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The true costs of heavier passengers: Part two
Domestic carriers in Europe and North America
Figures 5.6 and 5.7, below, illustrate the corresponding passenger and bag weight data for European and North American carriers on domestic services. Over the period considered, North American carriers have designated a slightly higher standard weight to their passengers than their European counterparts until 1998, from which the reverse has been true. The data again exhibits a much higher variation each year amongst European airlines. Unlike the assessment of international services, the number of American carriers included in these statistics is higher than that of European carriers and thus the sample size of airlines from each region cannot, in this case, be considered as impacting the variation difference seen.
Figure 5.6: Individual passenger and baggage weight range of European domestic airlines
Figure 5.7: Individual passenger and baggage weight range of North American domestic airlines
Domestic services in Europe also demonstrate a much more significant growth over this period compared to North American domestic services. Furthermore, it can again be seen that the majority of reported designated weights used on domestic services in both Europe and North America fall short of the prescribed recommended values offered within existing regulations. Comparison of this data with the international weights discussed above shows that there exists little difference between the domestic and international values used by European and North American carriers.
In considering the world’s largest carriers it is clear that there exists significant variation in this value between airlines and that in general the weight designated to passengers on international services is greater than those on domestic services. Furthermore, general trends of the largest carriers exhibit an increase in these values over the period considered. However, upon extracting the corresponding data for European and North American carriers, a number of important points are raised. First and foremost it can be seen that the statistics of North American carriers exhibit little change and variation over the two decades assessed, which in no way is corroborative with the known weight increase that has occurred in this region over this time. Although European carriers appear to have gradually designated increasing amounts of weight to each passenger, the weight value in both this region and North America appears to be significantly less than those of the prescribed values recommended for use by their respective governing regulations. Ultimately whilst it is each airline’s responsibility to monitor and assign a correct and valid weight to each of its passengers, reported statistics, particularly of North American and European carriers, do not demonstrate the consistent upward trend in this value that would be expected given the known weight gain that has occurred in both regions over the past two decades.
The International Size Acceptance Association (ISAA) is an established global lobbyist group protesting against obesity-based discriminatory practices facing the general public’s everyday lives. A topic, which has been well documented and discussed by ISAA, is the difficulties facing larger passengers in air travel. In ISAA’s experience, one US airline (Southwest Airlines), often makes larger passengers purchase a second seat in order to be allowed to travel. In reviewing sources of information for the purpose of this research many articles, press coverage and websites similarly laid a heavy focus upon Southwest’s policy on larger passengers. Whilst Southwest’s policy has undoubtedly generated a huge amount of attention from the media and the general public in recent years, it is a policy that has been in place since 1980, although not stringently enforced until 2002. Continuous press attention has understandably led to the development of a general public view, particularly in the US, that Southwest Airlines are the only carrier with such a policy. I will now seek to assess how valid this viewpoint is presently and to analyse to what extent other airlines throughout the world have size-related policies for the carriage of physically-larger passengers.
Nearly all airlines attach various conditions of carriage to the purchase of their tickets. These conditions are often set out in very lengthy documents that in most cases air travellers agree to without actually reading. Therefore in researching the presence of passenger size-related policies amongst airlines it is important to set out specific criteria relating to the presentation of information and its ease of access. For the purpose of this research, the world’s largest 50 domestic and 50 international airlines in terms of total passengers carried (as published in IATA WATS 2005) were assessed. The research took the form of an airline website survey and assessed whether each individual airline clearly and specifically published guidelines or policies relating to larger passengers within their websites.
With the exception of just a few, all of the airline websites surveyed demonstrated clearly marked and easily accessible information for passengers with special and specific requirements. These sections generally demonstrated a significant level of commonality, offering medical-based advice including information relating to disabled passengers, travelling with minors, expectant mothers and deep vein thrombosis. In total, only 10 of the airlines surveyed published policies specific to the carriage of larger passengers in a clearly marked section of their website.
Although the overall results of the survey show that currently one in ten airlines clearly exhibit ‘larger passenger policies’, it is imperative to highlight that nearly all of the airlines’ websites advise customers with specific or special requirements to contact ticketing agents directly for assistance and advice. In this respect it could be argued that all such airlines are, on some level, advising larger passengers to contact the airline if their specific requirements are not addressed directly on the respective website. Nevertheless, the survey results demonstrate that a fraction of airlines consider the carriage of larger passengers such a prominent issue that it should be directly addressed, set out in policies and detailed clearly to all of their existing and potential customers through their websites. Below is a summary of each of the 10 policies identified in the airline survey as published in relation to the carriage of larger sized passengers.
Ryanair: Larger passengers requiring an extra seat are able to do so by purchasing two seats or tickets both at their current price. Purchase of a second seat for one passenger does not entitle them to any extra baggage allowance. Passengers requiring two seats are advised to reach their departure gate early to ensure gaining two seats adjacent to each other.
Air France: Passengers with ‘high body mass’ must indicate if a second seat is required for their comfort. Aircraft seating corresponds to maximum waist measurements of 135cm (53.1in) to 200cm (78.7in), dependant upon the class in which the passenger has booked their seat. Air France agents will provide advice to individuals on the availability, fee scales and reductions of second seat requirements upon booking. If an aircraft is full and a passenger who has not booked a second seat is unable to sit in an individual seat, that passenger may be refused permission to board the aircraft on safety grounds.
Thai Airways: ‘Obese’ passengers are recommended to travel in Royal First Class or Royal Silk Class where seats are more accommodating. If economy seats are preferred an additional seat should be purchased.
