THRUST REVERSER SYSTEM
l
443cl TECHNICAL TRAINING SQUADRON
443cl MILITARY AIRLIFT WING, ING (MAC)
ALTUS AIR FORCE BASE, OKLAHOMA
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FOR TRAINING PURPOSES ONLY
NOT NECESSARILY CURRENT AFTER DISTRIBUTION
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C-141 THRUST REVERSER SYSTEM
OBJECTIVES
When you have completed this program, you should be able to :
1.
state the ind ication received when the Thrust Revers er doors are , extended.
2.
state the i ndication received when th e Thrust Reverser doors are NOT stowed
and lock ed.
3.
state the purpose of the Thrust Reverser Inter l ock.
4.
state the purpose of the Thrust Reverser Limiter .
5.
list the limits imposed on the Thrust Reverser system.
Air Force OC, 15 May 70· 2M
Page A
INTRODUCTION
This book is not arranged like an ordinary book.
The page numbers are
in order, but the text does not follow the page numbers.
not be necessary to read each page.
There will be directions on each page .
to guide you.
Now TURN to Page 1 and begin the program .
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Therefore, it will
..
Page 1
From Page A
THRUST REVERSER SYSTEM
Each nacelle is equipped with an independent Thrust Reverser system,
operated through the THROTTLE CONTROL QUADRANT.
The system permits reverse thrust application of engine power during
landing (after touchdown) and during a rejected takeoff.
Are the Thrust Reversers used in flight?
a.
Yes.
TURN to page 3.
b.
No.
TURN to page 2.
From Page 1
Page 2
You're right, the Thrust Reversers are NOT used in flight.
will function, but operation in flight is pPohibited.
THRUST REVERSERS IN FLIGHT!
Please TURN to Page 4 .
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The system
DON'T TRY TO USE
From Page 1
Page 3
Sorry, but the Thrust Reversers are NOT supposed to be used in flight.
They will operate, but in flight operation is prohibited.
THRUST REVERSERS IN FLIGHT!
Please TURN to Page 4.
DON'T TRY TO USE
,.
From Page 2 or 3
Page 4
Two target-type Thrust Reverser doors are EXTENDED or STOWED by hydraulic
actuators acting through a mechanica l linkage .
The picture above shows the Thrust Reverser doors:
a.
Stowed.
TURN to Page 6 .
b.
Extended.
TURN to Page 5.
,.
From Page 4
Page 5
Your answer:
Wrong .
"Extended."
The Thrust Reverser doors ar e in t he STOWED position.
doors are STOWED, they form t he r ear portion of the cowling.
Reverser s wer e extended, t hey would look like those below .
--
Please TURN to Page 7.
,,_.
- ---
When the
If the Thrus t
From Page 4
STOWED was your answer and this is correct.
Page 6
When the Thrust Reverser
doors are in the STOWED position, they form the rear portion of the cowling.
When the Thrust Reversers are extended, they are like this ...
Please TURN to Page 7.
From Page 5 or 6
Page 7
How can you tell when the Thrust Reverser doors are NOT stowed and locked?
j NO--_-l-THRUST - -,
Easy. On the center instrument panel there are four (4) ; REVN_()T ~_()CKED
lights, one for each engine.
These lights
illuminated when the Thrust Reverser doors
out of the STOWED and LOCKED position.
------Wi ll the
I
NO . I THRUST
REVt:!O_liOCKrn
lights be illuminated when the Thrust Reverser
doors are extended?
a.
Yes .
TURN to Page 8.
b.
No.
TURN to Page 9.
From Page 7
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Page 8
--------You said the
NO. I THRUST
I
REVNOT
LOCKED
---
lights would be i l luminated even when the
doors are extended and you are so right.
The lights remain il l uminated after
the doors get to the full extended position.
Now what about the full Extended position?
TURN to Page 10 and read on .
From Page 7
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You said the
I
-
-
Page 9
I
-- -
NO. I TH RUST
REVN9T LOCKED
light would NOT remain illuminated when the
Thrust Reverser doors reach the full extend ed position.
I
·----NO. 1 THRUST
REV NOT LOCKED
I t was a good try,
~--
however it is NOT cor rect.
The
light remains illuminated
even after the Thrust Reverser doors have reached the ful l extended position.
Now what about the full Ext ended position ?
TURN to Page 10 and read on .
From Page 8 or 9
The
Page 10
lights are on the center instrument panel just below
the THRUST REVERSER NOT LOCKED lights .
The
I '
I
r~
f ''
'
-'
•
,,
f
I
'
!
j
light will
i lluminate when the Thrust Revers er doors have reached the fuZZ extended
position.
