Deicing and Anti-Icing Operations for Business Jet Operators

Over the years, the business aviation industry has developed and refined the practice of deicing and anti-icing aircraft to ensure safe and efficient operations. These crucial procedures involve the application of freezing point depressant (FPD) fluids to prevent the formation of frost, snow, or ice on critical external surfaces of the aircraft. It is imperative for all business aircraft operators, aviation engineers, and de-icing service providers in the business aviation sector to integrate the Anti-Icing Code Procedure outlined in the AEA (Association of European Airlines) Guidelines into their operational protocols.

What Is Icing in Aviation?

Icing in aviation is a critical safety concern that occurs when supercooled water droplets freeze on the surfaces of an aircraft. This typically happens when an aircraft flies through clouds or precipitation at temperatures below freezing. The ice that forms can disrupt the smooth flow of air over the wings and control surfaces, leading to increased drag and decreased lift. This can compromise the aircraft’s performance, making it difficult to maintain altitude and speed. Icing can affect any part of the aircraft exposed to the elements, including the wings, propellers, and tail, and can occur rapidly, necessitating quick response from the flight crew to ensure safety.

Which Type of Ice Is Most Critical to Avoid?

Clear ice is the most critical type of ice for aviators to avoid. It forms when large, supercooled water droplets slowly freeze upon contact with the aircraft. Clear ice is heavy and adheres strongly to surfaces, significantly altering the aerodynamics of the aircraft. It can lead to severe control issues and increase the risk of stalling. Clear ice is also difficult to detect and remove, making it a dangerous hazard in aviation.

What Is the Most Common Type of Icing?

Rime ice is the most common type of icing encountered in aviation. It forms when small supercooled water droplets freeze rapidly upon contact with the aircraft, creating a rough, opaque coating. Rime ice typically affects the leading edges of wings and can be managed with standard de-icing equipment. While it is the most common, it is also less severe than clear ice and usually does not adhere as strongly to the aircraft’s surfaces.

How Crucial Are De-Icing and Anti-Icing Procedures?

De-icing and anti-icing procedures are essential for the safe operation of aircraft, particularly in cold weather conditions. These procedures involve the application of chemicals or heat to remove or prevent the formation of ice on the aircraft’s surfaces. Ensuring that the aircraft is free of ice is crucial for maintaining proper aerodynamic performance and preventing accidents caused by ice-related malfunctions.

When Is De-Icing Implemented?

De-icing procedures are implemented whenever conditions are conducive to the formation of ice on the aircraft. This is typically done before takeoff if there is visible ice, frost, snow, or slush on the aircraft’s surfaces. In-flight de-icing systems may also be activated if ice accumulation is detected during flight. The timing and method of de-icing depend on various factors, including temperature, humidity, and the presence of precipitation.

The objectives of aircraft de-icing and anti-icing procedures in the business aviation sector are as follows:

1. Removal of Frozen or Semi Frozen Moisture: The primary aim is to eliminate any frozen or semi frozen moisture from the critical external surfaces of business aircraft before initiating the flight. This process ensures that the surfaces are clear of any potentially hazardous contaminants, thereby safeguarding the aircraft and its passengers.
2. Protection of Critical Surfaces: By employing industry-standard de-icing and anti-icing techniques, business aircraft operators safeguard the aircraft’s surfaces from the adverse effects of contaminants during the time between treatment and takeoff. This protective layer prevents the accumulation of additional frost, snow, or ice on the aircraft, optimizing its aerodynamic performance.
3. Prevention of Contamination: It is essential for business aviation operators to eradicate any remaining frozen or semi frozen moisture from engine intakes and fan blades prior to takeoff. This precautionary measure minimizes the risk of subsequent contamination of the aircraft’s external surfaces and critical components, ensuring reliable engine operation and reducing maintenance requirements.

What is the Difference Between Deicing and Anti-Icing Fluids?

De-icing fluids and anti-icing fluids are distinct in their purposes and characteristics. De-icing fluids are formulated to remove existing ice, frost, or snow from aircraft surfaces through their high heat transfer capability and low viscosity. They effectively melt ice accretions and allow for easy penetration into ice layers, ensuring a clean surface. De-icing fluids have a shorter holdover time and are primarily used to eliminate ice contaminants before takeoff.

On the other hand, anti-icing fluids are designed to prevent ice formation on aircraft surfaces during flight. They offer an extended holdover time, higher viscosity, and reduced ice adhesion properties. Anti-icing fluids create a protective coating on the aircraft’s surfaces, inhibiting the adherence of ice and providing resistance against ice formation. They can be continuously supplied to critical areas during flight to maintain their effectiveness.

For example, Type I fluid is a de-icing fluid that effectively removes snow, slush, or ice from aircraft surfaces. In contrast, Type II fluid serves as an anti-icing fluid with a higher viscosity, extended holdover time, and improved resistance to ice formation.

Types of Icing for Business Aviation Operations

In deicing and anti-icing operations, various types of fluids are used, each with its specific characteristics and applications. When it comes to business jets, certain icing fluid types are commonly employed due to their compatibility with these aircraft.

Type I Fluid

Type I fluid, also known as “unthickened” fluid, is a water-based solution with added corrosion inhibitors. It is primarily used for the initial deicing of aircraft surfaces to remove snow, slush, or ice. This fluid has a low viscosity and can be heated for effective application.

