Travel Air Mystery Ship-2012/11

In the 1920s and early 1930s, the National Air
Races were very popular. The military dominated
the racing circuits with its powerful designs. The
Travel Air Company wanted to build racers that
would outrace the military airplanes.
Two young engineers, Herb Rawdon and Walter
Burnham, under the guidance of Walter Beech,
president and founder of the Travel Air Company,
started designing sleek, low-wing airplanes with
streamlined wheel pants and a National Advisory
Committee for Aeronautics (NACA) cowl.
The airplane was entered in the 1929 Thompson
Cup Race and won, beating more powerful military
entries by 8 to 20 mph. These races showed the
military that the era of biplanes was over.
Several versions of the Travel Air Mystery Ship
were built and raced. This particular racer is hanging
in the Chicago Museum of Science and Industry as a
symbol of the racing airplane that started the trend
toward low-wing, low-drag aircraft.
I always liked the airplanes from the Golden Age
of Aviation. I built several Scale models of aircraft
from that era, but never the racer. I decided to
build the Mystery Ship because it has the right
proportions of wing and tail surfaces to be a
relatively docile-fl ying airplane.
I chose 1/6-scale so the model would be a
good size. The challenge was how to access the
motor batteries without removing the wing,
which would require undoing all the fl ying and
landing wires on the wing. Access to the batteries
is through the front, by removing the propeller
and the cowl which is held to the fi rewall with
magnets.
For the wing skins, 1/16-inch
balsa sheet was used. The
skins were pinned while being
glued to the wing.
The wing halves were joined together using
shims to attain the proper dihedral.
This shows half of
the wing’s center
section during
construction.
I decided on a three-piece wing; the outer wing panels are
removable to transport the model. The aileron servos are
located inside each removable wing panel. The elevator and
the rudder servos are located inside the cockpit.
Because the Mystery Ship has a short nose, select the lightest
balsa for building. The model will require some lead in the
nose.
Building the Wing
Glue 1/16-inch balsa sheets to each other to form four wing
skins. Cut out all the ribs. The F1 rib shows the dotted lines
between the top and the bottom spars. This is the slot that will
be cut out for dihedral brace after the entire wing is built.
Stack ribs F4, F5, and F6 and drill a 1/4-inch hole for the
alignment dowel with a drill press. Take one of the wing skins
and using the plans, transfer the location of the ribs and spars
onto it. Pin the front and rear bottom spars to the skin. Place
the 1/8-inch high shim under the skin where the W13 rib is
located. Position and glue all of the ribs to the bottom spars
and to the skin.
The W1 rib is slightly tilted as per the dihedral angle. Glue
in top spars to the ribs. Shape the LE spar so the top and
bottom of it will be fl ush with the ribs. After sanding, glue the
LE spar to the ribs.
Glue in plywood supports between ribs W9 and W10
for hardwood blocks. In the bottom
sheeting, cut out holes for four
hardwood blocks. Glue the two landing
gear support blocks to the W4 rib and
two blocks to the plywood support
between ribs W9 and W10.
Glue the top skin to the wing using
slow-drying glue. Separate the aileron
from the wing panel. Glue the hinge
spar to the rear spars and the LE spar
to the aileron. Glue the plywood plate
to the bottom skin of the aileron to
support the aileron horn.
Glue the balsa caps to the ends of
the aileron and close the gaps inside the
aileron bay. Glue the wingtip balsa block
to the W13 rib then sand the wing.
Flip the wing upside down and drill 1/8-inch holes for the
landing gear legs. At the same time drill one 1/16-inch hole next
to them for attaching the X landing gear wires on the center
section. Drill 1/16-inch holes in each hardwood block between
ribs W9 and W10 for the landing and fl ying wires.
Cut the top and bottom skin between ribs W4 and W5 to
separate the outer wing panel from the center panel. Glue the
alignment dowel to ribs W5 and W6. Put this half of the wing
aside. Build the other side in the same manner.
When the other half is done, cut the slot in rib W1 between
the top and bottom front spars to accept the dihedral brace.
Before the two halves of the wing’s center section are glued
together, slide the plywood fl oating thong between ribs W2
and W7. This thong is not glued to any rib.
