WT9 Dynamic LSA. AIRCRAFT MAINTENANCE MANUAL (AS-AMM-01-000, 22. 05. 2017)

ENGINE COOLING

75-20

ENGINE COOLING

1. DESCRIPTION

Engine has combined air and water cooling system.
Water cooling system consists of water thermostat (5, Fig. 75-1) and water radiator (3)
through  which  the  coolant  flows  to  the  water  pump  (4)  and  then  is  distributed
to  the  water-cooled  engine  parts  inside  of  engine.  Water  radiator  (3)  is  attached
in the holder fixed in the middle of lower engine cowling. Overflow bottle (2) is attached
at  firewall  and  connected  by  a  hose  with  the  expansion  tank  (1).  Expansion  tank
located  on  top  of  the  engine  allows  coolant  expansion.  The  overflow  bottle
accumulates the coolant in the case of engine overheating.
Cooling air is received  through the two upper engine cowling intakes and is baffled
to the engine compartment. Towing version of aircraft has installed in addition cooling
air distributor on the top of the engine that baffles the cooling air directly to the cylinders
(12, Fig. 75-3).
The coolant temperature sensor is installed at the cylinder head of right rear cylinder
(in flight direction) (Chapter 77).
Total  coolant  volume  is  about  2.5  liters.  Information  about  used  coolant
by manufacturer is recorded on a placard at firewall in the engine compartment.
Maintenance practices and procedures concerning coolant volume check/replenishing
and coolant change are mentioned in Chapter 12-10.

NOTE

Recommended coolants are mentioned in the Rotax Service Instruction
No. SI-912-016

–

the latest issue.

ENGINE COOLING

2. MAINTENANCE PRACTICES

A. Water radiator

Type of maintenance:

Line

Personnel qualification:

Independent certifying staff qualified in accordance

with Part-66 or higher.

Recommended tools, materials, persons and documentation:

ITEM

QUANTITY

Screwdriver 5

1 pc

Hex key 5

1 pc

Pliers

1 pc

Persons

Tab. 75-1 Recommended tools, materials, persons and documentation

WARNING

ENGINE IGNITION MUST BE SWITCHED OFF. DISCONNECT
NEGATIVE TERMINAL OF AIRCRAFT BATTERY.
ALWAYS ALLOW ENGINE TO COOL DOWN TO OUTSIDE AIR
TEMPERATURE BEFORE START OF ANY WORK.

(1) Water radiator removal:

(a) Make sure that the

IGNITION

switches are set to

OFF

(b) Remove the engine cowlings (Chapter 71-10).
(c) Remove the edge protection (31, Fig. 75-2)

–

towing version only.

(d) Drain the coolant from the cooling system (Chapter 12-10).
(e) Disconnect air hose from the heating deflector (30) (Chapter 21-40).
(f)

Hold the radiator (1); remove hoses (8; 9) from the radiator (1),
by loosening hose clamps (6, 27). Remove the radiator (1)
with the holder (2).

(g) Remove holder (2), by unscrewing bolts (3) and removing washers

(4; 5).

(2) Water radiator installation:

(a) Make sure that the

IGNITION

switches are set to

OFF

(b) Check condition of the water radiator and hoses for cracks,

cleanliness.

radiator (1) with washers (4; 5) and bolts (3).

(d) Slide the radiator (1) with the holder (2) on the hoses (8; 9) and secure

with hose clamps (6, 27).

(e) Connect air hose to the heating deflector (30) (Chapter 21-40).
(f)

Check if hoses are firmly secured and sealed.

(g) Replenish the cooling system (Chapter 12-10).

Effectivity:

ALL

28. 04. 2021

ENGINE COOLING

(h) Install the engine cowlings (Chapter 71-10).
(i)

Install the edge protection (31) to holder (2) - towing version only.

(j)

Carry out engine ground test; check cooling system for leaks
and cooling system indication.

B. Water thermostat

Type of maintenance:

Line

Personnel qualification:

Independent certifying staff qualified in accordance

with Part-66 or higher.

Recommended tools, materials, persons and documentation:

ITEM

QUANTITY

Pliers

1 pc

Persons

Tab. 75-2 Recommended tools, materials, persons and documentation

WARNING

ENGINE IGNITION MUST BE SWITCHED OFF. DISCONNECT
NEGATIVE TERMINAL OF AIRCRAFT BATTERY.
ALWAYS ALLOW ENGINE TO COOL DOWN TO OUTSIDE AIR
TEMPERATURE BEFORE START OF ANY WORK.

