Rotax OM-912 User manual


OPERATORS MANUAL
FOR ROTAX® ENGINE TYPE 912 SERIES
ROTAX® 912 ULS 3 WITH OPTIONS
part no.: 899371
Ref. No.: OM-912

Before starting the engine, read the Operator´s Manual, as it contains
important safety relevant information. Failure to do so may result in per-
sonal injuries including death. Consult the original equipment manufactur-
ers handbook for additional instructions!
WARNING
These technical data and the information embodied therein are the property of BRP-
Rotax GmbH&Co. KG, Austria, acc, BGBI 1984 no. 448, and shall not, without prior
written permission of BRP-Rotax GmbH&Co. KG, be disclosed in whole or in part to
third parties. This legend shall be included on any reproduction of these data, in whole
or in part. The Manual must remain with the engine/aircraft in case of sale.
Copyright 2006 © - all rights reserved.
ROTAX®is a trade mark of BRP-Rotax GmbH&Co. KG. In the following document the
short form of BRP-Rotax GmbH&Co. KG = BRP-Rotax is used.
Other product names in this documentation are used purely for ease of identification
and may be trademarks of the respective company or owner.
Approval of translation has been done to best knowledge and judgement - in any case
the original text in german language is authoritative.

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1) Table of contents ............................................................................... 1-3
2) Index.................................................................................................... 2-1
3) Introduction ........................................................................................ 3-1
3.1) Remarks..................................................................................... 3-1
3.2) Engine serial number ............................................................... 3-1
4) Safety .................................................................................................. 4-1
4.1) Repeating symbols................................................................... 4-1
4.2) Safety information .................................................................... 4-2
4.3) Technical documentation ........................................................ 4-5
5) Index of pages.................................................................................... 5-1
6) List of amendments ........................................................................... 6-1
7) Description of design ........................................................................ 7-1
7.1) Type description ....................................................................... 7-2
7.2) Denomination of cylinders: ..................................................... 7-3
8) Technical data.................................................................................... 8-1
8.1) Dimensions ............................................................................... 8-1
8.2) Weights...................................................................................... 8-1
8.3) Fuel consumption..................................................................... 8-2
8.4) Direction of rotation ................................................................. 8-2
9) Description of systems ..................................................................... 9-1
9.1) Cooling system ......................................................................... 9-1
9.2) Fuel system ............................................................................... 9-2
9.3) Lubrication system................................................................... 9-3
9.4) Electric system ......................................................................... 9-4
9.5) Propeller gearbox ..................................................................... 9-5
9.5.1) Hydr. governor for const. speed propeller, vacuum pump: ...... 9-6
10) Operating instructions .................................................................... 10-1
10.1) General limits of operation .................................................... 10-1
10.1.1) Operating speeds and limits (912 UL / A / F)......................... 10-1
10.1.1.1) Performance graphs for stand. conditions (ISA) . 10-3
10.1.1.2) Performance graph for non-standard conditions... 10-4
10.1.2) Operating speeds and limits (912 ULS / S)............................ 10-5
10.1.2.1) Performance graphs for stand. conditions (ISA)... 10-7
10.1.2.2) Performance graph for non-standard conditions... 10-8
10.2) Operating media ..................................................................... 10-9
10.2.1) Coolant................................................................................... 10-9
10.2.2) Fuel...................................................................................... 10-10
10.2.3) Lubricants ............................................................................ 10-11
10.3) Standard operation............................................................... 10-13
10.3.1) Daily checks......................................................................... 10-13
10.3.2) Before engine start............................................................... 10-14
10.3.3) Pre-flight checks .................................................................. 10-15
10.3.4) Engine start.......................................................................... 10-16
10.3.5) Prior to take-off .................................................................... 10-17
10.3.6) Take-off................................................................................ 10-17

