Sapac Hawk - RC Groups
Thread Tools
This thread is privately moderated by Herb, who may elect to delete unwanted replies.
Aug 11, 2010, 04:03 PM
Lithium Member
Herb's Avatar
Build Log

Sapac Hawk


I got this one from Gregg for $40. It was a v1 version, so I got a set of FG ducts from sapac, instead of those comical vacuformed plastic ones. The rest of the ducting I did as usual with mylar.

It's a nice weekend flier, the wing's a bit too thin & flimsy for retracts so I eventually used fixed gear instead (kiss principle).

I've had about 15 flights on it, and it's nice and fast on ca. 1200W. But a bit of a vicious tipstaller in tight turns, if you slow it down too much.

Guy H took the very nice in-flight pictures below (Canon 7D).

.
Last edited by Herb; Nov 11, 2010 at 02:06 PM.
Sign up now
to remove ads between posts
Aug 11, 2010, 08:48 PM
Registered User
unknown flyer's Avatar
Do you think wing fences would help the tip stall? Maybe some reflex?
Aug 12, 2010, 01:11 PM
Lithium Member
Herb's Avatar
Yes and yes

My kit did not have the wing fences, they got lost somewhere in transit ...

The problem is of course that the wing is designed to be rather thin to get speed ... as a result the Hawk is indeed quite fast & low drag.
Nov 19, 2010, 01:42 PM
Lithium Member
Herb's Avatar
I noticed after a few months of flying that the Sapac Hawk does have a bit of a tipstalling tendency in moderately tight turns.

Not sure if this is a generic characteristic of the Hawk wing geometry, or is due to the specific choice of (relatively thin) airfoil.

In any case, I decided to try out a pair of good-sized wing fences -

If they have any noticeable effect I might try that later in the CMP T-45 as well ... I noticed Rolf also has fences in his DS T-45.

.
Nov 19, 2010, 01:49 PM
1.21 Gigawatts!
Steph280's Avatar
Even the E-Flite Hawk has wing fence, so I think they probably really are functional than just cosmetic. Anxious to see how your CMP T-45 flies with/without them...
Nov 19, 2010, 03:09 PM
Lithium Member
Herb's Avatar
Yes absolutely indeed, you are right that's another reason why I decided to fit them in the Sapac Hawk as well

It is interesting that the full sized Bae Hawk has fences, while the T-45 (licence built, modified Hawk) has many tiny turbulence generators.

.

Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Discussion Sapac Foam T-45 64mm EDF / Fox Hawk Lithonion Foamy EDFs 65 Feb 17, 2011 11:15 AM
Sold Sapac 100mm T-45 Hawk NIB tailslide5_0 Aircraft - Electric - Jets (FS/W) 4 Sep 23, 2010 12:36 PM
Discussion Sapac Hawk Converted Canadian CT-155 Hawk Action Jack Foamy EDFs 17 Oct 30, 2009 06:26 PM
Found 64MM FAN for Sapac Foam T-45 or GWS Fox Hawk Lithonion Aircraft - Electric - Jets (FS/W) 2 Sep 01, 2009 12:29 PM