a. Fuel low pressure light
A loss of boosted fuel pressure to the primary fuel pump, as sensed by the fuel pressure transmitter that is integral with the firewall fuel filter, is indicated by the steady illumination of the yellow FUEL PRESS light on the annunciator panel and steady flashing of the MASTER CAUTION light on the instrument panel. Activating the electric standby boost pump will restore boosted fuel pressure and extinguish both the MASER CAUTION and FUEL PRESS lights. The FUEL PRESS indicator light circuit breaker placarded FUEL PRESS is on the circuit breaker panel in the forward cockpit.
1) Engine-driven or electric (standby) fuel boost pump failure
The engine-driven primary fuel pump will sustain engine operation after failure of the engine-driven boost pump and the electric-driven standby fuel pump. In normal operations, the standby fuel pump is OFF, so illumination of the FUEL PRESS annunciator and MASTER CAUTION light indicates probable failure of the engine-driven boost pump. Illumination of the FUEL PRESS annunciator and MASTER CAUTION light may also indicate failure of the engine oil scavenge system. If the engine oil scavenge system has failed, engine failure because of cessation of lubricating oil circulation will occur, and the pilot should be prepared to land as soon as possible.
2) FUEL PRESS and MASTER CAUTION annunciator illuminated
a) PEL - EXECUTE
b)
Standby fuel pump switch - ON
If lights remain illuminated:
c) Descend below 15,000 feet, and avoid high power settings.
NOTE - Log time of illuminated FUEL PRESS light as solitary operation of the engine-driven primary pump. The max is 10 hours.
b. Direct to a VOR or TACAN
Procedures:
1) TUNE and identify the station
a) AVIONICS CONTROL. Ensure that you have avionics control (inform the IP if you intend to TAKE avionics command). Set the desired frequency or channel. If using TACAN, ensure you are tuned to the “X” band of the desired channel.
b) IDENTIFY. Place the appropriate audio switch forward on the audio panel until the station is positively identified, then turn the switch off.
NOTE - A TACAN station identification occurs only 35 seconds. If you do not know the MORSE identification, ask you instructor.
c) TOGGLE. Ensure the appropriate NAVAID is selected using the toggle switch above the CDI/NACWS.
2) TURN. Turn to place the single needle (VOR) or double needle (TACAN) under the heading index of the RMI.
3) TWIST. Twist the omni bearing selector (OBS) knob in the CDI until the CDI centers with a white flag under “TO” in the TO/FROM indicator. The course under the index in the CDI with the CDI centered is the current course direct to the station.
4) TALK. Report course to your instructor from the CDI. The maneuver is complete. ICS “SIR, THE COURSE IS 075 DEGREES.”
c. Oil system failure
1) Fluctuating oil
pressure
Because of the design and
installation of the oil pressure transmitting and indicating system, minor
fluctuations of oil pressure may be noted by the pilot with a normally
functioning engine oil system. A vibrating needle or minor fluctuations
of pressure with a steady mean, where extremes of needle movement remain
within the normal range and do not exceed +5 psi, are acceptable when no
secondary indications of engine malfunction are observed. With fluctuations
greater than plus or minus 5 or outside the normal range, accomplish the
following procedures:
a)
PEL - EXECUTE (utilize a maximum of 850 ft-lb torque and avoid
unnecessary PCL movements).
2) Low/high oil pressure or high oil temperature
If the oil pressure drops below 65 psi at power settings above 75% N1, rises above 80 psi, or oil temperature exceeds 100 C, accomplish the following procedures:
a)
PEL - EXECUTE (utilize a maximum of 850 ft-lb torque and avoid
unnecessary PCL movements).
3) Chip detector caution light illuminated in flight
Refer to section c.5. below.
4) Torque sensing system failure
If erroneous torque indications are suspected or torquemeter reads zero, reduce power to assure torque below limit. Monitor instruments and land as soon as practical.
