Low Frequency Oscillation In Flight; Failure Of Ac Generators And Rectifiers; Failure Of One Ac Generator - Kazan Helicopters Mi-17-1V Flight Manual

M,,·17·1B. Flight manual
1) Push the control stick forward to establish a pitch angle within
the range of -(5 to 10t with simultaneous advancement of
power up to takeoff.
2) On reaching an airspeed of 80 to 100 kmlh lAS establish the
horizontal flight condition and a desired forward speed.
(c) Reduction of the gas generator rotor speed below 85 to 88 % at an
airspeed close to zero even at the main rotor speed within the ac-
ceptable limits, causes transition of vertical descent at a speed up
to 20 mls (vortex ring condition).
(d) To recover from the vortex ring condition proceed as follows:
1) Push the control stick forward to establish forward speed at a
pitch angle within the range of -(5 to 10t.
2) On reaching an airspeed of 80 to 100 kmlh lAS smoothly in-
crease the main rotor collective pitch and establish horizontal
flight condition.
Note: Altitude loss is 50 m approximately in recovery from
vertical descent to horizontal flight. No peculiarities in
controllability characteristics in the course of recov-
ery are noted.
6.17. Low frequency oscillation in flight
(1) If low frequency oscillation occurs in flight, disengage the autopilot.
If vibration does not change considerably for 3 to 6 s after disengagement
of the autopilot, momentarily change the flight condition by reduction of
the main rotor collective pitch by 2 to 3°.
After oscillation disappears engage the autopilot and continue flight ob-
serving the requirements of the present Flight Manual without additional
limitations. If oscillation occurs after engagement of the autopilot, disen-
gage it, change the condition of flight in case of necessity, and abort the
mission.
6.18. Failure of AC generators and rectifiers
6.18.1. Failure of One AC Generator
(1) Indications
(a) The PV1-65 information reporting system gives the voice warning:
"Generator NO.1 failed" or "Generator NO.2 failed"..
(b) The GEN 1 (2) FAIL (rEHEPATOP 1 (2) OTKA3An) annunciator
becomes illuminated on the AC POWER (nEPEMEHHbllll TOK)
control panel.
(c) The failed generator ammeter pointer deflects to zero.
(d) With the voltmeter selector switch set to the failed generator posi-
tion the voltmeter pointer deflects to zero.
(2) Crew's actions
(a) Set the failed generator GENERATORS 1 (2) (rEHEPATOPbl
1 (2)) switch to OFF (BbIKn).
(b) Switch off the main rotor blades anti-icing system.
(c) The Captain should make a decision of further fulfilment of the mis-
sion.
Note: With one of the generators failed the second operating generator is
capable of powering all the helicopter loads except for the main and
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