An article caught my attention the other day and it is fascinating what is taking place behind the scenes with regard to saving fuel costs. Not only the fuel costs but the amount of carbon emissions the airlines will be taxed on.
We have seen how well slip streaming in sports such as formula one and cycling works so why not with passenger aircraft? The problem is safety and why it has not been a good idea up till now due to dirty air left by the leading aircraft that will result in severe dangerous turbulence for the secondary trailing aircraft.
How dangerous is the turbulent vortex that is created by the wing tips of a large aircraft? Well they create unstable air similar to a tornado that can create severed down draft making air drop at 500ft per minute and can last up to 2 minutes depending if there is wind or not. This is why there is a minimum set period of time between take offs and landings at airports. Heathrow used to have a plane taking or landing every 30 seconds, but they have multiple runways which makes this possible. Pilots will take off prior to the previous planes take off point and land on a slightly higher gliding path landing further on the runway than the previous plane. Interesting as I did not know this.
Airbus have been playing around with this with a project called Fello'Fly which is basically something the US Airforce have used in the past known as Vortex surfing. The slipstreaming plane has to be close enough which in this case is 3 miles or to make you understand the distance better approximately 20 seconds apart. The trailing plane has to be slightly higher so it receives the upward airflow generated by the leading plane.
The test done earlier in the year from Toulouse in France which is where the Airbus factory is situated to Montreal in Canada. Apparently the idea is based on the Geese formation flying which conserves the energy of the Geese. The test flight was successful with the second trailing aircraft saving roughly 5% fuel over the trip.
The problem is obvious and that one would need special onboard flight control software, route planning and timing like clock work to make this happen. Unless you have pilots who can do this who stay awake for the entire flight not using auto pilot then we have to wait for this to be developed before this actually happens. Airbus reckons by 2050 this will be normal flying practice and my head is telling me just charge me 5% more than placing me 20 seconds apart from another airline who could be 20 seconds away from another aircraft.
Looking at Flight Radar this evening you could see how this could easily work as most aircraft follow set routes controlled by air traffic control. Many of these flights are travelling at different altitudes in order to avoid collisions and turbulent air especially if there are much bigger planes around like the A380.
I have to admit not all ideas are good ideas and this sounds like one of those that it may not be practical. Safety should always be the first concern over cutting costs and this sounds like the health and safety is being tossed out the window. The good news is the technology is not around yet and the reason why planes have so many different wing tip designs is to try and get rid of the dirty air moving it away from your own aircraft. Now they need to design wing tips to help favor planes following them plus the on board flight software.
To give you an idea an airline like British Airways would spend around $11 billion per annum on jet fuel so a 5% saving is $550 million. Still it does worry me that they think this is a good idea.