(1) Water thermostat removal:

(a) Make sure that the

IGNITION

switches are set to

OFF

(b)  Remove the engine cowlings (Chapter 71-10).
(c)  Drain the coolant from the cooling system (Chapter 12-10).
(d)  Remove the water radiator (see 2.A.(1)).
(e)  Hold  the  thermostat  (7,  Fig.  75-2);  remove  hoses  (11;  12;  15)

from the thermostat (7), by loosening hose clamps (6).

(f)

Remove the thermostat (7).

(2) Water thermostat installation:

(a) Make sure that the

IGNITION

switches are set to

OFF

(b) Check condition of the water thermostat and hoses for cracks,

cleanliness.

clamps (6).

(d) Check if hoses are firmly secured and sealed.
(e) Install the water radiator (see 2.A.(1)).
(f)

Replenish the cooling system (Chapter 12-10).

(g) Install the engine cowlings (Chapter 71-10).
(h) Install the edge protection (31) to holder (2) - towing version only.
(i)

Carry out engine ground test; check cooling system for leaks
and cooling system indication.

ENGINE COOLING

C. Overflow bottle

Type of maintenance:

Line

Personnel qualification:

Independent certifying staff qualified in accordance

with Part-66 or higher.

Recommended tools, materials, persons and documentation:

ITEM

QUANTITY

Screwdriver 5

1 pc

Phillips screwdriver 2

1 pc

Wrench 10

2 pcs

Maintenance Manual (Line Maintenance) for Rotax Engine
Type 912 Series, Ref. No.: MML-912

Persons

Tab. 75-3 Recommended tools, materials, persons and documentation

WARNING

ENGINE IGNITION MUST BE SWITCHED OFF. DISCONNECT
NEGATIVE TERMINAL OF AIRCRAFT BATTERY.
ALWAYS ALLOW ENGINE TO COOL DOWN TO OUTSIDE AIR
TEMPERATURE BEFORE START OF ANY WORK.

(1) Overflow bottle removal:

(a) Make sure that the

IGNITION

switches are set to

OFF

(b)  Remove the upper engine cowling (Chapter 71-10).
(c)  Drain the coolant from the cooling system (Chapter 12-10).
(d)  Remove the hose clamp (20, Fig. 75-2) and hose (19) from bottle (18).
(e)  Unscrew nuts (24) and remove washers (25).
(f)

Remove the bracket (22) and bottle (18).

(2) Overflow bottle installation:

(a) Make sure that the

IGNITION

switches are set to

OFF

(b) Put overflow bottle (18, Fig. 75-2) on the appropriate place

on the firewall (29).

(c)  Attach the bottle (18) with the bracket (22), nuts (24) and washers (25).
(d)  Connect hose (19) to bottle (18) and secure hose clamp (20).
(e)  Replenish the cooling system (Chapter 12-10).
(f)

Carry out engine ground test; check cooling system for leaks
and cooling system indication.

(g) Install the upper engine cowling (Chapter 71-10).

ENGINE COOLING

–

Water radiator

–

Tube elbow

–

Radiator holder

–

Overflow bottle

–

Allen bolt M6 x 20

–

Hose

–

Serrated locking washer ø6

–

Hose clamp ø15

.5 - 6

–

Washer ø6

.4 x 18 x 1.6

–

Clip

–

Hose clamp ø32

- 12

–

Bracket

–

Water thermostat

–

Bolt M6 x 20

–

Hose

–

Self-locking nut M6

–

Hose elbow

–

Washer ø6

.4 x 12 x 1.6

–

Tube elbow

–

Washer ø6

.4 x 18 x 1.6

–

Hose

–

Hose clamp ø35

- 12

–

Hose

–

SK clamp 25 - 40 x 9

–

Triple tube

For information:

–

Hose

–

Firewall

–

Hose

–

Heating deflector

–

Tube

–

Edge protection

Fig. 75-2 Cooling System Removal / Installation (page 2 of 2)

D. Cooling air distributor

Type of maintenance:

Line

Personnel qualification:

Independent certifying staff qualified in accordance

with Part-66 or higher.

