Chapter 5 Flashcards
EXCEEDING OPERATIONAL LIMITS
Any time an operational limit is exceeded, an appropriate entry shall be made on DA Form 2408-13-1. Entry shall state what limit or limits were exceeded, range, time beyond limits, and any additional data that would aid maintenance personnel in the maintenance action that may be required. The helicopter shall not be flown until corrective action is taken.
INSTRUMENT MARKING COLOR CODES
RED markings indicate the limit above or below which continued operation is likely to cause damage or shorten component life.
GREEN markings indicate the safe or normal range of operation.
YELLOW markings indicate the range when special attention should be given to the operation covered by the instrument.
ROTOR LIMITATIONS
It is not abnormal to observe a % RPM 1 and 2 speed split during autorotational descent when the engines are fully decoupled from the main rotor. A speed increase of one engine from 100% reference to 103% maximum can be expected. During power recovery, it is normal for the engine operating above 100% RPM to lead the other engine.
MAIN TRANSMISSION MODULE LIMITATIONS
Momentary fluctuations in oil pressure may occur during transient maneuvers (i.e. hovering in gusty wind conditions), or when flying with pitch attitudes above +6°. These types of oil pressure fluctuations are acceptable, even when oil pressure drops into the yellow range (below 30 psi). Oil pressure should remain steady and should be in the 45-55 psi range for the UH-60A/EH-60A, and 45 to 60 psi range for the UH-60L. If oil pressure is not steady during steady state forward flight or in a level hover, or if oil pressure is steady but under 45 psi, make an entry on DA Form 2408-13-1. Sudden pressure drop (more than 10 psi) without fluctuation requires an entry on DA Form 2408-13-1.
FUEL QUANTITY
NORMAL 200-1500 LBS
PRECAUTIONARY 0-200 LBS
MAIN TRANSMISSION OIL TEMPERATURE (A+)
PRECAUTIONARY 105-120°C
CONTINUOUS -50-105°C
MAIN TRANSMISSION OIL PRESSURE (A+/L)
PRECAUTIONARY 65-130 PSI
CONTINUOUS 30-65 PSI
IDLE AND 20-30 PSI
TRANSIENT
ENGINE OIL TEMPERATURE (A+/L)
30-MINUTE LIMIT 135-150°C
CONTINUOUS -50-135°C
ENGINE OIL PRESSURE (A+/L)
5-MINUTE LIMIT 100-120 PSI
NORMAL OPERATION 26-100 PSI
IDLE 22-26 PSI
TURBINE GAS TEMPERATURE (A+/L)
12-SECOND TRANSIENT 903-949°C
2.5 MINUTE TRANSIENT 878-903°C
(CONTINGENCY POWER)
START ABORT LIMIT 851°C
10-MINUTE LIMIT 851-878°C
30-MINUTE LIMIT 810-851°C
NORMAL 0-810°C
ENGINE Ng (A+/L)
12-SECOND TRANSIENT 102%-105%
30-MINUTE LIMIT 99%-102%
CONTINUOUS 0%-99%
MAIN TRANSMISSION OIL TEMPERATURE (L)
PRECAUTIONARY 105-140°C
CONTINUOUS -50-105°C
MAIN ROTOR OVERSPEED
- 127%
- 137%
- ** 142%
ENGINE % RPM 1 - 2
12-SECOND TRANSIENT 105%-107%
TRANSIENT 101%-105%
CONTINUOUS 95%-101%
TRANSIENT 91%-95%
AVOID OPERATIONS IN 20%-40% AND 60%-90% RANGE EXCEPT DURING START AND SHUTDOWN
MAIN ROTOR % RPM R
POWER ON
TRANSIENT 101%-107%
CONTINUOUS 95%-101%
TRANSIENT 91%-95%
POWER OFF (AUTOROTATION)
MAXIMUM 110%
TRANSIENT 105%-110%
NORMAL 90%-105%ENGINE % TRQ (A+)
10-SECOND TRANSIENT
DUAL-ENGINE 100%-125%
SINGLE-ENGINE 110%-135%
CONTINUOUS
SINGLE-ENGINE ONLY 0%-110%
CONTINUOUS
DUAL-ENGINE 0%-100%
ENGINE % TRQ (L)
10-SECOND TRANSIENT
DUAL-ENGINE
ABOVE 80KIAS 100%-144%
80KIAS OR BELOW 120%-144%
SINGLE-ENGINE 135%-144%
CONTINUOUS SINGLE-ENGINE 0%-135% DUAL-ENGINE
ABOVE 80KIAS 0%-100%
80KIAS OR BELOW 0%-120%
ENGINE % RPM R LIMITATIONS:
Momentary transients above ___% RPM 1 or 2 are authorized for use by ________________ during autorotational rpm checks.
Momentary transients above 107% RPM 1 or 2 are authorized for use by maintenance test pilots during autorotational rpm checks.
ENGINE STARTER LIMITS:
At ambient temperatures of ___ °C and below, ___ consecutive start cycles may be made, followed by a __ minute rest period, followed by ___ additional consecutive start cycles. A ___ minute rest period is then required before any additional starts.
At ambient temperatures above ___°C up to ___°C, ___ consecutive start cycles may be made. A ___ minute rest period is then required before any additional start cycles.
At ambient temperatures of 15 °C and below, two consecutive start cycles may be made, followed by a 3-minute rest period, followed by two additional consecutive start cycles. A 30-minute rest period is then required before any additional starts.
At ambient temperatures above 15°C up to 52°C, two consecutive start cycles may be made. A 30-minute rest period is then required before any additional start cycles.
PNEUMATIC SOURCE INLET LIMITS:
The minimum ground-air source (pneumatic) required to start the helicopter engines is ___ psig and ___ ppm at ___°C. The maximum ground-air source to be applied to the helicopter is ___ psig at ___°C, measured at the external air connector on the fuselage.
The minimum ground-air source (pneumatic) required to start the helicopter engines is 40 psig and 30 ppm at 149°C. The maximum ground-air source to be applied to the helicopter is 50 psig at 249°C, measured at the external air connector on the fuselage.
ENGINE START LIMITS - CAUTION
Engine start attempts at or above a pressure altitude of (701C or 701D/CC) 18,000 feet could result in a Hot Start.
ENGINE START LIMITS:
Crossbleed starts shall not be attempted unless the __________ or __________ advisory does not appear, and operating engine must be at ___% Ng SPEED or above and rotor speed at ___% RPM R.
Crossbleed starts shall not be attempted unless the #1 ENG ANTI-ICE ON or #2 ENG ANTI-ICE ON advisory does not appear, and operating engine must be at 90% Ng SPEED or above and rotor speed at 100% RPM R.
ENGINE OVERSPEED CHECK LIMITATIONS:
Engine overspeed check in flight is _______. Engine overspeed checks, on the ground, are authorized by ___________________________ only.
Engine overspeed check in flight is prohibited. Engine overspeed checks, on the ground, are authorized by designated maintenance personnel only.
FUEL LIMITATIONS:
Fuel boost pumps shall be off except as required by emergency procedures and the following limitations:
Boost pumps shall be on when operating with JP-4 or equivalent at 5000 feet pressure altitude and above; when operating in crossfeed with JP-4 at any altitude.
When a helicopter operating with JP-4 is restarted within 2 hours of engine shutdown and the air temperature is above 21°C, a minimum of 2 minutes of dual engine ground operation at 100% RPM R is required prior to takeoff to purge possible hot fuel from engine nacelle area
