from Wiktionary, Creative Commons Attribution/Share-Alike License
- adj. Lacking sharp, recognisable crystal faces.
- n. the downward slope of an aircraft’s wing
from The Century Dictionary and Cyclopedia
- In mineral, and petrography, characterized by the absence of the external form of a crystal, though having its molecular structure.
Sorry, no etymologies found.
The opposite of dihedral is called anhedral, and, of course, refers to a wing that is angled down.
Sorry for going off topic, but I would appreciate some more aerodynamics posts: the one on anhedral and dihedral was especially good.
All this talk of anhedral and dihedral leads to the question of why one would want use either of these on an aircraft.
A good example of an aircraft with geometric anhedral is the Sea Harrier:
To counteract this large amount of dihedral, some geometric anhedral is required.
This is why most aerobatic planes and military fighters utilize some amount of anhedral.
DHC DeHavilland Canada (aircraft manufacturer) dihedral upward or positive slope of the wings or tail flats (anhedral is the downward or negative slope)
Features of the CH-53K helicopter include: a joint interoperable glass cockpit; fly-by-wire flight controls; fourth generation rotor blades with anhedral tips; a low-maintenance elastomeric rotor head; upgraded engines; a locking cargo rail system; external cargo handling improvements; survivability enhancements; and reduced operation and support costs.
The GE38-1B engine planned for the CH-53K is a derivative of the Oct 30 / 06: Sikorsky Aircraft has submitted test results for its 4th Generation ™ rotor blade, which builds on the work done for the Growth Rotor Blade ™ (GRB) currently used on their new UH-60M and S / H-92 helicopters, using anhedral tips.
… and was a fighter but almost all modern fighters use anhedral, e.g. the F18:
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