Ground-based communication between the flight deck and ground handling crews is not always perfect; mistakes do happen, sometimes resulting in costly collisions, but the issue is on many authorities’ radars
Communications links, whether an aircraft is in the air or on the ground, are inherently subject to interference or failures in hardware or software. Moreover, human errors are also a consideration when using communications equipment, explains Drazen Gardilcic, standards and procedures officer in the Universal Safety Oversight Audit Programme (USOAP) of ICAO’s Air Navigation Bureau. Depending on circumstances, communications failures may have an impact on safety, he notes.
Numerous ICAO provisions address communications links on the apron. As explained by Gardilcic, among them are the following:
Establish and implement procedures to control the movement of persons and vehicles on the manoeuvring area of the aerodrome
Establish and implement policies and procedures for co-ordination between air traffic service (ATS) and aerodrome operators
Ensure compliance with communications requirements of Annex 11 in relation to apron management services units
Promulgate regulations relating to apron management service, ground servicing of aircraft, aerodrome vehicle operations and surface movement guidance and control systems
Implement requirements for drivers to establish and maintain satisfactory two-way radio communication with the control tower
When warranted by traffic and operating conditions, require provision of apron management services to ensure the safety of aircraft operations on apron areas
Establish guidance on how these services are to be implemented whenever apron management services are provided
Provide radiotelephony communications facilities to apron management services
Ensure that aerodrome operators restrict the operation of personnel and vehicles on an apron during low-visibility operations
The USOAP verifies that state authorities establish corresponding regulatory provisions and ensure their compliance by aerodrome operators and ground handlers.
While ICAO can offer an international approach, individual national aviation authorities also have a very important role to play in their own territories
In the UK, for example, the Civil Aviation Authority (CAA) receives occurrence reports from ground handling personnel when any incident occurs, and it deals with these on an individual basis.
Also relating to the problems associated with ground-based communications on the apron in the UK is a joint CAA/industry group known as the Ground Handling Operations Safety Team (GHOST). A CAA spokesperson explains that GHOST is just starting work with the UK’s air navigations service provider, NATS, on ways to reduce the likelihood of communication-related errors occurring.
Plus, the Confidential Human Factors Reporting Programme (CHIRP) ¬– a confidential reporting programme designed to enhance aviation safety in the UK (and maritime safety worldwide) – is launching an initiative to encourage ground handlers to report safety concerns. This, it is hoped, will ensure that all airside workers have the opportunity to report issues to an independent body (CHIRP is actually a charitable trust) in complete confidence.
Although identification of specific ways to improve safety on the ground is the purview of individual state authorities, ICAO is certainly working on new enabling technologies that will help improve communications on the apron, explains Vaughn Maiolla, technical officer, communications, navigation and surveillance in the ICAO Navigation Bureau. The first is AeroMACS, which is a broadband (greater than 1Mbps) air-ground datalink to the aircraft. The other is known as SURF-IA and it is based on Automated Dependent Surveillance Broadcast (ADS-B) technology (ADS-B Out uses satellites’ GPS technology to determine an aircraft’s position, speed and other data and broadcasts that to ground stations, while ADS-B In allows aircraft to receive weather and positional data, including that from ADS-B Out-equipped aircraft). SURF-IA is basically ADS-B In adapted for surface operations, complete with alerts and alarms.
Thus, AeroMACS could allow pilots on a flight deck to download the latest airport map, replete with indications showing closed taxiways, construction zones and so on, while SURF-IA could then use this for a moving map display which would show other traffic, including surface vehicles and – what’s more – provide alerts and warnings to the pilot.
ICAO has just about finished the standardisation of AeroMACS, and has already produced some initial guidance on the SURF applications. Much more work needs to be done, however, and the technology is still some way off operational application.
Improving technology
Systems such as CPDLC – Controller Pilot Data Link Communications – have already eased the burden of voice communications between flight deck and tower. By using digital datalink communications such as CPDLC, not only can requests for air traffic control clearance be made that much earlier and more conveniently, acceptance of that request can also be received even before the pilot calls for push-back; moreover, in a busy operational airport environment where there were in the past large amounts of voice-based communication all competing for ‘air time’ and where mistakes could be made as a result, the process for obtaining ATC clearance has become safer.