Plug the outer panels into the center section. Smear the
glue onto the W1 ribsand onto the dihedral brace. Join both
halves together. Place the shims under the wingtips to get
proper dihedral. After the glue is dry, pull out the outer wing
panels from the center section. Cover the center section, top
and bottom, between the W2 ribs with two layers of 2-ounce
fi berglass. Pull the Y-connector wires into the center section of
the wing.
Building the Fuselage
Cut out all of the formers. Using 1/4 x 1/4 balsa, build the
A er the
airframe is
completed
and sanded,
UltraCote will
be used for the
covering.
A er the tail surfaces were completed, 1/4-inch balsa
sheet was glued to the bottom of the rudder to become a
continuation of the fuselage fairing.
With the cowl removed, there is access to the motor,
speed controller, battery, and the receiver. Notice
the lead attached to the side of the motor box.
Strengthen the
bond between
the wire and
the plywood by
wrapping the
legs with the
 berglass as
shown on the
drawing.
sides. The top longerons need to be formed from F10 to
F15. This can be done by wetting then pinning them to the
building board to follow the curvature on the drawing.
I used a different method. I slit the longerons in half
lengthwise and then pinned and glued them with CA glue.
On the inside of each fuselage side, between formers F3 and
F10, glue on the plywood doublers. After the doublers are glued,
stand the sides and pin them to the building board right side up.
On the outside, brace the sides with 90° braces. Between the
sides, glue in all of the balsa crossbraces and two spruce crossbraces
that will hold the brackets for the landing wires. Secure the two
brackets to them with two screws. These brackets should stick out 3/8
inch from the fuselage side skin.
Glue the side formers F4 to F15 to the fuselage. Glue the balsa skins to
these formers and to the longerons. Glue all of the top formers to the fuselage.
Glue balsa sheeting to these formers and the longerons. From formers F9 to F15, cap
the top with the 1/4-inch balsa sheet.
Remove the fuselage from the building board. Glue the bottom formers to the fuselage then glue on the bottom fuselage
sheeting. Trim the sheeting where the wing’s center section will be affi xed.
In the front, glue the F3 former to the fuselage and the 11/2-inch thick balsa block. Sand the fuselage.
Next, glue together the motor/battery box. The length of this box in front is dictated by the motor used. The propeller must
clear the cowl. Glue this box to the fuselage. Slide the cowl’s former F2 against the balsa block in front of the fuselage and mark
the location for the magnets and the holes for guide pins. Glue two magnets in the holes made in the balsa block.
Building the Tail Surface
Cut out the individual surfaces from a 1/16-inch balsa sheet. To one side, glue the LEs and TEs, then glue the ribs. Flip the
surfaces and do the same to the other side.
The rudder has one additional step. To hold the tail wheel to the
rudder, cut out and glue the 1/16-plywood piece to the bottom of the top
sheet. Insert and glue the tail wheel wire to it using epoxy.
Wrap the fi berglass around the wire and the plywood to secure the tail
wheel wire well. Now you can glue on the LE, TE, and 1/8-balsa sheet
that overlaps the joint line between the plywood and balsa to both sides
of the rudder.
Sand the tail surfaces. Glue and sand 1/4-balsa sheet to the bottom of
the rudder to become a continuation of the fuselage fairing. Glue the tail
surfaces to the fuselage. Before the stabilizer is glued in the opening in
the fuselage, insert the U-shaped fork that ties the two elevator surfaces.
Final Assembly
Build the cowl by fi xing formers F1 and F2 as shown on the drawing
and then covering them with the balsa sheet. Glue the 1-inch balsa
block to the F1 former. Sand the cowl. Glue two guide pins and two 1/2-
inch magnets to the F2
former.
Glue the wing to the
fuselage. After the glue is
dry, glue the wing fi llets
between the fuselage and
the wing.
Cut out all the pieces
for the main landing gear.
Bend then cut piano wire
to the shapes shown on
the drawing to create
four legs. Epoxy them
to the plywood center
pieces of the wheel
The landing gear
support wires
are permanently
attached to the
wheel pants. An
electrical eyelet
is soldered to the
other end.
The outer wing panels can be removed a er the flying
wires are detached. The attractive Mystery Ship flew
well on three- and four-cell LiPo batteries. For racer-like
performance, a four-cell battery is recommended.
pants. Strengthen the bond between the wire and the plywood
by wrapping the legs with the fi berglass as shown on the
drawing.