Air Canada: If an extra seat is required for the comfort of a passenger then they should directly contact reservations agents. The charge for additional seats will vary by destination and the applicable fare at time of booking.
Continental Airlines: Customers flying in economy cabins who cannot fit in a single seat are required to purchase an additional seat. Customers must purchase a second seat if they are unable to properly attach, buckle and wear a seatbelt with one extension, unable to remain seated with armrests down for the entirety of the flight or if they significantly encroach upon adjacent seating space. The second seat may be purchased for the same fare as the original seat if purchased at the same time. If a second seat is not purchased in advance then customers may be required to pay the current fare applicable on the day of departure. Customers also have the option to purchase a seat in first or business class cabins or elect to pay an upgrade fee.
Mexicana Airlines: Extra seats required for comfort may be requested at the time of reservation or purchase. Passengers purchasing additional seats will be charged 100% of the applicable fare on all flights.
Southwest Airlines: Customers who are unable to lower the armrests and/or encroach any portion of adjacent seating should book the number of seats needed when making reservations. Second seats will be sold at the lowest fare available and if a discounted fare is booked then the second seat will also be sold at the same discounted fare. Customers who purchase an unrestricted full fare ticket will be sold the additional seat at child’s fare level. If a flight is not full upon departure the full value of any additional seat purchases will be refunded to the passenger.
Alaska Airlines / Horizon Air: Customers are advised that seat widths are approximately 17in, seatbelt lengths are 46in (seatbelt extensions will add 25in to total length). If ‘passengers of size’ require more room than seat widths allow and occupy a portion of an adjoining seat then they are required to purchase a second seat. No price, fee or reduction information is given.
JetBlue Airways: Extra seats as required may be purchased online or by calling reservations. If additional seats are purchased then customers are given the corresponding additional increase in checked baggage allowance. No price, fee or reduction information is given.
Mesa Airlines: Passengers unable to use a standard airline seat or fasten their seatbelt even with the provision of an extension will not be accepted to fly.
In assessing the extent to which the world’s largest airlines of today have identified the issue of larger-bodied passengers as a fundamental management problem, several underlying key points are visible.
Whilst the clear prominence of North American carriers featured in the survey results emphasises the relative magnitude of the problem in this particular region of the world, it is by no means an issue exclusive to this area. The very presence of carriers actively responding to this problem operating from and within Europe, Asia and Central America suggests that it is indeed a real issue that is far-reaching in its extensiveness. It is somewhat surprising that given the existing magnitude and growth of body weight and obesity in North America, and increasingly in Europe also, that many airlines in both regions have yet to definitively set out a clear policy on requirements for passengers to purchase additional seats or conditions that customers are required to meet in order to travel.
It is indeed possible that many airlines may in fact have policies similar to those described above and advise passengers when specific enquiries are made to them in relation to additional requirements as advised within most of the airlines’ websites. If this is the case, however, it may be argued that this is no longer an acceptable means to inform potential passengers of airline-specific restrictions and policies, especially given the extent to which the travelling public now use websites to carry out reservations and bookings. For example if a ticket is booked through an airline’s website on which no size-related advice or policy is provided, it is very possible for a passenger unable to fit into a single seat to be requested to purchase a second seat upon arrival for a flight despite no such advice being clearly presented to them at the time of booking.
Southwest Airlines, which has clearly been subjected to damning commentary of its ‘passengers of size’ policy, insists that in no way are their policies set out to discriminate against larger people. Rather, it provides an essential precaution that must be taken in order to ensure and guarantee the comfort and safety of all passengers travelling with the airline. Comfort and safety undoubtedly form two of the primary objectives that all airlines aim to deliver to each and every one of their customers. Subsequently those airlines not clearly stating or publishing a policy relating to larger-bodied passengers could be viewed as failing to ensure that two of their most important objectives are met as far as possible, as exemplified in Virgin Atlantic’s legal case above.
Although the website survey only accounted for policies clearly set out within each airline’s website, it is possible that some carriers publish guidelines and limitations within their contract or conditions of carriage as provided to customers upon booking a flight. One such example is that of EasyJet which, in its ‘carrier’s regulations’ provides seat dimensions and advice regarding second seat purchases. Although undoubtedly it is a customer’s responsibility to ensure that they have read and understood the conditions attached to their journey, it may be argued that detailing such restrictions in ‘fine print’ is insufficient in providing advice to a problem that is increasingly being witnessed throughout many parts of the world.
The survey also highlighted that whilst only a small percentage of those airlines studied actually set out a clear policy for larger passengers, the differences between these policies varies considerably. Undoubtedly Southwest Airlines gained much attention as a consequence of emerging as a ‘first mover’ regarding such a policy, generating uproar amongst lobbyist groups and associations demanding that the airline’s seats should in fact be made larger rather than financially punishing those that are unable to fit into current seats. In comparing this policy with those of other airlines however, it would appear that Southwest Airlines does in fact operate one of the fairest policies for passengers of size, providing the only example of an airline stating that the cost of any additional seat will be fully reimbursed providing a flight is not completely full.
The majority of airlines in the survey demonstrate a common system that passengers must pay for what they require. This is undoubtedly based upon the economic principle of consumers paying for what they consume, and in this case the consumption of two airline seats. Even with this similarity shared between several of the airlines, further deviations can be seen with regards to the baggage allowance. Whilst both Ryanair and JetBlue are comparatively delicate in the way in which they word and set out their policies on their respective websites, only the latter offers a passenger purchasing two seats the equivalent checked baggage allowance of two seats.
