F18 la fontaineasa mamaan

Pages: 9 (2161 mots) Publié le: 9 mars 2011
n their joint arrangement, McDonnell-Douglas
McDonnell-Douglas handled and sold the US
Navy and US Marines carrier based variants
and Northrop continued developing an even
lighter and higher performance land-based
variant intended for international sales.
Northrop, unfortunately, was never successful
in marketing a land-based variant while
McDonnell Douglas not only was successful inwinning the Naval competition, but ironically
went on to sell its version to several foreign air
forces.
Designers had a formidable task to convert the
land-based YF-17 lightweight day fighter into
an all-weather fighter-attack aircraft capable
of carrier operations with heavy ordnance loads.
This meant the two manufacturers had to make
several significant improvements on the YF-17
design tomeet basic Navy requirements, which
included improving the combat radius and
adding a radar capability.
Furthermore, structural strengthening and a
new landing gear design were required for
catapult launches and arrested landings. The
aircraft gross weight rapidly grew from 23,000
pounds for the YF-17 to an anticipated weight
over 33,000 pounds.
Although the designers kept the generalconfiguration of the YF-17, the F-18 became a
completely new aircraft in the updated redesign
and was given the new F-18A designation.
tubes
for
cockpit
displays and appropriate controls
based on thorough pilot evaluations
in simulators, a single aircraft and
subsystems configuration for both missions was
evolved
First Flight Of The F/A-18A & B Hornet
T
he first flight of the F/A-18Hornet occurred
on November 18, 1978 and carrier trials
onboard the USS America began on October 30,
1979.
Both the F/A-18A and B variants underwent
most of their development testing at the Naval
Air Test Center at the Patuxent River Naval Air
Station in Maryland.
Under the new single-site testing idea, the
preproduction flight-test program occurred
from January 1979 to October 1982.Although
some designers and engineers were concerned
about various development problems, these
problems were for the most part typical in any
new aircraft program.
Most of these problems were in the basic aircraft
hardware and not part of the digital electronic
systems. They included under-strength landing
gear, poor acceleration above Mach 1 and lower
than specified roll rate. Although theseproblems
were quickly fixed, one problem that remained
was a shorter than expected maximum range.
This new US Navy aircraft was originally
designed to be procured in three models:
☛ F-18, intended to replace the F-4 Phantom
as a fighter
☛ A-18 attack aircraft to replace the A-7
Corsair II
☛ A two-seat TF-18 to be used as a fighter
trainer
However, McDonnell-Douglas discovered that
bycareful design engineering, the two single-
seat variants could be merged into a single dual-
purpose F/A-18A version capable of both fighter
and attack roles. Likewise, the two-seat trainer
was made combat capable of both roles and
was redesignated the TF/A-18A and TF/A-18B.
To meet the single-place fighter and attack
mission capability, the new technology of digital
computers was used.When these new
computers were combined with cathode ray
Copyright © 2006 Abacus (www.abacuspub.com)
Not all flights take place near the oceans for the F-A/
18! Two F/A-18E Super Hornets conduct a fly by of
Mount Rushmore during a recent training exercise.
Photo courtesy U.S. Navy
3
A few F-18 detractors used the performance
problem as a reason to cancel the entire F/A-18
program. Butengineers and designers were
able to identify several reasons for the poor
performance and began making the necessary
modifications. Although modifying the engines
and using an onboard computer to contgrol the
deflection of leading edge flaps and trailing
edge flaps reduced the cruise range deficit, the
aerodynamic drag remained a problem. These
modifications, as well as others, done on the...
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