Sportine Aviacija LAK-17B FES mini User manual

JOINT STOCK COMPANY
“SPORTINĖAVIACIJA ir Ko”
Pociūnųkm., Ašmintos sen.,
LT-59327, Prienųraj., Lithuania
Tel: [phone]
Fax: [phone]
E-mail: [email protected]
http://www.lak.lt
MAINTENANCE MANUAL
FOR THE
LAK-17B FES sailplane
with Front Electric Sustainer system
Type (Muster): LAK-17
Model (Baureihe): LAK-17B FES
Serial Number:
Registration: ______________
Date of Issue: ______________
Pages identified by "Appr." are approved by the European Aviation Safety Agency
Original date of approval: 31 October, 2014
EASA TCDS No.EASA.A.083, Issue 03
This sailplane is to be operated in compliance with the information and limitations contained
herein.

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Record of revisions
Any revision of the present Manual, except actual weighting data, must be recorded in
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Section
LAK-17B FES MAINTENANCE MANUAL 1 Page 1
Date: 06 December, 2013
Rev. No. 0
SECTION 1
General
Page
1.1 INTRODUCTION...................................................................................................................................2
1.2 WARNINGS, CAUTIONS AND NOTES...............................................................................................2
1.3 DESCRIPTION OF SAILPLANE..........................................................................................................2
1.4 ABBREVIATIONS.................................................................................................................................3
1.5 THREE VIEW DRAWING....................................................................................................................4

Section
LAK-17B FES MAINTENANCE MANUAL 1 Page 2
Date: 06 December, 2013
Rev. No. 0
1.1Introduction
This Maintenance Manual contains information for pilots, technicians and mechanics
about safe and proper maintenance of the LAK-17B FES sailplane with Front Electric Sustainer
system. This information is given in accordance with requirements of CS 22.1529.
1.2Warnings, cautions and notes
The following definitions apply to warnings, cautions and notes used in this manual.
Warning: Means that the non-observation of the corresponding procedure leads to an immediate
or important degradation of the flight safety.
Caution: Means that the non-observation of the corresponding procedure leads to a minor or to a
more or less long term degradation of the flight safety.
Note: Draws the attention to any special item not directly related to safety but which is important
or unusual.
1.3Description of sailplane
The LAK-17B FES is a new generation self-sustaining sailplane of FAI 15m-18m class
designed according to CS-22 requirements. Glider is equipped with Front Electric Sustainer
system.
The sailplane has flaps, T-shaped tail, retractable main gear wheel, water ballast tanks:
LAK-17B FESWater ballast
tank 15m 18m
Inner wings
158 ltr/41,7 US gal 158 ltr/41,7 US gal
Outer wings
0 30 ltr/ 7,9 US ga
Fin
8 ltr/ 2,1 US gal 8 ltr/ 2,1 US gal
The sailplane is made of composite materials. Wing shell is of three-layer construction
(composite material – foam - composite material). Carbon rods GRAPHLITE SM 315 have been
used in spar construction.
The airbrakes are located on the upper part of wing. The fuselage is of monocoque
construction. Pilot seats and pedals of rudder control are adjustable. The cockpit canopy opens
forward together with instrument panel. In case of emergency the canopy is ejected.
Main landing gear has a wheel of 5.00-5 size and a shock absorber.
The tow release is mounted near the main landing gear and (or) in front of pilot cockpit at
the bulkhead.

