Who's Online

We have 2448 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

Does a jet aircraft
There is almost no curvature, because the Earth is

Does an airline capt
I dont think the interview on our side (nautical)

A successful SIA Cad
I am a 3rd year student in Singapore polytechnic.

Cadet Pilots and Pil
captain how to in to the pilot career, becausee i

The twin-engine vers
Dave, in short, it depends on the severity of the

Engine Failure of QA
I heard the Captain of that flight was undergoing

What are the eyesigh
Sir, I am interested to become an airline pilot! T

My Boyfriend is Deat
4 engines plane more safe, remmember passenger pla

Eyesight requirement
HELLO SIR; I have a specks of 1.0 no. so can i eli

Cadet Pilots and Pil
hi capt lim, i want to know that does the cadet pi

Paperback Version

 For Local Availability - Check Here
 
Home > Flying the Plane > Is the heat from the friction of the wings used to deice a commercial jet?
Is the heat from the friction of the wings used to deice a commercial jet?
Flying - Flying the Plane
Thursday, 07 January 2010 10:55

Hello Capt Lim,

I was at a dinner party the other night when the topic of air travel came up. We were talking about de-icing in a commercial jet when someone said that they only do this to free up the flaps when the planes are on the ground.

He went on to say that not only are the wings of a passenger jet heated but even in the coldest of weather, when the jet is in flight, wind is passing so quickly over the wing, the friction that the air produces heats the wings to an almost HOT temperature...

I found this hard to believe... The space shuttle on re-entry - yes... but a passenger jet???

Can you shed some light on this for me?

Thanks

Toby

Hi Toby,

You are right. A commercial passenger jet does not fly at a supersonic speed and any heat generates at its usual cruising speed in the region of 500 to 550 mph is not enough to deice the plane.

In the air, heating is provided by the hot bleed air to the engines cowling and leading edges of the wings.

On the ground, especially during this bad winter season, planes sitting on the ground for a while with accumulated ice on its surface are deiced by special maintenance crew to ensure flaps; wings and body structure are cleared of ice before take off.

If you want to know in details the efficacy of heat generated from skin fiction, (we call it kinetic heating), lets see how much additional heating is attributed to a increase in air speed when trying to prevent the fuel from reaching its freezing point in the Polar Region.

For instance, an increase of 0.01 Mach (around 6 knots or 7 mph) from a plane’s usual cruising speed of around 0.84 Mach will result in a temperature increase of 0.5° to 0.7°C. So it would take approximately 15 minutes to 1 hour for you to observe any noticeable changes in the temperature. The rate of cooling of the fuel is approximately 3°C per hour. A maximum of 12°C per hour is possible under the most extreme cold conditions.

So as you can see, even though skin friction does generate heat, it is insufficient to deice a plane’s wing when caught in icing condition. Yes, you need the hot engine bleed air to do the job!


Deicing a Boeing 777 Wing


Deicing a Plane in Toronto

Trackback(0)

TrackBack URI for this entry

Comments (3)

Subscribe to this comment's feed
Friction on Wings...
Wow what an awesome response! I love it!

Thank you so much for your time!

I just knew there was something fishy about what that guy was saying!!!

Have a Happy New Year Capt. Lim!!!

Toby
Toby , 08 Jan, 2010
De-Icing
Hi TOby,
if I may add, temperatures from the engine bleed to anti-ice the leading edges, cowling is around 220degC.
Regulations states that if the TAT,esp on ground is 10degC or less and there is visible moisture on aircraft body, snow.etc..it must be De-ICED prior to flight. Chemicals called Etylene Glycol are used.
my short 2 cents.
Lefthandseat , 27 Jan, 2010
De-icing torch not ice proof
Beware of the possibility for the deicing torch to freeze too.
http://www.youtube.com/watch?v=tOvbFgkn8VM
Mike , 24 Mar, 2010

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