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10.3.7) Cruising ............................................................................... 10-18
10.3.8) Engine shut-off .................................................................... 10-18
10.3.9) Cold weather operation ....................................................... 10-18
10.4) Abnormal operation..............................................................10-20
10.4.1) Engine stop - Start during flight ........................................... 10-20
10.4.2) Exceeding of max. admissible engine speed ...................... 10-20
10.4.3) Exceeding of max. admissible cyl. head temperature ......... 10-20
10.4.4) Exceeding of max. admissible oil temperature .................... 10-20
10.4.5) Oil pressure below minimum - during flight ......................... 10-20
10.4.6) Oil pressure below minimum - on ground ............................ 10-20
11) Checks ..............................................................................................11-1
11.1) Engine preservation ...............................................................11-1
12) Trouble shooting..............................................................................12-1
12.1) Reporting ................................................................................. 12-4
13) Authorized Distributors for ROTAX®Aircraft Engines.................13-1

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2) Index
A
Abnormal operation 10-20
Acceleration (912 UL / A / F) 10-1
Acceleration (912 ULS / S) 10-5
AVGAS 100LL 10-10
C
Carburetor 10-14
Certification 7-2
Check of hydraulic propeller governor
10-17
Checks 11-1
Cold start 10-18
Cold weather operation 10-18
Configuration 7-2
Cooling system 9-1
Cruising 10-18
Cylinder head temperature
(912 ULS / S) 10-5
D
Daily checks 10-13
Denomination of cylinders 7-3
Description of design 7-1
Description of systems 9-1
Dimensions 8-1
Direction of rotation 8-2
Documentation (technical) 4-5
E
Electric system 9-4
Engine preservation 11-1
Engine serial number 3-1
Engine shut-off 10-18
Engine start 10-16
Engine start, operating temperature
(912 ULS / S) 10-5
Equipment 8-1
Exceeding of max. admissible cyl. head
temperature 10-20
Exceeding of max. admissible engine
speed 10-20
Exceeding of max. admissible oil tem-
perature 10-20
Exhaust system 10-14
F
Fuel 10-10
Fuel consumption 8-2
Fuel pressure (912 UL / A / F) 10-2
Fuel pressure (912 ULS / S) 10-6
Fuel system 9-2
H
Hydr. governor for const. speed propel-
ler 9-6
I
Ignition check 10-17
Ignition unit 9-4
Index of pages 5-1
Introduction 3-1
L
List of amendments 6-1
Lubricants 10-11
Lubrication system 9-3
M
magneto side 7-3
O
Oil consumption 10-12
Oil pressure (912 UL / A / F) 10-1
Oil pressure (912 ULS / S) 10-5
Oil pressure below minimum - during
flight 10-20
Oil pressure below minimum - on
ground 10-20
Oil specification 10-11
Oil temperature (912 UL / A / F ) 10-1
Oil temperature (912 ULS / S) 10-5
Oil viscosity 10-12
Operating media 10-15
Operating speeds and limits
(912 UL / A / F) 10-1
Operating speeds and limits
(912 ULS / S) 10-5
Overload clutch 9-5

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P
Performance (ISA) (912 UL / A / F) 10-1
Performance (ISA) (912 ULS / S) 10-5
Performance data 10-4, 10-8
Performance graphs for stand. conditi-
ons (ISA) 10-3, 10-7
power take-off side 7-3
Pre-flight checks 10-15
Propeller gearbox 9-5
Propeller governor 9-6
R
Remarks 3-1
Repeating symbols 4-1
Reporting 12-4
S
Safety 4-1
Safety information 4-2
Speed (912 UL / A / F) 10-1
Speed (912 ULS / S) 10-5
Symbols 4-1
T
Table of lubricants 10-12
Take-off 10-17
Technical data 8-1
Technical documentation 4-5
Throttle response 10-17
Trouble shooting 12-1
Type 7-2
Type description 7-2
V
Vacuum pump 9-6
W
Warming up period 10-17
Weights 8-1

