2.1 INTRODUCTION
At the time this research project was in its genesis in early 1994, there were only nine research papers in the literature, including five from Scandinavia, that reported on studies of manual handling in the baggage handler workforce: ARTEX (1981) measured the instance of baggage handler back injuries in a cross-section of its member airlines in 1977; Stălhammar et al (1986), studied the manual handling workload of nineteen baggage handlers in Helsinki and explored the back injury prevention benefits to the baggage handlers of resting supine; Stokholm (1988) canvassed opinions of baggage handlers at four Scandinavian airports concerning the perceived benefits of a trial Sliding Carpet installation in an SAS DC9; Jorgensen et al (1987), investigated the frequency of back injuries in baggage handlers at three Scandinavian airports and measured the effect on workload of six baggage handlers using a trial installation of an ACE loading system in an SAS DC9 aircraft; Lundgren, Soderqvist, Larsson and Jernberg (1988) investigated the costs of injures to SAS baggage handlers at Stockholm Airport in 1988; Leskinen et al (1991) reported on the back injury prevention benefits to the baggage handlers of resting supine; Queinnec and Daniellou, (1991) investigated the instance of back injuries resulting from baggage handling work; Egeskov (1992), looked at the effect of using a belt loader on the manual handling load of baggage
handlers required to work in the doorway of Australian Airlines B737 aircraft baggage compartments; and Ruckert, Rohmert and Pressel (1992) explored the strain on baggage handlers during luggage handling at a German airport. These were reported in more detail in Chapter 1.
Several questions remained unanswered in the literature:
What were the aircraft manufacturers doing about the baggage handler injury problem, after all the aircraft and aircraft equipment designs were at the core of the issue?
What was the magnitude of the baggage handler injury problem world-wide?
Had the airlines’ safety personnel looked into the issues and what were their views?
What were the opinions of the baggage handlers themselves about the causes of the injuries?
What were the comparative benefits of the ACE and Sliding Carpet narrow- body baggage systems that were being promoted in the industry as potential solutions?
Were any aircraft ground support equipment manufacturers or others offering any solutions and if so, what were the merits of those solutions?
While it could be argued that there were many more questions unanswered regarding the causes and prevention of baggage handler injuries, widespread improvements were considered to be unlikely unless these questions were clearly answered. Accordingly, this research project, in five phases, was developed to investigate answers to these questions. In addition to the overall project aims and objectives, each phase of the study had its own research aims, objectives and methods. The five project phases were conducted in sequence and as such, each phase added to the body of knowledge and informed the conduct of subsequent phases.
The phases of this research project were:
Phase 1 Meetings were held with representatives of the major aircraft manufacturers, aviation safety organisations and aviation industry bodies to ascertain the level and nature of industry activity in relation to airline baggage handler back injuries.
Phase 2 A survey of airlines worldwide was conducted to quantify the magnitude of the baggage handler injury problem and to ascertain the opinions of airline safety professionals concerning causes and prevention.
Phase 3 A survey of airline baggage handlers was conducted
worldwide to ascertain their views on causes and prevention
Phase 4 Laboratory trials, analysis and testing was carried out of two commercially available baggage systems, ACE and Sliding Carpet suggested by some to be part of the solution to the baggage handler injury problem
Phase 5 A risk assessment of the Longreach Loader, a prototype ground handling technology designed to reduce the manual handling workload of baggage handlers loading aircraft was carried out.
To maximise the impact of the research on the worldwide aviation community, the results of each phase were to be published in the literature after
completion of the phase, or where appropriate, presented at aviation industry safety symposia.
Only one other empirical study has been published since 1998 in the baggage handler injury area. Korkmaz et al (2006) conducted laboratory trials involving twelve healthy male university students who had been trained in baggage handling techniques used by airline baggage handlers. The trial subjects were required to perform a baggage stacking task in a laboratory mock-up that simulated the low baggage compartment ceiling of a B737 aircraft. It was of interest that Korkmaz and colleagues relied significantly on the papers published earlier in this study (Dell (1997) and Dell (1998)) to contextualise their work. The authors investigated the effect of two administrative
interventions; the effectiveness of providing weight information on each bag to forewarn the baggage handler before lifting and the effect of stacking bags on end instead of the horizontal orientation usually adopted by baggage handlers. The measures used were spinal loading and trunk and shoulder muscle
activity, determined using a Lumbar Motion Monitor, a ground force plate and surface EMG to measure muscle activity. The study found that there was no significant difference in trunk kinematics or spinal loads as a result of subjects being forewarned regarding the weights of bags being handled when loading order was random as would normally be the case during actual aircraft loading operations. However, if the weight of bags was used to inform the order in which the bags were loaded, mean spinal compression reductions of 13.5% were achieved, mean spinal anterior/posterior shear loads were reduced by 16.2% and mean spinal lateral shear loads were reduced by 17.5%.
Korkmaz and colleagues also claimed that stacking bags on end significantly reduced spinal loads. Reduction in mean peak spinal compression of 21.4% was measured, mean spinal anterior/posterior shear loads were reduced by 20.4% and mean spinal lateral shear loads were reduced by 32.4%,
suggesting alteration to baggage stacking methods by airlines in this fashion could be an effective intervention. However, for this part of the analysis, Korkmaz and colleagues indicated that each trial subject was measured tipping only one bag on end and this was compared to loadings measured when stacking only three bags horizontally on top of one another. The possible effects of attempting to stack a full aircraft load of baggage in this fashion, where the practicality of maximising use of volumetric baggage compartment capacity, a daily problem for baggage handlers, was not considered. This places serious doubt about the real world viability of this potential solution.
Excluding the contributions made by the presentation and publication of the first three phases of this research, the research questions posed above remain largely unanswered in the literature at the time of writing this Thesis, underpinning the validity of the rationale taken in the original research design and study methodologies described here.
2.2 RESEARCH AIMS AND OBJECTIVES
Project Aims and Objectives
The aim of this research project was:
To investigate the level of awareness of global stakeholders on the baggage handler back injury problem, measure the magnitude of the problem in the aviation industry, identify the causes of baggage handler back injuries, identify potential solutions and measure their effectiveness, where possible.
There were eight project objectives. These are detailed in Table 2.1.
Table 2.1
Objectives of the Project
Objective 1 Engage the major jet passenger transport aircraft manufacturers and industry associations in the issue of baggage handler back injuries
Objective 2 Investigate the level of awareness of the issue amongst international safety organisations
Objective 3 Encourage aircraft ground support equipment manufacturers to examine the issue and develop solutions technologies
Objective 4 Investigate the costs of baggage handler back injuries in the world's major airlines
Objective 5 Canvass the opinions all the airlines' safety professionals regarding the causes and prevention of baggage handler back injuries
Objective 6 Survey the opinions of a cross-section of baggage handlers worldwide regarding the causes and prevention of baggage handler back injuries
Objective 7 Explore whether safe design interventions can effectively reduce the risk of injuries occurring in one of this most severe manual handling work environment by comparing the effectiveness of the ACE and Sliding Carpet narrow body aircraft baggage systems
Objective 8 Assessing the change in manual handling risk associated with the use of the prototype Longreach Loader that was designed to reduce the need for baggage handlers to lift baggage and cargo when loading or unloading narrow body aircraft
Objective 9 Develop a series of recommendations to reduce the occurrence of back injuries in the airline baggage handler workforce