a. Engine failure indications
Engine instruments, in particular
the N1 and ITT, are provided to assist in determining the condition of
the engine. These instruments should be monitored closely on an active
schedule to detect early indications of impending engine problems.
An indication of impending
engine failure or flameout may be preceded by unstable engine operation.
One or a combination of symptoms may prevail such as fluctuating turbine
rpm, torque, and ITT, illumination of fuel system warning lights, dropping
oil pressure, loss of thrust, etc. In the event engine failure or
unexpected flameout occurs, an airstart my be accomplished provided time
and altitude permit.
Do not attempt an airstart
if the engine failure can be attributed to:
1) A mechanical malfunction
2) was accompanied
by an explosion, overheating condition, vibration,
strong fuel fumes in the cockpit, or fire.
3) or if the N1 tachometer
indicates zero rpm (engine seizure)
4) or if you intentionally
shutdown the engine.
A flameout condition indicated
by a drop in ITT, torque, and turbine rpm. Propeller rpm will remain
at the rpm selected with the condition lever as long as the airspeed is
maintained above 110 KIAS. If flameout was caused by fuel flow interruption,
restart may be spontaneous within 10 seconds because of residual heat retention
in the combustion chamber.
CONDITION TORQUE N1
ITT PROP
RPM FF
TEMP PRESS
-------------------------------------------------------------------------------------------------
Rollback | low | 40-62%
| decr’g from | decaying
| 80-100 pph | norm. norm.
|
| | normal
| below 2200 rpm |
|
-------------------------------------------------------------------------------------------------
Flameout | zero | 10-12%
| decr'g twd | if <110 KIAS | <50
pph | decr. var.
|
| | 200 deg
C | decr to 200 rpm |
| ~10psi
-------------------------------------------------------------------------------------------------
Compressor | fluct. | fluct.* | fluct.*
| minor surges | fluct.
| norm. norm.
Stall |
| |
|
|
|
* Possible flameout or overspeed
-------------------------------------------------------------------------------------------------
Fuel control stuck at minimum flow (Rollback)
1) 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.
When should I feather the
prop?
1) Check the VSI while
descending at 100 KIAS clean. A descent rate in excess of 600-800
fpm will require the propeller to be feathered.
Compressor stalls
1) Characterized by
an audible change in engine noise (a loud bang or backfire) with fluctuations
in torque, ITT, N1, and fuel flow. Additionally, flames and smoke
may be visible from the engine exhaust stacks. A severe compressor
stall may result in engine damage and/or flameout.
2) Compressor stalls
my be caused by damaged or degraded compressor or turbine blades, disrupted
airflow, or compressor bleed valve malfunction.
Uncontrollable high power
1) The bearings or
shaft in the FCU could fail without prior fluctuations, causing fuel flow
to go to maximum, resulting in a very high-power condition that will be
unresponsive to PCL movements. If torque, N1, fuel flow go to maximum
and the engine is unresponsive to PCL movements, execute UNCONTROLLABLE
HIGH POWER procedures. Take advantage of the power available to climb
to within dead engine gliding distance (DEGA).
Power losses
1) Power losses fall
into two main categories
a) Those that occur immediately
b) Those that present ample warning
2) The instant failure
generally occurs due to fuel starvation and dependent upon altitude, may
require immediate response. Impending engine problems may be prefaced
by loss of oil pressure, excessive ITT, fluctuating N1 or prop rpm, vibrations,
chip light, etc..
b. T-34C glide characteristics
Several of the many factors
that affect power-off glide performance can usually be controlled to some
degree by the pilot. Primary among these controllable factors are
airspeed, aircraft configuration (gear, flaps, canopy), propeller condition,
angle of bank, and balanced or unbalanced flight. Maximum range power-off
glide airspeed (VBEST GLIDE) differs with changes in aircraft configuration.
Power-off glide performance at any particular VBEST GLIDE will be optimized
with a closed canopy, feathered propeller, and level wings in balanced
flight.
