Spectators Balcony (Spotters Corner) If you're not a professional pilot but want to discuss issues about the job, this is the best place to loiter. You won't be moved on by 'security' and there'll be plenty of experts to answer any questions.

Deicing question

Old 3rd Feb 2019, 22:13
  #1 (permalink)  
Thread Starter
 
Join Date: Apr 2002
Location: UK
Posts: 1,022
Deicing question

Deicing has, as I understand it, to be undertaken within a specified time before takeoff or the plane has to be deiced again.

Is that time calculated from when the first drop hits the aircraft or the last drop or some other time? In the same vein must the take off roll be started within the alloted time or wheels off or some other measurement point?
Hartington is offline  
Old 3rd Feb 2019, 22:32
  #2 (permalink)  
Gender Faculty Specialist
 
Join Date: Mar 2002
Location: Stop being so stupid, it's my turn
Posts: 1,592
Hold over time (time of protection) starts from the first drop.

Chesty Morgan is online now  
Old 4th Feb 2019, 19:07
  #3 (permalink)  
 
Join Date: May 2000
Location: Seattle
Posts: 3,063
Do you have a calculator for the time from start of takeoff roll to takeoff? If not, use start of roll.
Intruder is offline  
Old 4th Feb 2019, 19:39
  #4 (permalink)  
 
Join Date: Mar 2001
Location: I wouldn't know.
Posts: 3,872
Holdover times have usually a time range. Something like 25 minutes to 45 minutes. So for the first 25 minutes at the given conditions, protection is assured. Once those 25 minutes are over the flight crew needs to ascertain that the anti-ice protection is still holding, that can be done via a visual inspection. And yes, it is first drop to start of take off roll, during the take off rall the anti-icing fluid will flow mostly off the wings carrying with it the contamination and leaving the wing clean. Once in the air the aircraft installed ani-ice equipment has to take over if needed.
Denti is online now  
Old 4th Feb 2019, 22:04
  #5 (permalink)  
Thread Starter
 
Join Date: Apr 2002
Location: UK
Posts: 1,022
That's rather what I suspected but it's nice to get the proper answer. Thank you all.
Hartington is offline  
Old 5th Feb 2019, 16:09
  #6 (permalink)  
 
Join Date: Apr 2002
Location: EGSS
Posts: 891
Originally Posted by Intruder View Post
Do you have a calculator for the time from start of takeoff roll to takeoff? If not, use start of roll.
Holdover time is calculated using multiple factors such as fluid type/brand, fluid mix, OAT, current weather condition (frost, snow, no precipitation etc etc). There is not a "standard" time
Flightmech is offline  
Old 10th Feb 2019, 16:38
  #7 (permalink)  
 
Join Date: Jun 2003
Location: Canada
Age: 63
Posts: 259
May be of some interest to the OP.

http://www.tc.gc.ca/en/services/avia...N_Original.pdf
604guy is offline  
Old 11th Feb 2019, 04:56
  #8 (permalink)  
 
Join Date: May 2002
Location: somewhere near an airport
Posts: 168
Are we talking deicing or anti icing-
2 very different subjects with there own requirements, though both are normally carried out at the same time that is certainly not always the case in all parts of the world or airports.
Deicing is at it says-removing the contamination from the aircraft-thats it.
Anti icing however is a different ball game with many variables, ambient temperature, weather conditions-ie rain, sleet, snow etc, temperature and mix of the fluid being applied and of course the type of fluid-there not all the same-this will directly effect the "hold over time"...can be minutes to hours...once the hold over time has expired you have to "reapply anti/de icing fluid again if the weather conditions/aircraft require it.
And afterwards you need to wash the aircraft as its leaves a sticky mess...
nitro rig driver is offline  

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread

Contact Us Archive Advertising Cookie Policy Privacy Statement Terms of Service

Copyright 2018 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.