If you have no secondary indications of possible AC failure (26Vac), utilize the fuel flow indicator and N1 to determine where you should place your PCL. I recommend using a fuel flow of no more than 250 pph and N1 83-87%
The torquemeter sense switch
located in the reduction gear box measures the amount of torque applied
to the propeller shaft by measuring the oil pressure. If pressure
drops to 240 +60, the autoignition light goes out and the ignition light
comes on.
Torquemeter oil pressure is routed to three power plant accessories: the torque limiter, autoignition sense switch, and the torque transmitter. The torque transmitter, located on the reduction gearbox flange, converts the torquemeter oil pressure to a 26Vac electrical signal to operate the torque indicators in the cockpits.
5) Chip light
A magnetic chip detector
is located at the bottom of the RGB to provide the pilot with a warning
signal for metal particles in the oil and possible engine failure.
The chip detector is a dual-element probe with one probe magnetized and
connected to a dc potential and a second element comprised of an insulated
wire to the fault circuit. The detector is exposed to the oil flow,
and functions as a normally open switch. If a large metal chip or
mass of small metal particles bridges the detector gap, a circuit is completed,
illuminating the flashing MASTER CAUTION light and a yellow CHIP light
on the annunciator panel.
1) PEL - EXECUTE (utilize a maximum of 850 ft-lb of torque and avoid unnecessary PCL movements)
WARNING - Torque indications may be erroneous because of reduction gearbox failure. Careful attention should be given to rate of descent, and to rate of climb, setting PCL as required to maintain proper PEL profile.
NOTE - For comparison purposes only, an 850 ft-lb climb on a standard day should yield an approximate minimum rate of climb of 1,200 fpm (clean), 700 fpm (gear down). If indicated climb rates are significantly lower, suspect erroneous torque indications and increase power cautiously to achieve proper airspeed/VSI combination.
Closely monitor engine instruments for secondary indications of rising ITT, high oil temperature, and/or fluctuating oil pressure. If secondary indications of engine failure occur while on or above ELP profile, consideration shall be given to securing the engine.
If engine failure/mechanical
malfunction occurs:
2) Condition lever
- FUEL OFF
3) Emergency fuel
shutoff handle - PULL
4) Execute appropriate
engine failure procedures
NOTE - Illumination of the magnetic CHIP detector light indicated that metal particles are present in the propeller reduction gearbox.
d. Fuel control rollback
CONDITION TORQUE N1
ITT PROP
RPM FF
TEMP PRESS
-------------------------------------------------------------------------------------------------
Rollback | low | 40-62%
|
| decaying | 80-100
pph | norm. norm.
|
| |
| below 2200
rpm |
|
-------------------------------------------------------------------------------------------------
Reduced fuel flow (rollback)
is typical of a fuel control unit pneumatic sensing system malfunction.
If engine will not respond to PCL movements and ITT and N1 indicate the
engine is running at a very low power settings, advance the EPL in an attempt
to regain control of engine power by use of the manual fuel control system.
N1 above 40% but less than 62% - indicating a "rollback" (fuel control unit stuck at minimum flow), proceed as follows:
1) Condition lever
- FULL INCREASE RPM
2) EPL - ADVANCE TO
DESIRED POWER SETTING
If sufficient power is restored:
3) PCL - IDLE
4) PEL - EXECUTE
CAUTION - Use of BETA is not recommended when performing a landing using the manual fuel control system. If the use of BETA is required, ensure the EPL is in the IDLE range or DISCONNECT before selecting BETA with the PCL.
If the resultant power available
is insufficient to execute a PEL:
5) EPL - DISCONNECT
6) Proceed to the
nearest landing field and execute the ENGINE
FAILURE procedure.
WARNING - When the engine is so underpowered that high rates of descent occur, any delay in feathering the propeller may result in insufficient altitude to reach a suitable landing site.
