Showing posts with label Acceleration Altitude. Show all posts
Showing posts with label Acceleration Altitude. Show all posts

Opinion: Air India pilots should not resort to scare tactics

by Devesh Agarwal
The Indian Commercial Pilots Association (ICPA) of the erstwhile Indian Airlines, who fly the narrow body A320 family fleet of national carrier Air India is resorting to scare tactics accusing the airline "of arbitrarily changing the flight operating procedures for narrow-body A320 aircraft, affecting flight safety."

The issue revolves around the carrier's decision to reduce the acceleration altitude to 800 feet AGL (above ground level).

Bangalore Aviation readers will recall our report last month on German carrier Lufthansa reducing its take-off acceleration altitude, as a method to save fuel and reduce harmful emissions.

Immediately after take off, an aircraft usually ascends at a constant speed with the flaps extended until it reaches a certain altitude. In an effort to preserve engines, and since most modern aircraft generally do not require the maximum thrust available, a reduced level of take-off thrust is used. When the aircraft reaches a certain initial target altitude, the engines thrust is reduced, flaps retracted, and then the aircraft is switched to climb thrust. Soon after that the aircraft starts speeding up. The altitude at which the speed increase begins is called the acceleration altitude. This is also when the aircraft commences entering a "clean configuration" which is flaps up, etc. - a configuration it will fly in.

In India, IndiGo was one of the first airlines to work on reducing the acceleration altitude. Initially it was driven by safety as a counter measure to avoid bird strikes, so common around Indian airports. The Airbus A320 typically maintains an angle of 15 degrees when it takes-off, till it reaches the clean configuration. This high nose-up attitude prevents forward visibility and thus prevents the pilots from taking any corrective action in case of bird activity. An additional benefit was fuel savings. The airline worked closely with aircraft manufacturer Airbus, and today the airline commences flap retraction at 500 feet AGL and enters a clean configuration before 1,000 feet. The two Boeing 737 operators in India, Jet Airways and SpiceJet too maintain an acceleration altitude of 800 feet AGL.

The flap with the pilots appears to be, that a Regional Director issued the norms instead of a senior person like a Director Flight Operations, or a Director Training and it is altogether possible the egos of these pilots are bruised. On the flip side, I acknowledge that proper procedure and protocol should be followed, but my issue is the public scare tactics the pilots are resorting to. It hurts the image of an airline, and it hurts the image of the pilots themselves, who are already perceived as a pampered and selfish lot. Today's companies are teams and employee loyalty is a critical component to their very survival.

Air India is making a change that is already being practised by its fellow airlines, and one that will save it money.

I, for one, would expect to see the pilots of the ICPA support such proven cost saving initiatives.

Do feel free to post your comment in agreement or disagreement. I would like to hear from other pilots, especially A320 pilots. Just request to keep the comment clean and civil. We do have the young generation reading this site.
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Lufthansa to lower take-off acceleration altitude globally to save fuel

Lufthansa is set to change its take-off procedure for all departures outside Germany, and implement one standard, worldwide.

As of 1 June 2013, the airline will lower the acceleration altitude, for using the climb thrust and for further accelerating by its aircraft that are taking off, from 1,500 feet (approx. 457 metres) to 1,000 feet (approx. 305 metres).

What does 1000-foot acceleration altitude mean?


Immediately after take off, an aircraft usually ascends at a constant speed with the flaps extended until it reaches a certain altitude. Modern aircraft generally do not use the maximum thrust available at this point, but rather a reduced level of take-off thrust. When the aircraft reaches an initial target altitude, the engines’ thrust is switched to climb thrust.

As the aircraft continues to take off, it has to accelerate so that the flaps can be retracted and it can climb to its cruising altitude at a higher speed.

As passengers we experience this flaps retraction, which leads to a momentary reduction of lift in the wing, by a sinking feeling.

Soon after that the aircraft starts speeding up and the nose is raised higher to continue the climb.

The altitude at which the speed increase begins is called the acceleration altitude.

By reducing the altitude from 1,500ft to 1,000ft above ground level (AGL), decreases the wind resistance when the flaps are retracted, thus lowering fuel consumption. Lufthansa expects that changing the procedure at Frankfurt alone would save around 2,200 tonnes of fuel per year and a reduction of around 7,000 tonnes of CO2 emissions. Globally, Lufthansa will save around 6,000 tonnes less kerosene, around 18,000 tonnes less CO2.

A reduction in the acceleration altitude from 1,500 feet to 1,000 feet is permitted under ICAO (International Civil Aviation Organisation "pronounced Eye-Kay-Oh") regulations and is standard practice at most German and international airports and is already used by many airlines as it leads to lower fuel consumption and a reduction in CO2 emissions.

Lufthansa has already notified the German aviation regulator the Luftfahrt-Bundesamt (LBA), or "Federal Aviation Office" of the modified procedure, and has received approval. The German Federal Ministry of Transport, Building and Urban Development have already granted Lufthansa permission to change the procedure.
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