A rather unique approach to size-related policies demonstrated by two of the airlines was the clear identification of the marketing opportunity that it provides. Both Continental Airlines and Thai Airways recommend that those passengers that have difficulties sitting in an economy class seat would benefit from purchasing or upgrading their tickets to a premium class ticket. Undoubtedly this is representative of these airlines harnessing what is considered an awkward situation into one that could essentially assist in the airlines’ profitability through the generation of business and first class revenues (often an airline’s most profitable seats). This is emphasised in Table 6.1 below which compares the cost of purchasing two economy class seats with one business or first class seat with each of the airlines discussed in the above survey on which a premium product is also offered. Each of the prices shown in the table represents the cost of a return trip departing on 2nd June 2008 and returning on 6th June 2008.
Table 6.1: Price comparison of premium seats with two economy seats
The results show that for the flights considered, with the exception of Alaska airlines, it is cheaper to purchase two economy class seats than a single business or first class seat. With respect to Thai Airways and Continental Airlines in particular, this is perhaps misrepresented through their recommendations to larger passengers that travelling in a premium class may be more suitable given that the seat width of two adjacent economy seats far exceeds that of a single premium class seat on both airlines.
For the purpose of this research a number of UK airlines were contacted in order to evaluate how increases in the physical sizes of passengers are being directly viewed from a carrier’s perspective and approached as a management issue. Although the majority of the carriers that were contacted declined to comment on this topic in any detail, British Airways7, MyTravel Airways and Highland Airways agreed to answer questions presented at interviews and in a questionnaire. The outcomes of these interviews and contacts provide a unique and very real insight into how UK airlines perceive the problems of passenger size increases and their current perspective towards this issue.
British Airways (BA) is the UK’s national flag carrier and has consistently been one of the world’s largest airlines in terms of the number of passengers carried on international services over the past 20 years. Participating in several interviews for the purpose of this research, various personnel provided detailed information as to how the airline perceives, monitors and deals with the issues surrounding western passengers getting physically larger over the past two decades.
Recognising that weight is one of the most fundamental factors in their aircraft’s performance, BA employs a ‘weights’ team within its operations department, consisting of four personnel including one engineer. The role of the team is to monitor and assess the physical weight of the airline’s passengers, baggage and aircraft.
Although BA does not operate a policy specific to the carriage of larger-bodied passengers, the physical weight of passengers and their associated baggage is an operational element that is treated with utmost importance. For the purpose of weight and balance control on its flights, BA designate passenger weights derived from the prescribed values issued under JAR OPS -1 on all but one of the routes the airline serves.
Table 7.1: British Airways’ standard passenger weights
Table 7.1 summarises the standard passenger weights as used in BA’s scheduled operations of large aircraft. The values shown consist of the total weight designated per passenger (comprised of the combined weight of both the passenger and their hand luggage) and the weight designation for the hand luggage itself.
As detailed earlier, standard weight values prescribed by JAR OPS-1 allocate 88kg per male and 70kg per female, including an incorporated hand luggage weight of 6kg. BA’s standard weight values demonstrate that the weight assigned to each of their passengers is a product-dependant variable that differs between travel classes. The values shown in table 7.1 account for premium-class passengers being allowed and indeed carrying a larger amount of unchecked baggage compared to economy-class passengers. This is clearly an aspect that the prescribed values of JAR OPS-1 do not account for and as such is a weight element that is specific to each individual airline and their carry-on baggage allowance policies.
During the interviews carried out with the airline, BA expressed that the standard provision of 6kg of hand luggage per passenger as set in 1991 by JAR OPS-1 is a value that may no longer be realistic. This is primarily due to increases in the number of passengers using so called ‘carry-on wheelie bags’ as well as a significant rise in passengers carrying additional items including personal electronic equipment. One possible explanation for these trends is the attitudinal and behavioural changes of consumers that have taken place over the past 10 years. Assisted by the relative decrease in the cost of air travel following the emergence of low-cost carriers, there has been a clear increase in travellers opting for shorter ‘city break’ trips whereby passengers commonly prefer to carry all belongings as hand luggage for convenience and in some cases to save on potential additional checked baggage charges. With these trends in mind, BA suggests that it would not be uncommon for many airlines to have passengers carrying hand luggage in excess of 10kg and especially so in cases in which airlines operate a volumetric and not weight-limited carry on baggage policy. These changes in passenger trends are reflected to a certain extent in BA’s current standard values by the designation of an additional 1kg to the prescribed values for each of its economy passengers.
Revising standard values
JAR OPS-1 sets out guidelines and restrictions for operators wishing to revise or self-assess their own standard passenger weights. In the early 1990s BA’s operations department believed that the average passenger weights on several services between London and the Far East were significantly lower than prescribed standard weights based upon Far Eastern passengers generally being significantly smaller compared to their western counterparts. Subsequently BA began carrying out passenger surveys in 1995.
Prior to the commencement of weight surveys, a total of six routes were identified to undergo passenger weight checks, comprising of services operating between London and Kuala Lumpur, Beijing, Singapore, Bangkok, Honk Kong and Japan. An initial assessment was carried out on each of these services to analyse the average proportion of Asian passengers on each of the services. This initial analysis found that only the Hong Kong and Japanese services consisted of a significantly high percentage of Asian travellers and thus warranting a comprehensive weight survey to be carried out.