NOTE - If resultant power is sufficient to maintain a rate of descent less than the feathered condition (600-800 fpm clean), consideration should be given to allowing the engine to operate until the field is made.
If application of power results in compressor stall indications (possible compressor bleed valve malfunction/failure), execute the COMPRESSOR STALLS procedure.
e. IND-350 Course Deviation Indicator (CDI)
Each cockpit station has a CDI to indicate the aircraft’s actual course of flight relative to a course selected with the OBS knob. The CDI in each cockpit is individually set to a desired course heading with the respective OBS selector to or from the selected NAVAID. The NAVAID for both CDIs is determined by the cockpit having avionics command. The CDI needle of the cockpit selecting a center vertical position will deflect left or right of center if the flight course drifts. The VOR-TACAN selector switch and the OBS selector knob on one cockpit CDI do not affect operation of the other CDI.
The amount of drift will be indicated in degrees of course deviation to the right or left of centered alignment, 2 degrees per mark). To correct for a course deviation drift, proper sensing is determined and the aircraft is turned toward the direction of the needle deflection. When course alignment is reestablished, the CDI needle will be at the center vertical position for the cockpit from which correction is being made.
The TO/FROM indicators in
the CDI will indicate whether the course selected by the OBS knob will
take the aircraft to or from the selected NAVAID. The VOR-TACAN switch
above each NACWS CDU selects which navigation system control the respective
indicator. A red off flag will appear in the CDI anytime the respective
NAVAID selected is not strong enough to lock on and indicates an unreliable
signal.
2. Introduce:
a. Constant rate turns (CRT)
During normal airways flight in the navigation stage of your training, all turns will generally be done at a specified rate, either standard or one-half standard-rate turns. The standard-rate of turn is 3 degrees per second. At 3 degrees per second, a turn of 180 degrees will take 1 minute and a 360 degree turn will take two minutes. The figure below is a chart showing the AOB necessary to produce a 3 degree per second turn at various airspeeds and altitudes. From the chart you can see that an aircraft operating at high speeds requires a steep AOB to produce a 3 degree per second turn. Steep turns are more difficult to fly than shallow turns, since they result in heavy load factors; for example, a 60 degree bank turn applies a two “G” force to the aircraft and pilot. To avoid these “G” forces, an FAA rule states, “use either a standard-rate turn (SRT) or 30 degree AOB whichever occurs first.
ANGLE OF BANK REQUIRED FOR A HALF AND FULL SRT: CORRECTED FOR ALTITUDE
AOB
TEMP/ALT IAS TAS ½ SRT SRT
13 C 100 101 8 deg 15 deg
120 122 9 deg 18 deg
1000’ 150 152 12 deg 23 deg
------------------------------------------------------
5 C 100 108 8 deg 16 deg
120 130 10 deg 20 deg
5000’ 150 162 12 deg 24 deg
------------------------------------------------------
-5 C 100 117 9 deg 18 deg
120 140 12 deg 21 deg
10000’ 150 175 13 deg 26 deg
------------------------------------------------------
-15 C 100 127 10 deg 19 deg
120 152 12 deg 23 deg
15000’ 150 190 15 deg 29 deg
------------------------------------------------------
-25 C 100 137 11 deg 21 deg
120 154 13 deg 25 deg
20000’ 150 205 15 deg 31 deg
------------------------------------------------------
NOTE - Do you have to memorize this? No way! Look at it from the 10% and 20% rule perspective. For example, let’s look at 15000’: 10% of 15000’ is 15, thus your ½ SRT AOB is 15 degrees. On the other hand, 20% of 15000’ is 30 which is approximately the AOB required for a SRT.