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LAK-17B FES MAINTENANCE MANUAL 1 Page 3
Date: 06 December, 2013
Rev. No. 0
Technical data b=15 m b=18 m
Wing span 15 m (49,2 ft) 18 m (59,06 ft)
Wing area, m
2
9,18 m
2
(98,81 ft
2
) 10,32 m
2
(111,08 ft
2
)
Wing aspect ratio 24,51 31,39
Wing dihedral angle, degrees 3 3
Fuselage length, m 6,555 m (21,5058 ft)
Height, m 1,29 m (4,23 ft)
Max airspeed in calm air, km/h 275 275
Max airspeed in rough air, km/h 190 190
Max flight mass, kg 550 600
Max wing loading, kg/ m
2
59,91 58,13
Min sink rate, m/s yet not defined 0.53
Best L/D without ballast at 104 km/h yet not defined 50.2
Best L/D with ballast at 121.5 km/h yet not defined 50.2
g limits without water ballast -2,65/+5,3 -2,65/+5,3
g limits with water ballast -2,65/+5,3 -2,65/+5,3
1.4Abbreviations
Abbreviations used in this document:
A - ampere,
Ah - ampere hour,
*C - degree Celsius,
C.G. - center of gravity,
cm - centimeter,
daN - decanewton,
g - gram,
h - hour,
kg - kilogram mass,
kG - kilogram force,
km - kilometer,
L/D - glide ratio,
ltr - liter,
m - meter,
mm - millimeter,
Mpa - megapascal,
V - volt.

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LAK-17B FES MAINTENANCE MANUAL 1 Page 4
Date: 06 December, 2013
Rev. No. 0
1.5Three view drawing

Section
LAK-17B FES MAINTENANCE MANUAL 2 Page 1
Date: 06 December, 2013
Rev. No. 0
SECTION 2
Description of sailplane and systems
Page
2.1  INTRODUCTION.......................................................................................................................................2 
2.2  AIRFRAME CONSTRUCTION.................................................................................................................2 
2.2.1  W ING ...................................................................................................................................................2 
2.2.2  F USELAGE .............................................................................................................................................3 
2.2.3  V ERTICAL TAIL .....................................................................................................................................3 
2.2.4  H ORIZONTAL TAIL .................................................................................................................................3 
2.2.5  L ANDING GEAR .....................................................................................................................................4 
2.3  CONTROL SYSTEMS................................................................................................................................4 
2.3.1  A ILERONS AND FLAPS CONTROL SYSTEM ................................................................................................4 
2.3.2  A N ELEVATOR CONTROL SYSTEM ...........................................................................................................5 
2.3.3  T RIMMER CONTROL SYSTEM ..................................................................................................................5 
2.3.4  R UDDER CONTROL SYSTEM ....................................................................................................................5 
2.3.5  A IRBRAKES CONTROL SYSTEM ...............................................................................................................6 
2.3.6  W ATER BALLAST CONTROL SYSTEM .......................................................................................................6 
2.3.7  T OW RELEASE CONTROL SYSTEM ...........................................................................................................6 
2.3.8  M AIN LANDING GEAR CONTROL SYSTEM ................................................................................................7 
2.3.9  L ANDING GEAR BRAKE CONTROL SYSTEM ..............................................................................................7 
2.4  EQUIPMENT AND SYSTEMS ..................................................................................................................7 
2.4.1  P ITOT AND STATIC SYSTEM ....................................................................................................................7 
2.4.2  F LIGHT AND NAVIGATION INSTRUMENTS ................................................................................................8 
2.4.3  FCU INSTRUMENT .................................................................................................................................8 
2.4.4  E LECTRIC AND RADIO EQUIPMENT ........................................................................................................10 
2.4.5  C ANOPY VENTILATION SYSTEM ............................................................................................................11 
2.4.6  C OCKPIT CANOPY AND ITS EMERGENCY JETTISON SYSTEM ....................................................................11 
2.4.7  C OCKPIT EQUIPMENT ...........................................................................................................................12 
2.4.8  F ASTENING OF BAGGAGE .....................................................................................................................12 
2.5  FES SYSTEM............................................................................................................................................12 
2.5.1  G ENERAL LAYOUT ...............................................................................................................................12 
2.5.2  M OTOR ...............................................................................................................................................12 
2.5.3  B ATTERIES ..........................................................................................................................................13 
2.5.4  M OTOR CONTROLS ..............................................................................................................................13 
2.5.5  P ROPELLER .........................................................................................................................................13 
2.6  PLACARDS AND MARKING OF CONTROLS.....................................................................................13 
2.7  DATA FOR RIGGING..............................................................................................................................14 
2.7.1  A LLOWED CLEARANCES IN CONNECTIONS OF AGGREGATES ...................................................................14 
2.7.2  A LLOWED CLEARANCES IN CONTROL SYSTEMS .....................................................................................14 
2.7.3  A LLOWED FORCES IN CONTROL SYSTEMS .............................................................................................15 
2.8  ILLUSTRATIONS ....................................................................................................................................15 

