Technically ….

Technically ….

Service Bulletin MTB-33-01R: Lights – Replacement of Entry and Ice Light Sockets

Original Date: October 7, 2019
Revision 1 Date:
July 28, 2020

Effectivity: Revision adds Model A200CT (C-12D), Serial Numbers BP-046 through BP-071.

Reason: To provide a spares replacement for faulty entry and ice light sockets.

Original Compliance – OPTIONAL: This service document can be accomplished at the discretion of the owner.

Revision Compliance – NO EFFECT: Airplanes previously modified by this service letter are not affected by this revision.

Service Letter MTL-25-02: Equipment/Furnishings – Aft Curtain Placard Inspection

Date: August 12, 2020

Effectivity: This service document is only applicable to the airplanes that have an aft toilet installed.

Super King Air B300, Serial Numbers FL-1 through FL-1224 and Super King Air B300C, Serial Numbers FM-1 through FM-85;

The equivalent of this service document has been incorporated on production airplanes B300, Serial Numbers FL-1225 and on and B300C, Serial Numbers FM-86 and On.

Reason: An incorrect placard may have been installed for the aft curtain divider.

Compliance – RECOMMENDED: This service document should be accomplished at a scheduled maintenance period or inspection. 

From Multi-Engine Turboprop Communiqué ME-TP-0021

Date: July 2020

ATA 34 King Air Weather Radar

Effectivity: BY-324 and after; FL-1140 and after and FM-76 and after

As of 2019, there are two weather radar options available on the King Air 200 series and 300 series: the standard RTA-852 WXR or the optional MultiScan RTA-4112 WXR. The MultiScan Weather Radar combines several radar scans to display an optimized weather picture. While operating, the radar scans automatically and provides additional information such as turbulence detection and ground clutter suppression. Technicians need to be aware of the model and interface differences when troubleshooting or re-installing a weather radar. System data plates are located at the bottom of the base of the radar.

The RTA-582 WXR provides a single output that is daisy-chained to all AFD’s. The MultiScan RTA-4112 WXR provides data to each side of the flight deck display system. If the connectors or the wiring for these systems become switched, the system will not function properly. Many of the same receptacles are used throughout the wiring harnesses for both systems. Utilize the notes on the wiring diagrams to verify that the correct connectors are paired.

ATA 34 King Air Weather Radar SB8
Effectivity: BY-324 and after; FL-1140 and after and FM-76 and after

Communiqué ME-TP-0016 described potential for the RTA-4112 weather radar to lock up and display an error message after 300 flight legs without a manual reset. This is due to non-volatile memory (NVM) capacity management.

Collins has released Service Bulletin RTA-41XX-34-8 Digital Signal Processor (DSP) Communication (COM) Fault Reliability Improvement to prevent faults caused by non-volatile memory re-writes.

Previously, Collins released information document (IDOC) 0168-19 titled Information and Usage of the RTA-41XX NVM Erasure Tool. The IDOC contains procedures and lists equipment to allow the NVM to be cleared in the field prior to it reaching this limit.

To ensure ongoing operation of the RTA-4112, Textron Aviation recommends that operators with this radar either clear the NVM during routine inspections using the procedures in IDOC 0168-19 or incorporate SB RTA-41XX-34-8 so that resets will no longer be necessary.

The RTA-4112 was installed in production as standard equipment beginning at FL-1161 and was a factory option on BY-324 and after. Any Phase 3 B200GT, B200CGT, B300, B300C aircraft could have also had the radar installed post-delivery.

The information provided in this column may be abbreviated for space purposes. For the entire communication, go to

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