The turns are practiced initially in level flight, cross checking the nose with the VSI and altimeter and the wings on the turn needle. A one-needle-width deflection produces a ½ SRT and a two-needle-width deflection a full SRT. The performance of the turns will be checking on the RMI by checking for 30 degrees in 10 seconds for a SRT. Since the AOB required to produce a constant-rate turn will vary with airspeed, we need some method of determining proper bank for a specific needle deflection. An accurate rule of thumb is to establish an AOB equal to 10% of the airspeed for a ½ SRT, i.e., at 150 kts, a 15 degree AOB should be initially established. Double the above value for bank necessary in a full SRT. However, use 30 degrees maximum AOB while flying instruments. This 10% rule is valid only in balanced flight.
Procedures for ONE-HALF STANDARD-RATE TURN (½ SRT):
1) For practice, ½ SRT will be started in normal cruise on a cardinal heading and with the clock’s second hand on 6 or 12, using a three second lead to compensate for attitude change.
2) Roll into a turn on the gyro using the 10% rule to establish the desired bank. Once the attitude is set on the gyro, commence the crosscheck scan of turn needle for an exact one needle-width deflection and altimeter and VSI for nose attitude.
3) When the RMI is 30 degrees past the cardinal heading, check for 20 seconds elapsed time on the clock. The next checkpoint is 60 degrees of turn and the clock for 40 seconds of elapsed time.
NOTE - There are two valid reasons for checking the heading change against
the clock rather than checking the time prior to referring to the heading.
1. The instruments are arranged on the panel in groups.
The attitude gyro, RMI, altimeter, and airspeed indicator are grouped together.
Thus, while scanning the instruments, you do not have to shift you point
of vision very far to check the RMI.
2. Since the clock tells you nothing about the aircraft’s attitude,
the time spent scanning is actually wasted. If the clock is checked
only once every 20 seconds, rather than 4-5 times, you will be able to
devote more time to the attitude instrument scan.
4) If by checking
the RMI and clock, you find that the turn is less than ½ SRT, you
must then increase the AOB and check the turn needle for a greater deflection
in order to catch up with the clock. When the turn has caught up
with the clock, the AOB must be readjusted to maintain ½ SRT.
To roll out of the desired heading, use the 1/3 rule for constant AOB turns
to gyro heading.
5) Never use more than 20 degrees of bank to catch up or less than 10 degrees of bank to slow the rate. If larger corrections are made, the rate of correction will be too rapid and you bypass the heading. Have patience and catch up slowly but deliberately.
Procedures for the STANDARD-RATE TURN (SRT):
1) Timed SRT’s are accomplished in the same manner as ½ SRT except at an airspeed of 120 kts vice 150 kts (slow cruise config). Roll into the turn on the attitude gyro doubling the 10% rule and crosscheck the turn needle for two-needle-width deflection, but do not exceed 30 degrees AOB.
2) Since you are now turning twice as fast (3 degrees per second), it will be necessary to check the clock every 30 degrees for ten seconds of elapsed time. The scan pattern corrections for desired rate of turn and the procedure for leading the rollout on the desired heading are exactly the same as the ½ SRT.
3) Remember to crosscheck the nose attitude with the altimeter and VSI making power and attitude adjustments as necessary due to the resultant degrease in vertical lift.
4) Never use more than
30 degrees of bank to catch up or less than 15 degrees of bank to slow
the rate.
NOTE - Transition from 150 KIAS to 120 KIAS (slow cruise configuration) by reducing power to 300 ft-lbs. Retrim.
Common errors:
1) Not using a 3 second lead.
2) Not relying on the wing attitude instrument (turn needle) but trying to fly performance instruments. The turn needle is one of the most accurate instruments in the aircraft-believe it. Remember, the performance checks are only readable every 30 degrees.
3) Unbalanced flight.
4) Over correcting AOB - never greater than 20 degrees or less than 10 degrees for a ½ SRT, never greater than 30 degree AOB or less than 15 AOB for a SRT.
5) Improper nose attitude, losing altitude.
b. Constant rate climbs/descents (CRC/D)
Proficiency in performing climbs and descents at a definite vertical speed is very important in actual instrument flight. The vertical speed as well as airspeed must be controlled accurately during a precision GCA, ILS approach, instrument takeoff, etc.
