Doing No Harm
By Vahid Norouzalibeik|October 2016
Preventing ground personnel from damaging aircraft
Any plane at a passenger or freight terminal has delicate sensors and aerodynamic structures around which ground personnel must take care when operating equipment such as loaders. These areas include wings, flap track fairings, landing gear, engine cowlings, antennas and sensors. Among the most important features are the aircraft’s angle of attack sensors, also called alpha probes. They calculate the angle between the direction in which a wing is pointed and the direction of the air flowing over it. If damage to an AOA sensor were to go undetected, the consequences could be fatal. In 2008, a leased XL Airways Germany A320 that was being prepared to be turned over to Air New Zealand crashed into the Mediterranean Sea, because the aircraft had been repainted and rinsed off by high-pressure water that entered the AOA sensors and froze at a high altitude. All seven aboard were killed.
Of course, steps are taken to detect sensor or other damage to an aircraft before takeoff. Most importantly, there is the walkaround. A pilot circles the aircraft slowly clockwise, eying the various components and systems. Some faults can only be revealed by visual inspection. It will be especially important with the converted A320 passenger aircraft to conduct visual inspections of sensors before and after ground handling operations. In addition, with one engine running, AOAs and other sensors, including temperature probes and static ports that measure altitude, are electrically heated to prevent ice formation. It would be impossible to expunge all risk of human error by ground handlers, any more than errors by flight crews can be eliminated. But risks must be mitigated on the ground because the safety of a flight starts from there. The airlines should update manuals, standard operating procedures and training curricula to communicate the locations of AOAs and other critical sensors to ground personnel. This is especially important as airlines incorporate more Airbus jets into their fleets alongside the Boeing planes that some ground workers might be more familiar with.
Also, prototype work is underway at the company where I work toward converting A320 passenger planes to freighters, which means that all parties in ground operations will need to become familiar with the new A320Fs. On a Boeing cargo plane, the cargo operations areas are clear of sensors, but on a newly converted A320F, there will be sensors in the area where cargo will be loaded and unloaded. Ground handlers who have not worked with Airbus planes have to learn about the new safety hazards and precautions.
When an A320 is converted to a freighter, pains are taken to ensure that any sensors that must be removed temporarily are returned to their original locations. This removal is necessary because the fuselage must be cut and a cargo door installed that’s large enough to accommodate unit load devices. These ULDs are used for grouping, transferring and restraining cargo for transit, as well as overhanging cargo. ULDs may consist of a pallet with a net or may be a container. An aluminum frame shell also must be added to the exterior fuselage to reinforce the opening before the cargo door goes in. Because two AOA sensors are located on the area of the fuselage where a hole must be cut, these sensors will be removed and refastened. One is on the door and the other is on the shell.
During loading and unloading, cautions will need to be taken, because the reinstalled AOA sensors will protrude farther into the surrounding workspace. Off-the-shelf AOA covers should be placed over the AOAs during cargo handling operations to give some protection in the event of a collision. To reduce the risks of that, a guidance marshaller should be present to constantly guide the loader operator. Door-sill rollers, which provide a surface for moving ULDs into or out of the plane, can be of significant help to mitigate risks.
Notably, altering the design of an aircraft like the A320 in a passenger-to-freighter conversion, or PtoF, requires going through a rigorous process to earn a Supplemental Type Certificate, the document showing that the plane remains airworthy and in full compliance without the need for an entirely new type certification, as would be required for a new aircraft. The FAA and the European Aviation Safety Agency, EASA, will only sign off on the A320 Freighter if it meets their Continued Airworthiness requirements. Training the ground personnel is the airline or aircraft operator’s task. Operators need to update their standard operating procedures and their matching training courses, including textbooks and curricula, to address and highlight the AOA sensor safety hazard. Airlines and other operators of this type of aircraft will have to supervise operations and also monitor their personnel strictly for some time to assure compliance.
These updates and changes are currently being documented by the subject-matter experts involved in the PtoF conversion. A320F operators will then update the documentation used by ground handlers.
Performing any kind of operation on the ramp or airside is inherently risky, and achieving 100 percent safety would be wishful thinking. A significant responsibility for preventing runway incursions rests on the shoulders of the airport operations staff as well as other vehicle and ground support equipment operators who drive on the airfield.
