User Guide

UH-60L. Replaced UH-60A in production for US Army from October 1989 (aircraft
89-26179 onwards); prototype (84-23953) first flight 22 March 1988; first delivery
7 November 1989 to Texas ArNG. Powered by T700-GE-701C engines with
uprated 2535 kW transmission. Current production aircraft fitted with hover infra-
red suppression system (HIRSS) to cool exhaust in hover as well as forward flight;
older UH-60s retrofitted. Composites wide-chord main rotor blades of improved
design flight tested at West Palm Beach, beginning 8 December 1993; projected
retrofit from 1997.
DESIGN FEATURES
Represented new generation in technology for performance, survivability and ease
of operation when introduced to replace UH-1 as US Army’s main squad-carrying
helicopter; Four-blade main rotor; one-piece forged titanium rotor head with elas-
tomeric blade retention bearings providing all movement and requiring no lubrica-
tion; hydraulic drag dampers; bifilar self-tuning vibration absorber above head;
blades have 18° twist, and tips swept at 20°; thickness and camber vary over the
length of blades, based on Sikorsky SC-1095 aerofoil; blades tolerant up to 23mm
hits and spar tubes pressurised with gauges to indicate loss of pressure following
structural degradation.
Two pairs of tail rotor blades fastened in cross-beam arrangement, mounted to
starboard; tail rotor pylon tilted to port to produce lift as well as anti-torque thrust
and to extend permissible CG range; fixed fin large enough to allow controlled
run-on landing following loss of tail rotor.
AVIONICS
Configurations vary between aircraft, particularly on HH/MH-60G versions.
Additional avionics and self-protection equipment installed in Enhanced Black
Hawk, as described under Current Versions.
Comms. E-Systems AN/ARC-186 VHF-FM, GTE Sylvania AN/ARC-115 VHF-AM,
Magnavox AN/ARC-164 UHF-AM, Collins AN/ARC-186(V) VHF-AM/FM,
Bendix/King AN/APX-100 IFF transponder, Magnavox TSEC/KT-28 voice security
set, and intercom. HH/MH-60G has AN/URC-108 Satcom.
Radar. MH-60K has Texas Instruments AN/APQ-147A terrain-following/terrain-
avoidance radar, HH/MH-60G has Bendix/King AN/APN-239 (RDR-1400C) radar.
AH-60L and some export S-70s also equipped with radar.
Flight. Hamilton Standard AFCS with digital three-axis autopilot, Bendix/King
AN/ARN-123(V)1 VOR/marker beacon/glide slope receiver, Emerson AN/ARN-89
ADF, Honeywell Plessey Electronic Systems AN/ASN-128 Doppler, AN/ASN-43
gyrocompass, Honeywell AN/APN-209(V)2 radar altimeter. HH/MH-60G has
GEC-Marconi AN/ASN-137 Doppler, Rockwell Collins AN/ASN-149 GPS and
Litton ring laser gyro INS (replacing Carousel IV).
Instrumentation. HH/MH-60G has Teldix KG-10 map display.
Mission. HH/MH-60G has Hughes AN/AAQ-16 FLIR.
LONGBOW 2
7.8