Learn when to use pitot heat, engine anti-ice and wing anti-ice in a flight simulator, including icing triggers, limitations and common mistakes.
Use pitot heat before entering visible moisture and whenever the aircraft checklist requires it; many types use it for the whole flight. Use engine, wing, propeller and windscreen anti-ice according to the aircraft’s temperature-and-moisture criteria, before ice accumulates. In a simulator, follow the modelled aircraft’s checklist rather than one universal rule.
Which ice-protection system should you use?
Each system protects a different part of the aircraft, so turning on pitot heat does not protect the engines or wings.
| System | What it protects | Typical timing |
|---|---|---|
| Pitot or probe heat | Pitot probes and, on some aircraft, angle-of-attack, temperature or static probes | Before moisture exposure, before take-off or throughout flight, depending on the checklist |
| Engine anti-ice | Engine inlets and associated components | Before entering the aircraft’s defined icing conditions |
| Wing or airframe anti-ice | Selected leading edges | Preventively or after an ice indication, as specified for that aircraft |
| Propeller heat and de-ice boots | Propeller blades or boot-equipped leading edges | At the checklist’s stated icing trigger; boots are normally activated according to the POH rather than after an arbitrary amount of ice |
Anti-ice is intended to prevent or limit accumulation. De-ice systems remove ice that has formed. Simulator controls sometimes group these functions together even though the real aircraft treats them separately.
What counts as icing conditions?
Icing conditions generally require visible moisture and a temperature within the range defined by the aircraft manufacturer.
Visible moisture includes cloud, fog, rain, wet snow and sleet. A common jet criterion is a total air temperature of 10°C or below in flight, or an outside-air temperature around that level on the ground, combined with visible moisture. That is not a universal threshold: the aircraft flight manual or checklist always takes precedence.
Standing water, slush, ice or snow on a taxiway can also trigger ground engine anti-ice procedures even when precipitation has stopped. Our explanation of the conditions that produce aircraft icing covers the weather risks and the limits of ice-protection systems in more detail.
When should pitot heat be switched on?
Pitot heat should be on before the probe can become blocked, not after the airspeed indication has already failed.
- Use it before entering cloud, rain, snow or other visible moisture when required by the checklist.
- Switch it on before take-off if the normal procedure calls for continuous probe heat in flight.
- Leave automatic probe heating in its prescribed automatic mode unless an abnormal checklist directs otherwise.
- Observe any ground-use limitation. Some light-aircraft pitot heaters become extremely hot and impose a significant electrical load.
For the underlying instrument behaviour, see our guide to pitot heat timing and blocked-pitot symptoms. A completely blocked pitot tube and drain can make the airspeed indicator rise during a climb and fall during a descent; a blockage with an open drain may send the indication towards zero.
When should engine and wing anti-ice be used?
Engine anti-ice is commonly selected before entering defined icing conditions, while wing anti-ice timing varies much more between aircraft.
- Check the temperature and moisture. Use the correct temperature source specified by the aircraft, such as outside-air, static-air or total-air temperature.
- Select engine anti-ice early. Waiting for visible engine icing can lead to inlet ice, compressor damage, surging or loss of thrust.
- Use wing anti-ice exactly as prescribed. Some aircraft require preventive use in icing conditions; others call for activation after an ice detector or visual cue. Ground and take-off use may be restricted.
- Allow for the performance penalty. Bleed-air systems can reduce available thrust and increase fuel flow. Detailed simulator aircraft may reproduce those effects.
- Leave icing conditions if protection is insufficient. Freezing rain and severe icing can overwhelm a correctly operating system.
Should all anti-ice systems be switched on together?
No. Select only the systems required by the aircraft’s procedure and the conditions.
A mistake we see constantly is treating every ice switch as one master control. Engine anti-ice may be required while wing anti-ice remains off, and pitot heat may be on during an entirely ice-free flight. Some systems also have ground-use or temperature limitations.
Can anti-ice remove frost or snow before take-off?
Aircraft anti-ice systems are not a substitute for starting with a clean airframe.
Frost, snow and frozen contamination must be removed before departure under the applicable procedure. Pitot heat cannot clean a wing, and running wing anti-ice does not make a contaminated take-off acceptable. The distinction is explained in our guide to removing contamination through pre-flight de-icing.
Why might anti-ice appear not to work in a simulator?
Ice protection may fail because the system lacks power, the wrong protection was selected or the simulated icing exceeds the aircraft’s capability.
- No electrical or bleed-air supply: a switch can be on while an unpowered bus, closed valve or unavailable bleed source prevents heating.
- Incomplete system modelling: simpler aircraft may use a single generic icing control, while detailed add-ons model individual probes, valves and heated surfaces.
- Late activation: anti-ice may prevent accumulation without quickly removing ice that is already present.
- Wrong diagnosis: carburettor icing, a blocked static source and structural icing require different responses.
- Severe conditions: ice protection provides time and protection within stated limits; it does not make prolonged flight in every icing encounter safe.
Use the switch position, system annunciations, electrical or bleed status and aircraft performance together. If the simulator provides only generic controls, follow the closest available checklist logic while recognising that the underlying model may be simplified.