SMALL - espritmodel.com SMALL - Telemetry SMALL - Radio
Reply
Thread Tools
This thread is privately moderated by TRWolf, who may elect to delete unwanted replies.
Old Nov 04, 2012, 10:11 PM
Registered User
United States, CA, Santa Barbara
Joined Jun 2012
32 Posts
Discussion
81" Brian Taylor DH Mosquito FBVI (1/8 scale)

I built this airplane from plans purchased from Bob Holman. It is a Brian Taylor design, originally 71" wing span, and Bob Holman blew the plans up to 81". The Mosquito has been my favorite airplane ever since I saw the movie "633 Squadron" when I was a young boy. When I saw these plans advertised in the model magazine, I decided that I just had to take this project on. The plans came with a canopy, fiberglass nacelles, and spun aluminum spinners. I did everything else...

It took me a little over a year to complete the plane, and it first flew in June of 1991. I've been flying it ever since, although the airplane has evolved over the years. It originally was modeled after SY-B / HP927 of the RAF and carried this paint scheme until late 2002. At that time, I had gotten involved with scale competition on the Scalemasters circuit using my TBM Avenger. The Mosquito was such a good flying airplane, I decided to re-finish it as TH-M / NS850 of the RCAF, and take it into serious scale competition (which I did starting in 2003). During this refurbishment process, a lot of scale detailing was added, including weathering, landing gear details, and inspection/access panels, etc. I have competed with the updated airplane until recently, and did quite well with it; finishing in the top 10 at the Scalemasters Championships on multiple occasions, and finishing in second place in Expert at the 2011 Scalemasters Championships. It also has been to Top Gun twice (2007 and 2008) and finished 13th and 11th in Expert.

This airplane weighed about 18 pounds when originally completed, and was powered by a pair of OS .46 SF two stroke glow engines. The plane few very well with those engines. During the re-finish / scale detailing process, the airplane picked up about another pound of weight (now weighs about 19 pounds). Several years ago, I replaced the (by then) worn out .46s with a pair of OS .50 SX engines. These engines were direct bolt-in replacements with significantly more power. A significant performance improvement was noted.

Other features of the plane are as follows: Scratch-built retractable main landing gear (uses Robart air cylinders), the design of which followed the layout shown on Taylor's plans. These gear have worked almost flawlessly for the life of this airplane. The plane also has bomb releases on the wing hard points. To provide positive ground handling during take-off and landing, I added wheel brakes that are slaved to the rudder channel to provide positive steering. The engine throttles are also on two channels, the slave channel mixed to the master channel via a mixing curve, allowing accurate rpm matching throughout the throttle range. The throttle channels are also mixed to a small degree with the rudder channel, to provide some throttle response (~15%) with the application of rudder. This greatly aids taxiing and provides some additional illusion of realism. I had also thought this might aid during take-off, but it does not: The throttle response of the engines is much too slow to be effective for directional control. The brakes, however, react instantly are are very effective. This plane can be easily taken off with good directional control, even in a cross-wind.

Since I have now completed a much larger version (124" span) of the Mosquito, this smaller one has been retired from the competition circuit. I still fly it every couple of months. It is a blast to fly, and still looks really great in the air. Folks ask me how many flights I've put on this airplane over the 20+ years I've been flying it. I have not kept track, but they must certainly number in the several hundreds (maybe 600-800?). No serious mishaps over that period of time, although I did manage to survive three separate in-flight engine out occurances early in the life of this plane, when I didn't completely have the engine cooling sorted out.

I've attached photos below, some of the original scheme, and some of the refurbished airplane.

Here are a couple of short video clips of this airplane:
Tom Wolf's 81" DH Mosquito FBVI (0 min 29 sec)

Tom Wolf's DH Mosquito: Fast fly-by (0 min 25 sec)
TRWolf is offline Find More Posts by TRWolf
Last edited by TRWolf; Dec 13, 2012 at 02:28 AM.
Reply With Quote
Sign up now
to remove ads between posts
Old Nov 08, 2012, 09:47 PM
Registered User
CSpaced's Avatar
Oak Ridge, NC
Joined Jun 2006
1,432 Posts
Beautiful plane, with a great history. Thanks for sharing.
CSpaced is offline Find More Posts by CSpaced
RCG Plus Member
Reply With Quote
Old Nov 26, 2012, 10:52 PM
Jack of all master of none
splinterz25's Avatar
Baltimore MD USA
Joined Jan 2011
4,455 Posts
Very nice Tom I only hope I can make mine look half as good as yours do! I'm at the stage where I'll be gluing the Flap actuator in and to the flaps them selves, just hope it all works like I've planed guess I just need to go for it.

