You wouldn’t get very far with a designated pilot examiner by showing up for your practical test with an expired airman knowledge test report—unless you could show the DPE that a temporary exception to eligibility requirements permits you to do so.
When unusual circumstances make it impossible—or even hazardous—for a current regulation to function as intended, one remedy is a special federal aviation regulation (SFAR). Many special regulatory situations have been addressed this way; some of the more familiar SFARs cover airspace procedures.
“Consequently, an SFAR has an expiration date, usually no more than 3 years from its effective date. SFARs are listed at the beginning of the most relevant Code of Federal Regulations (CFR), and may be cross-referenced to other regulations. SFARs can prohibit, restrict, or have additional requirements to operate in the airspace the SFAR applies to.”
SFARs have also been applied to pilot training when general provisions applicable to a category and class of aircraft were found insufficient to satisfy proficiency requirements for flying a specific type, including some Robinson helicopters and Mitsubishi MU–2 twin turboprop airplanes.
As for that expired airman knowledge test report: A prerequisite for taking a practical test (for which a knowledge test is required) is in most cases to have passed the knowledge test within a prescribed period.
However, a recent SFAR issued to address aviation disruptions caused by the coronavirus pandemic extended the validity of knowledge tests “by a duration of three calendar months” for individuals whose knowledge tests expire between March 2020 and June 2020.
If you fall into that category and plan to schedule the practical test as soon as feasible given the coronavirus pandemic’s impact on flight training, be sure to verify that your DPE is familiar with the SFAR and will accept your eligibility.
Give a knowledgeable explanation of how the SFAR applies to your situation and you will create a favorable impression—just the thing to get the practical test off to a good start.