A Study of the Temperature Correction Methods for Reciprocating Engine Flight Testing under non Standard Conditions

Federal Aviation Regulations require aircraft reciprocating engines to comply with temperature limits under pre-defined hot-day conditions. When the test is conducted on other than those conditions, the Regulations provide equations to convert the temperature registered into values considered to be corresponding to a hot-day scenario.

It is known by the flight test community that those equations over compensate for flying in non-hot day conditions. As a consequence of that, an aircraft that could be certified under hot day conditions may not be certifiable in a colder atmosphere.

This thesis confirmed that the Piper Saratoga complies with the regulations on cooling for cylinder head temperatures, and provides a better rationale to correct for other than hot-day conditions.