Both the Japan and Hong Kong survey weighed approximately 10,000 passengers during the winter (in order to account for heavier winter clothing) of 1995. Both surveys yielded important results and indicated, as expected, that the average weight of passengers on these services were indeed significantly less than those of the JAR OPS-1 values. Whilst the regulatory bodies did not approve the average weights derived from these surveys, a second survey was carried out in 2005 on the Japan route, again yielding similar results. The results of this second survey were approved and subsequently economy class passengers on Japanese flights are now designated a standard adult weight of 79kg (6kg lighter than the value used on all other services).
BA acknowledged that its western passengers have grown physically over the past two decades, although it is not an issue that is perceived as impacting their operations in any great way. First and foremost the airline operates a fleet consisting mostly of medium- and large-sized jet-powered aircraft, and as such gradual weight changes of passengers in recent years is not something that compromises the ability of such aircraft to carry out their operations in a safe and efficient manner. Furthermore it was highlighted that extensive post-flight data monitoring is carried out, analysing aircraft performance subsequent to each flight carried out. Through conducting post-flight performance analysis, any slight and gradual increases in passenger weight and subsequent implied changes in fuel requirements is a variable that is fed back through to the flight planning process and adjusted as necessary to ensure that subsequent flights carry the optimum amounts of fuel.
Whilst BA also acknowledged that it is likely that this ‘optimum fuel’ value has risen with increases in passenger weight over the past two decades it is a cost increase that is neither fed nor incorporated into the pricing of its services and as such is a cost that has essentially been absorbed by the airline. This is attributable to the ‘secular’ nature of weight increases, and therefore significant or sudden secondary effects are unlikely to be noticed over short periods of time or in the environment of the day-to-day operations of an airline.
Although it may be argued by any airline that the increasing efficiency of aircraft brought about by technological advances has meant that the overall fuel efficiency of aircraft has continuously improved, the direct economic impact of heavier passengers seems for the most part relatively unknown. Whilst new composite materials and improvements in engine technology may reduce the overall fuel requirements on a particular sector substantially, there will undoubtedly still exist some fuel expenditure directly attributable to the carriage of any extra weight increases of passengers. The incremental increase in fuel requirements and its subsequent cost brought about by increases in passenger weights is an operational element that BA has not to-date modelled nor investigated.
The physical size of passengers is an integral input into the design process of seating on BA aircraft. Whilst BA has been subject to relatively few occurrences of problems arising from larger passengers and their aircraft seating, it is an element that is carefully accounted for. In the late 1980s BA considered placing economy seating in the upper deck of its Boeing 747-200 fleet. This was never carried out, as the structural strength of the upper deck would have been unable to support the combined weight of economy seats and the weight of passengers. This yields an important design consideration for airlines and manufacturers with smaller seat pitches corresponding to a greater amount of weight per unit area on an aircraft’s cabin flooring. Arguably therefore, increases in passenger weights combined with high-density cabin configurations may potentiality adversely impact the structural integrity of aircraft flooring.
Current European regulations require that any airline (European-based) which, upon carrying out a passenger weight survey, finds that the average weight of passengers is greater than those of the prescribed values provided by JAR OPS-1 must use the new revised weights in all loading, balance and fuel requirement calculations. The extremely competitive aviation industry of today has placed increasing emphasis upon the reduction and minimising of all operating costs across all airlines. The combination of these two elements has therefore given rise to an environment in which airlines may be reluctant to carry out passenger surveys to ensure against increases in the provisioning of extra fuel directly attributable to higher standard passenger weights.
BA suggests that there has been at least one case in recent times whereby an airline has inadvertently discovered a higher average weight of passengers than the regulatory standards and is subsequently lobbying for a new revision of standard weights across Europe. Essentially, the airline in question has been bound to provisioning more fuel to carry the new higher weight of passengers (as well as the fuel required to transport this extra fuel) whilst all other airlines operating in an almost identical environment are not, a fact that understandably is being deemed unfair and discriminatory.
Regardless of the reasoning that lies behind an airline’s decision to carry out a passenger weight survey, it is a complicated logistical exercise requiring careful planning and execution. From the interviews it provided, BA highlighted a number of core issues that surround the successful execution of a weight survey, including in particular the difficulties of communicating with passengers; liaising with an array of airport and airline staff; opening gates and aircraft boarding earlier than normal; ensuring that aircraft are still dispatched on time; ensuring only one passenger is weighed at any one time; ensuring hand luggage is not passed between passengers inadvertently; participation of premium class passengers; the weighing of children or infants; and a clear policy on how to deal with refusals. Undoubtedly assisted by the permanent provision of the airline’s specialist weights team, BA has been able to overcome such difficulties in the past. However, the financial cost and logistical difficulties of carrying out a passenger weight survey is likely to deter smaller airlines from carrying out passenger surveys, thus placing dependence upon the standard weight provisions of JAR OPS-1.
As a charter operator MyTravel operates within a significantly different environment to that of a network carrier such as BA. Traditionally European charter operators have achieved strong profit margins through high load factors and comparatively low unit costs, partly attributable to high-density single-class cabin configurations. Over the past decade the charter market has been subject to major changes including consolidation, vertical and horizontal integration, and the readdressing of their product offering in an attempt to withstand the impact that the low-cost segment began to impose. Although MyTravel states that it ha not experienced any operational difficulties or issues arising from increases in the sizes of their passengers, the airline highlighted a number of important points relating to the designation of weight of its passengers.