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LAK-17B FES MAINTENANCE MANUAL 2 Page 2
Date: 06 December, 2013
Rev. No. 0
2.1Introduction
In this section there is given description of sailplane aggregates, systems, equipment,
tables and markings and information about proper sailplane maintenance.
2.2Airframe construction
2.2.1Wing
Sailplane wings (fig.2.2.1_01, fig.2.2.1_02) made of composite materials consist of four
parts: right inner wing (pos. 1), left inner wing (pos. 2) and two outer wings with winglets.
The outer wings are of two different lengths. For wingspan 18 m of length, the outer
wings 3500 mm of length (pos. 3) are used. For span 15 m of length, the outer wings 2000 mm
of length (pos. 4) with winglets are used.
The wing airfoils:
18m- 15m-
s (m) c (m) Profile s (m) c (m) Profile
0.0 0.741 LAP7-150 0.0 0.741 LAP7-150
1.2 0.711 LAP7-131/17 1.2 0.711 LAP7-131/17
4.6 0.625 LAP7-131/17 4.6 0.625 LAP7-131/17
6.5 0.5 LAP7-129/18 6.7 0.38 LAP7-128/19
8.0 0.38 LAP7128/19 7.355 0.226 LAP93/148
8.855 0.226 LAP93/148
Construction of wings is of one spar monocoque type. Their spars are 2-T shape in
section. Carbon rods GRAPHLITE SM 315 are used for spar shelves. Wing shells are stuck of
two parts: an upper and lower shell parts. The shell is of three-layer construction. External and
internal shell layers are made of carbon and glass fiber. Between them there is foam. Thickness
of foam of wing shells is 6 mm.
Spars of right and left wings are joined together with the help of two pins. Spar panel of
right wing is cut off pyramid-shaped. Spar panel of left wing is fork-shaped. An outer wing is
connected to the wing with the help of outer wing spar pins. The pins are fixed by the help of
special key.
There are an adjustable hubs in the wing root ribs to fasten the wings to the fuselage.
Wings have flaps and flap-aileron type ailerons. Their shell structure is analogical to the
wing shells structure.
A flap has 6 hinges. Its length is 3.42 m, area 0.4 m
2
.
Length of ailerons (wing 15m) is 3.55 m, area 0.32 m
2
. With wing span of 18 m an
aileron is extended to 5.05 m. Its area then is 0.445 m
2
. As wing the outer wing is connected to
the wing the part of an aileron on the outer wing is connected to an aileron on the wing
automatically.
On an upper part of wing shell there are covers (pos. 16) of airbrakes. Their contour
coincides with the wing surface.
Air gaps between wings and control surfaces are closed with seals (fig.2.2.1_03;
fig.2.2.1._04). The Seals-Turbulator scheme also shows the positioning of turbulator.
The sealing tape on the lower part of the wing must close the gap and connect the control
surfaces and the wing surfaces. On the upper part of the wing only the control surfaces are

