because climate matters
Aircraft wings and the battle for efficiency
1. Wing defines aircraft
Sturdy, short and swept for speed or delicate, long and straight for efficiency? During the past 70 years, the airliner’s wing geometry hasn’t changed much. Advanced materials allow nowadays light-weighted and delicate designs and all current airliners are optimised for high subsonic speeds, e.g. 900 km/h / M 0.85. Why is this so? Continue reading “The Wing”
Jet airliner’s engines slow evolution towards fuel efficiency
1. Early jet engines
Above formula shows thrust depending on the mass of air passing through the engine and on the (excess) speed at which this air leaves the engine’s nozzle. Early jet airliners used engines which ejected all air with a very high velocity thought their nozzles. These engines were most effective at speeds close to the speed of sound, e.g. Mach (M) 0,85. Continue reading “The Jet-Engine”
Airlines balance the costs for fuel against costs for delays
EU air passenger rights in case of denied boarding, a delayed flight or a cancelled flight grant delayed passengers a compensation of up to € 600.-!
Pilots, flight attendants, passengers or luggage, generate extra costs when missing a connecting flight. Cheap fuel is spent for high speed flying to minimise any costs due to chronic airline delays.
To stay on top of the punctuality-rankings, airlines nudge pilot’s to depart not one minute late. Up to 50% of the flights are therefore flown high speed to catch up delays into congested European hubs. 2018 OAG Aviation Worldwide Limited, On-time performance for airlines and airports and Top 20 busiest routes.
How airlines spoil fuel in order to keep pilots off their payroll
Flights must be manned with 2 pilots. However, longer intercontinental flights must be manned with 3 or 4 pilots, because legal work and rest times regulations require pilots to have inflight-rest periods.
Many of such flights are just beyond these regulatory limits. Due to the low price for fuel, airlines prefer to fly these flights with maximum speed instead of employing another copilot.
5% to 10%, 3-15 tons, more fuel is regularly burned for such purposes. This practice is frequently used and increases fuel consumption per flight significantly. The lower the costs for fuel, the more likely, an airline will prefer to fly fuel-spoiling fast.
Cheap kerosene makes airlines fly kerosene-spoiling fast to safe costs for maintenance
Aircraft maintenance costs go by the hour. The faster the flights, the lower the maintenance costs. Airlines prefer to consume more fuel and fly at higher speeds instead of saving fuel when prices are low.
In order to get the cheapest fuel, big airlines buy much of their fuel in advance. This creates different prices at airports for each airline. Big airlines get usually the lowest prices at their home-bases. From there, airlines often fly their fuel over to other airports with higher prices. E.g. German Lufthansa flys it’s fuel from Munich to Amsterdam and the Dutch KLM flys it’s fuel from Amsterdam to Munich. Continue reading “Aviation spoils tons of kerosene for small financial profits, nr. 1”