Fokker D7 - A Free-Flight Model Airplane

8/9/2019 Fokker D7 - A Free-Flight Model Airplane

1/6

* * *MOST FAMOUS GERMAN SHIP!

The recognition granted by Americans to the Fokker D-7 as Germany's

leading World War battle plane is by no means ill-deserved. For had thiscraft been in the bloody game prior to those few final months, the Alliedsong of victory might never have been sung. Read the full story of thisgreat ship in Henry Struck's article below, and then take his fine modelplans and instructions into your workshop and prepare to-

Fly a Fokker D-7

Trail Blazers of the Air No.9* * *

by Henry Struck

EARLY in 1918, undoubtedlyaware of the fact that she wasnearing her last chances for victoryin the World War, Germanydesperately launched a vast programof expansion and improvement for

her flying force. And among otherfeverish activities, an opencompetition for a new single-seaterfighting ship was announced byGeneral von Hoeppner, commanderof the Imperial Air Force.

Naturally, the leading aircraftfirms entered ships, and among thenew craft was a unique biplanedeveloped by Tony Fokker. Fokker,

it seemed, was pretty sure of hisground--for just a few months before,he had presented that now-famousred "tripe" to Baron Manfred vonRichthofen, and with this ship as anintroduction he had been able to chatwith the Baron and otherexperienced action-airmen about

what might constitute the idealpursuit ship.

So, armed with this knowledgeright from the skies of war, Fokkerhad taken great care and much timein the design and construction of his

entry for the competition. But whenconstruction was completed, the shipshowed an alarming tendencytoward spins!

Undaunted, Fokker and acouple of mechanics sawed off therear of the fuselage, inserted anextra section, added a larger fin, and


2/6

tried the ship again. The "bug" waskilled-and the ship flew perfectly!And the open competition proved thenew Fokker far more maneuverablethan any German ship of the day. It

is true that other ships werefaster-

butthe front line aces who had test-flown the biplane stated theirpreference was for peppy combatperformance rather than speed.

With the introduction of the newships-which became known as theFokker D-7, the subject of our TrailBlazer model this month-a definitechange occurred in aerial combattactics. Mass formations were

emphasized, as opposed to theearlier days of the war whenindividual air duels formed thegreater part of sky fighting. Thischange took place because theeasier maneuverability of the newships made it possible for flyers whowere not "born birdmen" to handletheir crates in closer quarters. Andso satisfactory were these newgroup tactics of the German army in

the World War the basis of air tacticsthroughout the world is almostentirely laid upon the system whichthey devised.

Like most truly greatachievements, the keynote of theFokker D-7 was simplicity, andclean, efficient lines marked itsexternal appearance-there was no"birdcage" of wires and thick struts.The fuselage and tail group were of

welded steel tubing, a type ofconstruction pioneered andperfected by Fokker .

The wings were entirely ofwood, and the very thick "high lift"airfoil tapered off to a thin section atthe tips. With the 160 h.p.

Mercedes power plant, the Fokker D-7 could make a speed of 120 m.p.h.which, while not quite up to many ofthe Allied ships she met in combat,was close enough to give her pilots

satisfaction.

CONSTRUCTION

AND now for our model D-7,which you'll find simple to build, andsturdy. The scale is 1/2" on themodel to 1' on the original ship. Thethree-view drawing (Plate 1) is halfthe size of the model, while the

layouts on Plate 2 are drawn to fullsize.

The fuselage sides are cut from1/32" sheet balsa to the pattern onPlate 2. Stiffener strips of 1/16" sq.are cemented across the inside ofeach blank as indicated. Glue thesides to the nose bulkhead of 3/16"sheet balsa. The formers are cutfrom 1/16" sheet, and Nos. I, II, andIII are cemented in position at the top

of the fuselage.

Connect the bottom with 1/16"sq. cross pieces, pull the rear of thebody together, and insert former IVand the remaining bottom crosspiece.

The bottom section of the nose


3/6

back to the rearmost landing gearstrut is filled in with 1/8sheet, thegrain running crosswise to the body.Round this off to match the contourof the nose bulkhead. The top of the

fuselage is covered with 1/32" sheet,and a wedge shaped sheet, not quitereaching the fuselage sides, coversthe turtle back as shown in the three-view. Cut away the cowling for thedummy motor and cockpit.

The nose plug is a block 1/2" by1 1/4" by 1 3/8 carved and sandedto meet the fuselage lines smoothly.Drill a hole at a slight downward

angle and cement bearings ofwashers with bushings inserted.