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3) Introduction
Congratulations on your decision to purchase a ROTAX aircraft engine.
Before operating the engine, carefully read this Operator's Manual. The Ma-
nual provides you with basic information on the safe operation of the engine.
If any passages of the Manual are not clearly understood or in case of any
questions, please, contact an authorized Distribution- or Service Center for
ROTAX aircraft engines.
We wish you much pleasure and satisfaction flying your aircraft with this
ROTAX engine.
3.1) Remarks
The purpose of this Operator's Manual is provided to familiarize the owner/
user of this aircraft engine with basic operating instructions and safety infor-
mation.
For more detailed maintenance, safety and flight information, consult the do-
cumentation provided by the aircraft manufacturer and dealer.
For further information on maintenance and spare parts service, contact the
nearest ROTAX distribution Center (see Chapter 13).
3.2) Engine serial number
On all enquiries or parts orders, always indicate the engine serial number,
as the manufacturer makes modifications to the engine for product improve-
ment. The engine serial number should always be used when ordering parts
to ensure correct part selection prior to shipment.
The engine serial number is located on the top of the crankcase, magneto
side. See fig. 2.

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NOTES

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4) Safety
Although the mere reading of these instructions will not eliminate a hazard, the un-
derstanding and application of the information herein will promote the proper use of
the engine.
The information and components-/system descriptions contained in this Operator's
Manual are correct at the time of publication. ROTAX however, maintains a policy
of continuous improvement of its products without imposing upon itself any obliga-
tion to install them on its products previously manufactured.
ROTAX reserves the right at any time to discontinue or change specifications, de-
signs, features, models or equipment without incurring obligation.
The illustrations in this Manual show the typical construction. They may not repre-
sent in full detail or the exact shape of the parts which have the same or similar
function.
Specifications are given in the SI metric system with the USA equivalent in paren-
thesis. Where precise accuracy is not required, some conversions are rounded off
for easier use.
This document has been translated from the German language and the original
German text shall be deemed authoritative.
4.1) Repeating symbols
This Manual uses the following symbols to emphasize particular information:
▲WARNING: Identifies an instruction which, if not followed, may
cause serious injury including the possibility of
death.
■CAUTION: Denotes an instruction which, if not followed, may
severely damage the engine or other component.
◆NOTE: Indicates supplementary information which may be
needed to fully complete or understand an instruc-
tion.

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4.2) Safety information
▲WARNING: Never fly the aircraft equipped with this engine at loca-
tions, airspeeds, altitudes, or other circumstances from
which a successful no-power landing cannot be made,
after sudden engine stoppage.
Unless correctly equipped to provide enough electrical
power for night VFR (according latest requirement as
ASTM), the ROTAX 912 UL/ULS/ULSFR is restricted to
DAY VFR only.
- This engine is not suitable for acrobatics (inverted flight, etc.).
- This engine shall not be used on rotorcrafts with an in-flight driven rotor
(e.g. helicopters).
- It should be clearly understood that the choice, selection and use of this
particular engine on any aircraft is at the sole discretion and responsibility
of the aircraft manufacturer, assembler and owner/user.
- Due to the varying designs, equipment and types of aircraft, ROTAX
grants no warranty or representation on the suitability of its engine’s use
on any particular aircraft. Further, ROTAX grants no warranty or repre-
sentation of this engine’s suitability with any other part, component or
system which may be selected by the aircraft manufacturer, assembler or
user for aircraft application.
- Whether you are a qualified pilot or a novice, complete knowledge of the
aircraft, its controls and operation is mandatory before venturing solo.
Flying any type of aircraft involves a certain amount of risk. Be informed
and prepared for any situation or hazard associated with flying.
A recognized training program and continued education for piloting an
aircraft is absolutely necessary for all aircraft pilots. Make sure you also
obtain as much information as possible about your aircraft, its mainte-
nance and operation from your dealer.
- You should be aware that any engine may seize or stall at any time. This
could lead to a crash landing and possible severe injury or death. For this
reason, we recommend strict compliance with the maintenance and ope-
ration and any additional information which may be given to you by your
dealer.
- Respect all government or local rules pertaining to flight operation in your
flying area. Fly only when and where conditions, topography, and air-
speeds are safest.
- Select and use proper aircraft instrumentation. This instrumentation is not
included with the ROTAX engine package. Only approved instrumentati-
on may be installed.

