Aviation Basics - Aero Guide

Aircraft Washers

Aircraft washers used in airframe repair are either plain, lock, or special type washers. Plain Washers Plain washers, both the AN960 and AN970, are used under hex nuts. [Figure 1] They provide a smooth bearing surface and act as a shim in obtaining correct grip length for a bolt and nut assembly. They are used … Read more

Use of Computer for Weight and Balance Computations

Almost all weight and balance problems involve only simple math. This allows slide rules and hand-held electronic calculators to relieve much of the tedium involved with these problems. This post compares the methods of determining the center of gravity (CG) of an airplane while it is being weighed. First, it shows how to determine the … Read more

Aircraft Nuts

Aircraft nuts are made in a variety of shapes and sizes. They are made of cadmium-plated carbon steel, stainless steel, or anodized 2024T aluminum alloy and may be obtained with either right- or left-hand threads. No identifying marking or lettering appears on nuts. Only the characteristic metallic luster or color of the aluminum, brass, or … Read more

Commuter Category and Large Aircraft Weight and Balance Control

This section discusses general guidelines and procedures for weighing large fixed-wing aircraft exceeding a takeoff weight of 12,500 pounds. Several examples of center of gravity (CG) determination for various operational aspects of these aircraft are also included. Persons seeking approval for a weight and balance control program for aircraft operated under Title 14 of the … Read more

Aircraft Bolt

Aircraft bolts are fabricated from cadmium- or zinc-plated corrosion-resistant steel, un-plated corrosion-resistant steel, or anodized-aluminum alloys. Most bolts used in aircraft structures are either general purpose, AN bolts, NAS internal wrenching or close tolerance bolts, or MS bolts. In certain cases, aircraft manufacturers make bolts of different dimensions or greater strength than the standard types. … Read more

Weight and Balance Control – Helicopter

Helicopter weight and balance management demands a higher degree of precision than most fixed-wing aircraft operations. Because a helicopter relies on rotor thrust for both lift and control, even small shifts in center of gravity (CG) can significantly affect controllability, stability, and performance. Unlike many airplanes that tolerate relatively wider CG ranges, helicopters operate within … Read more

Aircraft Seals

Seals are used to prevent fluid from passing a certain point, as well as to keep air and dirt out of the system in which they are used. The increased use of hydraulics and pneumatics in aircraft systems has created a need for packings and gaskets of varying characteristics and design to meet the many … Read more

Center of Gravity Change After a Repair or Alteration

The largest weight changes that occur during the lifetime of an aircraft are those caused by alterations and repairs. It is the responsibility of the FAA-certificated mechanic or repairman doing the work to accurately document the weight change and record it in both the maintenance records and the Pilot’s Operating Handbook/Aircraft Flight Manual (POH/AFM). Equipment … Read more

Nonmetallic Aircraft Materials

The use of magnesium, plastic, fabric, and wood in aircraft construction has nearly disappeared since the mid-1950s. Aluminum has also greatly diminished in use, from 80 percent of airframes in 1950 to about 15 percent aluminum and aluminum alloys today for airframe construction. Replacing those materials are nonmetallic aircraft materials, such as reinforced plastics and … Read more

Multiengine Aircraft Weight and Balance Computations

Accurate weight and balance control is especially critical in multiengine airplanes, where higher performance and greater loading flexibility can quickly lead to unsafe center of gravity (CG) conditions if not carefully managed. Because multiengine aircraft often carry more passengers, baggage, and fuel than smaller airplanes, pilots must have a clear understanding of how each item … Read more