Aircraft IT Operations – August / September 2015

Aircraft IT Operations – August / September 2015 Cover


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eTechLog: Digital trumps paper in the cockpit

Author: Vera Suhova, Project Manager, Conduce Group


Digital trumps paper in the cockpit

The value of eTechLog, explains Vera Suhova, Project Manager at Conduce Group, can be demonstrated with a life cycle cost analysis

For decades, the airline industry has been pursuing the holy grail of eliminating the traditional inefficient, error prone and often un-readable paper based technical log by replacing it with an electronic system. Early pioneers launched products in the noughties, enabling a couple of European Airlines to introduce the first EASA certified systems, but to date neither product has been significantly adopted by other airlines. This lack of progress is generally attributed to legacy technology constraints, which made the cost/benefit determination for these systems difficult to justify.

However, moving up to date in 2015, a perfect storm of technologies have come together to allow a second generation of electronic tech log (ETL) systems to be developed. These new technologies are finally enabling the cost/benefit advantage of the electronic tech log to be recognized.

These components of this perfect storm comprise:

  1. Ability to develop secure, unbreakable, quick-to-use touch screen Apps.
  2. Availability of rugged powerful tablet devices.
  3. Worldwide expansion of speedy low cost data communications.

Systems using these admittedly still maturing technologies are now becoming available as COTS (commercial off the shelf) products which can be relatively inexpensively rolled out within an airline, bringing the huge benefit of eliminating the paper tech log within reasonable timescale and cost parameters.

This article aims to document the costs and benefits of an electronic tech log system versus legacy paper systems by performing a life cycle cost analysis (LCCA) of a tech log page for a flight sector, comparing handwritten hardcopy costs and subsequent use with electronic data capture. The analysis has been developed into a computer model, to enable the costs and benefits to be quantified for airlines of different fleet size and composition (long and short haul). At the end of the article an example airline fleet is applied to the model to illustrate the potential costs and benefits of an electronic tech log compared to a typical paper based system.

Life Cycle Costing Analysis (LCCA)

Performing a life cycle costing analysis is an accepted scientific approach to examine and understand all aspects of a system. The analysis involves determining the costs associated with each of the system’s life phases from conception through to cradle to grave.

The currently used industry paper based technical log systems consists of various handwritten forms which have specific functions. These manual systems are approved by the relevant National Aviation Authority (NAA).

For an aircraft technical log page (TLP) (assuming one page = one flight sector) the following points have been considered:

Scope of the system

Timeframe: 5 years – The repeated cycle of completing TLP’s for 5 years has been observed. Only direct airline costs/expenses occurring within the airline are considered. The following two scenarios have been studied and compared:

Scenario 1 – Paper – A medium sized airline carrying out both long and short-haul regular operations using a conventional paper-based technical log system. It is assumed that the paper tech log system consists of 3 different forms (a paper TLP form along with cabin defect and deferred defect forms), each of which are manually filled in using multi-copy books that are carried by the aircraft.

Scenario 2 – Electronic – The same airline carrying out both long and short-haul regular operations using an electronic technical log. The electronic log also replaces the deferred defect and cabin defect paper log books.

Stages of Life of a technical log page

In order to conduct the life cycle costing analysis it is essential to define the life stages of the functional unit that will be then assessed and compared for the scenarios observed. The functional units for this study are the TLP records which are handwritten or typed into the respective paper or electronic technical log system during the specified period of time – 5 years.

The ‘Life Cycle’ for a typical TLP have been analysed and the generic life stages of a TLP are described:

Stage 1 – Concept/Design
The technical log with all its workflow and data capture functions is an EASA requirement (Part-M M.A.306) for an aircraft to legally operate. For both the Paper and Electronic systems it is the airline’s responsibility to design a TLP that meets the EASA requirements and allows the efficient capture of technical data. Subsequently the data is used for reliability/statistical analysis. Usually a TLP is designed in-house by airline staff, so for the purpose of this study, the design cost has been ignored for both paper and electronic systems.

Stage 2 – Implementation

Once a paper based technical log system is approved an airline must arrange for the printing of the necessary number of books for the fleet and ensure a stock control system is in place to make sure the airline never runs out of the relevant books. There must be at least one book/set of forms of each type on board an aircraft prior to each flight.

For an Electronic system the airline must arrange for the purchase and maintenance of the selected electronic devices.

Stage 3 – Service life/Usage in flight.

Whilst on board, the tech log (paper or electronic) must be stowed in an approved location, and it is available to pilots and engineers to be used as required.  During the sector, the pilots complete the TLP flight details section of the TLP, with entries for data such as flight number, route details, OOOI (Out of gate / take Off / On the ground / In the gate) times, crew members, fuel and oil levels, etc. Pilots may also record the details of any defects that arise during the flight, which may include cabin defects passed to them by the cabin crew as well as defects observed from the cockpit.