The below figure summarizes
VBEST GLIDE for various configurations and shows typical values for sink
rates and glide ratios (L/D) to be expected at 100 KIAS (the airspeed called
for in the ELP):
AIRCRAFT CONFIG. PROPELLER
SINK RATE AT GLIDE RATIOS
GEAR FLAPS
CONDITION VBEST GLIDE
100 KIAS (FPM) AT 100 KIAS
UP UP FEATHERED 100 KIAS 800 12 : 1
DOWN UP FEATHERED 87 KIAS 1200 8 : 1
UP
DOWN FEATHERED
93 KIAS 1250
8 : 1
DOWN DOWN
FEATHERED 88 KIAS
1650
6 : 1
UP UP UNFEATHERED 117 KIAS 2400 3 : 1
The configurations shown
above include canopy closed, level and balanced flight. With both
canopies open, the sink rate typically increases by 300 fpm.
Rate of sink changes as
altitude changes. The sink rate and glide ratio values shown are
for comparison purposes only.
1) Prop feathered
2) Configuration
3) Airspeed
4) Slip (approx 2000
fpm when executing the slip procedures outlined
in FAM 6)
c. ELP interception techniques
Maintain 100 kts maneuvering
to high key. To dissipate excess altitude to arrive at a proper high
key, use "S" turns, slip, or a combination of the two (bow ties also work
well). You may also lower the flaps early (unpaved field) or the
gear early (paved field only) if necessary.
Do not become so totally
absorbed in the airstart procedures that you do not fly the aircraft to
a safe landing. Continually scan altitude, airspeed and position
as you fly the ELP profile.
If the gear/flaps were not
previously used to dissipate altitude, lower either the gear or flaps at
high key (depending on what type field at which you are landing), altitude
permitting, and RETRIM.
If low at high key, it may
be necessary to hold the gear/flaps (or retract them if previously lowered)
until back on altitude within the ELP profile. If holding the gear/flaps,
report it to the instructor.
d. Emergency voice reports
Emergency voice reports consist
of Identification, Situation, Position, and Intention (ISPI). Emergency
reports of an immediate or serious nature are prefaced by the word, "MAYDAY."
Emergency reports of a delayed or less serious nature are preceded by the
words, "PAN-PAN."
Repeating either word three
times is the widely accepted method of clearing the frequency for an emergency
voice report (ISPI format). Example:
"MAYDAY, MAYDAY, MAYDAY,
6E123, ENGINE FAILURE, SEVEN MILES NORTHEAST
OF BREWTON AT 3500
FT. I INTEND TO LAND IN A FARMER'S FIELD TO THE
SOUTHEAST."
2. Demonstrate:
a. Feather while airborne
This maneuver will not be
performed by the student. The zero-thrust torque setting for the
T-34C is 205 ft-lbs at VBEST GLIDE of 100 KIAS with gear and flaps up.
This power setting approximates the performance of the aircraft with the
propeller feathered.
Procedures:
1) Maintain an altitude
of at least 5000 ft AGL over a hard surface
runway. Trim the aircraft for 100 KIAS glide (torque at
200 ft-lbs). Note the rate of descent and nose attitude.
2) PCL - IDLE (note the deceleration and increased rate of descent)
3) Condition lever
- FTHR (note the acceleration effect and decreased
rate of descent as the prop goes to +87.5 degrees)
To return to normal propeller
operating speed:
4) Condition lever
- FULL INCREASE RPM (note the time it takes for the propeller to return
to governing range, and deceleration at flat pitch)
NOTE - the propeller should unfeather in approximately 15 seconds.
5) PCL - NORMAL OPERATING
RANGE AFTER PROPELLER RPM RISES TO A
STABILIZED RPM.
b. High altitude power loss (HAPL)
The simulated HAPL will be
initiated above 2500 ft AGL by the instructor reducing power to idle and
informing the student he has a simulated power loss. The HAPL may
occur at any airspeed and configuration. Fly to intercept the ELP
profile while simultaneously executing the appropriate procedures.
Power losses may be caused
by engine seizure, flameout, or malfunction of the pneumatic sensing system
of the fuel control unit resulting in a "rollback." In the last case,
the pilot may restore power by utilizing the EPL enabling him to execute
a PEL at a paved field. However, if power cannot be restored, executing
the HAPL procedures will be required when above 2500 feet AGL.
