructions ?
Sign up now
to remove ads between posts
Nov 20, 2011, 06:52 PM
It should fly at least once
clive45's Avatar
It looked like it just stopped in mid air...., certainly looked tail heavy.
Nov 20, 2011, 06:53 PM
Registered User
Gaz-b's Avatar
Very
Nov 20, 2011, 06:58 PM
Registered User
Quote:
Originally Posted by Gaz-b
Was this with CG as per instructions ?
Yep pilot said it was. tail heavy it appeared, even weight added to tail to balance.

Some flap used for take off

I think underpowered on stock, not 1-1 power, 6s.

Crying out for a turbine
Last edited by mk1spitfire; Nov 20, 2011 at 07:04 PM.
Nov 20, 2011, 06:59 PM
It should fly at least once
clive45's Avatar
Gaz....did it look like to you that as soon as it came of the bungee it had no power to push on forward and then tip stalled, I thought at first it had caught the bungee line but then noticed the dolly. It just came to a halt.

What power system was it using, sounded like the jet 90??????
Nov 20, 2011, 07:04 PM
It should fly at least once
clive45's Avatar
mk1spitfire what power system were you using???? also what bungee pull did it have (pounds or Kgs) lot of drag from the grass so low air speed all combined from what I saw.............
Nov 20, 2011, 07:08 PM
Registered User
Quote:
Originally Posted by clive45
mk1spitfire what power system were you using???? also what bungee pull did it have (pounds or Kgs) lot of drag from the grass so low air speed all combined from what I saw.............
I was video, not pilot. I believe stock power system, assuming fan/motor came with HK kit.

6s.

Jepe launch bungee system.

Pretty plane, but underpowered

Bungee appeared to overcome drag of grass, just not enough oomfff from edf after.

Shallower pitch MIGHT have helped but it was all touch and go. Slight headwind too.
Nov 20, 2011, 07:13 PM
Registered User
hey Spitfire-
where did you have the CG set? I have the same plane and would like to learn from your experience- sorry that it happened to you- lovely plane.
How many watts does your power system produce? I am planning to use a 3000 watt setup, yielding a bit more than 400 watts per pound, if I can keep the weight at 7 pounds, that is.To my eye, it did appear tailheavy and or underpowered. I have read that the CG recommendation in the "manual" is incorrect- too far back.
Last edited by bonefishfool; Nov 20, 2011 at 07:18 PM.
Nov 20, 2011, 07:20 PM
Registered User
Gaz-b's Avatar
Quote:
Originally Posted by mk1spitfire
Yep pilot said it was. tail heavy it appeared, even weight added to tail to balance.

Some flap used for take off

I think underpowered on stock, not 1-1 power, 6s.

Crying out for a turbine
As discussed before on this airframe the instructions are 20 odd mm out from what I have read cg works from 95 to 110 mm 110 seems to be the norm.it loked to me like as soon as it was clear of the ground it dropped its ass.
Nov 20, 2011, 07:24 PM
Registered User
Gaz, i agree. am planning right now to use 105 mm measured back from the wing/fuse junction.
Nov 20, 2011, 07:26 PM
It should fly at least once
clive45's Avatar
As far as I know it does not come with fan or anything. The fan sounded quiet like a jet 90 or CS 12 blade. I would be interested to know just exactly what he was running as well as to the battery's, a wattage figure would be good.
Very sorry to see such a nice plane hit the deck but it seemed to survive quite well.
I wonder if HK will sell spare parts or how long it is before they come back into stock, I assume they will come back into stock soon. Might be worth getting an extra one for spares.
If its like the viper 90 they say the C of G is about 30 mm too far back, the more I look at the vid my opinion is lack of power and tip stall. C of G may have been contributing to the crash but lack of air flow and no control does it every time
Nov 20, 2011, 07:34 PM
MAAC SAVED RC!!
vettster's Avatar
Sorry for your friends loss mk1spitfire... But that was a well made video!

For sure that was the stock CG of 135mm. 105mm seems to be the sweet spot from what Im reading.
Nov 20, 2011, 09:48 PM
Registered User
Any crash is unfortunate. However, it can be rewarding for lessons learned.

Bungee launching is in my plan for a CMPro T-45 (Nitroplanes). What I have picked up from RCGroup Forums: The bungee shall be pull capable of five times the aircraft weight; bungee attachment at 33% forward of the CofG; Power shall be applied only after release and the aircraft is flying level.

If the aircraft is balance, it should fly straight and level (?) with all control surfaces in neutral when released into a headwind. Perhaps, if the aircraft is allowed to glide, CofG may be evaluated.

Just my $.02.
Nov 20, 2011, 10:04 PM
It should fly at least once
clive45's Avatar
Are we to assume that the crashed Hawk did not have sufficient pull as it seemed to stop on launch even with the motor running. I did also detect a noise as it left the dolly, could it be the aircraft was caught on the dolly thereby loosing significant launch speed
Nov 20, 2011, 10:10 PM
Registered User
evo101's Avatar
it looked pretty slow to me when it launced in to the air.


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Build Log Jet Teng Models Full Composite 90MM Bae Hawk V2 From RC-Warbirds Build & Video's FlyBoyTha1 Electric Ducted Fan Jet Talk 701 Mar 23, 2015 06:32 PM
Discussion HK 90mm BAE Hawk Build Thread! OneHundretMoons Electric Ducted Fan Jet Talk 33 Jan 23, 2012 02:21 AM
Discussion BAE Hawk Full Composite for 90mm EDF Kerberos Electric Ducted Fan Jet Talk 79 Oct 15, 2010 12:57 AM
Build Log ETM Signature Series Composite BAE Hawk 90mm FL62 Electric Ducted Fan Jet Talk 86 Jun 19, 2010 01:48 PM