Whilst MyTravel does not have a policy in place relating to the seating requirements of larger passengers, the airline recognises the importance of passenger weights from an operational viewpoint and uses the standard values as prescribed under JAR OPS-1 for use on the majority of their services. The airline does, however, make some adjustments to standard passenger weights under certain circumstances, including flights with very high proportions of either male or female passengers. As a holiday charter operator the airline also accounts for increased weights on some charter operations, including winter sports flights in which skiing equipment adds significant weight to its aircraft. Furthermore the airline obtains private charter contracts also requiring adjustments to standard passenger weight values. Past examples of this include Hajj charters to and from Indonesia whereby both passengers and baggage were considered lighter than the typical European values.
As at BA, MyTravel carries out post-flight analysis and carefully monitors fuel burn and aircraft performance on all services. The airline therefore states that any increases in fuel requirements, as a subsequence of passengers getting larger, is an issue that is resolved internally by this monitoring process. Thus once again whilst the airline ensures as far as possible that an aircraft is fuelled and loaded correctly, any gradual change in fuel quantity is not monitored nor accounted for from an economic viewpoint over time.
Whilst the airline acknowledges that the JAR OPS-1 standard weight values may be in need of updating, MyTravel Airways does not nor plan to carry out weight surveys of its passengers for a number of reasons. Predominantly MyTravel believes that the implementation of a survey would constitute too large a financial expense and logistical exercise for an airline of its size to carry out. Furthermore, from an operations perspective the airline states that a single universal standard passenger weight value is desirable, and for an operator to obtain a statistically significant corresponding value would require an extremely extensive survey covering all routes. Ultimately MyTravel believes that if and when standard passenger weights need updating it should be done so at a regulatory level.
Whilst Highland Airways was unable to participate in a direct interview for the purpose of this research, the airline agreed to answer a brief questionnaire sent to them. In doing so, the airline provided an important insight into passenger weight increases from the perspective of a regional operator of very small commercial aircraft, which has been clearly documented as being particularly susceptible to the effects of higher passenger weights and aircraft loads.
Highland Airways does not operate a policy specific to the seating requirements of physically larger passengers and, to date, has not been subject to any operational difficulties relating to this issue. From an operational viewpoint, having never chosen to conduct a passenger weight survey, the airline allocates the JAR OPS-1 prescribed mass values to its passengers for use in loading calculations. Due to the small aircraft types that Highland Airways operates, passengers are not permitted to carry hand luggage onboard flights and as such the prescribed mass values are adjusted accordingly. In order to ascertain the weight of checked baggage, all bags and items are weighed prior to their loading.
An interesting point raised by Highland Airways is its belief that the impact of passenger weight gain will be most felt in the event that the JAR OPS-1 prescribed passenger weight values are updated. As a PSO operator, an important aspect of the airline’s operations are the revenues generated from postal and cargo contracts serving the highlands and islands of northern Scotland. If and when they are required to designate a higher amount of weight to each of its passengers, the airline believes that this may potentially affect postal and cargo revenues as a direct result of having less weight available for non-passenger items. Although Highland Airways does not consider the trend in western passengers getting physically bigger as a current management issue, the airline believes – although not yet considered in any detail – that this has the ability of affecting their operations in the future.
Through direct contact with three UK airlines it is apparent that one of the most pertinent issues surrounding increases in the physical size of passengers from a management viewpoint is that of weight designation for use in aircraft loading and fuel calculations. Perhaps from an objective viewpoint it would be disadvantageous and therefore unlikely for any airline to directly communicate direct issues that may have been faced related to this topic. Although no other airlines originally contacted were willing to participate in interviews, Thomsonfly confirmed that it too uses the standard passenger weights prescribed by JAR OPS-1 for flight planning purposes.
An important issue highlighted by the interviews is the trend that has occurred in passengers carrying increasing amounts of unchecked baggage. Whilst such trends lie outside the context of this research, when combined with the current estimated weight of UK adults made earlier, the need for a revision of current standard passenger weights prescribed under European regulations is re-emphasised and, if anything, heightens the urgency for such revisions to be made. As the UK regulatory body, the CAA was contacted in relation to this need. The CAA confirmed that despite medical data suggesting that following the implementation of JAR OPS-1 in 1991 that the size and weight of Europeans has increased, it is the responsibility of airlines to ensure that the weight and loading of each of their aircraft is accurately known. Whilst this is indisputably true, the interviews conducted highlight that the cost and complexity of carrying out a passenger weight survey is likely to encourage most airlines to use standard prescribed values. Furthermore, given that airlines are required to revalidate survey-derived weights after five years, it may often be clearly advantageous for an airline to opt for standard prescribed values in order to avoid this repetitive expense.
Both Highland Airways and the example cited by BA in its interview highlight how changes in the weight designated to passengers may inadvertently impact an airline’s operation and flight planning processes. For this reason combined with a clear tendency for airlines to use standard regulatory weights, there exists an obvious requirement for the updating of European regulations in order to avoid the adverse consequences of aircraft loading miscalculations whilst ensuring equity and fairness from the impact of weight revisions to all airlines.
The economic impact of passenger weight gain
Very little research has been conducted to quantify in any significant detail the financial and economic costs that airlines are subject to in relation to the carriage of increasingly heavier passengers. Interviews with airlines discussing this very issue yielded a level of commonality between operators in that any economic cost resulting from increases in passenger weights is a cost that is likely to increase at such a slow rate over time that it is not accounted for, and that any gradual changes in aircraft’s fuel requirements are adjusted by extensive post-flight performance monitoring. Therefore we should establish and model the magnitude of the additional fuel costs specific to particular aircraft and routes using UK anthropometric data, and more specifically the known weight gain amongst UK adults that occurred between 1988 and 1998 (see above).