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LAK-17B FES MAINTENANCE MANUAL 2 Page 3
Date: 06 December, 2013
Rev. No. 0
covered with sealing tape. Mounting the seals must ensure the free movement of control
surfaces.
2.2.2Fuselage
The sailplane fuselage (fig. 2.2.2_01, fig. 2.2.2_02) is made of composite materials,
construction is monocoque. The fuselage is oval-shaped in section (fig. 2.2.2_02), slightly
narrowing at top and turning into circle at the fuselage end part. The fuselage end part is cone-
shaped turning into fin.
The fuselage shell is glued of two symmetric parts, right and left (pos. 2, 3). Shell gluing
seams are in vertical plane (in upper and lower shell parts).
Glass and carbon fiber are used in shell construction. Kevlar is used in the pilot cockpit
zone. The fuselage is reinforced by a metal girder (pos. 4) at wing attachment to the fuselage
zone. Landing gear (pos. 5) is fastened to it. The gear is fully retractable. Its recess has an
hermetic hood in order to avoid getting dirt and dust inside the body. As the gear is retracted the
landing gear door is closed.
The tail wheel (pos. 6) is fixed at the fuselage end part. The pilot cockpit is covered with
a canopy (pos.1) which opens upward.
2.2.3Vertical tail
The vertical tail (fig. 2.2.3_01) consists of a fin (pos. 1) and a rudder (pos. 2).
The fin is made together with the fuselage. The fin shell is of monocoque three-layer
construction. Its internal and external layers are molded of composite materials and between
them there is foam 6 mm of thickness. The frame of the fin consists of a spar (pos. 3) of three-
layer construction., a rear wall molded together with right fin shell (pos. 4) and 3 ribs going from
nose till the spar, an upper, middle and lower (pos. 5, pos. 6, pos. 7).
A water ballast tank (pos. 8) of capacity 8 ltr is fitted inside the fin between nose and spar
and between lower and middle ribs.
Along the spar forward side a container for batteries (pos. 9) is mounted between the
middle and upper ribs.
The radio aerial (pos. 10) is fixed in a nose of the vertical tail.
An elevator push-pull rod (pos. 12) is in the space between fin spar and rear wall.
A rudder (pos. 2) is hung up on the right fin shell with 3 suspended brackets of composite
materials with bronze hubs (pos. 13). Shells of the rudder like ones of the fin are of three-layer
construction (an external layer, foam 3 mm of thickness, an internal layer).
The wall of the rudder (pos. 14) is of three-layer construction, as well.
2.2.4Horizontal tail
The horizontal tail (fig. 2.2.4_01) consists of a stabilizer (pos. 1) and an elevator (pos. 2
and pos. 3).
The stabilizer is made of composite materials and construction of its shell is similar to
wings shell construction.
The elevator consists of two parts: left (pos. 3) and right (pos. 2). Control surfaces are
partially balanced and made of composite materials. Each part of the elevator is fastened to the
stabilizer with 3 pins.
The horizontal tail is attached onto the upper fin part (fig. 3.1.6_05).
The elevator is joined to control system automatically.

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Rev. No. 0
2.2.5Landing gear
The landing gear consists of a retractable main wheel (fig. 2.2.5_01, pos. 5) and fixed tail
wheel (fig. 2.2.2_01, pos. 6).
Landing gear main wheel type TOST 045100 with Simplex shoe brake (or BERINGER
wheel with brake) is attached to metal girder (fig. 2.2.2_02, pos. 4) by the help of stands (fig.
2.2.5_01, pos. 6, pos. 7) and a shock absorber (fig. 2.2.5_01, pos. 8). The opening for the wheel
is covered with a main wheel box (fig. 2.2.5_01, pos. 9). It protects the fuselage internal space
from dust and dirt.
With main wheel up the landing gear door (fig. 2.2.5_02, pos. 2) is closed.
Tail wheel (fig. 3.4.8_01) 6x1 1/4” (or 200x50) of size is attached to fuselage shell with
help of an axle (pos. 4), bolt (pos. 3) and washer (pos. 1).
2.3Control systems
2.3.1Ailerons and flaps control system
In order to ensure required rigidity and reduce unsteadiness, ailerons and flaps control
system (fig. 2.3.1_01, fig. 2.3.1_02, fig. 2.3.1_03) is made of metal levers and rods. The ailerons
are suspended, i.e. with changing flaps position ailerons deflect as well.
Movement from the control stick (pos.1) is transmitted by help of rods and intermediate
bellcranks (pos. 4, 5) to coaxial ailerons-flaps shaft (pos. 7) which transfers this movement by
help of an automatic joint to shaft in the wing (pos. 9). Further the bell crank (pos. 10) turns
rotational movement to forward movement and transmits it to summary mechanism (pos. 11).
From this mechanism the movement is transmitted by help of rods and differential bellcranks
(pos. 12, 13, 14) to an aileron and deflects it in required direction. There are three ailerons.
Aileron 2 is connected to control rod. The movement of aileron 2 is transmitted to aileron 1 and
aileron 3 by the help of root and tip ribs of the ailerons. Option: if the outer wing have control
rod (fig. 3.4.1_01), the aileron 3 moves independently.
The control handle of the flaps (pos. 2) is attached to the left side of the cockpit.
Movement by help of rods and a bell crank (pos. 6) is transmitted onto coaxial shaft (pos. 7) and
by help of an automatic joint is transmitted to flaps shaft (pos. 15) in the wing. The movement
from the shaft is transmitted onto the flaps by help of the bell crank (pos. 16), summary unit
(pos. 11) and differential bell cranks (pos. 12, 13, 14) deflects the ailerons.
The position of flaps is fixed by a plate at control handle in the cockpit.
Ailerons and flaps deflection angles are given in table 2-1.
Hanging up angle ±1
o
Position
of flaps Flaps Ailerons Ailerons deflection angle ±2
o
-1 -3
o
-3
o
-15
o
+22
o
0 0
o
0
o
-16
o
+21
o
+1 5
o
5
o
-20
o
+20
o
+2 10
o
10
o
-22
o
+18
o
+3 15
o
14
o
-24
o
L 20
o
17
o
-25
o
+10
o
+14
o

