McDonnell Douglas was an airplane manufacturer that merged with Boeing on August 1st, 1997. A result of a merger itself from the entities of McDonnell and Douglas years earlier, the unique plane designs of Douglas including the DC-9 and DC-10 were revamped and improved leading to the MD-80 series and the MD-11. All under the Boeing brand today, these models have unique designs when compared to other aircraft of the time and today and although production of these aircraft have ceased many still fly today.