Glue 1/2-inch balsa pieces to both sides of the center piece to
create the wheel well. Make sure that the holes for the metal
bracket are aligned. Next, glue the plywood walls of the wheel
well to both sides, making sure that the wheel axle and bracket
holes are aligned.
Glue 1/8-inch sheet to the outside of the wheel pants and
sand them to shape. Insert and glue two brackets into the
holes, one in front of the wheel well and the other behind.
Finishing the Model
Cover the Mystery Ship with your favorite material. I used
UltraCote. I cut out templates for most of the trims to get the
scallops correctly shaped.
After the covering is fi nished, install the hinges, servos, and
the horns. Plug in the landing gear and install all of the wires
holding the landing gear and the wing. Each wire has the
electrical eyelet soldered to it on one end. The other end is
attached permanently to the brackets.
Install the motor and the battery. The battery is installed in
the top of the open motor box. Slide the cowl on and balance
the model so the CG is 21/2 inches from the LE. The best way
to check the balance point is to fl ip the model onto its back.
As I mentioned at the beginning of this article, some lead will
be needed. I attached the lead to the sides of the motor box
near the motor.
Check all of the controls. The maximum defl ections at the
widest point should work. The elevator should move 3/4 inch
up and down, the rudder 1 inch to the left and right, and the
ailerons 3/8 inch up and down.
Flying
The model taxies with positive control and tracks straight
in takeoff. In the air, the Mystery Ship feels solid with crisp
controls.
Before the fi rst landing, fl y high and then slow down until
the aircraft stalls to get an idea of what to expect. My model
would mush and sometimes the nose would drop, picking
up fl ying speed. Other times the wing would drop and start
spinning. Centering the controls and increasing power stops
spinning and landings are easy.
Good luck with this Golden Age of Aviation racer!
—Laddie Mikulasko
[email protected]
SOURCES:
Parker Motel Ltd. Motors
[email protected]
www.parkermodel.com
UltraCote
(800) 338-4639
www.hangar9.com
Castle Creations
(913) 390-6939
www.castlecreations.com
Photos by the author

In the 1920s and early 1930s, the National Air
Races were very popular. The military dominated
the racing circuits with its powerful designs. The
Travel Air Company wanted to build racers that
would outrace the military airplanes.
Two young engineers, Herb Rawdon and Walter
Burnham, under the guidance of Walter Beech,
president and founder of the Travel Air Company,
started designing sleek, low-wing airplanes with
streamlined wheel pants and a National Advisory
Committee for Aeronautics (NACA) cowl.
The airplane was entered in the 1929 Thompson
Cup Race and won, beating more powerful military
entries by 8 to 20 mph. These races showed the
military that the era of biplanes was over.
Several versions of the Travel Air Mystery Ship
were built and raced. This particular racer is hanging
in the Chicago Museum of Science and Industry as a
symbol of the racing airplane that started the trend
toward low-wing, low-drag aircraft.
I always liked the airplanes from the Golden Age
of Aviation. I built several Scale models of aircraft
from that era, but never the racer. I decided to
build the Mystery Ship because it has the right
proportions of wing and tail surfaces to be a
relatively docile-fl ying airplane.
I chose 1/6-scale so the model would be a
good size. The challenge was how to access the
motor batteries without removing the wing,
which would require undoing all the fl ying and
landing wires on the wing. Access to the batteries
is through the front, by removing the propeller
and the cowl which is held to the fi rewall with
magnets.
For the wing skins, 1/16-inch
balsa sheet was used. The
skins were pinned while being
glued to the wing.
The wing halves were joined together using
shims to attain the proper dihedral.
This shows half of
the wing’s center
section during
construction.
I decided on a three-piece wing; the outer wing panels are
removable to transport the model. The aileron servos are
located inside each removable wing panel. The elevator and
the rudder servos are located inside the cockpit.
Because the Mystery Ship has a short nose, select the lightest
balsa for building. The model will require some lead in the
nose.
Building the Wing
Glue 1/16-inch balsa sheets to each other to form four wing
skins. Cut out all the ribs. The F1 rib shows the dotted lines
between the top and the bottom spars. This is the slot that will
be cut out for dihedral brace after the entire wing is built.
