C12V Limits

Question 1

Purpose

Answer 1

This chapter identifies or refers to operating limits and restrictions that shall be observed during ground and flight operations.

Question 2

General

Answer 2

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.

Question 3

Exceeding Operation Limits

Answer 3

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.

Question 4

Minimum Crew Requirements

Answer 4

The minimum crew required for aircraft flight operations is two pilots.

Question 5

Seats

Answer 5

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.

Question 6

Instrument Markings

Answer 6

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.

Question 7

Instrument Marking Color Codes CAUTION

Answer 7

The pilot is responsible for monitoring all engine limits, including transient limits not accounted for
by the engine indicating system (EIS).

Question 8

Instrument Marking Color Codes

Answer 8

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.

Question 9

Pneumatic Pressure

Answer 9

G= 12-20 PSI Normal Operating Range
R= 20 PSI Maximum

Question 10

Propeller Deice Ammeter

Answer 10

G= 18-24 AMPs Normal Operation

Question 11

Fuel Quantity

Answer 11

Y= 0-265 LBS No Takeoff or Go Around Range

Question 12

Cabin Altimeter and Differential Pressure

Answer 12

G= 0-6.6 PSID Normal Operating Range
R= 6.6 PSID Maximum

Question 13

Flap Position Indicator

Answer 13

W= 40% Takeoff and Approach

Question 14

Gyro / Vacuum Suction

Answer 14

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

Question 15

Airspeed Tape Markings Red Marker (Vmo)

Answer 15

259 KIAS maximum operating speed or .52 Mach, whichever is slower.

Question 16

Airspeed Tape Markings Blue Line

Answer 16

121 KIAS one engine inoperative best rate-of-climb speed.

Question 17

Airspeed Tape Markings White APP Arrow

Answer 17

200 KIAS maximum speed permissible with flaps APPROACH.

Question 18

Airspeed Tape Markings White DN Arrow

Answer 18

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.

Question 19

Airspeed Tape Markings Low Speed Cue/Impending Stall Speed

Answer 19

75 KIAS stallings speed (Vso) at maximum weight, flaps DOWN, and POWER IDLE.

Question 20

Airspeed Tape Markings Red Line (Vmca)

Answer 20

86 KIAS minimum control airspeed (Vmca)

Question 21

Propeller Limitations CAUTION

Answer 21

Extended ground idle operations with PROP below 600 RPM in feather position may result in increased propeller blade erosion.

Question 22

Propeller Limitations

Answer 22

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.

Question 23

Propeller Autofeather

Answer 23

The propeller autofeather system must be operable for all flights and must be armed for takeoff, climb, approach, and landing.

Question 24

Starter Limitations

Answer 24

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.

Question 25

Rudder Boost

Answer 25

Must be operational for all flights.

Question 26

Fuel System Limits
Operation with either _______________annunciator illuminated is limited to _________before overhaul or replacement of the engine driven fuel pump. Log the duration of time that the L or R FUEL PRESS annunciator is illuminated on DA Form 2408-13-1.

Answer 26

Operation with either FUEL PRESS annunciator illuminated is limited to 10 hours before overhaul or replacement of the engine driven fuel pump. Log the duration of time that the L or R FUEL PRESS annunciator is illuminated on DA Form 2408-13-1.

Question 27

Fuel System Limits

Operation with JP-4 requires the use of the standby pumps above ________ ft.

Answer 27

Operation with JP-4 requires the use of the standby pumps above 30,000 ft.

Question 28

Fuel System Limits AVGAS NOTEs

Answer 28

Aviation gasoline (AVGAS) contains a form of lead that has an accumulative adverse effect on gas turbine engines. Use AVGAS with the lowest available octain rating (less lead content). If any AVGAS is used, the total operating time must be entered on DA Form 2408-13-1. Operating time on AVGAS is computed based on quantity used and average consumption.

Crossfeed fuel will not be available from the side with an inoperative standby boost pump.

Question 29

Fuel System Limits
Crossfeed of aviation gasoline (AVGAS) to an engine with a failed engine driven boost pump is___________.
Crossfeed of AVGAS to an engine with a failed engine driven boost pump will result in________________ to the high pressure pump on that side.

Answer 29

Crossfeed of aviation gasoline (AVGAS) to an engine with a failed engine driven boost pump is prohibited. Crossfeed of AVGAS to an engine with a failed engine driven boost pump will result in less than minimum fuel pressure to the high pressure pump on that side