Aircraft De-Icing / Anti-icing Risk Assessment & Mitigations
Review by Sofema Online (SOL) www.sofemaonline.com
Considering the Risks Associated with Aircraft De-Icing / Anti-icing Risk
Risks Associated with De-Icing / Anti-icing Process include
» Risks to the Person
o Accident using the Equipment
o Health & Safety to the Person related to the Chemicals Used
» Risks to the Aircraft & effectiveness of the De-Icing / Anti-Icing Process
o If a turbine-engine aircraft has been exposed to frozen deposits whilst parked on the ground prior to intended fight without having blanks/covers fitted to engine intakes, detection of snow or slush within the engine is likely to be difficult or not possible using normal visual inspection techniques.
o Removal of contaminants is equally difficult so qualified engineering assistance should be sought.
» Risks to the Operation
o Failure to De-Ice / Anti Ice the Aircraft Correctly – loss of Flight
o In-effective De-Icing – leading to a build-up of residue
o Accident using the Equipment
o Health & Safety to the Person related to the Chemicals Used
o Not taking off
» (If there is no applicable holdover time for the weather conditions which have prevailed at any time since the commencement of ground anti-icing) – applicable for Heavy Snow, Hail, Snow or Ice Pellets and Moderate or Heavy Freezing Rain.
Mitigations
To protect against loss of control, the following precautions should be taken prior to flight in weather conditions that are or have recently been conducive to ice accretion:
» A thorough inspection of all the airframe critical surfaces to establish if any existing contaminant is present
» A consideration of the weather conditions which prevail - and are likely to prevail - after the start of any treatment of ice already on an airframe to determine if anti-icing is necessary.
» The determination and monitoring of the applicable Holdover Time (HOT) by the flight crew so that take off is not attempted if it cannot be completed within that time.
» Every effort should be made to prevent the ingress of snow, rain, etc. by the use of engine inlet covers and blanks.
Note – It is mandatory that all blanks etc which are fitted are recorded in the Aircraft Technical Log.
It is important to note that the applicable Holdover Time may change if prevailing conditions change. (Take particular care to reduce holdover times if the effect of either jet blast or high wind speeds indicate that this would be prudent.)
Note the prevailing surface temperature of the aircraft skin is an important consideration and should be referenced against the prevailing Outside Air Temperature (OAT).
General Recommendations
» All flight crew and all other persons involved in the inspection of aircraft for contaminants and the application of ground de/anti-icing fluids shall receive initial and recurrent training on the subject.
» Flight Crew must have up to date information concerning the latest Holdover Time (HOT) Tables.
» Effective Quality Control procedures should be in place to ensure that due process is carried procedures to ensure effective delivery of ground de/anti-icing by the service provider
» Aircraft operators should ensure that Quality Assurance Process validates all elements of the Ground De/Anti Icing process.
» Communication at all times should be in accordance with the De/Anti-Icing Code
» All details of the aircraft treatment were carried out to avoid any misunderstandings.
» Regarding engine intake de/anti-icing, operators are recommended to follow the advice contained in EASA SIN 2008-29 (Please see SAS Download Area)
Concerning the Post de-Icing / Anti-Icing Check
If the post-de-/anti-icing check is “incorporated” into the de-icing/anti-icing operation, a suitable time should be available to allow for the de-icing steam to disperse to ensure that the de-icing operator has good visibility to conduct the post-de-icing check. Lighting should also be effective and serviceable for night operations.
Next Steps
Sofema Aviation Services (SAS) and Sofema Online (SOL) provide EASA Regulatory Compliant and Vocational training delivered as classroom, webinar and online certificated courses – for details please see the websites or email team@sassofia.com