On completion of the flight, the crew sign to indicate that the entered flight details are correct. Electronic tech log systems will then automatically transmit the completed flight details to the airline Operations and Maintrol departments. Paper based TLP systems require this communication to be carried out manually or via some other electronic system. Engineers and other ground staff then generally take ownership of the tech log and perform the usual turnaround activities preparing the aircraft for the next flight.

Stage 4 – Service Life/Usage on ground

Airlines generally benefit substantially if the aircraft ground turnaround time is kept to an absolute minimum. During the turnaround, airline staff use the tech log to record any defects and associated actions along with any Out of Phase (OOP) tasks carried out. Staff will also record any servicing (fuel or oil uplifts) that are completed; indeed every action carried out on the aircraft during the turnaround must be recorded and signed for in some way on the TLP. If any engineering activity is required then eventually a certified engineer signs a CRS (Certificate of Release to Service) with the authority of their 145 organization to release the aircraft from a technical perspective for the next flight. If no technical work is completed during the turnaround, then the pilots will complete a pre-flight inspection and authorize the aircraft to be technically ready for the next flight.

In due course, the pilots for the next flight use the paper or electronic tech log to assess the aircraft technical status, reviewing the turnaround activities that have been carried out by the various ground staff and, if satisfied, sign the TLP to accept the airworthiness of the aircraft for the intended flight.

At this stage paper TLP systems require the top copy of the completed TLP to be torn out of the book and left on the ground prior to flight, for physical onward transmission plus, often, sending a fax or email copy to the airline Maintrol/Operations departments.

These manually posted or faxed/emailed TLP’s are then processed by HQ based Operations and Technical Records staff which involves interpreting and physically transcribing data into various airline systems. This interpretation of the handwritten documents is often fraught with error, where potentially inexperienced clerical staff are required to understand technical handwritten text (including abbreviations) and accurately record engineers/pilots technical write ups. Any cabin defect pages or completed deferred defect pages will also have to be torn out of the respective books and transmitted to HQ for further interpretation and data input to various airline systems as required.

Electronic systems generally automatically transmit the completed TLP data in digital form to the airline, updating the respective MRO/Operations systems in real time electronically.

Stage 5 – Archiving.

EASA MA-06 requires that the paper originals of the TLP are retained for three years. In practice, after the paper TLP is processed it is stored in the company’s archive, usually in a fire-proof/flood-resistant and secure environment. The paper records are also required to be migrated from one operator to another as the aircraft ownership changes during the aircraft lifetime. Digital TLP’s are generally kept online in PDF format and indefinitely.

Stage 6 – Discard.
After a prescribed period, paper records can be removed from storage and destroyed. Digital records are generally kept indefinitely.

The following table contains a high level comparative overview of the types of costs associated with the paper and electronic scenarios for the previously described life phases:

A Computer model for the TLP Lifeblood costs of an Airline

The importance of the airline TLP system should not be underestimated. The aircraft TLP’s are essentially the combined blood and nervous system for an airline. The blood (data) enables essential information to be distributed around the airline and the quick intelligent understanding of that data (from this nerve system) enables the company to react and make decisions to survive in a fast changing world.

Traditional paper based TLP systems are generally accepted as just too slow for collecting data that needs to be acted on in a live environment. As a consequence airlines have invented all sorts of additional ‘work around’ systems to enable essential flight/technical data to be collected and acted on. Often the paper based TLP’s are regarded as simply archive data that is eventually typed into the backend MRO system, which may not occur till a few days or even weeks after the flights have occurred. Real time operations and line maintenance decisions are made by phone/email or other unofficial computer systems (often Excel or Access based). This is necessary to simply to enable the airline to plan day to day activities and function.

Airline Operations and Engineering staff have been known to occasionally ponder the merits of an electronic TLP and even wonder if a totally electronic system could provide the real time operational data access/knowledge to run the airline and eliminate at least some of the currently used ancillary operations/line maintenance communication systems.

The good news is that COTS electronic TLP systems are now available. To establish if these systems are cost effective a computer model has been devised. This model enables airline management to quantify the costs/benefits of paper versus electronic for their specific fleet size and operation and enables various airline profiles (fleet size/long/short haul numbers) to be analyzed. The model also allows for known airline direct costs for paper and electronic systems to be input and, although not exhaustive, gives an idea to the decision makers as to what expect with respect to cost and benefit from the competing scenarios.

The Computer model has 6 main sections:

Section 1 – Airline specific data
Fleet size, type of operations and utilization. The data comes from the airline.

Section 2 – Calculations for Paper System Cost
This section simply documents the costs of the paper system for the three books the aircraft carries. Sensitivity factors from section 1 are used to determine these costs, e.g. the number of defects per flight experienced by the airline, the number of pages in the books and the costs of the books themselves.

Section 3 – People costs including delays and cancelation

In this section the routine employee costs for completing the legacy paper based forms are calculated. Also the industry standard costs for delays and cancelations are applied; each airline will experience different levels of delays and cancelations and the relevant airlines figures can be applied here.

Section 4 – Electronic system costs

The implementation and hardware costs for the electronic system are detailed here, including the ongoing running costs for the software, hardware and communications.

