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Hello Capt Lim,
Thank you again for this really great site. I have a few questions to ask about the Concorde and flying generally.
I noticed that the Concorde did not have any flaps or slats. Instead, it would change the position of the nose. How does this work?
Do you think they will ever bring back the Concorde?
What design specifications make the Concorde able to break the sound barrier while, if any other airplanes come near the sound barrier, they would break apart?
Do you think the Concorde was as safe as the Boeing 777?
Do pilots sometimes cut the power too soon after takeoff? I remember being on a flight and the pilot reduce the power as soon as the airplane left the ground and the airplane, kind of, slowly went down a little. It was not scary because it happened so fast. How common is this though?
Andrew Henry.
Hi Andrew,
Yes, the Concorde did not have flaps or slats. Instead of the normal conventional wings of commercial airplanes, it has only delta-shaped wings. Further, rather than the usual elevator and aileron, it has elevon. An elevon is an aircraft control surface that combines the functionality of the elevator and the aileron.
When the elevon are moved in the same direction (up or down) they will cause a pitching force to be applied to the airframe. When moved differentially, (one up, one down) they will cause a rolling force to be applied.
Because it has no flaps or slats to slow the plane down, the Concorde has to increase the pitch angle to decelerate. So it lands and takes off with a high angle of attack (or high nose angle). As a result of this pointed nose, it obstructed the pilots* view of taxiways and runways. The Concorde*s ?droop nose? was thus designed to allow for different operations.
After take-off and after clearing the airport, the droop nose would be raised and shortly before landing, the nose would be lowered for maximum visibility. Upon landing, the nose was quickly raised to avoid the possibility of damage. On very rare occasions, the aircraft could take off with the nose fully down as well.
The Concorde wing does not just sweep back (by 55 degrees) but it twists and droops, making what appears to be a very simple design, but in reality, very complex.
Well, this design that allows the Concorde to generate sufficient lift at low speeds by increasing the angle of attack of the wing, also enable it to perform very efficiently at high speeds as it generates very little drag.
On a traditional aircraft*s wing, a swirling vortex is formed only at the wing tips. On a delta wing at low speeds, such a vortex is formed nearly enough along the entire wing surface and produces most of the lift in those conditions.
With Concorde*s high angle of attack at low speeds, the amount of vortex lift that is generated by the wing increases significantly, and this is fundamental for Concorde to be able to fly at slow speeds during take off and landing.
What makes the Concorde able to break the sound barrier while, if any other airplanes come near the sound barrier, they will break apart?
Well, its delta-shaped wings and structure were specially designed for supersonic flights whilst subsonic planes were not made to stress beyond the speed of sound. Four powerful turbojet engines with reheat (after burners) enabled the Concorde to fly up to its top speed of Mach 2.04
Was the Concorde as safe as the Boeing 777?
If you look at my topic on "Which is the safest airplane?" the Concorde registered an accident rate of 12.2. This poor ranking is misleading because the Concorde flew very few flights as compared to other commercial aircraft. It did about 80,000 takeoffs in its entire 24 years of operation. A million takeoffs are usually considered the point where accident rate starts to mean something.
Although the Concorde was a technological marvel when it was introduced in the early 1970s, thirty years later, her cockpit was getting out dated. With no competition, there was no commercial pressure to upgrade this supersonic jet with enhanced avionics or passenger comforts as occurred with other airliners of the same vintage, for instance, the Boeing 747-400s. What*s more, when compared to the Boeing 777?
It is unlikely that the Concorde would be brought back to service after British Airways and Air France had retired this supersonic jetliners in 2003.
Do pilot cut the engine power as soon as the airplane leaves the ground?
No. Power reduction normally occurs at around 1500 feet and not immediately after it leaves the ground as what you have perceived. The captain was probably complying with the nose abatement procedures in some airports. Because of this, an airplane may sometimes, not only have to reduce power, but also turn away from runway heading to avoid populated areas. Failure to do so would be an infringement of the local regulations.
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