Oleo Strut Servicing

Summary

This video script offers a detailed look at the maintenance and servicing of olio shock struts in aircraft, highlighting their critical role in absorbing shock during landings and supporting the weight of the aircraft on the ground. The presentation covers the construction, operation, and importance of proper servicing, stressing the need for regular maintenance to prevent directional control problems or structural damage. It also provides step-by-step instructions on checking and inflating the struts, as well as ensuring proper fluid levels and seal integrity for safe and efficient aircraft operation.

Takeaways

• 😀 Aviation Maintenance Publishers focuses on educating and training aviation technicians to meet the growing demand for skilled personnel in the industry.
• 😀 The video series is designed to complement the personal training of aviation technicians, providing guidelines alongside FAA documents and manufacturer's publications.
• 😀 The landing gear system, particularly the olio shock strut, is one of the most critical and stressed components of an aircraft, bearing the weight and absorbing forces from landings.
• 😀 Olio shock struts use compressed air and hydraulic fluid to absorb shock loads, much like a car's shock absorbers, and must be regularly inspected and serviced.
• 😀 Damaged or poorly maintained shock struts can cause serious issues with aircraft control during taxiing, takeoff, or landing, and may prevent proper retraction or extension of the landing gear.
• 😀 A typical olio shock strut consists of two telescoping tubes (cylinder and piston), with the lower chamber containing hydraulic fluid and the upper chamber containing compressed air or nitrogen.
• 😀 The strut's metering pin controls fluid flow between chambers, while a damping or snubbing device helps prevent damage from rapid extension.
• 😀 Proper servicing involves ensuring the correct amount of hydraulic fluid and nitrogen are present, along with ensuring the air valve is properly inspected and resealed.
• 😀 When servicing, the technician must wear protective gear, depressurize the strut carefully, check fluid levels, and measure nitrogen inflation using a high-pressure air gauge.
• 😀 A red indicator tape can be used to detect strut bottoming during inspections, and any strut issues must be promptly addressed to ensure safe and smooth ground handling and flight operations.

Q & A

What is the primary function of olio shock struts in aircraft landing gear?

Olio shock struts are responsible for absorbing shock loads during landings and supporting the weight of the aircraft on the ground. They ensure smooth takeoffs and landings and prevent directional control issues.

What are the key components of an olio shock strut?

An olio shock strut consists of two tubes: the outer cylinder, which holds hydraulic fluid, and the inner piston, which contains compressed air or nitrogen. Together, they create upper and lower chambers that function to absorb shock.

Why is it important to maintain olio shock struts?

Proper maintenance of olio shock struts is crucial for ensuring safe aircraft operations. Poorly maintained struts can lead to problems such as loss of control during taxiing, takeoff, or landing, as well as improper retraction or extension of landing gear.

What is the purpose of the metering pin in an olio shock strut?

The metering pin controls the flow of hydraulic fluid from the lower chamber to the upper chamber during compression, regulating the shock absorption process. This pin also helps prevent excessive compression of the strut.

What is the difference between the two types of air valves used on shock struts?

The standard air valve has a valve core and a 5/8 inch swivel hex nut, while the winterized air valve has no valve core and a 3/4 inch swivel hex nut. The winterized version is designed for colder environments.

What should be done if air pressure is trapped between the valve core and valve seat?

If air pressure is trapped, it should be released by carefully depressing the valve core. This should be done cautiously, using protective goggles, as high-pressure air can be hazardous.

How do you check if the fluid level in the shock strut is correct?

To check the fluid level, remove the filler plug after collapsing the strut completely. If necessary, add the approved hydraulic fluid and fill the strut to the level of the filler plug opening.

What safety precautions should be taken when servicing the olio shock strut?

Always wear protective goggles and keep your face to the side when releasing trapped air to avoid injury from high-pressure air. Ensure all components are securely reassembled, and test for leaks after inflation.

What is the purpose of rocking the aircraft during strut inflation?

Rocking the aircraft gently while inflating the strut helps to overcome packing friction and prevents overinflation, ensuring the correct extension is achieved.

How can you test for leaks in the shock strut after inflation?

To test for leaks, apply a small amount of soapy water to the valve core and look for bubbles. If bubbles appear, it indicates a leak that needs to be addressed by deflating and repairing the strut.