Name:      AH-64.
Nickname:  Apache/Longbow.
Maker:     McDonnell Douglas.
Type:      Attack helicopter.
Rotor:     14.63 metres. [diameter]
Length:    14.68 metres. [excl main rotor]
Max.Speed: 296 km/h.
Engine:    2 x General Electric T700-GE-701
	   turboshafts, each rated at 1,696 shp.

NOTES.
The need for a heavier, more robust, and powerful 
helicopter than the AH-1 was called for by the Army.
The AAH (Advanced Attack Helicopter) program was put to test, with Hughes and 
McDonnell Douglas as the competitors.
     Hughes won out, and various changes were made to the airframe.  These
included an extension of the rotor mast by 9.5 inches to avoid contacting the
fuselage, the tailplane was moved from the top of the fin, to the base of the
tailcone, and other improvements.  3 more prototypes were built, and more
modifications were then made.  An additional lengthening of the rotor mast, 
the swept-back tips were added, 3 inch increase to the tail rotor diameter,
and the introduction of the 'Black Hole' IR-suppressors.  After these
modifications the US Army eventually ordered 11 Hughes AH-64A Apaches.  446
helicopters were planned, with the number rising to 807 by 1994, built by
McDonnell Douglas from 1984 after buying Hughes.
     Beginning with Model 77, Hughes used the Bell attack helicopter formula
of a thin, tandem-seated, and heavily armoured helicopter.  The main rotor
has four wide-chord blades, with swept tips.  The blades could also be folded
or removed, making it possible to transport the 6 AH-64s in a C-5 Galaxy.
One interesting aspect of the tail rotor is the 55/125 degree seperation 
angles between the four blades, apparently the quietest setting for rotors.
     Other design features included a 30-mm chain gun just in front of the 
main gears, a mass of avionics on the nose, including a PNVS and TADS systems,
stub wings each with two hardpoints, and a 'Black Hole' IR suppressor around
the engine outlets.
     What makes the AH-64 so expensive is the shear range of electronic equip-
ment on board.  The Pilot's Night-Vision Systems incorporates FLIR for night
vision.  The PNVS is encorporated into the IHADSS (Integrated Helmet and
Display Sighting System), sensors in the helmet sense where the head is,
move the camera accordingly, and project a life-size image in front of his
right eye.  The PNVS turrent swivels 90 degrees left and right, 20 degrees up
and 45 degrees down.
     The Target Acquisition Designation System combines a TV Camera,
laser tracker and laser ranger/designator.  The TADS may be swivelled left or
right 120 degrees, 30 degrees up or 60 degrees down.  The FLIR can be used
for night vision, the DTV (Daytime TV) in the near infra-red band can look
through smoke and haze, and the DVO (Direct View Optics) and give a display
with a magnification of 126x!   This all interacts with an inertial attitude/
heading reference system, Doppler navigation, allowing the crew to fly NoE 
missions easily in any weather condition.
     The performance of the AH-64 is quite amazing.  The Apache will produce
a 100 degree per second rate of roll, and a high instantaneous turn rate.
The Apache can accelerate to 100 knots in 250 yards, equivalent to 0 to 60 in
4.6 seconds - quite impressive for a 7 ton helicopter!
     The AH-64D Longbow has a mast-mounted Longbow fire-control radar that
can detect, classify and prioritise multiple air and ground targets.  This
makes coordination a lot easier, as a full 360 degree acquisition is available
and communication between other Apaches is easy.  This is all made possible
by a MIL-1553B digital databus for the integration of the Longbow radars
millimetric wavelength radar, and Hellfire RF missiles.

AVIONICS.
Built into the AH-64A Apache are the following:
   Singer-Kearfott Doppler navigation.
   Martin Marietta TADS and PNVS.
   Honeywell IHADSS.
   Teledyne fire-control system.
   CPG stabilized sight with FLIR & laser ranger/designator/tracker.
   Radar warning receiver.
   IR warning receiver.
   Laser warning receiver.
   Radar jammer.
   IR jammer.
   Chaff/flare dispenser.

ADDITIONAL SPECIFICATIONS.
Height:  5.12 metres.
Main Rotor Disc Area:  168.11 sq metres.
Crew:  2.
Empty Weight:  4881 kg.
Takeoff Weight:  9525 kg.
Range:  483 km.
Ceiling:  6400 metres.
Rate of Climb:  762 metres per minute  [initial vertical climb rate].

WEAPONS:  McDonnell Douglas AH-64A Apache.
AGM-114A Hellfire anti-tank missiles.
Hughes M260 pod for 19 x 2.75-in rockets.
LAU-61/A pod for 19 x 2.75-in rockets.
30-mm Hughes M230E1 cannon plus 1200 rounds.

Versions:  Ah-64Am Ah-64B, AH-64C, AH-64D, possible British export version.
Users:  (United Kingdom?), United States.