The concept of an electronic signature – an electronic rendition of signing one’s name – is not new, even in aviation. In fact, we’ve been using electronic signatures for years on telegraphs and faxes! In 1903, Orville Wright sent a telegram to his father confirming the first successful four flights of his heavier-than-air flying machine. Orville has signed his name at the bottom of the Telegram, arguably the aviation industry’s first electronic signature!

Electronic signatures as we recognise them now first became widely used and accepted when key areas of aviation moved onto electronic software systems, such as Maintenance Information Systems (MIS). For these systems, used by back office staff with wired in internet, it was comforting to implement digital signatures alongside the electronic signature squiggle for added security. These digital signatures compare the metadata (such as the authentication code, location, and time) accompanying the electronic signature with certain parameters (such as a list of approved authentication codes). If these parameters are met the signature is accepted.

It is therefore tempting to apply the same logic to ELB solutions. We think this is a major factor as to why so many other ELB projects have failed over the years. From an IT back office perspective, digital signatures are great. But from a practical Pilot and Engineer’s perspective, they simply aren’t suitable for use in the Cockpit or on the Line.

All paper logbooks require multiple handwritten signatures because the technical logbook is the legal record of an aircraft’s status and journeys.

The handwritten signature is universally accepted because it meets certain criteria. For the purposes of EFBs and ELBs, the key criteria have been explicitly clarified by regulatory authorities such as in EASA NPA/2016-12. According to EASA, any handwritten or electronic signature for an ELB solution must guarantee:

1. Uniqueness
2. Significance
3. Scope
4. Security
5. Non-Repudiation
6. Traceability

We’ll take a look at how our ELB solution, eTechLog8, guarantees these six criteria in more detail below.

It’s important to note that “digital signature” and “electronic signature” have distinct and different legal meanings. An electronic signature is simply an electronic form of a handwritten signature. A digital signature is an encryption mechanism for giving the electronic signature extra security.

Digital vs Electronic

There are several reasons why digital signatures are not suitable for ELB solutions, but a key blocker is that digital signature require a constant internet connection.

In contrast, an ELB solution must be fully native. This means it should work seamlessly with or without an internet connection. If the solution is not native it can cause expensive delays or become a safety issue. A digital signature requires a constant, reliable internet connection, so this simply doesn’t work for ELBs.

But what about security? Well the digital signature itself isn’t being validated, just the associated metadata, so the security benefits a digital signature provides are extremely limited. Technology has been developed to compare the one signature squiggle to a master signature by the same individual, but this relies on AI and the technology simply isn’t good enough to consistently identify true signatures over forgeries, or even true signatures written quickly or sloppily. So by trying to include a digital signature you’re adding a great deal of cost and complexity for very little benefit in return.

A common scenario is when an emergency diversion happens, and a third-party engineer (who is unknown to the system) is legally required (and legally allowed) to electronically sign for the aircraft. If a digital signature is required, there are time consuming and complicated processes to follow to get them set up on the system. And that’s assuming you’ve got a good internet connection and the right people available! Other similar scenarios include when a contracted third-party company hire a new engineer; they need to remember to tell your airline to add those details into the ELB system, and there’s no guarantee this will happen all before the Engineer needs to get to work.

The ELB solution must be able to handle scenarios like this smoothly and without causing costly delays. Using a digital signature, or even just adding unnecessary complexity to an Electronic signature make this impossible.

The Regulations

It is currently the responsibility of the National Airworthiness Authority (NAA) overseeing an Airlines’ AOC to accept the airline’s use of electronic signatures for ELBs in line with applicable regulations.

There are a few different regulations that may come up when discussing Electronic Signatures, depending on your geographical area.

If you’re in the EU, or follow EASA rules, you may think you need ELB electronic signatures to comply with (EU) No 910/2014 of 23 July 2014 (eIDAS).

eIDAS is a general framework for electronic identification. It lays down rules and conditions generically, which shall be enforced when there are no specific regulations applicable to a particular industry, situation or transaction. However, when a specific regulation exists, it is generally accepted that it overrules eIDAS regulations.

As EASA is the governing body with specific rules and regulations for the aviation industry, any EASA regulation related to electronic identification should be prioritised over eIDAS or any other general law.

Conduce has identified that the paragraph (g) of the AMC3 SPA.EFB.100(b)(3) is the specific EASA rule applicable to electronic signatures. Conduce’s “Sign On Glass” mechanism clearly complies with this rule for eTechLog8 signature mechanisms. Read on to find out more about how Sign On Glass works.

Furthermore, paragraph (g) in the EASA AirOps states: “Advanced electronic signatures, qualified certificates and secured signature-creation devices needed to create them in the context of Regulation (EU) No 910/2014 are typically not required for EFB operations.” This unequivocally has led Conduce to conclude that eIDAS electronic signature regulations do not apply in the case of eTechLog8.

To date, no NAA has required eTechLog8 to demonstrate specific compliance with eIDAS, both within EU jurisdiction and outside.

If you’re in the USA or follow FAA rules, you will find the legal framework for electronic signatures currently comprises two statutes, the e-Sign and the UETA.

Industry specific regulations follow up on the e-Sign and UETA. For the aviation industry, the FAA issued the AC 120-78A dated 22 June 2016 as a soft law tool (i.e., it is not an enforceable law) that operators could use when signatures, records or manuals are electronic.

The Conduce signature mechanism complies with all the criteria set out in e-Sign, UETA, and AC 120-78A. Therefore “Sign On Glass” signatures are legally acceptable and valid under US regulations.

Sign on Glass

eTechLog8 is unusual in the ELB market because eTechLog8 captures the handwritten signature as a “Sign on Glass” action.

“Sign on Glass” means the signature on the device is captured exactly in the same manner as it would be captured on a standard paper techlog, using a dedicated stylus.

The use of a handwritten signature for an ELB is patented by Rolls Royce and Conduce uniquely has a lifetime licence from Rolls Royce to use a handwritten signature for an ELB.

Signature Criteria and eTechLog8