For the purpose of this research, Airbus provided aircraft data corresponding to the fuel requirements of three of its aircraft over varying sector lengths under different payloads. The data details the performance and fuel requirements of the A319-100, A330-200 and A340-300 aircraft under different average passenger weights ranging from 44kg to 150kg over sector lengths of up to 6,500nm. The following analysis only utilises data corresponding to the A319 and A340 aircraft in order to assess how the impact of increases in average passenger weight may differ between two very differently sized jet-powered aircraft that are representative of the typical range of aircraft size seen in today’s aviation market. Table 8.1 shows a sample of the data as provided by Airbus corresponding to its A340-300 aircraft.
Table 8.1: A sample of the Airbus provided data for the A340-300 aircraft
It is important to highlight that both within and between airlines, two identical aircraft operating on the same route are likely to be subject to differences in their respective operating environments. Examples of these differences include prevailing weather conditions, air traffic control routings, and seating configurations, all of which will affect an aircraft’s performance in some way. In order to model the economic impact of passenger weight upon specific aircraft, a number of assumptions have been made in the original data and subsequent analysis.
The data provided by Airbus is representative of the manufacturer’s typical aircraft performance values and have not been subject to any specific customisation. Fuel burn data is representative of average performance values as observed over a series of flight tests conducted by Airbus assuming ISA conditions with zero wind. The A319-100 data is based upon the aircraft being powered by CFM56-5B6/P engines with a passenger capacity of 124, typical of that found in a two-class configuration of this aircraft type as operated by British Airways (Airbus A319 2007). The A340-300 data is based upon the use of CFM56- 5C4/P engines and a capacity of 300 passengers, typical of that found in a two-class configuration of this aircraft type as operated by Air France and Lufthansa.
Analysis of this data therefore enables the economic modelling of aircraft performance, and more specifically fuel requirements, subject to changes in average passenger weight operating within the same hypothetical conditions to be made. Whilst this subsequently makes any results and analysis derived from the data hard to directly apply to a specific airline operating outside of the parameters of the above assumptions, it does allow for the assessment of the overall magnitude of any economic impact that heavier passengers may impose upon airlines operating aircraft of a similar size to be made.
The purpose of this economic modelling is predominantly to gauge the impact, and more specifically the additional fuel requirements, of transporting passengers subject to body weight increases. In order to quantify this, total passenger weight and block fuel data have been extracted from the Airbus performance tables and used to determine the quantity of fuel consumed on a per-flight, per-kg of passenger weight and per-average passenger basis under conditions of different average passenger weights.
Table 8.2 below provides a sample of this initial stage of calculations corresponding to an A319-100 flight from London to Dublin. Fuel costs are based upon a fuel price of US$0.69 per kg or US$2.1 per gallon.
Table 8.2: A sample of the initial fuel calculations for an A319-100 aircraft LHR-DUB sector subject to different average passenger weights
As illustrated in both Tables 8.1 and 8.2, the Airbus data is broken down by 5kg increments of average passenger weight. In order to model the fuel requirements of particular sectors using the known weight of UK adults and the impact of historical weight changes as accurately as possible interpolation of these increments is therefore required. To achieve this, a statistical software package was used to derive the mathematical relationship between average passenger weight and fuel consumption by plotting the tabulated data and fitting a trend line. This is illustrated in Figure 8.1, below, which shows the relationship between average passenger weight and fuel consumption (on a per-kg of passenger weight and average per-passenger basis) on the A319 LON-DUB flight of 64kts.
Figure 8.1: Plotting the relationship between average passenger weight and fuel consumption of A319-100 aircraft on LHR-DUB sector
The applied trend lines fitted to the data (as shown in Figure 8.1) provide the relationship between average passenger weight and fuel consumption of an A319-100 aircraft operating this particular sector under the assumed conditions of the original data. The corresponding relationships of the A340-300 aircraft have also been obtained specific to sectors that an aircraft of its size are typically operated on. Use of these relationships therefore provides a means of analysing changes in fuel consumption under fractional changes in average passenger weights lying outside of the 5kg increments provided in the original Airbus data, and thus allowing the assessment of how UK population weight changes have impacted different aircraft across different sector lengths.
Impact of known weight increases
In order to initially ascertain to what extent, if any, an increase in passenger weight would impact an airline’s fuel cost, the above methodology has been employed for an A340-300 operating between London Heathrow Airport (LHR) and New York John F. Kennedy International (JFK).
As summarised in Table 8.4 below, the results of this initial analysis were based upon average passenger weights equal to the known body weight of UK adults from anthropometric surveys carried out in 1988 and 1998. As it is extremely unlikely that the average weight of UK adults has decreased since 1998 this value has been assumed as the average weight of passengers today. The modelling in this case also assumes that all passengers are UK adults, there is an equal split of male and female passengers, and that each passenger is carrying an average of 15kg of baggage.
Table 8.3: Comparison of fuel consumption and cost before and after known UK adult weight gain on LHR-JFK sector operated by A340-300 aircraft
The results show that an increase of just over 4kg in average passenger weight requires the consumption of an additional 330kg of fuel per flight. The significant change in fuel price distorts the cost of this additional fuel and only offers an indication of the change in the flight’s total fuel costs over this period.