Dummy cylinders and theexhaust pipe are shaped of suitablescraps of balsa and are thencemented to a flooring of 1/32" sheetfitted between the top edges of thefuselage sides. A door is cut at therear of the body as shown, and amotor hook of .028 piano wire solidlycemented therein.

The landing gear consists ofV's made from 3/64" by 1/16"streamlined bamboo struts. Theupper ends are pointed andcemented into the fuselage bottom.The small spreader wing betweenthe wheels is built up of 7 ribs, a 1/8"sq. leading edge, and a 1/16" by1/8" trailing edge. When dry, thisframe is attached to a triangular sparbearing an axle of .028 wire and

which (the spar) has already beencemented in the apex of the landinggear V's. Mount a pair of 1 1/4"balsa wheels with thin tires, andwe're ready to begin work on the

WINGS AND TAIL

THE taper of the wingsnaturally requires ribs of differentsizes. Toward this end we havedeveloped the following simplesystem. Cut out the tip and centerribs as shown on Plate 2. Thenarrange a block of 1/32" sheet balsaslats and the shaped ribs, as shownin the rib taper detail sketch on Plate1. With knife and sandpaper, usingthe finished ribs as templates, shapethe wood into a tapered block. Sparslots are now cut, and you have aset of perfect taper ribs. Since thereis no taper in the center section, five

No.1 ribs are required.

The trailing edges (1/16" by3/16" balsa) are pinned to a softboard. Cement the end ribs againstthem. Pin the leading edge (3/32"sq. stock) to the nose of these ribs,after which the remainder of the ribsmay be slipped into place.

Add tips of 1/32" sheet and aspar of 1/16" sheet which is tapered

from 3/16" at the center to 3/32" atthe ends. Note that the spar andtrailing edge of the lower wing arecontinuous and fit into slots at thebottom of the fuselage sides.

The tail group is flat in section,and is simply constructed of 1/16"sheet and 1/16" sq. balsa.

COVERING AND ASSEMBLY

SANDPAPER the entireframework evenly, removing anybumps that might prevent a perfectfinish. A simple yet striking coloringis the basic color scheme on vonRichthofen's famous "JagdstaffelOne"-all red with white rudder and


4/6

insignia outline. The various whitebands and other designs thatmarked the individual members ofthis squadron may be selected fromthe many photos of Fokkers that

have been published.Cover all exposed parts of the

fuselage and the airfoil surfaces withcolored tissue. Apply it in separatesections at the tips and other curvedplaces.

All wing struts are of 3/64" by1/16" streamlined bamboo. Struts Care pointed, then cemented into thebottom of the fuselage just abovelanding gear struts A. They are thenbraced with the short struts D and E.A single pair of struts, F, alsosupport the upper wing.

Mount the upper wing panel,allowing the struts to project slightlyinto the wing on the outside of theNo.1 ribs, to provide ample surfacefor a strong joint. Check thealignment and the 1/16" incidence ofthe wing. The bottom wing and the

elevator are cemented directly to thefuselage at zero incidence.

The entire model may now besprayed with water and doped lightlyto tighten the tissue. Keep an eyeon all surfaces and correct anytendency to warp before the tissue isdry. The interplane struts G, H, andI, are now cemented in the givenorder to the outside of the No.4 ribsand the inside of the No.11 ribs.

Two thin bamboo struts, J, brace thestabilizer.

PROPELLER AND FLYING

CARVE the prop from amedium hard block 5/8 by 1 1/8 " by5 1/2". After finishing with fine

sandpaper, dope the prop forstrength and smoothness. The propshaft, formed of .028 piano wire, ispassed through the nose plug andprop and embedded in the hub, with

a couple of washers included forbearings.

Four strands of 3/32" flat brownrubber are required to fly a D-7model weighing. 75 oz., and fourstrands of 1/8 flat brown rubber areneeded for a heavier job. The modelshould be adjusted with clay so thatit balances level at point 1 from theleading edge of the upper wing.Minor adjustments can be made by

warping the elevators up slightly incase of a glide that is too steep, orwarping them downward to correct atendency to stall. Adjust the modelto fly in fairly tight right circles, andthen lubricate the rubber and wind itwith a winder for flights that willmake this ship one of your favorites.

Details not needed on a flyingmodel such as steps, hand grips,radiator, guns, and the like-areshown on the three-view plan andcan be easily made up from balsascraps and pins.

Flying Aces April, 1938


5/6


6/6

Documents

Fokker D7 - A Free-Flight Model Airplane