Stack ribs F4, F5, and F6 and drill a 1/4-inch hole for the
alignment dowel with a drill press. Take one of the wing skins
and using the plans, transfer the location of the ribs and spars
onto it. Pin the front and rear bottom spars to the skin. Place
the 1/8-inch high shim under the skin where the W13 rib is
located. Position and glue all of the ribs to the bottom spars
and to the skin.
The W1 rib is slightly tilted as per the dihedral angle. Glue
in top spars to the ribs. Shape the LE spar so the top and
bottom of it will be fl ush with the ribs. After sanding, glue the
LE spar to the ribs.
Glue in plywood supports between ribs W9 and W10
for hardwood blocks. In the bottom
sheeting, cut out holes for four
hardwood blocks. Glue the two landing
gear support blocks to the W4 rib and
two blocks to the plywood support
between ribs W9 and W10.
Glue the top skin to the wing using
slow-drying glue. Separate the aileron
from the wing panel. Glue the hinge
spar to the rear spars and the LE spar
to the aileron. Glue the plywood plate
to the bottom skin of the aileron to
support the aileron horn.
Glue the balsa caps to the ends of
the aileron and close the gaps inside the
aileron bay. Glue the wingtip balsa block
to the W13 rib then sand the wing.
Flip the wing upside down and drill 1/8-inch holes for the
landing gear legs. At the same time drill one 1/16-inch hole next
to them for attaching the X landing gear wires on the center
section. Drill 1/16-inch holes in each hardwood block between
ribs W9 and W10 for the landing and fl ying wires.
Cut the top and bottom skin between ribs W4 and W5 to
separate the outer wing panel from the center panel. Glue the
alignment dowel to ribs W5 and W6. Put this half of the wing
aside. Build the other side in the same manner.
When the other half is done, cut the slot in rib W1 between
the top and bottom front spars to accept the dihedral brace.
Before the two halves of the wing’s center section are glued
together, slide the plywood fl oating thong between ribs W2
and W7. This thong is not glued to any rib.
Plug the outer panels into the center section. Smear the
glue onto the W1 ribsand onto the dihedral brace. Join both
halves together. Place the shims under the wingtips to get
proper dihedral. After the glue is dry, pull out the outer wing
panels from the center section. Cover the center section, top
and bottom, between the W2 ribs with two layers of 2-ounce
fi berglass. Pull the Y-connector wires into the center section of
the wing.
Building the Fuselage
Cut out all of the formers. Using 1/4 x 1/4 balsa, build the
A er the
airframe is
completed
and sanded,
UltraCote will
be used for the
covering.
A er the tail surfaces were completed, 1/4-inch balsa
sheet was glued to the bottom of the rudder to become a
continuation of the fuselage fairing.
With the cowl removed, there is access to the motor,
speed controller, battery, and the receiver. Notice
the lead attached to the side of the motor box.
Strengthen the
bond between
the wire and
the plywood by
wrapping the
legs with the
 berglass as
shown on the
drawing.
sides. The top longerons need to be formed from F10 to
F15. This can be done by wetting then pinning them to the
building board to follow the curvature on the drawing.
I used a different method. I slit the longerons in half
lengthwise and then pinned and glued them with CA glue.
On the inside of each fuselage side, between formers F3 and
F10, glue on the plywood doublers. After the doublers are glued,
stand the sides and pin them to the building board right side up.
On the outside, brace the sides with 90° braces. Between the
sides, glue in all of the balsa crossbraces and two spruce crossbraces
that will hold the brackets for the landing wires. Secure the two
brackets to them with two screws. These brackets should stick out 3/8
inch from the fuselage side skin.
Glue the side formers F4 to F15 to the fuselage. Glue the balsa skins to
these formers and to the longerons. Glue all of the top formers to the fuselage.
Glue balsa sheeting to these formers and the longerons. From formers F9 to F15, cap
the top with the 1/4-inch balsa sheet.
Remove the fuselage from the building board. Glue the bottom formers to the fuselage then glue on the bottom fuselage
sheeting. Trim the sheeting where the wing’s center section will be affi xed.
In the front, glue the F3 former to the fuselage and the 11/2-inch thick balsa block. Sand the fuselage.