Perhaps more important is the evaluation of what the current cost of transporting this additional weight is and thus assessing the magnitude of the current economic impact of
passenger weight gain that airlines are subject to. By applying the current fuel price to the 1988 data it is possible to show typically how much the known weight gain of UK adults would additionally cost an airline operating particular sectors today. This has been carried out for three routes of varying sector lengths, the results of which are summarised in Table 8.5 below. The table summarises the total fuel requirements of each different sector under average passenger weights based upon 1988 and 1998 data, the cost of this fuel and the calculated difference indicating the direct economic impact of UK weight increases on operators of these particular aircraft and routes.
Table 8.4: The current cost of transporting known weight increases of UK adults across three different sectors
The results clearly demonstrate that increases in the average weight of passengers impose an economic impact upon airlines and as such require the additional consumption of fuel and its implied additional cost. In absolute terms the impact of this change in passenger weight increases with the distance of the sector being considered. From a relative viewpoint the additional cost of carrying this extra weight on a LHR-DUB route represents 0.54% of the flight’s total fuel cost with corresponding values of 0.69% and 0.70% for JFK and LAX services, respectively. The results therefore suggest that the relative financial impact of carrying heavier passengers increases with aircraft size and sector length.
The impact of additional weight increases
As detailed, the results from the initial modelling of the three routes described above were based upon the impact of the known weight increases of UK adults that occurred between 1988 and 1998. Although no anthropometric data has been obtained for periods subsequent to 1998, medical-based statistics suggest that weight increases are likely to have continued to occur at a similar rate following this period. Figure 8.2 (below) illustrates the same three routes under the same assumptions as modelled above and shows the additional cost (at a fuel price of US$2.1 per gallon) on a per-flight basis of further increases in average passenger weights subsequent to 1998 values. Average passenger weights include 15kg of baggage.
Figure 8.2: The impact of further weight increases
If the UK adult population has been subject to an average weight increases over the past nine years of similar rates to those experienced between 1988 and 1998, then average passenger weights would have increased by a further 4kg. Accounting for the total weight gain from 1988 to today under this assumption would result in a total increase in average passenger weight of more than 8kg and a subsequent calculated additional fuel cost of US$640 per LHR-LAX flight, US$446 per LHR-JFK flight and US$15 per LHR-DUB flight. If this rate of weight gain were to continue into the future and a further 4kg increase is experienced then these results suggest, again based on current prices, that the additional cost directly attributable to the carriage of this extra weight would then amount to US$952 per LHR-LAX flight, US$662 per LHR-JFK flight, and US$23 per LHR-DUB flight.
Fuel price sensitivity
The impact analysis carried out thus far has been modelled based upon a current fuel price in order to reflect the economic impact that airlines are subject to as a subsequence of passenger weight gain. It is therefore also important to consider the impact that variations in fuel price may impose upon this issue. If for example the average weight of passengers increases over a certain period of time whilst simultaneously the cost of fuel also increases, then the economic impact of this weight gain would grow in magnitude as a product of these two variables. This is illustrated in Figure 8.3 that shows, across the same three routes, the cost of transporting the known weight increase that occurred between 1988 and 1998 at varying fuel prices.
Figure 8.3: The effect of fuel price upon the economic impact of known passenger weight gain
The chart highlights, in particular, the economic impact of UK weight gain in a situation of fuel prices reaching US$3 per gallon and US$4 per gallon. For example, as discussed above, the economic impact of UK weight increases on a LHR-LAX sector at current fuel prices amounts to an additional cost of US$329. If the fuel price increased to US$3 per gallon this cost would rise to US$471 and furthermore should fuel prices increase to as high as US$4 per gallon this cost would then increase to US$627 per flight.
A further assumption that has been made in the above economic modelling of heavier passengers is the presence of an equal split of male and female passengers. It is a well- understood concept that this split is not necessarily always equal and that proportional differences often exist both between certain types of flights and the airports that airlines operate between. This variation in the proportion of male and female air travellers in UK airports is documented in national CAA airport surveys, the latest of which suggests that, for example, females make up 42.5% of Heathrow’s passengers whilst at low-cost hub Luton Airport the respective proportion is 48%. This variation combined with the natural weight difference that exists between UK males and females ultimately means that the proportion of male and females on any one flight will impact upon an aircraft’s payload, fuel requirements and therefore the magnitude of the impact of passenger weight increases.
In order to illustrate how passenger composition impacts these fuel costs, Figure 8.4 plots the additional fuel cost of known UK weight gain across the same three routes under different male and female passenger proportions. For example, on the LHR-LAX route subject to an equal split of male and female passengers, the economic impact of the weight gain between 1988 and 1998 corresponds to a cost, at fuel prices, of US$329. If this same flight were only carrying males then this cost would increase to US$370.
Figure 8.4: The effect of passenger composition on the additional fuel costs of weight increases
With medical data showing that UK adult males have a natural higher weight than females, the chart correspondingly illustrates that the economic impact of weight gain increases as the proportion of male passengers also increases. It should be highlighted however, that this increase is relatively small and that the results show that passenger composition does not significantly alter the magnitude of the modelled fuel impact. CAA surveys suggest that in recent years many UK airports only exhibit a slightly higher proportion of male passengers than females. Subsequently the estimations generated in the preceding analysis, which have been based upon an equal split of males and females, are likely to have slightly underestimated the actual economic impact of passenger weight increases.
