abstract. A number of full service network carriers have recently stated their ambition to develop certain ultra-longrange (ULR) routes, such as Doha to Auckland, Dubai to Auckland, Dubai to Panama City, Singapore to San Francisco, Singapore to New York, all of which require a great circle distance between 7,000-9,000 nautical miles (nm) with an estimated travel time between 15 and 20 hours. This paper examines the capability of the current generation of wide-bodied passenger aircraft to satisfy this evolving strategy, and the impact, if any, on the provision of air cargo transportation. An exploratory study is presented herein based on an assessment of each aircraft type's payload-range envelope, taken from the appropriate Aircraft Airports Handling Characteristics Manual. The key findings reveal that airlines wishing to pursue this ultra-longrange strategy have a surprisingly limited choice of current-generation passenger aircraft which are capable of flying the desired mission profile without compromising significantly on passenger numbers and cargo payload.

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The purpose of this paper is to see if airlines in general, and U.S. air-carriers in particular, are meeting their IATA-agreed 1.5% average annual fuel efficiency improvements between 2010 and 2020. To assess the fuel efficiency performance, a quantitative analysis was performed using data provided by ICAO, IATA and the U.S. Bureau of Transportation Statistics (BTS) Form 41 Schedules P 12(a) and T-2. The metric used to assess fuel efficiency is the one advanced by ICAO, namely Litres per Revenue Tonne Kilometre performed. Trends are examined over an extended timeframe to establish annual fuel efficiency improvements. The findings show that the overall performance of U.S. air-carriers from 2010 to 2018 has just met IATA’s 1.5% target with a 1.52% year-upon-year annual fuel efficiency improvement, with domestic operations showing a greater level of improvement than international operations. Such performance suggests that the U.S.A, and by inference, the rest of the world, are just likely to meet their IATA target by 2020. This achievement has largely been made possible through industry’s tremendous efforts to enhance aircraft engine technologies, implement operational improvements, and reduce airframe weight through the extensive application of composite materials.

This article has arisen from a general investigation into the payload-range envelope of a multirole-tanker transport aircraft and how this envelope is modified as a result of the tanker’s refuelling activities. To this end, the Breguet range equation is used in conjunction with a simple fuel budget to model different scenarios in which the tanker aircraft can perform towline or trail missions. For the common radius of action case, a closed-form solution is obtained for the payload-range variation; for instances where the outbound journey and the return journey are of unequal lengths, the governing equation is found to require a numerical solution. The act of dispensing a significant quantity of fuel whilst some distance into a flight can have a dramatic impact on the tanker’s overall range and payload capability. An assessment of this payload-range modification needs to be made prior to commencing the flight to ensure the mission can safely be accomplished, which provides the motivation for the current work. Three case studies are presented to demonstrate the efficacy of the method, and comparisons with published data show strong agreement. This model will be of use to planners wishing to investigate typical ‘ what if?’ scenarios on the overall mission.

This paper has arisen from a more general investigation aimed at identifying appropriate manned aircraft that would make suitable stand-off cruise missile platforms. One primary measure of an aircraft's ability to fulfil such a role is found in its payload-range envelope for flight profiles involving one or more payload drop. To this end, a generalisation of the Breguet Range equation is developed initially for a radius-of-action scenario in which the entire payload is ejected at altitude at the designated drop point and the aircraft returns home. The more general problem is then addressed, namely that of establishing the payload-range envelope for an aircraft flying a predefined mission profile comprising a maximum of four consecutive legs each separated by a single payload release point. The ability to include a partial payload release at any drop point is built into the model to permit planners to investigate typical ‘what if?’ effects on the overall mission. Six numerical examples are included, all based upon the Boeing C-17 as the parent aircraft. These examples describe in detail missions of increasing complexity in order to demonstrate the versatility and efficacy of the current method. Attention is confined to turbojet-powered aircraft cruising in the stratosphere, although the analogous case of a turboprop-powered aircraft can be simulated simply by amending a single group of constants that appears in all the formulae. Neither air-to-air refuelling policies, nor complicating atmospheric effects such as headwinds, are considered in this paper.