Where to land:
1) The best landing
site is an established airfield
2) Next best substitute
is a hard-packed, long (5000 ft or more) and smooth field with no obstructions
(trees, power lines, etc.) on the approach end. If a plowed field,
land with the furrows. Avoid all obstructions.
3) When nothing is
available, altitude permitting, BAILOUT.
4) If you are near
a large body of water, ditch near the shoreline.
5) And as a last resort,
land on the tops of the trees.
Procedures:
1) SPEED. Transition to 100 KIAS. If fast, smoothly raise the nose to trade excess airspeed for altitude. If you are at 100 KIAS or below, expeditiously lower the nose to maintain 100 kts.
2) CHECK. Check engine instruments. Report actual N1 (the current reading) to your instructor. The instructor will reply with a simulated condition of:
a)
N1 above 40% but less than 62% - indicating a "rollback"
(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 is insufficient to execute a PEL:
(5) EPL - DISCONNECT
(6) Continue below with ENGINE FAILURE procedures.
b)
N1 at 0% - indicating a "frozen engine" or "seizure"
(1) Continue below with ENGINE FAILURE procedures and DO NOT attempt an
airstart!
c)
N1 at 12% - indicating a "flameout"
(1) Continue below with ENGINE FAILURE procedures.
d)
Unintentional feather (normal N1, high torque, low prop rpm)
(1) Condition lever - FULL INCREASE RPM
If propeller remains feathered:
(2) PCL - ADVANCE (as required)
NOTE - In the event of a primary governor shaft failure, the propeller
will move toward feather; however, unboosted engine oil pressure alone
may be sufficient to maintain propeller pitch between feather and normal
governing rpm range at high-power settings. Resultant power may be
sufficient to maintain level flight.
If the resultant power does not improve performance (torque is greater
than 200 ft-lbs):
(3) PCL - IDLE
(4) Continue below with ENGINE FAILURE procedures and DO NOT put the condition
lever into feather, perform an airstart, or shutdown the engine until the
last possible moment!
NOTE - Because it is possible for the propeller to unfeather and restore useful power, consideration should be given to leaving the condition lever at FULL INCREASE RPM until intercepting the ELP.
3) FEATHER. Simulate condition lever to feather. The instructor will simulate feather by advancing the power to 200 ft-lbs torque. UNLESS it was an unintentional feather, in which case you'll leave it alone.
ICS "SIMULATE CONDITION LEVER TO FEATHER"
4) CLEAN. Select gear and flaps up and report:
ICS "AIRCRAFT CLEAN"
5) LOOK. Select a runway or field and report your intended landing site to your instructor. If no field is available and airstart is not possible, prepare for BAILOUT or DITCHING. DEGA = (D/2 x 1000) + 2500 + FE
ICS "I INTEND TO LAND AT BREWTON, 6 MILES SOUTHEAST OF MY POSITION."
6) LOCK. Check and report your harness locked.
ICS "HARNESS LOCKED, LOCKED (as reported instructor), BOTH COCKPITS."
7) AIRSTART.
UNLESS due to a seizure, feather, fuel fumes, smoke, fire, intentional
shutdown, or similar event, check altitude above 1500' AGL and perform
a simulated airstart reporting each item to your instructor but do not
move any controls/switches!
a) PCL - IDLE
b) Emergency fuel shutoff handle - DOWN, CLIP IN PLACE
c) Standby fuel pump - ON
d) Starter - ON
e) N1 and ITT - MONITOR FOR START INDICATIONS
f) Starter - OFF WHEN ITT PEAKS OR THERE IS NO INDICATION OF START
g) Standby fuel pump - OFF
CAUTION - If an airstart is attempted and unsuccessful, sufficient battery power may not be available to lower the flaps or gear electrically.
If
a successful start:
h) Condition lever - FULL INCREASE RPM
i) PCL - ADVANCE AS REQUIRED
j) PEL - EXECUTE
If
not successful with an airstart:
k) Continue below with ENGINE FAILURE procedures.
