0006 00
TM 1-1670-260-12&P
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3. RECOVERY FLIGHT PARAMETERS AND PRECAUTIONS
Flight parameters for the CH-47 recovery helicopter are specified in Table 1.
Table 1. Recovery Helicopter Flight Parameters
Maximum Airspeed:
40 Knots Indicated Air Speed (KIAS)
Maximum Bank Angle:
20 Degrees
Maximum Rate-of-Climb
1000 Feet Per Minute (FPM)
Maximum Rate-of-Descent
1000 Feet Per Minute (FPM)
Drogue Chute
No
Maximum Sink Rate
5.6 Feet Per Second (See Note Below)
Terrain Lifting Limits Fore/Aft Slope
12 Degrees
Terrain Lifting Limits Lateral Slope
12 Degrees
Note: If maximum sink rate cannot be determined then perform a hard landing inspection in accordance with the
applicable technical manual.
WARNING
Once the disabled helicopter is connected to the
recovery helicopter and lifted to a hover, the pitch
attitude of the disabled helicopter must be checked to
ensure a nose down attitude is achieved.
A disabled helicopter may rotate while in a hover. This
rotation may cause slings of some UMARK rigging
configurations to twist or to tighten at the main rotor
assembly. The rotation will generally stop as airspeed is
increased to approximately 5 to 10 knots. The recovery
helicopter flight crew should minimize hover time.
If oscillations of disabled helicopter develop during
flight, tests have shown that lowering airspeed,
returning to wings level flight, and initiating a climb
has a stabilizing effect.
It is critical for the recovery helicopter flight crew to
report any unusual occurrences. For example, vertical
bounce, severe jerking of the disabled helicopter, hard
landing of the disabled helicopter following recovery,
UMARK component failure, or exceeding the flight
parameters. Report any unusual occurrences to the
unit responsible for the disabled helicopter.
Exceeding the flight parameters may severely damage
the main rotor assembly of the disabled helicopter,
requiring component replacement. Report the amount
and duration of any flight parameter exceeded to the
unit responsible for the disabled helicopter.
The height above ground level may be difficult to
determine during low-level UMARK operations due to the
length of the sling system. Flight crews should exercise
extreme caution during recovery operations to ensure the
disabled helicopter remains clear of ground obstacles.
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