Different Types of Aircraft Rain Protection Systems

Aircraft are designed with a wide range of devices, units, and systems that allow them to traverse the skies with ease. For instance, a majority of planes are equipped with aircraft rain protection/rain-removal systems that grant pilots a clear view of the airport when taxiing, in addition to a better view of the approach path, departure path, and runway environment when taking off and landing in rainy weather. That being said, these systems are not commonly used during flight at high altitude.

There are several different ways to remove rain from aircraft windshields, but this usually varies according to each aircraft. In fact, many aircraft lack a rain removal system; instead, they feature one form of rain removal, or a combination of the following systems: windshield wipers, chemical rain repellents, hydrophobic windshield seal coatings, and pneumatic rain removal (jet blast) equipment. In this blog, we will outline each of the aforementioned methods in detail.

Wiper Systems

Serving as the most common rain protection feature, aircraft windshield wipers usually take advantage of electric motors, but some may utilize hydraulic wiper motors. Generally, the wipers are operated by separate systems to ensure that ample visibility is maintained through one of the windows should one system malfunction. Each wiper assembly consists of a wiper, wiper arm, and a wiper motor/converter. In most cases, windshield wiper systems have a limited airspeed, above which they cannot be operated. For the most part, wipers are used during ground operations, for takeoff, during the final stages of the approach, and for landing.

Chemical Rain Repellents

When water is poured onto clean glass, it typically spreads out evenly, but leaves a thin, wetted film of liquid. However, when glass is treated with certain chemicals, a transparent film is formed that causes the water to bead up only on some areas, rather than the entire windshield. The chemical rain repellent can be applied by pushing a button or flicking a switch in the cockpit.

It is important to note that this system should only be used in very wet conditions. If applied on dry windows, the repellent hinders visibility by increasing smearing. Concentrated repellent or residue should be removed with a thorough rinse of fresh water as soon as possible. Reapplication is also necessary, as the repellant film slowly deteriorates when frequently flying in rainy conditions. Due to the toxicity associated with some repellents, many operators have chosen to disable the rain repellent systems on their aircraft.

Hydrophobic Seal Coating

Hydrophobic seal coatings provide an alternative to chemical repellents, and they are usually applied on the outside of the windshield, causing raindrops to bead up and roll off. Such coatings reduce the need for wipers and give flight crews better visibility during heavy rain. Today, most windshields are treated with surface seal coatings, and the effect they provide is similar to that of chemical repellents with the exception that they last longer.

Pneumatic Rain Removal Systems

The aircraft wiper system faces two major problems. The first is the tendency of slipstream aerodynamic forces to reduce the wiper blade loading pressure on the window, causing ineffective wiping or streaking. The second is the difficulty in achieving quick wiper oscillation to keep up with high rain impingement rates during heavy rainfall. To remedy these issues, pneumatic rain removal systems remove rain by directing a flow of hot air over the windshield. The hot air brakes rain drops into small particles that are easily blown away and it heats the windshield amply enough to prevent moisture from freezing. The air can be supplied by an electric blower or by bleed air.

Conclusion

Integrated Jet Parts is a leading distributor of aircraft rain protection parts and a number of other industrial-grade components that suit a myriad of sectors. With over 2 billion new, used, obsolete, and hard-to-find products on our database, customers have no issue meeting rigid time constraints and strict budget parameters. Get started with a competitive quote on any featured item, and see how Integrated Jet Parts can serve as your strategic sourcing partner!