It is some way off, but we could reach a point where a ‘silent’ airfield could be achieved as a result of digital datalink communications entirely replacing voice communications between a flight deck and tower, suggests Steve Landells, a flight safety specialist for the British Airline Pilots Association (BALPA), the British pilots’ representative body.
Where there is potentially more of a problem is in the pushback process (or, similarly, when an aircraft is being towed onto a stand). The pilot will typically be in voice communication with the team leader, and in cases of any doubt the team leader will also have wing tip walkers to provide guidance on potential physical hazards during the tow. They will communicate with their ground handling team leader by means of physical signals – but mistakes have been made in this regard, and there could well be room for improvement by means of bringing together all members of the handling team on the same radio communications network.
Untethered communications
Traditionally, ground handling teams working on the apron to escort aircraft off a stand have employed hand signals and tethered communications where available and appropriate. Those needing voice communication with the aircraft flight deck – typically the handling team leader – will plug their communications system into a jack in the fuselage (usually the nose) of the aircraft. However, there is another option – untethered, wireless communications.
A wireless system is going to be more expensive than a tethered option, but there are certainly advantages to it. It requires less maintenance, for example, as it avoids the perennial problem of wires being snagged and broken. It is also thought to be safer in lighting storms.
There are a number of suppliers of wireless communications equipment suppliers active in the aviation market. In the UK, for example, 3M Peltor and David Clark have for many years played leading roles, A relatively new entrant is dBD Communications, a Basildon, Essex-based radio frequency and microwave specialist that has long been active in the rail industry but only relatively recently extended its expertise into the aviation sector.
dBD is marketing its untethered wireless communication systems to those active on the apron, including ground handling marshallers and de-icing teams. It’s vital, says managing director David O’Connell, to provide robust wireless links that enable ramp teams to work in what he describes as a more “joined-up” way on the same communications network. dBD can also offer multi-user network systems for between three and eight people for other aviation-related roles, such as baggage handling.
“I am convinced that this sort of technology will become the standard in the aviation industry,” O’Connell says. And, even though it’s early days for dBD in this sector, the company is certainly making headway. Existing customers include the likes of Safeaero, while the company’s communications systems are also currently undergoing extensive trials with a major carrier at one of the UK’s busiest airports.
dBD uses Bluetooth wireless technology, which is both well-proven and used in many other industries, O’Connell explains. It’s robust and operates well in congested communications bandwidths. But there are particular challenges to communicating on the ramp that have tested the systems dBD had previously supplied in bulk to the rail industry. For example, the noise on the apron can be little short of deafening (especially when dealing with the aircraft of those carriers that choose to push back with engines running), and suppression of noise is key for pushback teams. While it does produce its own headsets, the company has temporarily offered its wireless Bluetooth communications as an integrated package with another company’s headsets that offer the very highest levels of noise cancelling capability.
The language barrier
Landells observes that the issue of communications on the ramp has not been frequently highlighted by BALPA members, but that is not to say there are no issues to address.
“Every airport is different in the way that they handle communications on the ground,” he observes. “Some airports do it particularly well, but even within the same country ground communication at another airport might be something of a challenge.”
Over the years, there have been plenty of incidents of aircraft being pushed back at the wrong time, or being towed into jetties and other objects. Frequently, these incidents are the result of poor communication, and historically ICAO has not been slow to realise that a problem existed.
Its answer in large part was to make further efforts to see that communication between flight crew and ground handlers was improved by means of consistent adherence to standardised terminology, Landells recalls. Clearly, at gateways where English is not the first language of ground service providers, the need for clear and easily understood language is key (as it is between aircraft and tower, something that has also been a problem in the past on occasion). It can be a problem on both sides – pilots have continued to express themselves in ways that are not easily understood by non-native speakers, while ground crews may not always receive the training in English that they should in order to work safely and effectively as, for example, aircraft tug operators.
Generally, the changes made to the ICAO lexicon for ground communications have been well received, Landells notes. But there still remain a few who either deliberately ignore it, are genuinely ignorant of it or are just not very good at using it. In cases where there is any doubt at all, it is the pilot’s responsibility before and during any manoeuvring to ensure that all concerned fully understand any instructions and are able to confirm their understanding to the flight deck.
For most airports handling regular scheduled flights, language-based problems are very rare, Landells says. They can be more common at smaller gateways used by charter carriers or business jets, where English may be less familiar.
