Taylorcraft Rebuild


A couple of years ago, I purchased this used Hanger Nine Talorcraft for $250, including Zenoah G-23, servos and Futaba receiver.  It had its rendezvous with the ground on the third flight.  A strong cross wind was blowing that made the base leg downwind and I slowed it too much and when the turn to final was initiated, it stalled.  The whole of the front of the fuselage was wiped out.  There was no damage to the emphanage.  The wing had some leading edge damage in a couple of places but minor.

The windscreen and all but one side window was totaled.  The cowl was badly mangled but not torn up and could have been repaired with a lot of effort.  The wreck was looked at a few times and left set aside.  A new windscreen and cowl were available for about $80.  Interest in the rebuild came about for two reasons, first I'd finished repairing everything else and had a new build waiting but wanted to clean out all waiting repairs first.  Sort of a motivation to make me get the plane rebuild.  Second, Hanger Nine introduced another version of the Talorcraft and I wondered if the cowl and windshield would fit.  When I compared prices,  $50 cheaper on the cowl and windscreen plus the cowl was painted (a big item to me because I hate having to try to match paints and fuel proof) and the windshield trimmed, I got to thinking that even if they were slightly different in size, being that the whole front end needed rebuilt, then it could be built to fit, so the parts were ordered.

The cowl is only slightly smaller, perhaps .5 - .75 inches narrower and about .5 inches shorter.  The windscreen however at 8 inches 1.125 inches narrower.  That however is the width at the aft wing saddle so a rebuild will then have the cockpit parallel typical to most models instead of the expanding width typical to the scale Taylorcraft.  It is likely that all the emphanage of the two models was the same and that the fuselage was redesigned with a parallel cockpit to better suit using a two piece wing and wing tube.  I can very well understand the thinking of the redesign as the wing on the earlier model was one piece and very large.  Another issue is that building the center section of the wing into the fuselage allows strengthening the mid section which is very weak because of the footwell windows.  There are only three small areas of wood on each side plus the belly pan, leaving the model weak in the middle. 

Here are some pics.


Obviously, Before the Crash


More obvious, after crash


After Some Debrieding


Fitting Enough Together To Get A Side Pattern


Separating the Emphanage

  Everything forward of the emphanage had to go so that the rebuild could be done with a parallel cockpit section.


Side Pattern

While it may look like the side is intact enough for a rebuild, it is actually a bunch of pieces glued back together enough to get the pattern.  Also, this was not the first crash of this plane and there are several mended breaks.


The firewall fitted to to the cowl


Middle cockpit bulkhead glued to side sections


Belly Pan glued in place... note: landing gear doubler was first glued in.


Forward cockpit bulkhead in place


Firewall glued in place


Bulkhead doubler and fuel tank tray installed


The wing hold down block will serve also to hold the two halves of the plane together


The wing hold down extends aft enough for triangle stock to lock the tail to the foreward section


Turtle deck formers, fuel tank bracing and firewall triangle stock are installed


Servo tray, basswood triangle joiner, lateral brace, fuel line acess and landing gear blind nuts installed.
Everything is ready for joining except finishing the turtle deck, and forward belly pan.


Forward belly pan fitted


Cowl fairing blocks being fitted


Test Joining


Tail section to the forward section


Cowl fairings shaped


Cowl fitted

As can be seen in the above picture, the forward deck sheeting hasn't been installed.  I've been waiting to decide what to do about the engine.  The model was previously powered by a G-23 but it is heavy.  While I can find no evidence that any tail weight was added,  my belief is that the rebuild is going to add forward weight as a few structural efforts were made to beef up the strength of the forward air frame plus I've rebuild with 3/16 luan instead of light ply and balsa doubler. 

About four ounces can be reduced by using another set of wheels on hand rather than the very large balloon tires.  Another option is a lighter motor such as an MLD 28 that would provide a full one pound savings, provide more power and hand starting.  Other advantages would be it would almost completely be contained in the cowl.  None of the issues are deal makers except I don't want to add weight anywhere.


Fitted together to test the balance

I'm very surprised to see the plane tail heavy.  I'd expected the rebuild of the front end to make it nose heavy but looking more carefully, I can see that more material is aft of the CG than forward.  It's now clear that the heavier G-23 is well suited and it's looking like the projected 15 pounds (equal to pre repairs) is about where the end result will be if the tail heavy condition can be solved without adding weight.  Used were 1/4 scale HiTec servos on rudder and elevator and they and the throttle servo weigh a whopping 9 oz and set in a tray at the aft end of cockpit.  Repositioning the servos forward was tested and solved the balance issue so the servo tray will be moved and linkages added to.


Servo tray needs moved forward to balance


A couple of narrowing effects can be seen.  The wing leading edge has to be filled (no problem) .
The gear strut is now too wide (I'll live with it as the wing struts are dependent upon it and they survived the crash).


Leading edge filler pieces and overhead window fillers have been fitted

Several steps have been completed.  The cowl is fitted and cutouts made for spark plug, and exhaust pipes.  The two sections have been glued together.  Servo tray has been moved forward and linkages adjusted.    This leaves the remaining repairs to the wing.  There is about one rib bay on the left wing near the tip that needs some repair and about three bays worth of leading edge repair on the right wing panel.  The wing incidence has not yet been verified, though I really don't know what else to do with it other than zero it.  At the moment, the trailing edge has to be pushed down about 1/4 inch, which may be forcing a slight bit of negative so it needs checked as likely the forward dowel holes need relieved slightly.