Recommended tools, materials, persons and documentation:

ITEM

QUANTITY

Hex key 5

1 pc

Hex key 6

1 pc

Wrench 10

1 pc

Torque wrench

1 pc

Pliers

1 pc

Oetiker pliers

1 pc

Cable ties (as appropriate)

Maintenance Manual (Line Maintenance) for Rotax Engine
Type 912 Series, Ref. No.: MML-912

Installation Manual for Rotax Engine Type 912 Series
(Ref. No. IM-912)

Persons

Tab. 75-4 Recommended tools, materials, persons and documentation

Effectivity:

ALL

28. 04. 2021

ENGINE COOLING

WARNING

ENGINE IGNITION MUST BE SWITCHED OFF. DISCONNECT
NEGATIVE TERMINAL OF AIRCRAFT BATTERY.
ALWAYS ALLOW ENGINE TO COOL DOWN TO OUTSIDE AIR
TEMPERATURE BEFORE START OF ANY WORK.

NOTE

The following procedure for Removal / installation is used
for a towing version of aircraft. Before Removal / installation review the
Installation

Manual

and

Maintenance

Manual

for Rotax Engine Type 912 series.

(1) Cooling air distributor removal:

(a) Make sure that the

IGNITION

switches are set to

OFF

(b)  Remove the upper engine cowling (Chapter 71-10).
(c)  Drain the coolant from the cooling system (Chapter 12-10).
(d)  Drain the fuel from the fuel system (Chapter 12-10).
(e)  Disconnect  the  fuel  hoses  (1,  Fig.  75-3)  from  the  engine  fuel  pump

(Chapter 28-20).

(f)

Remove the compensating tube assy (2).

(g) Remove the air intake manifolds (3).
(h) Remove the water hoses (4) with sockets.
(i)

Disconnect the hoses (5, 6) from the expansion tank.

(j)

Disconnect the cable (7) from the oil temperature sensor.

(k) Disconnect and remove the cables (8, 9).
(l)

Disconnect the connector (10) from the electronic module (11).

(m) Remove the electronics module (11).
(n) Remove the cooling air distributor (12).

(2) Cooling air distributor installation:

(a) Make sure that the

IGNITION

switches are set to

OFF

(b) Install the cooling air distributor (12, Fig. 75-3) on engine in the correct

position.

(c)  Attach the water hoses (4) with sockets.
(d)  Install the electronics module (11).
(e)  Connect the connector (10) to electronic module (11).
(f)

Install and connect the cables (8, 9)

(g) Connect the cable (7) to the oil temperature sensor.
(h) Connect the hoses (5, 6) to expansion tank.
(i)

Install the air intake manifolds (3).

(j)

Install the compensating tube assy (2).

(k) Connect the fuel hoses (1) to engine fuel pump (Chapter 28-20).
(l)

Secure the hose clamps.

ENGINE COOLING

(m)  Check if all hoses are well sealed and secured.
(n)  Check if all bolts are tightened.
(o)  Replenish the fuel system (Chapter 12-10).
(p)  Replenish the cooling system (Chapter 12-10).
(q)  Install the upper engine cowling (Chapter 71-10).
(r)  Carry out engine ground test; check cooling and fuel system for leaks,

and cooling system indication.

–

Fuel hoses

–

Cable

–

Compensating tube assy

–

Ignition cables

–

Intake manifolds

–

Engine ground wires

–

Water hoses with sockets

–

Connector

–

Hose to water thermostat

–

Electronics module

–

Hose to overflow bottle

–

Cooling air distributor

Fig. 75-3 Cooling Air Distributor Removal / Installation

GENERAL

ENGINE

CONTROLS

76-00 GENERAL

1. INTRODUCTION

This chapter describes the aircraft engine control. The engine has following controls:

•

Throttle

•

Choke (starting carburetor).

2. TROUBLESHOOTING

TROUBLE

POSSIBLE CAUSE

REMEDY

Engine will not start.

Choke control not
correctly adjusted.

Adjust the

CHOKE

control.

Cannot control the
engine.

Broken throttle bowden
cable.

Replace the broken
bowden cable.

Throttle control not
adjusted correctly.

Carry out a range of
movement check.

Adjust the

THROTTLE

controller.

Bowden cable not free to
move.

Replace the bowden
cable.

Engine does not get to
maximum RPM.

Throttle control not
adjusted correctly.

Carry out a range of
movement check.

Adjust the

THROTTLE

controller.

Engine does not get to
idle.

Throttle control not
adjusted correctly.

Carry out a range of
movement check.

Adjust the

THROTTLE

controller.