Bruce
splinterz25 is offline Find More Posts by splinterz25
Reply With Quote
Old Dec 06, 2012, 05:49 PM
Registered User
SOCAL
Joined Jul 2006
69 Posts
I read your comment about the engine cooling and I see the air scoops in the photos. Are those scoops actuated by a servo? and Where does the hot air exit the nacelle?
xfly-er is offline Find More Posts by xfly-er
Reply With Quote
Old Dec 06, 2012, 07:46 PM
Registered User
United States, CA, Santa Barbara
Joined Jun 2012
32 Posts
Quote:
Originally Posted by xfly-er View Post
I read your comment about the engine cooling and I see the air scoops in the photos. Are those scoops actuated by a servo? and Where does the hot air exit the nacelle?
The scoop is manually positionable pre-flight. It can be closed for static display or static judging during a scale contest. For flying, it hinges open and has spring latches to keep it that way. The cooling air exits out the back end of each of the exhaust shrouds on the sides of the cowl (the front part of the shroud is blocked off, and there is a generous opening into the cowl that allows free flow out the rear of the shroud), and there is an opening in the bottom of the scale carburetor scoop at the bottom of the cowl. In some of the photos you can see fuel tubing hanging down from the bottom of the cowl. That tubing is coming out the cooling air exit in the bottom of the carb scoop. The total cooling air exit area is a little more than 2X the inlet area. There also is a duct that takes all of the air that is coming into the cooling scoop and forces it to flow around the cylinder head before it dumps to the cowl interior.

The initial setup that did not provide sufficient cooling had a smaller inlet scoop, no ducting, and less exit area (more like 1:1).
TRWolf is offline Find More Posts by TRWolf
Reply With Quote
Old Dec 06, 2012, 10:05 PM
Registered User
SOCAL
Joined Jul 2006
69 Posts
Thanks for the info. Since I am building two DH98s everything I can learn helps!
xfly-er is offline Find More Posts by xfly-er
Reply With Quote
Old Dec 07, 2012, 12:05 AM
Registered User
United States, CA, Santa Barbara
Joined Jun 2012
32 Posts
Wow! Building two at the same time? Pretty impressive. Are these from plans?

If you want to see a little close-up detail of the cooling scoops, take a look at the first video that is posted in my 1/5 scale Mosquito blog; there is some close-up stuff at around the 8 minute mark. The cooling design for that larger airplane is essentially the same as what I did for the 81" version (just scaled up appropriately, of course).
TRWolf is offline Find More Posts by TRWolf
Reply With Quote
Old Dec 10, 2012, 05:32 PM
Registered User
SOCAL
Joined Jul 2006
69 Posts
I have watched your videos several times. Very nice flying. BTW how did you get Santa Ynez field? It usually seems busy when I'm there for glider rides.
FIrst Mosquito is from a Don Smith plan and a Precision kit. Lots of headaches. I often think I would have been better off scratch building. I had not heard of the BT designs at the time. When I did I bought the 81" PR version with laser cut wood. It's going together slowly with all the usual delays of work and life in general. I decided to get going a bit since the full size one is now flying in NZ. I'm about ready to sheet the wings and join the fuse halfs. Then comes all the controls and engines............
xfly-er is offline Find More Posts by xfly-er
Reply With Quote
Old Dec 10, 2012, 06:19 PM
Registered User
United States, CA, Santa Barbara
Joined Jun 2012
32 Posts
Re: Test flight at SY airport. We got permission from the airport management to do a single test flight on a weekday morning, when there is very little full size activity. We had a two way radio to monitor the unicom frequency, We got the flight off fine with absolutely no conficts. There were no depatures or arrivals within about 15-20 minutes of our less than 5 minute flight. Had anyone called an approach during the test flight, we would have immediately landed to clear the airspace.

I've heard similar comments about the Don Smith design from other builders. My experience with the BT Mosquito was that most things went together very well and the structural design was very efficient from a strength to weight standpoint.
TRWolf is offline Find More Posts by TRWolf
Reply With Quote
Old Dec 11, 2012, 12:10 PM
Registered User
SOCAL
Joined Jul 2006
69 Posts
More Mosquito

The Don Smith Mossie suffers from inadequate development. BT built his designs and flew them before releasing the plans and parts. The BT Mosquito stays more to the original design of wings and fuse. That makes it easier to figure out where unspecified things go. The Don Smith plan, and kit, leaves much up to the builder. See my thread on RCSB under Uncontrolled Descent. Later I found out that Sparc Laser in Austrailia is making a 124" kit of the BT plan. If I had known about that in the begining I would have gone with that rather than the Don Smith. Live and learn.....
About Santa Ynez. The glider service guys told me of conflicts on landing with powered aircraft that did not want to yield and go around.........
xfly-er is offline Find More Posts by xfly-er
Reply With Quote
Reply

Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Build Log FB Mark VI DeHavilland Mosquito NF Brian Taylor- Plans 81" wing span splinterz25 Fuel Warbirds 1524 Nov 18, 2014 01:33 PM
Discussion Brian Taylor 1/8 Scale F4 Corsair Thrawn150 Electric Warbirds 2 May 11, 2010 12:31 PM