Which type of bonds are secured by specific assets like airplanes?

The type of bonds that are secured by specific assets, such as airplanes, are known as Equipment Trust Certificates. These certificates are a form of financing typically used by transportation companies where the airline financing is collateralized by the aircraft themselves. This means that if the issuer fails to meet the obligations of the bond, the bondholders have a claim on the specific assets serving as collateral.

In this context, Equipment Trust Certificates allow investors to have security in the physical asset, ensuring that their investment is backed by tangible property. This characteristic makes them attractive to investors, as they can potentially recover their investments through the sale of the asset if necessary.

The other options refer to different types of debt instruments that do not specifically involve securing bonds with particular physical assets. Collateralized Mortgage Obligations, for instance, are backed by pools of mortgages, and secured bonds may have broader definitions that do not focus on specific asset types. High-yield bonds, often associated with higher returns, are typically unsecured and carry more risk, emphasizing the importance of understanding the distinction when investing in various securities.