Whilst the modelling of the economic impact of heavier passengers has not outputted additional expenses of overwhelming proportions, it is imperative to highlight that these values are representative of the magnitude of these costs on each individual hypothetical flight. It is therefore important to gain an appreciation of how these costs may accumulate over an airline’s entire operations and furthermore over a longer period of time.
EasyJet is firmly established as one of the dominant competitors in Europe’s low-cost market. The Airbus A319-100 constitutes 75% of the airline’s 122 aircraft fleet, and as such provides an ideal case upon which to estimate the cumulative economic impact of weight gain upon a short-haul airline’s entire operations. UK Airline Statistics show that in 2006 EasyJet carried out more than 225,000 flights over a total of 227 million aircraft kilometres. This data corresponds to an average sector length of 1,005km or 542nm. As a European-wide operator there is insufficient anthropometric and medical data to model actual population weight changes that have occurred across the entire region in which EasyJet operates. However, as it is documented within academic literature that weight gain trends and obesity are affecting many European countries, it is relevant to model and estimate how arbitrary weight increases of passengers would impact the airline’s total fuel costs.
As detailed above, in applying the aircraft data and calculating fuel costs to a specific airline’s operations, a number of assumptions have to be made and as such offer only an indication into the magnitude of the economic impact of passenger weight. In order to apply data as an approximation to EasyJet, the fuel consumption for the A319 was assessed over a sector length of 500nm (comparable to that of the airline’s average sector length) under differing average passenger weights and an assumed average baggage weight of 15kg per passenger. EasyJet’s A319 aircraft are configured to seat 156 passengers and therefore the assumption within the original aircraft data of an aircraft capacity of 124 passengers is representative of a load factor of 80%, a value close to that of the airline’s recorded average load factor for 2006. An equal passenger split of male and female passengers was applied as typically demonstrated by the survey results of low-cost bases such as Luton (CAA Airports Survey 2006). The economic modelling showed that on a near-typical 500nm flight, each 1kg increase in average passenger weight would correspond to the consumption of an additional 4.5kg of fuel at a current cost of US$3.20. If these values are then scaled by the total number of flights carried out in 2006 this represents an annual additional fuel consumption of over 1 million kg at a total cost of US$723,000.
Medium and long-haul operators
Virgin Atlantic Airways represents the only UK-based airline that operates A340-300 aircraft. Although the airline’s six aircraft of this type are configured slightly differently to the assumed aircraft capacity of the original data, it provides an opportunity to estimate and demonstrate how the economic impact of heavier passengers may accumulate based upon an operator of medium- and long-haul services. Virgin operates this particular aircraft over a total of 38 transatlantic flights per week, all originating from or destined for LHR. Whilst the airline does not operate the A340-300 on either of the UK-US sectors discussed thus far, all of the US destinations served represent greater sector distances than that of LHR-JFK. Therefore by using the modelled LHR-JFK sector it is possible to calculate a conservative approximation of the cumulative economic impact of heavier passengers across these particular flights.
With all flights originating from or destined to LHR, the economic model has been adjusted for a typical passenger split of 57% male and 43% female based upon data from the CAA (2005) airport survey. In doing so it has been calculated that on a sector length equivalent to LHR-JFK the additional fuel burn based upon 1988 and 1998 weight data would amount to a cost of US$235. Applying this cost to Virgin’s 38 transatlantic flights per week amounts to an accumulated additional annual cost of US$464,000. However, it should be noted that this approximation is based upon UK weight changes and that airlines operating transatlantic flights are likely to have been subject to direct economic impacts of greater magnitudes given that American passengers travelling on such services have exhibited greater weight increases over the same period. Virgin also utilises this aircraft on two other, non-transatlantic, long-haul sectors. Incorporating these additional 28 flights per week under the same assumptions as made for the transatlantic flights would amplify the economic cost of known weight gain to an annual total of US$807,000.
It should be reiterated that these values represent just an approximation to this airline and results are only indicative of the magnitude of the economic impact of weight gain because of the assumptions made and limitations of the aircraft data provided. However, if it is considered that this aircraft type accounts for just 16% of Virgin Atlantic’s total fleet it is clear that the additional cost of heavier passengers across the airline’s entire operations is likely to be of a highly significant amount.
Aircraft data used in the above modelling process was only available for three specific aircraft types. To accurately evaluate the economic impact of passenger weight gain upon a specific airline’s entire operations would ideally require corresponding data for each aircraft type operated within their fleet and anthropometric data for all passenger types applied accordingly. In using the results obtained from the economic modelling of the three routes discussed above, it was found that at current fuel prices the additional cost of transporting the known weight gain of UK passengers ranged from US$0.016 to 0.038 per km. Whilst these values will clearly differ between different aircraft types, sectors and operating conditions, they have been used to approximate how this cost may accumulate for entire UK airlines.
Table 8.5 has been compiled showing the UK’s top 10 scheduled airlines in terms of total aircraft kilometres performed. Using this statistic, an estimation of the total economic impact of passenger weight gain has been made for each airline and the UK in total. Three separate estimations have been made based upon different average costs of transporting the known 4.3kg weight increase that UK adults were subject to between 1988 and 1998. The low estimate corresponds to a cost of transporting this extra weight of US$0.005 per km (US$0.01/nm), the medium estimate based upon a cost of US$0.021 per km (US$0.02/nm) and the high estimate based upon US$0.043 per km (US$0.08 /nm).
Table 8.5: Total economic impact estimation. Total aircraft kms Performed in 2006 (000s)
28 August 2012