The standard rate for climbs and descents has been established at 500 fpm. However, since jet powered aircraft operate most efficiently at high altitudes, a higher rate of altitude change may be used by these aircraft, often as high as 4000 fpm. In this manual, we shall consider primarily descents and climbs at 1000 fpm. By using the same principles, the procedures for different rate of change may be derived.
A constant rate descent is in reality a constant airspeed descent, performed at an exact rate. In other words, attitude (airspeed) is the primary consideration and performance (rate) secondary. You learned in the previous section that nose attitude controls airspeed; now you will learn to maintain a constant airspeed and vary your rate of descent by use of power adjustment. Power controls rate of descent or climb.
Constant rate climbs and descents are performed in VPS configuration. They are started on a numbered heading using a 3 second lead prior to the clock’s second hand reaching a 6 or 12 to compensate for attitude change. The transitions, scan, power settings, and trim are the same as constant airspeed climbs and descents with the inclusion of the VSI and clock as additional performance indicators.
In order to check the performance in a 1000 fpm descent, crosscheck the VSI and utilize checkpoints on the altimeter. For every 250 feet of altitude change, check the clock for 15 seconds of elapsed time or every 500 feet, 30 seconds of elapsed time.
If the descent becomes less than 1000 fpm, the rate of descent must be increased to a value greater than 1000 fpm to catch up with the time schedule. Be decreasing power and changing nose attitude (to maintain constant airspeed), you will increase the rate of descent. As soon as a checkpoint indicates that the aircraft is back on performance, attitude and power are again adjusted to maintain a 1000 fpm descent.
Let’s consider the corrections necessary for a rate of descent greater than the desired rate of 1000 fpm. If, for example, after descending 500 feet, only 25 seconds have elapsed, you are ahead of desired performance; power must be added and nose attitude adjusted up to slow the are of descent to less than 1000 fpm. As soon as the altitude change and time agree (500 feet at 30 seconds or 750 at 45 seconds), power and attitude must then be adjusted to a value between the initial setting, which resulted in a descent greater than 1000 fpm, and the first adjustment, which gave less than 1000 fpm descent.
NOTE - These power and attitude adjustments will continue to be made until altitude change and elapsed time coincide with a 1000 fpm descent. A constant rate cannot be maintained without a constant airspeed (130 kts), therefore prior to making power corrections, crosscheck airspeed.
The same principles apply for 1000 fpm climbs. A 1000 fpm climb will normally be achieved by using 850 ft-lbs torque. However, if you determine that the rate is insufficient and the addition of power to maximum allowable does not yield a 1000 fpm climb, maintain 130 kts, regardless of rate of climb.
Common errors:
1) Starting the maneuver off altitude.
2) Not using the 3 second lead. An incorrect or late transition will adversely affect your arriving at the first checkpoint at the correct time.
3) Attempting to fly performance scan and neglecting airspeed. Positive performance checkpoints occur only once every 250 feet. The common tendency is to allow airspeed to remain off until a performance check indicates a deviation from the desired rate. If the airspeed is not 130 kts, the attitude is incorrect and the performance cannot possibly be proper. Make appropriate nose correction for airspeed when any deviation from 130 kts is indicated.
4) Not retrimming after making a correction. Remember, if you correct for airspeed or change power and ease the nose to maintain airspeed, you have “set” a new attitude. You must trim to hold it.
5) Correcting the rate with nose movement: power controls rate.
6) Correcting airspeed with power: nose attitude controls airspeed.
NOTE - Errors 5 and 6 are the most common.
7) Over correcting for airspeed (equate nose movement to airspeed correction.
c. Direct to a VOR or TACAN
Refer to 1.b. above in the Discussion items.
3. Practice:
a. Straight and level flight
b. CABT
c. Constant airspeed climbs and descents