Type II Fluid

Type II fluid, often referred to as “thickened” fluid, is a mixture of propylene glycol and water. This fluid has a higher viscosity compared to Type I and provides enhanced residual anti-icing capabilities. It adheres to the aircraft’s surfaces for a longer duration, offering protection against ice formation during takeoff. Type II fluid is commonly used for business jets, such as the Gulfstream G650 and Bombardier Global series, which require efficient anti-icing performance.

Type IV Fluid

Type IV fluid, also known as “supercooled large drop” (SLD) fluid, is specifically designed to combat icing conditions caused by supercooled large water droplets. These droplets can quickly freeze on aircraft surfaces, posing a significant hazard. Type IV fluid contains a polymer additive that increases its resistance to shattering upon impact, thereby providing improved ice adhesion prevention. Although Type IV fluid is not as widely used as Type I and Type II, it may be applied in certain business jet operations, particularly those involving flights into regions with known SLD icing conditions.

Type II/IV Hybrid Fluid

A more recent development in icing fluid technology is the Type II/IV hybrid fluid. This fluid combines the characteristics of Type II and Type IV fluids, offering both thickened fluid properties and enhanced protection against SLD icing conditions. The hybrid fluid provides extended holdover times and improved ice adhesion prevention, making it suitable for various business jet models operating in diverse weather environments. For the Dassault Falcon 8X, both Type II fluid and Type IV fluid may be used depending on the specific operating conditions.

Regulatory Considerations for Deicing & Anti-Icing

In the business aviation sector, adherence to regulatory guidelines is paramount to ensure safe and standardized deicing and anti-icing procedures. The following regulations and guidelines play a significant role:

FAA Advisory Circular AC 120-60

The Federal Aviation Administration (FAA) issues Advisory Circular AC 120-60, which provides comprehensive guidelines for ground deicing and anti-icing of aircraft. This document outlines recommended practices, equipment specifications, and training requirements for personnel involved in these operations.

FAA Part 91.527

Within the framework of FAA regulations, Part 91.527 specifically mandates procedures for flight crew members regarding the timely removal of ice, snow, or frost from critical surfaces. This regulation emphasizes the responsibility of flight crews to ensure that the aircraft’s surfaces are free from contaminants before takeoff.

ICAO Doc 9640

The International Civil Aviation Organization (ICAO) publishes Doc 9640, a comprehensive publication that outlines international standards and recommended practices for aircraft deicing and anti-icing operations. This document covers various aspects, including the types of fluids to be used, recommended holdover times, and safety considerations.

EASA SIN 2008-29

EASA published Safety Information Notice (SIN) 2008-29, which provides important guidance and recommendations for aircraft deicing and anti-icing operations in the European Union. This notice addresses key aspects such as the use of deicing/anti-icing fluids, holdover times, and procedures for monitoring and reporting fluid dilution. Business aircraft operators in the European Union should be familiar with and adhere to the guidelines outlined in EASA SIN 2008-29 to ensure compliance with European regulations and maintain high standards of safety in their operations.

Check Procedures for Deicing and Anti-Icing Operations

To enhance the effectiveness and adherence to de-icing and anti-icing procedures, it is crucial to consider the following improved version:

Updated Holdover Time (HOT) Tables

It is essential to include the latest Holdover Time tables in the Aircraft Operations Manual (AOM) or Pilot’s Operating Handbook (POH) for flight crews. These tables provide specific guidelines on the duration of protection provided by de-icing/anti-icing fluids under various weather conditions. Ensuring that flight crews have access to up-to-date HOT tables helps them make informed decisions regarding the timing of de-icing or anti-icing operations.

Quality Control Procedures

Ground deicing/anti-icing service providers should implement effective Quality Control procedures to ensure adherence to proper de-icing/anti-icing procedures. This includes rigorous oversight of the deicing process, training of personnel, and regular inspections of equipment. Aircraft operators should also include ground de/anti-icing procedures in their Quality Assurance procedures to verify that the service providers are following the recommended protocols.

Use of De/Anti-Icing Codes

The use of standardized De/Anti-Icing Codes is vital for effective communication and documentation of aircraft treatment. These codes provide a concise and consistent way to convey information about the type of fluid used, application methods, and any specific instructions or observations. Employing De/Anti-Icing Codes helps minimize miscommunications and ensures that all relevant details are accurately recorded.

Engine Intake De/Anti-Icing

Following the instructions for de/anti-icing engine intakes, as recommended in EASA SIN 2008-29, is crucial. Engine intakes are particularly susceptible to ice accumulation, which can adversely affect engine performance. Adhering to the recommended procedures and using appropriate de/anti-icing methods for engine intakes helps maintain their efficiency and prevents potential hazards associated with ice ingestion.

By incorporating these recommendations into their de-icing and anti-icing procedures, aircraft operators can enhance safety, improve communication, and ensure the effective removal and prevention of ice accumulation on critical surfaces, including engine intakes.

At Just Aviation, we understand the utmost importance of prioritizing the implementation of best practices in the field of aviation, especially when it comes to de-icing and anti-icing procedures. We are committed to upholding the highest standards of safety, efficiency, and regulatory compliance in all our operations.