8) BAILOUT. If
airstart is not attempted or is unsuccessful, there is no landing site
available and altitude permits:
a) BAILOUT
9) CONDITION LEVER.
If forced landing is to be continued:
a) Condition lever - FUEL OFF (UNLESS due to prop feather)
10) T-HANDLE - PULL. UNLESS due to a prop feather.
11) BROADCAST. Simulate just like everything else a MAYDAY call by switching to GUARD on the UHF and SQUAWK 7700.
ICS "MAYDAY, MAYDAY, MAYDAY, 6E123,
ENGINE FAILURE, 2 MILES SOUTH OF
BREWTON AT 5000'. I WILL LAND IN A FARMER'S FIELD WEST OF MY
POSITION."
12) CONDITION LEVER - FUEL
OFF (if not already there due to feather)
EMERGENCY FUEL SHUTOFF HANDLE - PULL
13) ELP. Enter the ELP at or below HIGH KEY. Refer to the techniques listed above in paragraph 1.c.. Secure the engine if held due to prop feather.
ICS "HIGH KEY"
and
CH X "(field name) RDO, 6E123,
HIGH KEY, RUNWAY 23"
14) GEAR/FLAPS. Lower the gear (if to a paved runway) or flaps (if to an unprepared surface), and conduct the landing checklist. Remember to think about fumes or streaming fuel in which you'll not want to operate gear/flaps electrically.
ICS "HARNESS LOCKED (both cockpits),
LANDING GEAR 3 DOWN AND LOCKED
(both cockpits), PARKING BRAKE OFF BRAKES PUMPED FIRM, ENGINE
INSTRUMENTS CHECKED, LANDING LIGHTS ON."
15) X-WIND. 2000' AGL, 100 KIAS, use a 10-15 deg AOB
16) LOW KEY. 1200' AGL, 100 KIAS, 2/3 WTD and report:
ICS "LOW KEY"
and
CH X "(field name) RDO, 6E123,
LOW KEY/PATTERN LOW KEY, GEAR DOWN AND
LOCKED."
17) If making a gear down approach to a paved field, lower full flaps (wind and emergency permitting) when the field is made but no earlier than low key).
18) 90 POSITION. 600-800' AGL, 100 KIAS, ADJUST THE NOSE TO TRANSITION TO 90/95. You may have to slip the aircraft if it appears as though you are in a high final.
19) FINAL. 1200-1500' straight-away, 90/95 KIAS, and report:
ICS "CANOPY BLOWN, BATTERY OFF"
20) WAVEOFF. This will
be taken by the instructor and must be completed by no lower than 500'
AGL for TW-5 aircraft or at any time it is evident that the aircraft is
approaching a point from which a safe landing could not be made.
a) POWER to max allowable
b) Raise the nose towards the 100 kt climbing attitude and retract
the gear and/or flaps.
c) Climbout to a suitable low key position for a suitable landing
field.
Common errors:
1) Failure to establish
100 kt glide, TRIMMED.
2) Failure to use
proper procedures for power loss conditions.
3) Failure to maneuver
aircraft toward high key while conducting
procedures.
4) Failure to complete
landing checklist.
5) Not using "S" turns,
slip, or lowering flaps to dissipate excess
altitude.
6) Not judging wind
conditions or compensating for drift in order to
arrive at high key headed in desired direction of landing.
7) Failure to allow for field elevation.
8) Excessive angle of bank turning from high key toward low key.
9) Failure to maintain 100 kts off high key.
10) Failure to level wings at low key to check low key position.
11) Turning too tightly off low key.
12) Not flying a proper 90 degree position.
13) Not using paved field when available.
3. Introduce:
a. Slip (at altitude)
b. PPEL
4. Practice:
a. Ground procedures
b. Takeoff/departure
c. Course rules/COMM/IFF/HFE
d. ATS
e. Landing pattern
f. Full flap landings
g. No flap landings
h. Waveoff
5. Non-graded:
a. TP
b. OFO
c. GPU start (if not previously completed)