Editing Flap (aeronautics) (section)

=== Flap tracks ===
Manufactured most often from PH steels and titanium, flap tracks control the flaps located on the trailing edge of an aircraft's wings. Extending flaps often run on guide tracks. Where these run outside the wing structure they may be faired in to streamline them and protect them from damage.<ref>{{cite web|url=https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19960052267.pdf|title=High-Lift Systems on Commercial Subsonic Airliners|author=Rudolph, Peter K. C.|date=September 1996|page=39|publisher=NASA|access-date=7 July 2017|archive-date=21 December 2019|archive-url=https://web.archive.org/web/20191221145349/https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19960052267.pdf|url-status=live}}</ref> Some [[Aircraft fairing|flap track fairings]] are designed to act as [[anti-shock body|anti-shock bodies]], which reduce drag caused by local sonic shock waves where the airflow becomes [[transonic]] at high speeds.