Chap 7 Flashcards
What is one of the main hazards encountered during severe climatic conditions for parked aircraft?
The accumulation of frost, ice, and snow on parked aircraft can degrade performance and lead to equipment failure.
For example, deposits of frost, snow, or ice can severely inhibit aircraft performance, including loss of lift and increased drag.
What can freezing conditions prevent in aircraft?
Freezing conditions can prevent the correct functioning of controls, undercarriage, wheel brakes, and many other aircraft components.
What happens if ice forms in aircraft pitot heads?
Ice formation in aircraft pitot heads can cause the malfunction of pressure instruments such as airspeed indications and altimeters.
How can the presence of ice in engine intakes affect aircraft?
Ice in engine intakes can affect engine performance and may prevent the rotation of gas turbine engine compressors.
What is operationally essential regarding ice accumulation on aircraft?
It is essential to protect aircraft systems from ice accumulation or to adopt de-icing measures as soon as possible.
What methods are used to overcome frost, ice, and snow hazards?
Specialist equipment fitted to the aircraft, special ground equipment, and the application of de-icing/anti-icing fluids are used.
What is the difference between anti-icing and de-icing?
Anti-icing is the treatment before the accumulation of frost, ice, or snow, while de-icing is the treatment after contamination.
How are de-icing fluids used?
De-icing fluids may be used in a diluted form for both anti-icing and de-icing aircraft.
What precautions should be taken when using de-icing fluids?
Care must be taken to minimize fire risks and ensure personnel do not accidentally inhale or consume the fluid.
What impacts should users consider when implementing anti-icing or de-icing operations?
Users must consider the environmental and cost impact to avoid wasteful and unnecessary usage.
What factors determine the implementation of anti-icing or de-icing procedures?
The implementation is dependent on the role of the aircraft and may be completed prior to or after aircrew acceptance.
What is the most common method used to de-ice severely frosted and iced aircraft?
A mixture of hot de-icing fluid and water is applied to the affected surfaces.
See Fig 14.
What does the procedure for applying hot de-icing fluid depend on?
It depends on the type of equipment used, ranging from hand operated to mechanised trolleys and trucks.
What should remain on the aircraft surfaces after de-icing?
A thin film of fluid should remain to prevent ice or frost from reforming before the aircraft is due to fly.
What method is used to remove accumulations of soft snow from aircraft surfaces?
Surfaces are swept with a soft brush.
See Fig 15.
What precautions must personnel take during snow clearance operations?
Personnel must wear rubber-soled footwear and must not use hard or sharp tools to remove the deposits.
How should frozen snow and slush be removed?
They cannot be removed by mechanical means and should be removed with a hot de-icing fluid and water mixture.
What must be done to aircraft during snow clearance operations?
Aircraft must be earthed to prevent static build up from brushing snow.
How should snow be removed from aircraft surfaces?
Carefully remove snow to avoid brushing it into control seals, honeycomb structures, intake ducts, and similar places.
What is the recommended method for removing snow from control seals and shrouds?
Remove snow by hand from control seals, control shrouds, and any positions that may freeze and interfere with controls.
What should be applied to prevent reformation of ice on aircraft?
Apply a thin film of de-icing fluid.
What is anti-icing?
Anti-icing is the treatment applied to prevent frost and ice formation on aircraft surfaces.
What are the benefits of anti-icing methods?
They reduce the adhesion of snow and ice deposits to treated surfaces.
What is one method of anti-icing for aircraft?
Fitting of Approved Aircraft Covers and Blanks during severe climatic conditions.
What is the most effective way to avoid frost and ice formation on aircraft?
Parking the aircraft in a heated hangar.
What happens if there are freezing rain or snow conditions outside the hangar?
The temperature of the aircraft will melt the rain and snow, which may then refreeze when the aircraft reaches outside ambient air temperature.
What is the purpose of cold soaking an aircraft?
To bring its temperature to a similar level as the outside temperature by opening the hangar doors.
How can temporary protection be provided for an aircraft parked in wintery conditions?
By applying a film of neat de-icing fluid.
What factors affect the duration of protection provided by de-icing fluid?
Local weather conditions and the type of de-icing fluid applied.
What is the importance of inspecting an aircraft after de-icing?
To ensure that all traces of frost, ice, and snow have been removed.
Which areas of the aircraft require particular attention during inspection?
Control surfaces, shrouds, hinges, and engine compressors.
What should be done if aircraft tyres freeze to the ground?
They may need to be freed by the application of warm air to the ice.
What is required between the completion of de-icing and scheduled take-off under freezing conditions?
A periodic re-examination of the aircraft surfaces.
Why is periodic re-examination necessary after de-icing?
To ensure that melted ice or snow does not refreeze and interfere with the engine compressors and operation of the controls.