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Date: 06 December, 2013
Rev. No. 0
2.3.2An elevator control system
The elevator control system (fig. 2.3.2_01) consists of metal rods and bellcranks. In order
to ensure rigidity the main rod in the fuselage is supported by guide rollers (pos. 5).
Movement from the stick (pos. 1) by help of rods and intermediate bellcranks (pos. 2, 3,
4) is transmitted to the elevator and deflects it in required direction.
2.3.3Trimmer control system
An adjustable trimmer for the elevator (fig. 2.3.3_01) takes over long-lasting loads on the
control stick from the pilot and levels the sailplane in all ranges of airspeeds, C.G. positions and
allowed flap angles.
The trimmer is mounted on the left side of the cockpit in a molded trimmer box (pos. 1).
It consists of:
-a handle (pos. 2) with a hub welded, a fixing edge and a plate for springs,
-a bronze bar (pos. 3) the handle is moving along,
-a ring (pos. 4) screwed to the elevator’s rod,
-a fixing plate with teeth (pos. 5) riveted on trimmer box side,
-two springs of the same tension *16x1.6 mm (pos. 6). The front spring connects the
trimmer handle to a plate (pos. 7) on control stick shaft and the end spring – the handle
with a ring (pos. 4) on the elevator’s rod.
The trimmer has two inspection hatches (pos. 8 and 9) covered with a glass fiber lid (pos.
10) and fastened by screw M4 (pos. 11).
Max motion of the trimmer handle is 80 mm. As the handle moves it pulls or pushes the
stick in the same direction.
The trimmer’s handle has a drop-shaped tip (pos. 12) painted in green.
The trimmer forces (force measuring place on stick -hand holding center):
Trimmer position Force on control stick, daN
forward 2.0 ÷2.5
backward 2.0 ÷2.5
2.3.4Rudder control system
The rudder control system (fig. 2.3.4_01, fig. 2.3.4_02, fig. 2.3.4_03) is of combined
type: steel cable from pedals to a bellcrank in the middle part of fuselage and steel rod φ16x1
mm, from the bellcrank till the rudder.
Pedals are adjustable according to a pilot height. The control handle of pedals is mounted
on the right side of cockpit, on the ailerons control rod hood.
Pedals junction (pos. 1) is mounted on longitudinal pipe with holes for fixing drilled on
it. Pedals cross pipe leans upon cockpit floor by textolite disks. The disks are fixed with wire
pins at the ends of the cross pipe.
The control rod (pos. 8) in the cylinder-shaped fuselage is supported by two guides (pos.
9) molded on frames. An adjustable rod tip is connected to the rudder.
Rudder control cables (pos.4) are stretched by two turn buckles (pos.3) of non-standard
construction.
Motion of the rudder is restricted by a bellcrank (pos.6) in the fuselage which is
supported by two non-adjustable supports (pos. 7) mounted at the center section girder.