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- Before flight, ensure that all engine controls are operative. Make sure all
controls can be easily reached in case of an emergency.
- Unless in a run up area, never run the engine with the propeller turning
while on the ground. Do not operate engine if bystanders are close.
- In the interest of safety, the aircraft must not be left unattended while the
engine is running.
- Keep an engine log and respect engine and aircraft maintenance sche-
dules. Keep the engine in top operating condition at all times. Do not ope-
rate any aircraft which is not properly maintained or has engine operating
irregularities which have not been corrected.
Since special tools and equipment may be required, engine servicing
should only be performed by an authorized ROTAX engine dealer or a
qualified trained mechanic approved by the local airworthiness authority.
- To eliminate possible injury or damage, ensure any loose equipment or
tools are properly secured before starting the engine.
- When in storage protect the engine and fuel system from contamination
and exposure.
- Certain areas, altitudes and conditions present greater risk than others.
The engine may require carburetor recalibration or humidity or dust/sand
preventative equipment, or additional maintenance may be required.
Consult your aircraft dealer or manufacturer and obtain the necessary in-
formation, especially before flying in new areas.
- Never operate the engine and gearbox without sufficient quantities of lu-
bricating oil.
- Periodically verify level of coolant.
- Never exceed maximum rated r.p.m. Allow the engine to cool at idle for
several minutes before turning off the engine.
- This engine may be equipped with an Airborne vacuum pump. The safety
warning accompanying the vacuum pump must be given to the owner/
operator of the aircraft into which the vacuum pump is installed.

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NOTES

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4.3) Technical documentation
These documents form the instructions for continued airworthiness of
ROTAX aircraft engines:
- Installation Manual 912 F
- Installation Manual 912 A
- Installation Manual 912 UL
- Installation Manual 912 S
- Operators Manual
- Maintenance Manual 912 Series (Line and Heavy Maintenance)
- Overhaul Manual 912 A / F
- Illustrated Parts Catalog 912 A / F / S / UL / ULS / ULSFR
- Alert Service Bulletins
- Service Bulletins
- Service Instructions
- Service Letters
Any reference to a document refers to the latest edition issued by ROTAX if
not stated otherwise.
◆NOTE: The status of Manuals can be determined by checking
the table of amendments of the Manual. The 1st column
of this table is the revision status. Compare this number
to that listed on the ROTAX WebSite: www.rotax-
aircraft-engines.com. Updates and current revisions
can be downloaded for free.
The information given in the are based on data and experience that are con-
sidered applicable for professionals under normal conditions.
The fast technical progress and variations of installation might render pre-
sent laws and regulations inapplicable or inadequate.
The illustrations in this Manual are mere sketches and show a typical arran-
gement. They may not represent the actual part in all its details but depict
parts of the same or similar function. Therefore deduction of dimensions or
other details from illustrations is not permitted.

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All necessary documentation is available from the ROTAX Distribution- and
Service Centers (see Chapter 13).
◆NOTE: The Illustrations in this Operator´s Manual are stored in
a graphic data file and are provided with a consecutive
irrelevant number.
This number (e.g. 00277) is of no significance for the
content.

