WTG900: The Military Grade Warning Tone Generator

Becker is a leader in digital avionics technology, setting the standard in customer-centric, state-of-the-art ground and airborne solutions.
Our focus is on meeting individual requirements with the highest commitment to quality and customer satisfaction, no matter what the mission.

When it comes to tailor specific solutions for our military customers, we respond with products that fit their needs and concerns. So when the German Armed Forces required a modern cockpit aural warning system for its CH-53GA medium-lift military transport helicopter, we responded with a state-of-the-art digital warning tone generator: the WTG900. The WTG900 manages all the warning tone requirements of the CH-53GA and is qualified according to MIL-STD-810E, MIL-HDBK-217F N2, DO-178B, DO-160C and EN 2282.

The system is based on a redundant design and achieves the highest level of reliability and availability. The WTG900 generates audio voice warnings. Each voice warning can be triggered by up to four activation sources.

Each of these four activation sources can be configured to be either a discrete input, an ARINC 429 message or a MIL-BUS-1553 message. The priorities, the alarm class, the repetition numbers and several other warning parameters are all configurable. The flexible design allows for generation of every desired voice warning. The voice warning is recorded in MP3 format and uploaded into the equipment.

In addition to internally generated audio warnings, the device provides an audio routing function for two analog audio inputs. The audio routing functions allow to block an audio warning of an external device in case of an internal generated warning of a higher priority.

The device has several control functions incorporated for warning acknowledgement and maintenance. These control functions can be activated via discrete inputs, Arinc 429 message or MIL-BUS-1553 message. Furthermore, the activation status of every warning activation or control input can be monitored and recorded via the MIL-BUS-1553 inputs.

Key facts on the WTG900


  • Up to 75 MP3 format warnings & messages (tone/voice)
  • Configuraton of up to 5 warning priorities
  • Configurable message repetition for each message
  • Equipment status available via MILBUS Interface
  • Redundant design of critical parts

Warning Tone Generation

  • Audio warning message generation from preconfigured MP3 files
  • Management of activating sources (up to 4 per warning message)
  • Priority handling of warning messages
  • Replay of warning if configured

Redundancy Management & Health Monitoring

  • Redundancy management of internal functions (monitoring)
  • Redundancy management for discrete inputs if required (comparator function)
  • Provision of warning and system status message on MILBUS
  • Comprehensive built-in tests (PBIT, CBIT, IBIT) including loop-back of audio outputs

The WTG900 is top-notch when it comes to available warning tone generators on the market. The unit has been selected for the CH-53GA, as well as for the NH90 and is targeted for aircraft platforms, such as the CH-53K, S-92, KC-390, C-130, just to name a few, where the operation requires a high end product for the safety of the crew and mission personnel.

The CH-53GA improvement package that fundamentally renews the avionics equipment of the aircraft is being implemented by Airbus Helicopters Deutschland GmbH for the German Army CH-53 fleet. The product improvement program ensures that the CH-53 helicopters remain suited for the expanding range of missions carried out by the German Armed Forces.

We are proud to support our military customers

with such world class products, tailored for their missions.
Everday, we work hard for the safety of those who protect us.