Mitsubishi MU-2B Service Letter
MITSUBISHI MU 2B · Service Bulletins
Overview
This document is a service letter issued by Mitsubishi Heavy Industries regarding the MU-2B series aircraft. It informs owners and operators about the Honeywell Operating Information Letter (OIL) OI331-11R23 and the recommended installation of an Auto-Ignition System to enhance safety during icing conditions.
- Issued by Mitsubishi Heavy Industries, Ltd.
- Covers Honeywell Operating Information Letter OI331-11R23.
- Recommends installation of an Auto-Ignition System.
- Aims to reduce engine flame-out risk in icing conditions.
- Does not supersede existing Airplane Flight Manual information.
- Emphasizes proper use of engine anti-ice and ignition systems.
- Icing can occur year-round under specific temperature and moisture conditions.
- Contact Honeywell for questions regarding the OIL.
Document
Source
Originally published by mhi.com. Sprinkle hosts a reference copy with an added summary, specifications and searchable full text.
Document details
- Type ·
- Service Bulletins
- Year ·
- 2025
- File size ·
- 1.2 MB
- Publisher ·
- mhi.com
- Language ·
- en
What is the Mitsubishi MU-2B Service Letter?
The Mitsubishi MU-2B Service Letter is a service bulletins for the MITSUBISHI MU 2B, dated 2025.
Where does the Mitsubishi MU-2B Service Letter come from?
This copy of the Mitsubishi MU-2B Service Letter was originally published by mhi.com and is hosted on Sprinkle as a free, searchable reference copy.
What year was the Mitsubishi MU-2B Service Letter published?
The Mitsubishi MU-2B Service Letter — the MITSUBISHI MU 2B service bulletins on file — is dated 2025.
Most owners only have the POH. Here's the essential set for the MITSUBISHI MU 2B.
- Pilot's Operating Handbook / AFM
- Checklist
- Maintenance Manual
- Parts Catalog (IPC)
- Systems & Wiring
- Service Bulletins on file
- Type Certificate (TCDS)
More MITSUBISHI MU 2Bmanuals & documents
- Mitsubishi MU-2B Service PublicationService Bulletins
- Mitsubishi MU-2B Service LetterService Bulletins
- Mitsubishi Service Publications TransmittalService Bulletins
- Service Bulletin No. 107/57-005Service Bulletins
- MU-2 Service Bulletin No. 243Service Bulletins
- Mu-2b-60 Pilot'S Operating ManualPilot's Operating Handbook
Related documents
- Mitsubishi Service Publications TransmittalMITSUBISHI MU 2B · Service Bulletins
- Mitsubishi MU-2B Service PublicationMITSUBISHI MU 2B · Service Bulletins
- Mu-2b-60 Pilot'S Operating ManualMITSUBISHI MU 2B · Pilot's Operating Handbook
- Mitsubishi MU-2B Service LetterMITSUBISHI MU 2B · Service Bulletins
- MU-2 Service Bulletin No. 243MITSUBISHI MU 2B · Service Bulletins
In this document
Purpose
This section outlines the intent of the service letter, which is to inform MU-2B owners/operators about the Honeywell OIL and its recommendations.
Auto-Ignition System
Details the recommendation for installing an Auto-Ignition System to reduce engine flame-out risk during icing conditions.
Icing Conditions
Reminds pilots of the importance of using anti-ice and ignition systems properly in known or potential icing conditions.
Operational Notes
Provides operational guidance regarding the use of ignition switches in icing conditions.
Safety notes
- Use ignition switches in 'CONT' position during icing conditions if equipped with Auto-Ignition System.
- Use ignition switches in 'ON' position if Auto-Ignition System is not installed during icing conditions.
- Icing can occur at any time of the year.
- Be cautious of visible moisture when outside air temperature is +10°C or less.
Full document text
MITSUBISHI HEAVY INDUSTRIES AMERICA INC. MITSUBISHI SERVICE PUBLICATIONS TRANSMITTAL The attached Mitsubishi MU-2B series Service Publication has been issued by Mitsubishi Heavy Industries, Ltd. in Japan, who is the type certificate holder of the MU-2 aircraft. It is the owner and/or operator’s responsibility to adhere to or comply with new information contained in the attached publication. SL 126 SL 099/71-020 Honeywell Operating Information Letter (OIL) OI331-11R23 NOTE THIS PUBLICATION IS PRINTED AND/OR DISTRIBUTED BY MITSUBISHI HEAVY INDUSTRIES AMERICA, INC., UNDER LICENSE FROM MITSUBISHI HEAVY INDUSTRIES LTD. FOR COMMENTS OR INQUIRIES REGARDING DISTRIBUTION OF THIS PUBLICATION OR RECEIPT OF ANY OF THE PUBLICATIONS LISTED HEREIN, PLEASE CONTACT: Mitsubishi Heavy Industries America, Inc. Aircraft Product Support Division 450 N. Freeport Pkwy Suite 3400 Coppell, TX 75019 USA Email: mu-2support@mhia.com THIS PAGE INTENTIONALLY LEFT BLANK MU–2 SERVICE LETTER MITSUBISHI HEAVY INDUSTRIES, LTD. NAGOYA AEROSPACE SYSTEMS WORKS 10 OYE-CHO, MINATO-KU, NAGOYA, AICHI, JAPAN Page 1 of 1 JCAB T.C. : No. 126 DATE: October 3, 2025 FAA T.C. : No. 099/71-020 SUBJECT: Honeywell Operating Information Letter (OIL) OI331-11R23 MODEL EFFECTIVITY: All MU-2B Airplanes PURPOSE This Service Letter is issued to ensure that owners/operators of MU-2B airplanes are aware of the release of Honeywell Operating Information Letter (OIL) OI331-11R23 and have received a copy of the attached OIL. If you have any questions, please contact Honeywell utilizing the contact information provided in the OIL. The OIL recommends the installation of an Auto-Ignition System which Mitsubishi Heavy Industries, Ltd. (MHI) agrees with. MHI has issued two Service Bulletins (S/B 226E for A2PC airplanes and S/B 086/74-002A for A10SW airplanes) to install an Auto-Ignition System in addition to the existing Continuous Ignition System to reduce the possibility of engine flame-out when icing conditions are encountered and the continuous ignition is not selected. As noted in the OIL, these general procedures do not supersede the information on operation in icing conditions presented in the JCAB and FAA approved Airplane Flight Manual for your particular model of MU-2B. (See NOTE below.) They do, however, serve as a reminder of the importance of using the engine anti-ice and ignition systems properly when operating in known or potential icing conditions. We remind pilots that icing can occur at any time of the year if the temperature and cloud moisture content are within the icing range. NOTE If your airplane is equipped with the Auto-Ignition System, the ignition switches should be placed in the “CONT” position when actual or potential icing conditions exist or in the “ON” position if the Auto-Ignition System is not installed. This includes all flight operations in any form of visible moisture when the outside air temperature is +10o C or less or the indicated OAT (RAT) is +10o C or less, when ice remains on the aircraft surfaces and/or during takeoff, climb out and landing when ice, rain, water, slush and/or snow is present on the runway. THIS PAGE INTENTIONALLY LEFT BLANK