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LAK-17B FES MAINTENANCE MANUAL 2 Page 6
2.3.5Airbrakes control system
The airbrakes are fixed in the closed position by a over-center lock which prohibits
spontaneous opening of the interceptors. Sudden breaking angle of the lock is adjusted by fixing
bolt (pos. 22).
The airbrakes control handle also controls the hydraulic brake of the main landing gear
wheel (fig. 2.3.9_02).
2.3.6Water ballast control system
The water ballast control system (fig. 2.3.6_01, fig. 2.3.6_02, fig. 2.3.6_03, fig. 2.3.6_04)
consist of integrated tanks in inner wings, outer wings and fin. The water ballast system of inner
and outer wings is controlled by the handle (pos. 1) located at the right side of the cockpit. The
movement of the handle is transmitted by rod (pos. 2) to a shaft in a fuselage (pos. 3). The
movement of the shaft in a fuselage is transmitted by automatic joints to the wing shafts (pos. 4).
The shaft in the wing lifts an arm (pos. 5) with a plug (pos. 6) and opens the water tank. The plug
is sealed (pos. 7).
The movement of shaft (pos. 4) is transmitted by rod (pos. 8) to lever (pos. 9) and carbon
rod (pos. 10). Adjustable rod end push the valve (pos. 14) of the inner wing tank water tap. The
tank of the inner wing is filled through the opening located at the end of the inner wing, the front
side of the rib.
The fin water ballast system is controlled by the handle (pos. 16) located at the right side
of cockpit.
The movement of the handle is transmitted by the carbon rod (pos. 17) to the water tap of
the fin tank (pos. 18). The fin water ballast tank is filled through the opening (pos. 19) at the top
of the fin
The wing and fin water ballast tanks have drainage systems and openings for drainage.
Warning: Before filling up the water tanks check that the drainage openings are not
2.3.7Tow release control system
A towing hook (fig. 2.3.7_01, fig. 2.3.7_02, pos. 6) is arranged in central part of fuselage
at the main frame and (or) in pilot cockpit at the bulkhead. If mounted, both towing hooks are
operated is with one handle.
Movement from the control handle (pos. 1) on the left side of a cockpit by steel cable
(pos. 2) is transmitted to the shoulder (pos. 5) which opens the hook. The cable looseness is
eliminated by an adjustment junction which comprises the junction (pos. 3) and fixing nut (pos.
4). The travel of the release handle in the case of only one hook is 55 mm. In the case of two
hooks the release handle travel is 92 mm.
The airbrakes control system (fig. 2.3.1_01, fig. 2.3.5_01, fig. 2.3.5_02) comprises the
control handle (pos. 3), attached to the left side of a cockpit and rigid rods and bellcranks.
Movement from control handle by help of an intermediate rod is transmitted to the shaft (pos. 8)
which through an automatic joint transmits the movement to the shaft (pos. 17) in the wing. The
bellcrank (pos. 18) transfers rotational movement into longitudinal one and through
intermediate rods transmits it to lifting equipment consisting of a bell crank (pos. 19) and
shoulders (pos. 20, pos. 21).
plugged up.
Date: 10 December, 2014
Rev. No. 1

