ICAO's flawed carbon calculator is symptomatic of a lack of industry transparency on aircraft performance
Mon 1 Feb 2010 – The International Civil Aviation Organization (ICAO) is increasingly promoting its online carbon calculator, which was launched in 2008, as an official tool of the United Nations. However, the validity of the carbon calculator is open to question and the policy of adopting a fundamentally unsound instrument risks damaging the credibility of international efforts at creating meaningful CO2 standards, argues Dimitri Simos (right) of Lissys, creator of the Piano commercial aircraft performance analysis tool. A more open, honest and scientifically correct process of aircraft assessment must instead be developed, and airframers, engine makers, airlines and other institutions should consider the long-term strategic benefits of increased transparency.
The ICAO calculator is centrally dependent on fuel burns extracted from Piano and post-processed with a multitude of assumptions. It provides a carbon footprint per passenger, yet states that it is “not suitable as a comparison tool”. The significance, usefulness and accuracy of this blanket number are all questionable. You cannot differentiate between aircraft, or know how many seats are occupied, or change any premise. Simple checks expose large deviations from reality.
For example, ICAO’s generic quotation from London to San Francisco is 589kg CO2 per passenger, one way. I recently flew on this route with Virgin Atlantic on an A340-600 – a typical, modern and efficient aircraft. In the best case with all seats occupied (as they were), Piano gives my CO2 footprint as 801kg. The number increases to 1,506kg for a half-empty flight.
The ICAO calculator is conceptually flawed in failing to provide comparisons and elementary adjustments. This makes it unusable for any purposes other than assigning collective blame, taxation or indiscriminate penalties. It also makes it potentially grossly misleading, as shown by the above example.
Although ICAO’s carbon estimates are extrapolated from Piano-derived fuel burns, you have to look to page 7 of its documentation (here) to learn this. In an action that strains credulity, ICAO has now signed a major commercial agreement with an IT supplier, Amadeus, to jointly exploit the calculator (here). Together they claim to use “the best publicly available sources of information” and offer a “unified and common approach to deal with the complex issue of calculating individual carbon footprints”. It appears to me that this venture has impacted the credibility of the whole process and unfairly devalues many other positive contributions.
The diversity of interests represented within ICAO can induce a collective numerical paralysis and unease about direct comparisons. This leads to discussions of percentage improvements in ill-defined quantities relative to ambiguous baselines (15% being a sound-bite throughout the industry). For example, the ICCAIA, which represents aerospace manufacturers’ interests, is unlikely to generate outputs that contrast competing products in meaningful terms. Few will proffer details in public, but many professionals take promises of future advances through various forms of alternative configurations and leap technologies with a heavy pinch of salt.
This is far from dismissing the major contribution of the manufacturers – no-one can doubt the commitment of airframers and engine makers to efficiency improvements. The direct connection between efficiency and profitability is a powerful driver, and it works wonders. However, the inherent commercial interest of manufacturers lies in promoting a product under all circumstances and this can, and regularly does, lead to inefficient usage and distorted market policies. Broad examples include the large-scale replacement of turboprops by jets in ultra-short routes, domestic usage of long-range aircraft (for example the B747-400D), and questionable strategic positioning of designs as exemplified by the B787-3 (now in limbo). Parallel issues are the non-retirement of older aircraft and the perpetuated use of ‘grandfathered’ versions.
These inefficiencies cannot be eliminated, but they can be reduced. Public transparency is as powerful a tool as coercion for reducing CO2 emissions. At a minimum, transparency is a prerequisite to fair regulation. Although Piano will not save the planet, it has a long established record in aircraft emissions assessment and can make some not insignificant difference. Lissys might encourage greater openness by releasing more of its Piano-X database models in the public domain. It calls on both manufacturers and operators to join it in this process.
The industry correctly protects its knowledge base, its technologies and capabilities that relate to how its products are conceived and built. However, the question of what aircraft do is one of vital public interest. Aviation CO2 emissions (i.e. fuel consumption) are a global concern. No scientifically sound path to their assessment can bypass the need for aerodynamic and fuel flow data. A call to release details like drag polars, engine decks, operating empty weights, performance deteriorations and in-service statistics (lapsing into aeronautical jargon) will meet resistance and horrify marketeers. But anything less is being economical with the truth.
Any argument that a policy of ‘open characteristics’ would damage commercial competitiveness is misleading. You cannot build aircraft from this information, binding guarantees between the supplier and operator are distinct from nominal performance levels and major purchasers regularly exercise their power to demand and receive full details. It is the public, not the professionals, that remains in the dark.
In fact, ICAO’s publicly available engine exhaust emissions databank is a good example of genuine usefulness. Seeking to replicate and extend this openness in the ways outlined above seems to be a more worthy organizational goal than an implausible carbon calculator.
Irrespective of the above, my company plans to gradually open up more of its own independent Piano-X aircraft models. The pace of releases will be under continual review but it is hoped to eventually contribute a reasonable fraction of the total database. I invite those visionaries who understand the correctness of a more honest approach, as well as its long-term strategic advantages, to join it. There are ways to support and simultaneously benefit from this initiative. Industry leaders with genuine environmental concerns can make a difference.
Lissys’ Piano is a professional tool for the analysis of commercial aircraft. It is used in preliminary design, competitor evaluation, performance studies and other developmental tasks by airframe and engine manufacturers, aviation research establishments and governmental or decision-making institutions throughout the world. Additional details can be found at http://www.lissys.demon.co.uk/Transparency_in_Aviation_Emissions.html