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5) Index of pages
Chapter Page Date Chapter Page Date
cover page 10 10-1 02 01 2008
11-2 01 01 2007 10-2 02 01 2008
1-3 01 01 2007 10-3 01 01 2007
1-4 01 01 2007 10-4 01 01 2007
10-5 01 01 2007
22-1 01 01 2007 10-6 02 01 2008
2-2 01 01 2007 10-7 01 01 2007
10-8 01 01 2007
33-1 01 01 2007 10-9 01 01 2007
3-2 01 01 2007 10-10 01 01 2007
10-11 01 01 2007
44-1 01 01 2007 10-12 01 01 2007
4-2 02 01 2008 10-13 02 01 2008
4-3 01 01 2007 10-14 02 01 2008
4-4 01 01 2007 10-15 02 01 2008
4-5 01 01 2007 10-16 01 01 2007
4-6 01 01 2007 10-17 01 01 2007
10-18 01 01 2007
55-1 02 01 2008 10-19 01 01 2007
5-2 01 01 2007 10-20 01 01 2007
66-1 02 01 2008 11 11-1 01 01 2007
6-2 01 01 2007 11-2 01 01 2007
77-1 01 01 2007 12 12-1 01 01 2007
7-2 02 01 2008 12-2 01 01 2007
7-3 01 01 2007 12-3 01 01 2007
7-4 01 01 2007 12-4 01 01 2007
12-5 01 01 2007
88-1 01 01 2007 12-6 01 01 2007
8-2 01 01 2007
13 13-1 02 01 2008
99-1 01 01 2007 13-2 02 01 2008
9-2 01 01 2007 13-3 02 01 2008
9-3 01 01 2007 13-4 01 01 2008
9-4 01 01 2007 rear page
9-5 01 01 2007
9-6 01 01 2007

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NOTES

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d02822.fm
6) List of amendments
Approval*
The technical content is approved under the authority
of DOA Nr. EASA.21.J.048.
Currt
no.
Chap-
ter Pages
Date
of
modification
Note
of
approval
Date of
approval
by authority
Date of
insertion
Marks/
Signa-
ture
01 to 13 all 01 01 2007 DOA*
1
1
1
1
1
1
4
5
6
7
10
13
4-2
5-1
6-1
7-2
10-1
10-2
10-6
10-13
10-14
10-15
13-1
13-2
13-3
02 01 2008
02 01 2008
02 01 2008
02 01 2008
02 01 2008
02 01 2008
02 01 2008
02 01 2008
02 01 2008
02 01 2008
02 01 2008
02 01 2008
02 01 2008
DOA*
DOA*
DOA*
DOA*
DOA*
DOA*
DOA*
DOA*
DOA*
DOA*
DOA*
DOA*
DOA*

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7) Description of design
4-stroke, 4 cylinder horizontally opposed, spark ignition engine, one central cam-
shaft - push-rods - OHV
Liquid cooled cylinder heads
Ram air cooled cylinders
Dry sump forced lubrication
Dual breakerless capacitor discharge ignition
2 constant depression carburetors
mechanical fuel pump
Prop drive via reduction gear with integrated shock absorber and overload clutch
◆NOTE: The overload clutch is installed on all serial production aircraft
engines which are certified and on non-certified aircraft engines
of the configuration 3.
Electric starter (12V 0,6 kW)
Electric starter (12V 0,9 kW), optional
Integrated AC generator with external rectifier-regulator (12V 20A DC)
External alternator (12V 40A DC), optional
Vacuum pump: (only for A1, A2 and A4 possible), optional
Hydraulic constant speed propeller governor: (for A3 only), optional

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7.1) Type description
e.g. ROTAX 912 A 2
◆NOTE: The type designation is of the following composition.
◆NOTE: This configuration is not available any lon-
ger and will be replaced by configuration 2.
Type: 912 ... 4-cyl. horizontalle opposed, normal aspirated
engine
Certification: A ... certified to JAR 22 (TC No. EASA.E.121)
F, S ... certified to
FAR 33 (TC No. E00051 EN)
JAR-E (TC No. EASA.E.121)
UL, ULS ... non-certified aircraft engines
Configuration: 1 ... Prop shaft with flange for fixed prop, P.C.D
100 mm
2... Prop shaft with flange for fixed prop, P.C.D
75 mm, P.C.D 80 mm and 4“ P.C.D
3... propeller P.C.D. 75 mm, P.C.D. 80 mm, P.C.D.
4" and drive for hydraulic governor for constant
speed propeller
4... Prop flange for fixed pitch propeller P.C.D.
75 mm, P.C.D. 80 mm, P.C.D. 4" and prepared
for retrofit of a hydraulic governor for constant
speed propeller
Type
(type)
Zulassung
(certification)
Baureihe
(configuration)
ROTAX
02091