On January 21, Boeing (BA) announced it does not expect regulators to approve the return of the grounded 737 MAX aircraft until mid-2020, erasing hopes of a first-quarter recertification. Boeing, under new CEO Dave Calhoun, now appears to be taking a more conservative approach to both its relationship with global regulators and its communications with Wall Street. However, continued slippage in the MAX's return-to-service timeline creates growing anxiety for income investors as Boeing's liquidity comes under greater pressure with each passing month.

Founded in 1833, Royal Dutch Shell (RDS.B) is one of the world's largest integrated oil companies with operations in over 70 countries. In addition to exploring for and extracting crude oil, natural gas, and natural gas liquids, Royal Dutch Shell owns a number of refineries, distribution terminals, and LNG tankers.Shell organizes its business into three operating segments: Integrated Gas (44% of earnings): manages liquefied natural gas (LNG) activities, including exploring for and extracting natural gas, converting gas into LNG, and delivering LNG to end markets Downstream (29% of earnings): refines crude oil to produce ready-to-use fuels like gasoline and diesel, and sells petrochemicals for industrial use

Public Storage (PSA) was founded in 1972 by two California business men who invested $50,000 in a single storage unit initially to generate temporary income. PSA, America’s largest self-storage REIT, now owns close to 2,500 storage rental properties in 38 states and seven European countries. Approximately 81% of the REIT's properties are in the U.S. and account for the majority of its cash flow. Here is Public Storage's breakdown of revenue and net operating income (NOI):

Formed in 1870 as part of business magnate John D. Rockefeller's Standard Oil empire, Exxon Mobil (XOM) is one of the world’s oldest oil companies. The firm has evolved from a regional refiner and distributor of kerosene used in lamps to the largest publicly traded petroleum and petrochemical enterprise in the world.  The firm's products drive transportation, power cities, lubricate industry, and provide petrochemical building blocks that are behind a wide variety of consumer and industrial products.  Exxon organizes its business into three integrated segments: