Flight data monitoring (FDM) is a key activity of flight operations departments at scheduled commercial airlines where it has been long established and supports safety and operational decision making at multiple organizational levels. FDM is not regularly used in business aviation, in part because it is not required for airplanes with a maximum takeoff weight (MTOW) threshold of less than 27,000 kg (59,525 lb). But the industry has acknowledged the benefits, and some operators—particularly larger ones—are implementing it. “ICAO Annex 6 Part 1 requires commercial operators of aircraft with an MTOW greater than 27,000 kg to establish and maintain a flight data analysis program as part of their safety management system. ICAO also recommends that states consider lowering the threshold to require flight data analysis for all airplanes above 20,000 kg,” said Willie Cecil, director of business development for aircraft data services at Teledyne Controls.

The MTOW threshold of 27,000 kg is established in the EASA regulations on air operations. As the regulations do not require aircraft below that MTOW to be monitored through FDM, smaller business jets are not usually included in the FDM programs of operators established in EASA member states. “However, it is possible that in the future this may change, and the MTOW threshold may be reviewed to a lower level,” said Nuno Aghdassi, head of flight safety at NetJets Europe. “The reason for this is the recognition within the industry, and specifically the safety community, that FDM is a vital part of any effective safety management process. The data collected from such an activity in combination with other complementary data sources allow a more accurate analysis of events and a better identification of potential operational risk. Not to mention, of course, the safety performance monitoring benefit and oversight advantage which can be gained from the analysis of aggregated data over time.”

For international general aviation (GA) operations, ICAO Annex 6 Part II requires operators to establish a safety management system appropriate to the size and complexity of their operations. “The reason FDM is often not accomplished in business aviation aircraft has more to do with the fact that business aviation consists of non-commercial operations and limitations on the maximum number of passengers that can be carried on board business jets," said Cecil. “Small business airplane operators usually have a lower number of flights and a lower number of passengers compared to larger planes and commercial operators, and the consequences of an accident may be deemed less compared to larger passenger-carrying aircraft.”

From the financial point of view, running an FDM program for a single aircraft or a small fleet, the cost of the program on a per-aircraft basis is potentially much higher compared to that for commercial operators with larger aircraft and fleets. “These aircraft often do not have quick access recorders (QAR), and operators have to use the flight data recorders (FDR), which then pose their own problems, i.e. they can be difficult to access and download and they may have limited storage capacity. Often, small airplane operators cannot justify the cost of installing a QAR, although many new aircraft are introducing built-in QAR functionality, utilizing, for example, commercial SD cards,” said Cecil. “Regardless of the MTOW threshold, it is recommendable to perform FDM, which is also promoted by bodies such as the Flight Safety Foundation under the Corporate Flight Operations Quality Assurance (CFOQA) term. Business jet manufacturers may also promote and offer CFOQA or FDM services which sometimes enable operators to benchmark across other operators of the same or similar aircraft types."

NetJets, which has a large global fleet of business aircraft, has been conducting FDM for 12 years now and its entire fleet is monitored in-house by a dedicated team of experts. “Of the eight aircraft types that we operate at NetJets Europe, only two of them [Global 6000 and Gulfstream G550] are above 27,000 kg and required to be included in FDM. All the others are voluntarily part of our FDM program," said Aghdassi.

FDM Benefits for Bizav

In recent years, as the business aviation industry has been coming to terms with the idea of reducing its carbon footprint, practices such as aircraft performance monitoring and the installation of QAR or other hardware have provided viable ways for flight data monitoring. The benefits of FDM are as applicable to business aviation as they are to commercial operations, provided that the appropriate data is acquired and recorded. “One problem for business aviation is that the availability of comparable performance monitoring services is limited and/or may be relatively costly. Thus making the business case to invest in airborne hardware is difficult. The resources available to small airplane operators to implement such programs are also limited,” said Cecil.

According to Marcel Martineau, a fuel management consultant, there are increasingly available low-cost recorders that can produce high-quality data. The data can even be downloaded automatically via Wi-Fi as soon as a flight lands. “Monitoring the flight path via appropriate systems is essential to improve an operator’s carbon footprint in many ways. It helps management to ensure that pilots are flying the flight plan, since today’s modern flight planning systems normally provide the best vertical, lateral and speed solutions. Monitoring also assists to verify whether the pilots are using the fuel-saving initiatives such as one engine taxi in and out, reduced flap landing, etc. There are numerous other possibilities to reduce fuel burn through flight data monitoring," he said.

Another main incentive to implement FDM in business aviation is the safety benefit. “For example, data can be used to support maintenance in troubleshooting technical issues or seeking the assistance from the original equipment manufacturer (OEM), it can help detect airworthiness exceedances which may have gone undetected and, certainly, it can also be used for operational performance analysis. All of these activities have an underlying safety interest, however, much will depend on the data parameters [type, quantity, and quality] available on the aircraft for recording,” said Aghdassi. “If you have a very limited set of data parameters, what you can do in terms of FDM will be severely limited. And here is where the cost/benefit argument is applied. Overall, though, most modern aircraft types record data parameters which exceed a thousand and this will allow the operator to take advantage of collecting and analyzing the data, to the fullest extent, through their FDM program.”

Despite the benefits that FDM provides, it might be difficult for a business aircraft operations department to make the case to senior management. Together with the fact that there may be possible incentives from insurance companies—hence making a better case for the return of investment (ROI)—focusing on proactive or predictive maintenance may be one way to ensure the buy-in of senior managers. “With such applications, an operator can work toward reducing spare parts inventory holding and/or achieve reduced costs in acquiring spare parts. Often, spare parts are required urgently and a business jet operator may pay high prices and delivery costs for spare parts in urgent situations. Having a deeper insight using FDM data, an operator can achieve more efficient maintenance and ultimately reduce costly unscheduled maintenance,” said Cecil.

FDM is a valuable safety tool to monitor aircraft systems and exceedances. For instance, should an engine be removed after an over-temp? It might save the operator a hot section overhaul and loss of the aircraft for some time. Good data will assist in monitoring performance degradation, engine loss of margin, and at what point an engine becomes due for removal,” said Martineau.

In addition to the traditional use of FDM for detecting potential safety issues, at NetJets the practice is used to provide each crewmember with a monthly report of his/her performance regarding unstable approaches and long landings. “We produce a monthly fleet-specific report for each chief pilot with the performance of their fleet and tailored safety performance indicators which are of specific interest to that aircraft type as well as an overall report of FDM-derived safety performance indicators for precursors of the key operational issues within our industry (such as CFIT, LOC-I, RE, etc.). These reports allow the different stakeholders to gain awareness of safety issues and supports them in the discharge of safety responsibilities within their domain”, says Aghdassi. “In addition, we provide formal input to the training syllabus so that when our crews go to the simulator for their 6-month recurrent training, they can hone their skills based on proactive FDM findings. FDM data is also used to help develop crew briefings for special airports and visualization tools which greatly enhance awareness at mountainous airports.”