Wing incidence has been checked and matches horizontal stab perfect.  Wing bolt holes have been set. 

As the wind screen and cowl were for the new version, there was some concern about the trim stripes matching up and especially the angle of the windscreen installation being such that the horizontal striping didn't end up being angular.  It is looking like the trim is very close to being correct with the cowl trim. 

One issue that still has me concerned a bit is the installation of the side windows.  All but one were destroyed in the crash and a decision has to be made about how to replace.  The new structure is 3/16" thick rather than 1/4" and one option would be simply to glaze them inside rather than flush outside though doing so would not be very clean.  Another is to make a frame for each window, glaze the frame and then sand the window to the frame and insert flush.  Another is to make dies for the windows and heat and fold the windows... this is the method I'd like to try.

Well, the technique was tried and works great... wow!


Used was a discarded crock pot oven
First the male mold is placed in the bottom


15 thousandths polyethelene sheeting cut about 1/2" oversize around is laid on the male mold


The female mold is laid over top keeping gaps equal
The female mold is the exact size of the window and the male mold cut 1/16 undersize around


On top of the glazing, a piece of plywood to keep the pane flat and finally a weight
Heat on low for about ten minutes and the weight will force the female mold down to the male
Cut power and let cool


Window panel completed


Finished window panel after trimming excess


Window fits flush outside and lips inside as the stock windows did
They will be installed of course after covering


This rebuild has six side windows.  Fortunately the molds will work for both sides so only three sets need be made and they are not difficult to make.  The project was far easier than I'd first thought it would be.

Had to lay off the project for a couple of days.  This morning a final CG test was made with struts installed and everything else except the covering and side windows and a few small repairs yet to be finished on the leading edge of the wing on the right side and the wing tip on the left side.  None except the covering will add any weight aft and the CG is showing right on the 4 1/4 point prescribed in the manual.  That is the good news, now the bad.  Total current weight is 15 lbs 8 oz and over the weight the manual suggest.  It list the plane as 13-15 with the G-23 making it on the heavier end.  Wing loading will be 28 oz sq/ft so right about the range of the newer version of the Taylorcraft.   The plane looks like this at the moment.



It did give an opportunity to mark the position for the strut anchor points under the fuselage where it is planned to use blind nuts and nylon screws.

Next, finish repairs to the wing and then sand and cover.


False ribs replaced
Note: Leading edge angle back on each side


Forward rib cap strip in place


Upper sheeting to forward rib cap


The gear strut is soft and relies on bracing
1/16 cable is used


Wing tip repair

Repairs are almost completed.  The one remaining item is the leading edge over the rib cap sheet when the rest dries.

The only hurdle left is the recovering and there is one issue.  The lateral striping remaining on the tail section does not line up with the striping on the new cowl and windscreen as can be seen  above.  I don't yet know how it will be resolved.

The most recent effort has been to rebuild the carb on the G-23 and dial it in.  Tuning produced 8650 rpms with an APC 16x8 and 1650 idle with smooth transition.  One discovery is that low throttle will not kill the motor so a kill method has to be worked out... either an opto kill or micro switch and servo.

Having an abundance of servos and several micro switches in the junk box, that is the route taken. 
Note: the engine kill is set up on the radio so as to require the aux trim to be run up rather than a toggle switch that can accidentally be flipped and shut down the engine.


Micro switch for engine kill

Of some interest might be the servo tray.  As noted earlier, the aft cockpit servo tray had to be abandoned because of balance.  Moving the tray forward meant it had to be removable to allow fuel tank access.  Also, installing radio gear fairly deep in a model is frustrating for those of us with large hands so a decision was made for an easy pull out tray with all radio gear on it as seen below.   The  flight battery is fastened under the tray.  There are no forward tray hold down screws as the forward part of the tray simply slides into a slot provided under the fuel tank tray at the forward cockpit bulkhead.


Flight battery fastened under tray
Note that the switch harness with charge plug can be disconnected from the flight system for easy removal of the tray
Heavy duty extensions are used


Servo tray slot under fuel tank tray


Servo tray in position
Note the extensions to the linkages

The antenna routing is out the top of the plane aft of the cockpit and will be secured to the vertical stab.  This was chosen to keep it some distance from the pull/pull rudder cables and to make it easier to remove the flight system tray. 

The total weight of the flight tray is 20 oz and with the 6 1/2" forward shift represents a fairly major weight adjustment forward compared to the original installation though it had used a smaller 4.8v flight battery that has been replaced with a 6v pack.  I bought the plane used from a good builder and confess to not having checked the CG before flying it, which if it had an aft CG, could have been a contributor to its stall and crash though I don't remember thinking the plane sensitive on elevator.  We will see. 

The solution to the striping alignment is to recover the entire sides and raise the striping as illustrated on the later model Hanger 9 Taylorcraft.  As noted above, covering has begun as the bottom covering can be seen.


Thanks for taking a look.  Rebuild progress will be added to this page as it takes place.