C12V Limits Flashcards
Purpose
This chapter identifies or refers to operating limits and restrictions that shall be observed during ground and flight operations.
General
The operating limitations set forth in this chapter are the direct result of design analysis, tests, and operating experiences. Compliance with these limits will allow the pilot to safely perform the assigned missions and to maximize use of the aircraft.
Exceeding Operation Limits
Anytime an operational limit is exceeded, an appropriate entry shall be made on DA Form 2408-13-1. The entry shall state the limits that were exceeded, range, time beyond limits, and any additional data that would aid maintenance personnel in any maintenance action that may be required.
Minimum Crew Requirements
The minimum crew required for aircraft flight operations is two pilots.
Seats
For takeoff and landing, each occupied forward-facing seat must be located in full aft and full outboard position with seat back upright. For takeoff and landing, each occupied aft-facing seat must be located in full forward and full outboard position with seat back upright and headrest extended to support occupant’s head.
Instrument Markings
Instruments which display operating limitations are illustrated in Figure 5-3 through Figure 5-8. The operating limitations are color coded on the instrument faces and digitally generated on the AFD. The airspeed display, Figure 5-9, uses white markings to denote the flap operating range. When blue markings appear on the airspeed display, it denotes the best rate of climb with one engine inoperative at 12,500 lb maximum forward CG for standard day conditions at sea level.
Instrument Marking Color Codes CAUTION
The pilot is responsible for monitoring all engine limits, including transient limits not accounted for
by the engine indicating system (EIS).
Instrument Marking Color Codes
Color coding is used to indicate operating limitations and ranges of the engine, flight, and utility system displays and readouts that appear on the adaptive flight displays in the cockpit. Figure 5-2 depicts propeller and engine torque parameters. Table 5-1 depicts instrument color coding parameters for various instruments. The engine related information is presented in white, and incorporates green, yellow, and red colors to give the pilot visual indications for
nominal operating parameters, limitations, and warnings. The green markings indicate the safe or normal range of operation. The yellow markings indicate the transient range when special attention should be given to the operation covered by the instrument. Operation is permissible in the yellow range, but should be avoided. White or green
color will display when in the normal limit region, then changes to yellow when in the transient limit region, and then to red when the transient limit time is exceeded or when conditions continue into the red line region.
Pneumatic Pressure
G= 12-20 PSI Normal Operating Range R= 20 PSI Maximum
Propeller Deice Ammeter
G= 18-24 AMPs Normal Operation
Fuel Quantity
Y= 0-265 LBS No Takeoff or Go Around Range
Cabin Altimeter and Differential Pressure
G= 0-6.6 PSID Normal Operating Range R= 6.6 PSID Maximum
Flap Position Indicator
W= 40% Takeoff and Approach
Gyro / Vacuum Suction
Narrow Arc (Normal from 35,000 to 15,000 feet) G= 2.8 to 4.3 Inches of Mercury Normal Operating Range Wide Arc (Normal from 15,000 feet to Sea Level) G= 4.3 to 5.9 Inches of Mercury Normal Operating Range
Airspeed Tape Markings Red Marker (Vmo)
259 KIAS maximum operating speed or .52 Mach, whichever is slower.
Airspeed Tape Markings Blue Line
121 KIAS one engine inoperative best rate-of-climb speed.
Airspeed Tape Markings White APP Arrow
200 KIAS maximum speed permissible with flaps APPROACH.
Airspeed Tape Markings White DN Arrow
157 KIAS maximum speed permissible with flaps extended beyond APPROACH.
99 KIAS stalling speed (Vs) at maximum weight, flaps UP, and POWER IDLE.
85 KIAS stalling speed (Vs1) at maximum weight, flaps APPROACH and POWER IDLE.
Airspeed Tape Markings Low Speed Cue/Impending Stall Speed
75 KIAS stallings speed (Vso) at maximum weight, flaps DOWN, and POWER IDLE.
Airspeed Tape Markings Red Line (Vmca)
86 KIAS minimum control airspeed (Vmca)
Propeller Limitations CAUTION
Extended ground idle operations with PROP below 600 RPM in feather position may result in increased propeller blade erosion.
Propeller Limitations
The propeller normal operating range is 1600 to 2000 RPM with a PROP reverse maximum limit of 1900 RPM. The maximum propeller overspeed limit is 2200 RPM and is time limited to 5 seconds. Sustained propeller overspeed of greater than 2000 RPM indicates a failure of the primary governor. Flight may be continued at propeller overspeed of up to 2120 RPM, provided torque is limited to 81%. Sustained propeller overspeed greater than 2120 RPM indicates a failure of both the primary governor and the overspeed governor.
Propeller Autofeather
The propeller autofeather system must be operable for all flights and must be armed for takeoff, climb, approach, and landing.
Starter Limitations
The starters are limited to an operating cycle of 40 seconds on, 60 seconds off, 40 seconds on, 60 seconds off, 40 seconds on, then 30 minutes off. Contact maintenance personnel for assistance if no engine start occurs during this cycle.