Section 5 – Benefits, costs that are avoided by using the electronic system
Avoided costs represent the benefits of introducing the electronic tech log system, based on assumptions accepted internationally recognized data. It is assumed that introduction of an electronic system will be beneficial to an airline in some of the following ways:
a.    Man hours required to complete the TLP are significantly reduced.
b.    Man hours required to process the TLP data in the back office are eliminated.
c.    A fast and efficient electronic tech log will facilitate shorter turnaround times.  Studies show that a 10 minute reduction in turnaround time allows aircraft utilization to be increased by 8% and reduces AROC (Aircraft Related Operating Costs) by 2%.
d.    A measurable reduction in delays can be achieved as a result of the faster turnarounds and the fact that real time data becomes available for effective line maintenance planning.
e.    Flight cancellation due to technical reasons should also be measurably reduced.

Section 6 – Summary of Costs and Benefits, showing anticipated ROI (return on investment)

The model provides a specific value for the benefits of the electronic system over paper, this value is determined from the legacy paper system costs, minus the savings achieved from using the electronic system, but plus the costs of that electronic system.

The model allows different sensitivity factors to be applied, showing an immediate value for the cost saving. For example with our considered airline, increasing the improvement in flight cancelations from 5% to 10% results in an increase in savings of 114K EUR.

The different sections of the model enable an airline to tune the calculation to reflect that particular airline relatively precisely. Of course subjective factors do have to be entered, but these should be justified from direct experience for the applicable airline.

An example airline – European holiday/charter carrier with a mixed fleet of long and short haul aircraft

  1. Relatively accurate data has been applied for a known airline and the cost savings over five years are consistently around 3-5M EUR. There are some significant factors that have to be considered carefully as they have a large effect on the result.
  2. Cost per minute for delays; currently the model is using 50EUR/minute, which is derived from papers released by EuroControl.
  3. Average cost to the airline for a cancelled flight, both short and long haul.  Again data has been derived from results published by EuroControl and the figures used are 17.3K EUR for a cancelled short haul flight and 81K EUR for a cancelled long haul flight. We believe these to be conservative values and an airline can of course apply their own figures and see the effect on the model.
  4. The costs of aircraft Power and Stowage modifications can be quite significant. This of course will depend on the age of the fleet, newer aircraft have mains power available in the cockpit as standard, whereas older aircraft will require very expensive modifications to be applied.  For example the cost of putting the Airbus power mods on an old A320 can be around 50 to 100K EUR.  Applying these mods to the aircraft also has an impact on the capital value of the asset, so care needs to be taken when setting a figure.
  5. Potential Reduction in delays and cancellations. This has a very large impact on the model results. During testing we have applied a very conservative 1% reduction in these costs by going electronic. Applying a more optimistic expected reduction of 5% for delays and cancellations results in almost 5M EUR of additional savings for this particular airline.

Summary of benefits and ROI for different scenarios

  1. Even with the most pessimistic assumptions with regards to electronic system benefits, replacing paper with electronic always results in a significant cost benefit. This should not be a surprise, as most other industries replaced paper forms with mobile devices many years ago and it is just the slow moving conservative nature of aviation that has not brought these benefits into play yet.
  2. It can be seen that potentially avoided costs can cover the required investment within the first few months of electronic system operation, particularly if hardware is leased.
  3. Surprisingly the costs of paper (buying the books and archiving) are actually higher than buying the devices and printers that replace the paper forms.

Conduce: eTechLog8

The electronic tech log used in this study is Conduce’s eTechLog8, which is a native Windows 8/10 Touch Application designed to fully function offline as an electronic tech log on a rugged tablet device. The system has been designed from scratch as an intuitive touch app that is fast and instinctive to use, completely replacing the ubiquitous legacy paper tech log systems currently in use by 99% of the airlines throughout the world.

Request Conduce ETL life cycle cost analysis spreadsheet

Contact Vera directly to request the Conduce ETL life cycle cost analysis spreadsheet and type in your own figures and numbers to determine how much your airline or operation could save using an eTechLog Solution. Email Vera:

Contributor’s Details


Conduce specialise in producing mobile applications for the aviation industry, writing native Win8/10 and IOS tablet “Touch” device solutions and integrating these with responsive modern connected websites.
The current flagship product eTechLog8 has now been selected by seven airlines and is currently in differing stages of contract, trial & acceptance. Various NAA’s are now also involved with respect to monitoring these projects, enabling the necessary approval for the eventual roll out of paperless tech log systems with multiple EASA approved airline fleets.


After completing a Master’s degree in Environmental Sciences at Riga Technical University Vera Suhova decided to attempt applying her “Green Technology” skills to the airline industry.
She soon found herself working within the Technical Records departments of airBaltic and later SmartLynx where Vera seized the opportunity to investigate replacing the aircraft paper technical log with a more efficient and environmentally friendly paperless system.
Vera now works as a Project Manager with Conduce, implementing eTechLog8 with airlines around the world.

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