Refining the numbers
MRTT flight crew options reviewed

Volume 48, No. 18, October 05, 2006

FULL TANK: The Multi-Role Tanker Transport as it may look in the future refuelling F/A-18s in flight. Digital image courtesy of DSTO, Melbourne

By Helen Ward

SOPHISTICATED controls in the new air-to-air refuellers are being put to the test as DSTO study crewing options.

The new refuellers, due to enter service in 2009, will support F/A-18, F-111, AEW&C Wedgetail, and Joint Strike Fighter aircraft.

Initial planning for the Air Force’s new Multi-Role Tanker Transport (MRTT) assumed that the flight crew for air-to-air refuelling operations would comprise four people; two pilots, a mission coordinator (MC) and an air refuelling operator.

However, the choice of the Airbus A330 for the MRTT presented an opportunity to re-evaluate this configuration, due in part to the high level of automation built into the Airbus systems.

DSTO research has contributed to this by modelling MRTT crew tasks to ascertain the likely impact of removing the MC from the crew.

DSTO researcher Dr Christopher Best explained that, “Work scenarios are broken down into a collection of individual tasks which are arranged into networks according to how the tasks relate to each other”.

For the MRTT analysis, data inputs in the form of task times and estimates of task workload were obtained via consultations with Air Force air-to-air refuelling and Airbus aircraft subject matter experts.

To quantify the difference between MRTT crews with and without the MC, a relatively high workload situation was modelled. The hypothetical scenario chosen involved boom refuelling of the future Joint Strike Fighter aircraft.

An unexpected event was included to model the crew’s responsiveness to unforeseen circumstances with three and four-person crews.

At a random time during the simulated air-to-air refuelling exercise, a request to transit and conduct a new refuelling operation in another area was introduced, requiring the crew to make changes to the flight plan.

Refuelling missions for three and four-person crew configurations were simulated, with and without various adverse workload-increasing conditions such as poor weather and difficult communications.

The number of missions simulated in the course of investigating all of these factors amounted to around 10,000.

The research indicated that while a crew with an MC outperformed a crew of three, the difference was small and unlikely to significantly reduce mission effectiveness.

“The DSTO study has informed finalisation of the A330 MRTT mission system design to enable the full range of tasks to be undertaken using either a three or four-person crew,” said GPCAPT Stephen Bucholtz, Director MRTT Transition Team.

A validation of the crew workload for the full range of scenarios and tasks will be performed by the Civil Aviation Safety Authority as part of their human factors program when the design implementation for all systems has been finalised and when system mock-ups are completed.

It is planned to complete this work to enable the A330 MRTT to be introduced into service with training and publications that support three-crew operations.

Fast facts:

• DSTO are reviewing flight crew options for the new air-to-air refuelling aircraft, the Airbus A330, coming into service in 2009.
  
  
• Initial planning assumed that four crew members, consisting of two pilots, a mission coordinator and an air refuelling operator, would be required for the MRTT.
  
  
• Due to the high level of automation in the Airbus A330, the crew configuration was re-evaluated.
  
  
• Research showed that while a crew with a mission controller outperformed a crew of three, the difference would not reduce mission effectiveness.
  
  
• The Civil Aviation Safety Authority will validate the research with a human factors program to complete the evaluation.
  

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