Does the
light illuminate as soon as the Thrust Reverser
doors crack from the stowed position?
a.
Yes.
TURN to Page 12.
b.
No.
TURN to Page 11 .
From Page 10
---- .
Your answer:
NO.
You made a good choice.
The
Page 11
-. .
light
will NOT illuminate until the Thrust Reverser doors are in the full EXTENDED
position.
There would now be two lights illuminated for each engine, the
--·
light and the
--·--··--
TI '
1
•
I
1 1.
l
, 1
r
T
11
1;
..
light.
You're doing fine, please TURN to Page 13.
l
~·
·-
NO. I THRUST
REV NOT LOCKEDI
From Page 10
Sorry you are wrong.
Page 12
Please RETURN to Page 10 and make another selection.
Page 13
From Page 11
The aft nacelle contour is composed principally of the Thrust Reverser
doors in the stowed position.
Actuation of these target type doors is
accomplished by two hydraulic actuators located on top and bottom of the
engine.
Take a look at the picture below .
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Please TURN to Page 14.
From Page 13
Page 14
The doors normally operate under a pressure of approximately 3000 psi,
but there i s NO indicator to tell you how much pressure is in the system.
The only indication of sufficient pressure are four Thrust Reverser
II
I! lights,
one for each engine .
These lights ar e located
on the Flight Engineer ' s Panel and wi ll illuminate when the supply pressure
Thrust Reverser system operation .
Please TURN to Page 15 .
Fro.m Page 14
Review time.
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1.
Page 15
Answer the questions below .
When the Thrust Reverser doors are fully extended a
~~~~~~~-
light illuminates.
~~~~~~~-
2.
What indication is given when the Thrust Reverser doors are stowed and
locked?
light illuminates.
a.
b.
c.
I light illuminates.
' NO. I THRUST
REVNOT LOCKED
NO. I THRUST ,.
REVNOT LOCKED
light extinguishes.
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3.
What do the Thrust Reverser pressure lights on the engineer's panel
indicate?
Please TURN to Page 16 and check your answers.
From Page 15
Page 16
Please CHECK your answers and make any corrections necessary.
.
1.
---·
NO. I THRUST
I light extinguishes .
2.
"c".
3.
That the system pressure exceeds 1,000 PSI.
REV NOT LOCKED
Satisfied with your answers?
..
If so, please CONTINUE to Page 17 .
From P_age 16
Page 17
Up to this point we have discussed the indiaations that are seen in the
,,
cockpit when the doors are STOWED or EXTENDED and the pressure light on the
Flight Engineer's panel that tells you system pressure exceeds 1,000 PSI.
sure in the system.
How is the Thrust Reverser system put into operation?
"
a.
Thrust Reverser system operates when spoilers are deployed.
TURN to Page 20.
b.
By the use of a t_oggle switch.
TURN to Page 19.
c.
By throttle movement.
TURN to Page 18.
Fram Page 17
'
Correct!
Page 18
Thrust Reverser operation is initiated by retarding the throttle
levers to the IDLE START position detent and then lifting them 1 and 1/8
inches to clear the detent stop.
Further aft movement of the throttle levers
causes the Thrust Reverser doors to extend.
Reverser doors is approximately 2 seconds.
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Please TURN to Page 21.
Extension time of the Thrust
See the schematic below .
From Page 17
Page 19
Well that was an excellent try; however, the onZy actions necessary to
extend the Thrust Reverser doors is to retard the throttles to the IDLE
START position, lift them approximately 1 and 1/8" over a stop on the
throttle quadrant and aontinue throttZe movement to the REVERSE position.
See the schematic below.
Please TURN to Page 21.
From Page 17
Page 20
Excellent try; however, the only actions necessary to extend the Thrust
Reverser doors is to Peta.Pd the throttles to the IDLE START position, Zift
them approximately 1 and 1/8" over a stop on the throttle quadrant and
aontinue throttle movement to the REVERSE position.
Please TURN to Page 21.
See the schematic below.
From Page 18, 19 or 20
Page 21
When the Thrust Reverser doors are fully extended, they deflect engine
exhaust gases forward to produce the desired reverse thrust.
Would you agree that if the Thrust Reverser doors didn't go to the
fu~ly
extended position and power could be applied in the reverse range
that it would be the same as applying power in the forward thrust range.
a.
Yes.
b.
No.
TURN to Page 22.
Think about it and then TURN to Page 22.
Page 22
From Page 21
You're right!
If the Thrust Reverser doors do NOT
fully extend and power could be applied, the engine
would produce forward thrust.
There would be no
deflection of the engine exhaust gases to produce the reverse thrust.