Next, glue together the motor/battery box. The length of this box in front is dictated by the motor used. The propeller must
clear the cowl. Glue this box to the fuselage. Slide the cowl’s former F2 against the balsa block in front of the fuselage and mark
the location for the magnets and the holes for guide pins. Glue two magnets in the holes made in the balsa block.
Building the Tail Surface
Cut out the individual surfaces from a 1/16-inch balsa sheet. To one side, glue the LEs and TEs, then glue the ribs. Flip the
surfaces and do the same to the other side.
The rudder has one additional step. To hold the tail wheel to the
rudder, cut out and glue the 1/16-plywood piece to the bottom of the top
sheet. Insert and glue the tail wheel wire to it using epoxy.
Wrap the fi berglass around the wire and the plywood to secure the tail
wheel wire well. Now you can glue on the LE, TE, and 1/8-balsa sheet
that overlaps the joint line between the plywood and balsa to both sides
of the rudder.
Sand the tail surfaces. Glue and sand 1/4-balsa sheet to the bottom of
the rudder to become a continuation of the fuselage fairing. Glue the tail
surfaces to the fuselage. Before the stabilizer is glued in the opening in
the fuselage, insert the U-shaped fork that ties the two elevator surfaces.
Final Assembly
Build the cowl by fi xing formers F1 and F2 as shown on the drawing
and then covering them with the balsa sheet. Glue the 1-inch balsa
block to the F1 former. Sand the cowl. Glue two guide pins and two 1/2-
inch magnets to the F2
former.
Glue the wing to the
fuselage. After the glue is
dry, glue the wing fi llets
between the fuselage and
the wing.
Cut out all the pieces
for the main landing gear.
Bend then cut piano wire
to the shapes shown on
the drawing to create
four legs. Epoxy them
to the plywood center
pieces of the wheel
The landing gear
support wires
are permanently
attached to the
wheel pants. An
electrical eyelet
is soldered to the
other end.
The outer wing panels can be removed a er the flying
wires are detached. The attractive Mystery Ship flew
well on three- and four-cell LiPo batteries. For racer-like
performance, a four-cell battery is recommended.
pants. Strengthen the bond between the wire and the plywood
by wrapping the legs with the fi berglass as shown on the
drawing.
Glue 1/2-inch balsa pieces to both sides of the center piece to
create the wheel well. Make sure that the holes for the metal
bracket are aligned. Next, glue the plywood walls of the wheel
well to both sides, making sure that the wheel axle and bracket
holes are aligned.
Glue 1/8-inch sheet to the outside of the wheel pants and
sand them to shape. Insert and glue two brackets into the
holes, one in front of the wheel well and the other behind.
Finishing the Model
Cover the Mystery Ship with your favorite material. I used
UltraCote. I cut out templates for most of the trims to get the
scallops correctly shaped.
After the covering is fi nished, install the hinges, servos, and
the horns. Plug in the landing gear and install all of the wires
holding the landing gear and the wing. Each wire has the
electrical eyelet soldered to it on one end. The other end is
attached permanently to the brackets.
Install the motor and the battery. The battery is installed in
the top of the open motor box. Slide the cowl on and balance
the model so the CG is 21/2 inches from the LE. The best way
to check the balance point is to fl ip the model onto its back.
As I mentioned at the beginning of this article, some lead will
be needed. I attached the lead to the sides of the motor box
near the motor.
Check all of the controls. The maximum defl ections at the
widest point should work. The elevator should move 3/4 inch
up and down, the rudder 1 inch to the left and right, and the
ailerons 3/8 inch up and down.
Flying
The model taxies with positive control and tracks straight
in takeoff. In the air, the Mystery Ship feels solid with crisp
controls.
Before the fi rst landing, fl y high and then slow down until
the aircraft stalls to get an idea of what to expect. My model
would mush and sometimes the nose would drop, picking
up fl ying speed. Other times the wing would drop and start
spinning. Centering the controls and increasing power stops
spinning and landings are easy.
Good luck with this Golden Age of Aviation racer!
—Laddie Mikulasko
[email protected]
SOURCES:
Parker Motel Ltd. Motors
[email protected]
www.parkermodel.com
UltraCote
(800) 338-4639
www.hangar9.com
Castle Creations
(913) 390-6939
www.castlecreations.com
Photos by the author