Use of Rounded Base Turns in General Aviation Traffic Patterns: A Quantitative Analysis

Prevention of in-flight loss of control (I-LOC) in General Aviation (GA) continues to be identified as a most-wanted safety improvement by the National Transportation Safety Board (NTSB), with emphasis on low-altitude maneuvering. A possible technique to mitigate I-LOC is modification of the rectangular traffic pattern used by aircraft arriving and maneuvering within the airspace around an airport. The rectangular pattern is used to align the aircraft with the runway for landing and consists of a “base leg” in which two 90-degree directional changes are accomplished. A “rounded-base” could instead be conducted, consisting of a constant 180- degree turn, potentially resulting in lower angles-of-attack (AOA), thereby keeping the aircraft further from the critical AOA at which I-LOC may occur. Using flight data monitoring equipment, a comparative statistical analysis was conducted between the rectangular method and rounded base method to evaluate variables that influence AOA and determine if the rounded-base method provides an increased level of safety. Results suggest that the rounded base method does allow for lower bank angles, lower pitch attitudes, lower vertical speeds, and more consistent indicated airspeeds throughout the maneuver. Additionally, the rounded-base method considerably reduces the likelihood of runway overshoot during the turn to final.

Name thesis:degree_name

Master of Science (MS)

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Aviation

Year

2017

Author dc:creator

• Archer, Lewis Robert James

Repository record dc:identifier

https://commons.und.edu/theses/384

OAI identifier oai:identifier

oai:commons.und.edu:theses-1383