To prevent application of power in reverse thrust, unless the Thrust
Reverser doors are extended, a simple Mechanical Interlock system will
automatically prevent movement of the throttle control beyond the interlock
position.
Each engine has its own independent interlock system.
Please TURN to Page 23.
From Page 22
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Page 23
Since the Mechanical Interlock actually prevents the throttle from being
pulled into the reverse range if the doors don't extend, what would be the
results if the Thrust Reverser doors on number one engine failed to open?
a.
All the throttles would be blocked.
TURN to
b.
Only the throttle for the affected engine
would be blocked.
TURN to Page 25.
Only the symmetrical throttles would be blocked.
TURN to Page 26.
c.
,,.
~age
24.
From Page 23
Page 24
You said "all the throttles would be blocked."
true.
Sorry, but that isn't
Perhaps you forgot that each engine is equipped with an independent
interlock system.
If one thrust reverser system fails, onZy the throttle for that engine
will be blocked.
The remaining engine thrust reversers could be operated.
The Thrust Reverser Interlock prevents power applications in the reverse
xange unless the Thrust Reverser doors are fuZZy extended.
Please TURN to Page 27.
From Page 23
Page 25
You remembered that each engine has a completely independent interlock
system and only the throttle for the affected engine would be blocked from
being positioned to the REVERSE position.
The Thrust Reverser Interlock prevents power application in the reverse
range until the Thrust Reverser doors are fully extended.
You're doing fine, please CONTINUE to Page 27.
From Page 22
Page 26
Your answer, "only the symmetrical throttles would be blocked."
that is incorrect.
Sorry
The onZy throttle that would be blocked would be the
throttle for the affected e.ngine.
The Thrust Reverser Interlock prevents power application in the reverse
range until the Thrust Reverser doors are fully extended.
Please TURN to Page 27 .
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From Page 24, 25 or 26
Page 27
Please fill in the blanks in the questions below.
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1.
When the Thrust Reverser doors are not stowed and locked, it will be
indicated by a
2.
light.
What is the indication when the Thrust Reverser doors are fully
extended?
3.
What does THRUST REVERSER pressure light on the engineer's panel
indicate?
4.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
What is the purpose of the Thrust Reverser Interlock?
Please TURN to Page 28 and check your answers.
From P_age 27
~age
CHECK your answers and make any corrections necessary.
1.
THRUST REV NOT LOCKED.
2.
A THRUST REV EXTENDED Hght illuminates.
3.
System pressure exceeds 1,000 PSI.
4.
Prevents power application in the reverse range if the Thrust Reverser
doors do not fully extend.
When you have checked your answers, TURN to Page 29 .
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28
From Page 28
Page 29
The next item in the thrust reverser system that is to be discussed
is the THRUST REVERSER LIMITER.
throttles.
Take a look .
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Please TURN to Page 30.
The knob is l ocated just below the copilot 's
From Page 29
Page 30
The purpose of the THRUST REVERSER LIMITER is to limit the amount of
reverse thrust that can be applied.
Numbers on the contour of the knob align
with an index mark above the knob to permit setting of the reverse thrust by
index number in accordance with a chart contained in T.O. 1C-1 41A-l-l.
What is the purpose of the Thrust Reverser Limit er?
a.
Limits the amount of throttle trave l.
TURN to Page 31.
b.
Limits the reverse thrust by changing th e mechani cal
advantage between the throttle and the fuel control.
TURN to Page 33 .
Limits the amount of door travel .
TURN to Page 32.
c.
From Page 30
Page 31
Logical reasoning; however, it doesn't work that way.
throttle travel does NOT change.
The amount of
Rotating the Thrust Reverser Limiter
knob changes the mechanical advantage between the throttle and the fuel
control.
In other words the fuel control can't travel as far in the reverse
range.
Nice try, please TURN to Page 34.
1
From Page 30
Nope!
Page 32
It doesn't limit the amount of door travel.
doors are either stowed or extended.
The Thrust Reverser
NO in-between position.
The purpose of the Thrust Reverser Limiter is to limit the amount of
thrust that can be applied in the reverse range by changing the mechanical
advantage between the throttle and the fuel control.
You're doing OK, please TURN to Page 34.
From Page 30
Page 33
You said the purpose of the Thrust Reverser Limiter was to Zimit the
amount of reverse thrust by changing the mechanical advantage between the
throttle and the fuel control.
Please TURN to Page 34 .
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Congratulations.
You are 100% correct.
From Page 31, 32 or 33
Page 34
The Thrust Reverse Limiter knob can correctly preset an engine fuel
control lever only if the related engine throttle is in the forward thrust
regime at the time the setting is made.