For low-cost service by a Boeing 737 or Airbus 320 in the U.S., the turnaround time can be as short as 15 to 20 minutes. When performing full service for a Boeing 747 on an international route, the turnaround time can be 1.5 to two hours. Some airlines have their own ground handling agents who carry out both airside and landside services at their base or hub airports. Others outsource their ground handling services to independent service agents or to different airlines to keep costs down, especially at non-hub airports. With outsourcing, it’s much harder to assure conformity and the level of safety can diminish.
My experience shows that situational awareness, judgment and decision-making skills can be improved through structured training, consisting of initial and refresher courses at the theoretical and practical levels. This is being done by the airlines and airport operations authorities today, and its importance should not be overlooked.
Let’s look at some specific examples: Among the safety precautions in the Ground Operations Manual published by the International Air Transport Association are the following, which are helpful, but not sufficient if not adhered to:
- “The rubber bumpers on a loader must NEVER make contact with the aircraft. The minimum distance to be maintained at all times is 1 in/2.5 cm from the fuselage.”
- “Do not drive GSE” — ground support equipment — “with lifting devices in the raised position, except for final positioning of the GSE onto the aircraft.”
- “Do not drive GSE faster than walking speed.”
- “In general, when operating loaders, the bridge needs to be moved slowly until it touches the aircraft — avoiding any aircraft sensors until either the protective bumpers touch the aircraft or the equipment’s proximity sensors stop the movement.”
There’s nothing wrong with these. The A320F characteristics need to be highlighted in this IATA manual in the future when the Supplemental Type Certificate for the PtoF conversion is granted by the FAA and the EASA.
In the IATA Airport Handling Manual, there is a chapter called Airport Handling Ground Support Equipment Specifications that addresses different aircraft, including the A320. Freighter versions will surely be added by IATA when this freighter receives a supplmental certificate and is ready to enter the fleets.
Unfortunately, human complacency being what it is, there is a risk that operations personnel will deviate from their training and tend to neglect what they learned. All A320F operators should be given a heads up with regards to the locations of AOA sensors in the cargo operations area, and this can be done via revised or updated training textbooks and refresher courses for all personnel.
Specifically, I would suggest adding something like the following to the affected textbooks, manuals, documents and other materials for the Airbus A320F:
“UTMOST CARE SHALL BE TAKEN WHEN OPERATING AIRBUS A320 CARGO AIRCRAFT. OUT OF THE THREE AOA SENSORS, TWO ARE LOCATED ON THE LEFT HAND SIDE OF THE FORWARD FUSELAGE: ONE IS LOCATED ON THE MAIN DECK CARGO DOOR AND ONE IS LOCATED RIGHT UNDERNEATH THE MAIN DECK CARGO DOOR IN THE VICINITY OF LOADER OPERATIONS. HITTING/SLAMMING INTO THESE SENSORS SHALL RESULT IN SEVERE CONSEQUENCES AND AOG [“aircraft on ground,”meaning the plane cannot takeoff] WILL FOLLOW! THE RULES OF ‘RAISE THEN APPROACH’ FOR THE LOADER OPERATORS AS WELL AS “DETACH THEN LOWER” MUST BE OBSERVED DURING UN/LOADING OPERATIONS.'”
The good news is that the human element is the most flexible, adaptable and valuable part of the aviation system. But we are all vulnerable to influences that can adversely affect performance. As long as airplanes are serviced and operated by humans, fatigue, distraction and other inherent weaknesses can only be managed, never erased. Without controlling and monitoring measures, safety won’t be assured because day-to-day operations can become habitual and routine. When that happens, a formalized plan for change is necessary because individuals sometimes resist change and they become accustomed to performing a particular process that becomes the preferred way. One of the solutions that comes from my own experience is an honest communication with respectful feedback. This increases the chances of success and helps eliminate the severe penalty in time, effort, and damage to the organization’s reputation.
Implementation of a non-punitive reporting system towards eradication of the name-blame-shame game must not be taken for granted. Voluntary reporting always helps in the wake of incidents or accidents. To support a reporting culture, the organization must cultivate the willingness of its members to contribute to the organization’s understanding of its operation. Since some of the most valuable reports involve self-disclosure of mistakes, the organization must make the commitment to act in a non-punitive manner when those mistakes are not the result of careless or reckless behavior.
With these approaches, we can convert A320s to freighters, or integrate new planes into fleets, without surprising the personnel and increasing safety risks. ★