POWER CONTROL

ENGINE

CONTROLS

76-10 POWER CONTROL

1. DESCRIPTION

Engine power is set using the

THROTTLE

controller (1, Fig. 76-1) from idle up to max.

power. A bowden cables connect between the

THROTTLE

controller in the cockpit and

the carburetors on the engine. The

THROTTLE

controller is a black knob installed

in the central console. The bowden cables go from the central console through
the firewall to the engine compartment and to the carburetors. The

THROTTLE

controller is configured so that the max. power is open in the forward position and idle
in the full aft position. There are two versions of

THROTTLE

controller:

THROTTLE

controller 1: It is operated by rotating the knob in clockwise direction

for  fine  increase  or  counter  clockwise  for  fine  decrease  of  engine  power.  For  rapid
or  large adjustments  the  knob  may  be moved  forward  or aft by depressing  the  lock
button in the end of  the

THROTTLE

controller and then positioning the

THROTTLE

controller as desired.

THROTTLE

controller 2 (simple

THROTTLE

controller): It is operated by moving

the controller forward for increase or backward for decrease of engine power.

Engine fuel mixture during engine starting is controlled by the

CHOKE

controller (2).

The

CHOKE

controller is a grey round knob located in the central console. The rich

mixture is full aft and the weak mixture is full forward position of choke knob.

–

THROTTLE

controller

–

CHOKE

controller

Fig. 76-1 Power Control

Effectivity:

ALL

24. 11. 2020

ENGINE
CONTROLS

2. MAINTENANCE PRACTICES

Throttle controller

Type of maintenance:

Heavy

Personnel qualification:

Independent certifying staff qualified in accordance

with Part-66 or higher.

Recommended tools, materials, persons and documentation:

ITEM

QUANTITY

Screwdriver 10

1 pc

Screwdriver 5

1 pc

Phillips screwdriver

1 pc

Hex key 2

1 pc

Hex key 3

1 pc

Hex key 4

1 pc

Wrench 8

1 pc

Wrench 9

1 pc

Special wrench 29

1 pc

Cable tie 2.6

Cable tie 4.8

Lockwire

ø0.8 mm

Loctite 243

Maintenance Manual (Line Maintenance) for Rotax Engine
Type 912 Series, Ref. No.: MML-912

Persons

Tab. 76-1 Recommended tools, materials, persons and documentation

WARNING

ENGINE IGNITION MUST BE SWITCHED OFF!

(1)

THROTTLE

controller removal:

(a) Make sure that the

IGNITION

switches are set to

OFF

(b) Remove the engine cowlings (Chapter 71-10).

(d) Disconnect

THROTTLE

controller´s inner cables (20, Fig. 76-3)

on both carburetors, by releasing the nuts (24).

(e) Remove lockwire (7) and remove spiral hoses (10).

(f)

Remove cable ties from the bowdens (18; 19).

(g) Behind central console, remove lockwire (7) and pull out the bowdens

(18; 19); coil the inner cables (20).

POWER CONTROL

ENGINE

CONTROLS

(h) Release the nut (13), fix the leading bracket (17) (plug the screwdriver

into the groove), and rotate the

THROTTLE

controller (14) until

the leading bracket (17) is unscrewed.

(i)

Pull out the ring (15) from

THROTTLE

controller (14) and disconnect

leading bracket (17).

(j)

Remove the nut (13), remove the washer (12) and pull out

THROTTLE

controller.

NOTE

For better performance use band wrench (Fig. 76-2).

Fig. 76-2 Band Wrench Size 29

(2)

THROTTLE

controller installation:

(a) Insert the

THROTTLE

controller (14, Fig. 76-3) with distance tube (11)

to the central console (26) from the cockpit.

(b) From the rear side put on washer (12) and screw the nut (13),

but do not finalize the nut.

NOTE

For better performance use special wrench (Fig. 76-2).

of groove.

NOTE

After engine test, safety clamp defines idle RPM.

(d) Grease with Vaseline and connect the leading bracket (17) and

THROTTLE

controller (14). Slide the ring (15) on the jont.

(e) Apply the Loctite 243 on the thread of

THROTTLE

controller (14) and

screw it fully with leading bracket (17). Tighten the nut (13).

NOTE

The groove of leading bracket (17) must be at the top.

WT9 Dynamic LSA. AIRCRAFT MAINTENANCE MANUAL (AS-AMM-01-000, 22. 05. 2017) - page 42