FIRST ...
THEN .. .
THROTTLES ----:~~
AT
IDLE START
OR
FORWARD
SET THE
LIMITER
KNOB
Please TURN to Page 35.
Page 35
From Page 34
The Reverse 'Ibrust Limiter Setting chart in the performance data book
has a Pressure Ratio Limited line (never exceed line) which shows a
ma:tirrrum att01JJabZe setting of 10.9.
'Ibis should NOT be exceeded.
.
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Please TURN to Page 36.
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~~
Page 36
From Page 35
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The last item for discussion is the use of the system and the limits
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imposed.
The Thrust Reversers should be operated in the following manner.
The
copilot will observe that all four 1HRUST REV EXTENDED lights are
illuminated.
After the nosewheel is on the runway, the pilot will move all
throttles smoothly to the desired reverse position.
At 80 knots, slowly advance all throttles back toward REV IDLE position
•
so as to have all throttles at REV IDLE by 60 knots.
-!
"80 knots."
The copilot will call,
After slowing to taxi speed, all throttles may be returned
to IDLE START position.
Please TURN to Page 37.
From Page 36
Page 37
The following limits must be observed when using the Thrust Reversers.
1.
When baaking the aircraft, limit application of reverse thrust to 30
SECONDS above idle maximum and then close the doors for better cooling.
2.
When ta:r:iing DO NOT operate No. 2 engine in REV IDLE for more than
MINUTES with the APU operating.
~
Prolonged mixing of engine exhaust
with APU .intake air can cause the temperature limits of the APU to be
exceeded.
3.
Use of thrust reversers in flight is PROHIBITED.
Please TURN to Page 38.
t
From Page 37
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Page 38
Before leaving the Thrust Reverser system lets REVIEW by answering
the questions below.
I.
What indicator shows that the Thrust Reverser doors have extended?
2.
What is the indication when the Thrust Reverser doors are stowed and
locked?
3.
What do the Thrust Reverser pressure lights on the engineer's panel
indicate?
4.
What is the purpose of the Thrust Reverser Interlock?
Please TURN to Page 39 and check your answers.
From Page 38
Page 39
Please CHECK your· answers and make any corrections necessary.
1.
THRUST REV EXTENDED light.
2.
THRUST REV NOT LOCKED light extinguishes.
3.
System pressure exceeds 1,000 PSI.
4.
Prevents power application in the reverse range if the Thrust Reverser
doors are not fully extended.
Please TURN to Page 40 .
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•
P_age 40
From P_age 39
Please CONTINUE with the review .
•
5.
6.
•
The Thrust Reverser Limiter:
a.
limits the amount of throttle travel.
b.
limits the reverse thrust by changing the mechanical
between the throttle and the fuel control.
c.
limits the amount of door travel.
advan~age
~i.'fo~
Reverse Thrust application for the purpose of backi.ng the aircraft is
limited to:
a.
Thirty (30) seconds above idle maximum and then close the doors for
better cooling.
b.
One (1) minute between cooli.ng periods.
c.
One and one half (1 1/2) minutes between cooling periods.
Please TURN to Page 41 and check your answers.
From Page 40
•
•
Please CHECK your answers and make any corrections necessary.
5.
"b".
Limits- the reverse thrust by changing the mechanical advantage
between the throttle and the fuel control.
6.
"a".
Thirty (30) seconds above idle maximum and then close the doors
for better cooling.
Please TURN to Page 42 and continue the review .
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Page 41
From Page 41
Page 42
Please CONTINUE the review.
7.
8.
•
When taxiing, with the APU operating, No. 2 engine cannot remain in
REV IDLE longer than:
a.
5 minutes.
b.
10 minutes.
c.
15 minutes.
d.
20 minutes.
Thrust Reverser operation is allowed in flight.
a.
True .
b.
False .
•
Please TURN to Page 43 and check your answers.
Page 43
From Page 42
Please CHECK your answers and make any corrections necessary.
7.
"c".
15 minutes.
8.
"b".
False
This completes the Thrust Reverser system, if you have any further
questions, the instructor will be happy to answer them.
An INDEX is
provided on Page 44 in case you wish to review any portion of the C-141
Thrust Reverser System.
•
From P_age 43
~age
INDEX
PAGES
SUBJECT
~
Thrust Reverser Doors
4 thru 6, 13
Thrust Reverser Indicator Lights
7 thru 11, 14
Thrust Reverser System Operation
18 thru 20
Thrust Reverser Interlock
22 thru 26
Thrust Reverser Limiter
29
Use of Thrust Reversers
36 and 37
thru 35
44