Performance, reliability, maintenance costs & intervals, environmental factors, impact on residuals and price. These are just some of the factors under consideration when selecting engines and, for the A320neo, that decision is further clouded by the relative lack of data released by the OEMs.
Whether it be the delivery ramp up, the initial performance after service entry, or the actual cost savings, there is much discussion surrounding the Neo.
Much of its evolution is centred on the engine options; the CFM LEAP-1A and the Pratt & Whitney PW1100. The engine is also the principal decision when speccing the aircraft and the factors below all need to be considered to in order to match the operation goals of the airline.
The excitement around the Neo’s benefits have generated many questions from operators keen to select the best engine for them. These include the choice, the price, the price to maintain, the price of the accessories (i.e. QEC kits, mounts and nacelles) and the performance expectations.
While IBA is able to make informed judgements, based on the hundreds on annual engine appraisal and 30 years of data, at present, many of these decision drivers are currently unreleased by the OEM, so operators and lessors often need third party input to improve decision making.
For operators, the primary concern is not initial cost as engines bundled into aircraft values often mean heavy discounts from the engine manufacturers. The traditional model of long term aftermarket services driving revenue is something that the respective OEMs are reliant upon more than before.
Indeed, the development of more OEM dedicated shops; two additional facilities on top of five for CFM and a reported 10 facilities for Pratt & Whitney, are indicators of this continuing trend.
Additionally, the anticipated time between removals and how these removals fit with LLP replacements and harmonisation can lead to easier shop visit planning.
A cynic might suggest that the headline statistics are often part of spirited marketing campaigns; fuel burn benefits if the cost of oil is high, while maintenance benefits, time-on-wing benefits, greenhouse gas and noise abatement benefits when oil prices are low.
Then there are the technical enhancements over yesterday’s engines; CMC materials, shaft speeds and the benefits they bring such as weight saving, ability to increase the Fan size and the noise benefit.
Whilst material and mechanical science proves that the presence of a gearbox enables a lower speed fan and larger fan diameter, other parameters such as the time-on-wing can only be a measure once the engines have been operating for a number of years and once any initial niggles, that are typically a factor no matter which engine programme, have been rectified.
It will also interesting to analyse how the headline statistics perform or change as the engine is used over its lifetime.
Beyond this, operator specifics are also an influence. Take for example hot and high operations or if a nation has a particular emphasis on the reduction of certain emissions – driving, for example, the introduction of CFM’s DAC engines in Central and Northern Europe.
In harsher environments and as a fleet develops, the cost of operation usually shows a greater disparity between engine types - for example in the A330 engine market. Notable differences can be: the achievable time on-wing, the tolerance to harsh climatic conditions and ultimately the cost to restore the engine.
The approach adopted by operators of the aircraft are also crucial and how they manage these unavoidable geographic/climatic elements. Historical trends do demonstrate that certain operators given the same elements get more from their engines resulting in lower costs per engine flight hour. For example the implementation of an engine washing programme or an additional emphasis on non-invasive or condition monitored maintenance.
In conclusion, what measures are most suitable when making an engine choice and what engine will be superior?
With little information available and potentially millions of dollars dependent on engine selection across a fleet, operators and lessors are ever more reliant on independent experts to inform their decision.