Product Highlight EUROPEAN ROTORS 2023

We make HUMS work

The (XRDS) identified a fault on the 27th of July. On the 17th of October, the main gearbox was removed from service following chip indicators, 100 flight hours after the XRDS identified the fault. Teardown analysis revealed the source of metal degeneration was from a planetary bearing.

The challenge for operators 

Is how the aviation authorities will legislate and govern the skies safely with all the new forms of aircraft, without restricting the ability of traditional aircraft to perform their roles.  In the past, legislation has usually come about because of thousands of hours of historical data on which to base decisions. The problem for the aviation authorities today, is that the skies are constantly evolving at a seemingly increased rate, and whilst change is needed now, there is very little data for the authorities to base their decisions on.  Widespread adoption of Health and Usage Monitoring systems across all platforms would help in this regard.

A major problem is that we now have a mixed array of old and new aircraft.  Many of the older aircraft performing inland roles do not have the safety enhancements of the military or the offshore oil and gas industries, making them higher risk and with lower availability in these busy and important roles.

Are there lessons that we can learn from other forms of transport? — Cars and other motorized vehicles have for some time been equipped with sophisticated vehicle monitoring. Many modern vehicles can communicate vehicle status and potential problems both to the driver and back to the manufacturer/dealer.  Communication is now key to driving down risk and can start a journey knowing the status of your vehicle. It seems incredible that more information is often available to a car driver than a pilot or operator! Part of the solution to de-risk using technology has been addressed by affordable advanced integrated Health and Usage Monitoring (HUMS).  In this paper, we will learn not only of the enhanced safety levels achievable using an HUMS system, but also the quantifiable cost benefits, and some of the technology advancement which has supported this.

Part of the solution enabled by technology

This has now been addressed by affordable advanced integrated HUMS and FDM (Flight data monitoring). These technologies can solve many of the safety issues faced by the aviation sector today, whilst at the same time providing significant real-time data that can be used by both operators and authorities alike.

Barriers to Entry

The main barriers to entry for an operator to incorporate HUMS have always been a lack of awareness, resistance to change, and the perceived cost of the technology.  Whilst awareness of such systems is increasing, there still seems to be some reluctance amongst operators to install them.  Resistance to change is an obstacle that needs to be overcome.  When the UK first introduced legislation that it was mandatory to wear seatbelts in cars, unbelievably, there was a lot of opposition to the new law.  Now it seems second nature to wear a seatbelt.  Both education and data proving that vehicle casualties were significantly reduced means that seatbelts are now regarded as essential, not something to be annoyed about! We will later detail in this paper both the safety benefits that a good HUMS system can achieve, and that the cost will almost certainly be outweighed by the savings the technology can deliver. When presented with these facts, this should help to overcome the resistance to change and demonstrate that a HUMS system can reduce, not increase, costs.

Safety Benefits

The key safety improvements are the accurate identification of potential faults before catastrophic failure, informed decision-making, risk mitigation, and avoidance, minimizing the risk of failure in flight, and decreased need for emergency landings. This enhanced level of safety when installed on U.S. army helicopters has already avoided 4 Class A Mishaps and could avoid 11% (or 40) material-related mishaps of all classes per year. (Source: U.S. Army)

Maintenance Benefits

A good HUMS system results in more efficient maintenance, troubleshooting, and diagnosis of potential faults, deferment, or elimination of certain maintenance inspection intervals, and diagnosis of problems before they cause collateral damage.

This was quantified by the US Army by a reduction of 343,278 maintenance man-hours/year with 4,958 maintenance events eliminated.  Optimized maintenance practices resulted in over 50 AWRs and 127 improved maintenance procedures.

Readiness Benefits

Demonstrable reduction in downtime for unscheduled maintenance events, proactive maintenance, allowing aircraft downtime to be a scheduled and anticipated event rather than an unexpected inconvenience, resulting in increased platform availability and readiness (up to 11.8% increase) and up to 11.3% non-mission-capable for maintenance reduction. Experienced, 1 less mission abort per 100 flight hours.

Operations and Support Cost Benefits
These include increased useful life and efficiency; identification of certain problems that warrant grounding the aircraft immediately, thereby preventing further damage, and extension of the life of an aircraft’s avionics and airframe by reducing overall vibration on the aircraft. Proven statistics were TBO extensions on 22 CBM+ monitored parts, a 5.8% reduction in maintenance test flights (MTFs), and a CBM+ CBA projection that the Mean Time Between Failure cost avoidance was in the region of

A further recent example has been the use of data by a customer when a part began to fail within the first 100 hours of operation. This resulted in a successful warranty claim, which in turn gave the customer a 200% return on investment.