Section
LAK-17B FES MAINTENANCE MANUAL 2 Page 7
Date: 06 December, 2013
Rev. No. 0
2.3.8Main landing gear control system
The landing gear control system (fig. 2.2.5_01) controls retracting and releasing of the
main wheel. It consists of a control rod (pos. 1) on the right side of cockpit , an intermediate rod
(pos. 2) and a bellcrank (pos. 3). A gas spring (pos. 4) makes it easier to retract the wheel. The
control handle in the retracted and released positions is fixed in the slots of plate (pos. 5).
2.3.9Landing gear brake control system
The main wheel brake is of mechanical type, controlled by a handle (fig. 2.3.9_01, pos.
1) arranged on the control stick. Movement from the handle to the brake shoulder (pos. 5) is
transmitted by the steel cable (pos.2). In order to eliminate loosening of the cable the adjustment
junction is mounted on the cockpit floor under the pilot seat. The junction consists of cable
support (pos. 3) and fixing nut (pos. 4).
The hydraulic brake (manufacturer: BERINGER) (option) is controlled by the air-brakes
control handle (pos. 1) (fig. 2.3.9_02). The movement of air-brakes shaft (pos. 2) is transmitted
to the master cylinder (pos. 4) by control rod (pos. 3). The master cylinder is connected to brake
fluid reservoir. The brake fluid is transmitted by hoses (pos. 7) through the relief valve (pos. 6)
to the piston caliper (pos. 5). To control the brake cylinder, only a half of the air-brakes control
handle's travel is used.
To adjust the travel of the master cylinder, a threaded plate with slot (pos. 8) is used. The
plate is fixed by nut (pos. 9).
The brake fluid DOT4 is used in the brake system. To fill the brake system,
recommendations of the manufacturer shall be used (www.beringer.fr).
2.4 Equipment and systems
2.4.1Pitot and static system
Pitot and static system of the sailplane is shown in fig. 2.4.1_01. The system consists of:
1.Static pressure receiving ports (pos. 9) which are located at a two sections on a fuselage
skin from the inside (distances from sailplane nose to the ports is given at fig.
2.4.1_01). Static pressure receivers consists of a glass fiber tanks with air inlet as a
holes drilled through the fuselage skin.
There are static pressure lines S1 and S2. The air gets from three receivers located on
the fuselage skin every 120°.
Warning: During a sailplane preflight inspection the holes of static pressure receiver on the
fuselage sides shall be checked for cleanliness.
2. Pitot (pos. 10) is a steel pipe mounted on the fin and right against the air flow. This
line is marked by the letter D.
3.Compensated pressure receiver (pos. 11) is a special Nix pipe mounted in fin. This line
is marked by the letter N.

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LAK-17B FES MAINTENANCE MANUAL 2 Page 8
Date: 06 December, 2013
Rev. No. 0
4.Flexible polyvinylchloride pipes of different colors transmit air pressure from receivers
to corresponding measuring instruments on the sailplane instrument panel. Each
separate pressure line has pipes of different colors:
-red – for total pressure line (D),
-yellow – for static pressure lines (S1 and S2),
-green – for compensated pressure line (N).
2.4.2Flight and navigation instruments
These flight and navigation instruments as option are mounted in the sailplane:
OPTION A OPTION B
1) air-speed indicator LUN-1106, scale 50-300 km/h, with
range markings 1) air-speed indicator WINTER 6 FMS 421
2) altimeter BD-10K or VB-10PS with altitude corrector 2) altimeter WINTER 4 FGH 20
3) mechanical variometer LUN-1141 3) variometer BOHLI
4) side-slip indicator LUN-1211 4) electronic variometer FILSER LX5000
or FILSER LX7000
5) compass KI-13 5) fly computer display FILSER LX5000
or FILSER LX7000
6) FCU instrument 6) side slip indicator LUN 1211
7) Radio ATR 600 7) radio Becker AR 4201 or Filser ATR
600
8) FCU instrument
All the instruments, except for the compass KI-13A, are mounted in the instrument panel.
The compass is attached to the canopy glass or on the instrument panel.
There is room left in the instrument panel for extra instruments (fig. 2.4.2_01).
It is possible to use other standard flight and navigation instruments and change
instruments positions on the instrument panel (fig.2.4.2_01). These instruments must correspond
with national regulations. Max instrument panel weight in flight - 4.1 kg.
2.4.3FCU instrument
FES parameters are controlled by the FCU instrument, produced by LXNAV Company.
The motor is operated with the Throttle knob located on the FCU instrument. Electronic safety
devices are provided to avoid miss operation. The details of the instrument are given below.
Operation
The FCU instrument was designed to control and improve safety of motor use. FCU instrument
must be continuously switched on when operating the motor.
Caution: Keep FCU instrument power supply always switched on during motor run!
Instrument indications
The FCU instrument for LAK-17B FES sailplane has on its front side three LED showing
the most important states of the system during all operation time. Additional a LCD display