Who's Online

We have 1311 guests online

Live Traffic Feed

Life in the Skies

'A Local Bestseller!'

What Tony says
(See here)
and Book Launch video here
 
What others say

Les Posen
(See
here)

Yvonne Lee
(See
here)

Louisa Lim & Allan Koay
(See
here)

Aireen Omar, Asran & Bo Lingam
(See
here)

38 Readers' Comments
(See here)

Get an autographed copy here

AMAZON.COM  -  To Order, please Click here 

(eBook) Kindle edition - please Click here

Latest Comment

What are the cruisin
"how in the hell can you reach JFK if you leave fr

What are the eyesigh
tjsoihsdojfsioufs f post

What are the procedu
Hello Sir, I am currently B737NG Cpt.TRI /TRE hol

Could an A320 pilot
I plan to do ATR 72 -600 type rating , for that be

Is there less turbul
Flying from San Francisco to Philippines, end of M

What you have to do
Hi Capt . Im a grade 12 student and i really want

Does a jet aircraft
Earth is flat.

What factors lead a
Hi Captain Lim! Thank you so much Sir, you enligh

What do you think ab
i am from Taiwan, now planing to PEA, but after re

Etihad Airways Cadet
hi sir i am Ashutosh mahajan from india and my dr

Paperback Version

 For Local Availability - Check Here
 
Home > Flying on the Boeing 777 > Why Boeing 777 has no critical engine and what is an aft loaded wing?
Why Boeing 777 has no critical engine and what is an aft loaded wing?
Flying - Flying on the Boeing 777
Tuesday, 11 December 2007 20:38

Hello Capt Lim,

I have two more questions. Why the Boeing 777 has no critical engine and what is a aft loaded wing?

Razaq,

Hi Razaq,

Unlike propellers aircraft, there is no critical engine in the right sense of the word because both the engines of the Boeing 777 are equally important. In a propeller aircraft, usually one engine is more critical than the other because both the propellers turns in the same direction. As a result, when an engine fails, it is more critical and difficult to control on one side than the other. That is why they have a critical engine, usually the right engine, I believe (I have not flown a propeller aircraft for quite sometime now!).

Aft loaded wing refers to where the lift force acts on a wing. If you were to look at a side profile of a wing called an airfoil, you could see the distribution of the pressure acting over the shape. On most traditional airfoil shapes, this distribution tends to be concentrated towards the forward portion of the airfoil.

While these sorts of airfoil shapes worked well on planes up through the start of World War II, they were not as efficient on newer aircraft that approached the speed of sound. On high speed flight, shock waves start at about Mach 0.7 and they result in large increases in drag. They may interfere with control surfaces thereby drastically degrading a plane's performance. A new kind of airfoil called the supercritical airfoil was thus designed. As the pressure is distributed over the surface of a supercritical airfoil, the pressure is distributed much more evenly with a large portion of the lift concentrated towards the aft end of the shape.

This supercritical airfoil is thus termed as 'aft-loaded' because the lift force is more significantly 'loaded' onto the aft portion of the shape. When Boeing refers to the Boeing 777 as having aft-loaded wings, what they are implying is that this aircraft use supercritical airfoils. This is because the cruise speeds of the aircraft is around Mach 0.84. These aft-loaded wings are more efficient than a conventional wing because they reduce or delay the adverse effects of shock waves in transonic flight.

Trackback(0)

TrackBack URI for this entry

Comments (0)

Subscribe to this comment's feed

Write comment

smaller | bigger

busy
 

Paperback Version

 For Local Availability - Check Here

Recommended By..


LIFE IN THE SKIES

'A Local Bestseller!'

Recommended by

Patrick Smith
Boston USA
(See
here)

Capt Meryl Getline
ex-United Airlines USA
(See
here)

Capt Doug Morris
Canadian Airlines
(See
here)

Capt  Robert J Boser
ex-United Airlines USA
(See
here)

38 Readers' Comments
(See here)

Get an autographed copy here

AMAZON.COM  -  To Order, please Click here 

(eBook) Kindle edition - please Click here

View Book Launch video here

Follow me

@CaptKHLim

Like What You Read?


If you like what you read, more stories are found in my book LIFE IN THE SKIES (Preview here) and you can purchase a copy here. To check for any latest updates or postings, you can follow my Twitter at @CaptKHLim or Facebook here

MH 370 Interviews

Click here to View

10 Most Popular Posts



Disclaimer | Privacy
2004 - 2011 © AskCaptainLim.com | Site Concept by eQuilec.com