737NG Bleed Air System explained | Real 737 Pilot
Summary
TLDRIn diesem Video erklärt Emmanuel, Pilot des Boeing 737 und Mitglied des PMDG Tech Teams, das Bleed-Luft-System des Flugzeugs. Er klärt, dass das System zwar anscheinend komplex ist, aber für Unterhaltungszwecke dargestellt wird. Er behandelt die normalen Betriebsabläufe, zeigt die verschiedenen Schalter und Leuchtanzeigen auf der Bedienpult-Platte und erklärt die Funktionsweise des Systems. Dabei betont er die Bedeutung des Bleed-Luft-Systems für das Flugzeug, einschließlich der Triebwerks- und Flügel-Anti-Icing, Start des Triebwerks, Hydraulik-Becken, Wassertank-Pressurisierung und Stickstoff-Generierungssystem. Zudem werden Warnlichter und deren Bedeutung für den Flugsicherheit erläutert.
Takeaways
- 😀 Das Bleedluftsystem der Boeing 737 ist nicht so kompliziert, aber für Unterhaltungszwecke und nicht für echtes Flugzeugstudium gedacht.
- 🛫 Luft für das Bleedluftsystem kann von den Triebwerks-APU oder einem externen Luftwagen geliefert werden.
- ✈️ Der APU kann bis zu 17.000 Fuß Bleedluft liefern, ohne elektrische Belastung zu tragen, und bis zu 10.000 Fuß, wenn er sowohl elektrische als auch Bleedluftbelastung liefert.
- 🔧 Es ist wichtig, das Bleedluftsystem nicht mit dem Druckbelastungssystem oder der Klimaanlage zu verwechseln, da sie sich gegenseitig abhängig, aber unabhängige Systeme sind.
- 💡 Die Systeme, die auf das Bleedluftsystem angewiesen sind, um zu funktionieren, sind die Klimaanlage, Druckbelastung, Tragflächen- und Triebwerkswärmeentladung, Triebwerkstart, hydraulischer Behälter, Wassertankdruckbelastung und Stickstofferzeugungssystem (falls installiert).
- 🚫 PMDG hat das Stickstofferzeugungssystem nicht im Flugzeug installiert, aber es kann in das Systemschema eingebunden werden, um ein zusätzliches Quellsymbol darzustellen.
- 🔄 Das Bleedluft kann vom fünften und neunten Stufe des Verdichterbereichs im Triebwerk bezogen werden, wobei der fünfte Stufe normalerweise für die meisten Betriebsbedingungen ausreichend ist.
- 🛑 Der Bleedluftventil wird durch die Bleedluftschalter gesteuert, und der Ablauf des Luftstroms wird durch verschiedene Sensoren und Ventile im System weitergeleitet.
- ⚠️ Die Warnlichter im System, wie das Bleed Trip Off und das Wing Body Overheat Licht, signalisieren, wenn es zu hohen Temperaturen oder Druckgrenzwertüberschreitungen im System kommt.
- 🔄 Der Dual Bleed Licht wird eingeschaltet, wenn der APU-Bleeder Ventil geöffnet ist und die Position der Triebwerksbleeder-Schalter und Isolationsventil eine mögliche Rückdrückung der Luft zum APU zulassen könnte.
Q & A
Welche Komponenten versorgt die Entlüftungsluftsysteme des Boeing 737?
-Die Entlüftungsluftsysteme des Boeing 737 können von den Triebwerks-APU oder einem externen Luftwagen versorgt werden.
Bis zu welcher Flughöhe kann die APU von Boeing 737 Entlüftungsluft liefern?
-Die APU kann Entlüftungsluft bis zu 17.000 Fuß liefern, wenn sie keine elektrische Belastung liefert, und bis zu 10.000 Fuß, wenn sie sowohl elektrische als auch Entlüftungsluft liefert.
Welche Systeme sind von der Entlüftungsluft abhängig?
-Die Systeme, die von der Entlüftungsluft abhängig sind, sind das Kälteanlagensystem, das Druckbelüftungssystem, die Triebwerks- und Flugzeugrumpf-Ent Eisung, das Triebwerksstartventil, das Hydraulikreservoir, das Wassertank-Druckbelüftungssystem und, falls installiert, das Stickstofferzeugungssystem.
Woher wird die Entlüftungsluft im Triebwerk bezogen?
-Die Entlüftungsluft kann vom fünften und vom neunten Stufe des Verdichterbereichs im Triebwerk bezogen werden, wobei der fünfte Stufe der Niedrigdruckbereich und der neunte Stufe der Hochdruckbereich repräsentiert.
Was geschieht, wenn die Entlüftungslufttemperatur oder -druck im System zu hoch ist?
-Die Entlüftungsluftventile schließen automatisch, und das entsprechende Warnlicht leuchtet auf, wenn die Temperatur oder der Druck zu hoch ist.
Was bedeuten die unterschiedlichen Schalter und Lichter auf dem Bedienfeld des Entlüftungssystems?
-Die Schalter und Lichter auf dem Bedienfeld steuern und zeigen den Status der Entlüftungsluftversorgung, einschließlich der Steuerung der Entlüftungsluftventile, der Isolationsventile und der Überwachung der Systemintegrität.
Wie wird die Position des Isolationsventils im Entlüftungssystem erkannt?
-Die Position des Isolationsventils kann durch die Anzeige auf dem Bedienfeld erkannt werden, wobei es normalerweise geschlossen ist, wenn die Bedienfeldkonfiguration normal ist und die Pack-Schalter auf Auto positioniert sind.
Was passiert, wenn die Warnleuchte 'Wing Body Overheat' aufleuchtet?
-Die 'Wing Body Overheat'-Warnleuchte leuchtet auf, wenn die Sensoren in kritischen Teilen des Entlüftungssystems eine Luftleckage mit zu hoher Temperatur erkennen. Dies erfordert die Durchführung des entsprechenden Nicht-Normal-Checklists.
Was ist der Zweck der 'Dual Bleed'-Warnleuchte?
-Die 'Dual Bleed'-Warnleuchte leuchtet auf, wenn die APU-Entlüftungsventil geöffnet ist und die Position der Triebwerksentlüftungsschalter und Isolationsventile eine mögliche Rückdrückung der Luft in die APU zulassen könnte. Dies muss vermieden werden, um die APU nicht zu beschädigen.
Wie hoch sollte der Duct-Druck sein, um die Triebwerke zu starten?
-Um die Triebwerke zu starten, sollte der Duct-Druck mindestens 30 psi betragen.
Outlines
😀 Einführung in das Druckluftsystem der Boeing 737
Der Pilot Emmanuel führt in diesem Video das Druckluftsystem der Boeing 737 vor. Er erklärt, dass das System nicht kompliziert ist und betont, dass die Informationen nur unterhaltsam und nicht für echte Flugzeugstudien gedacht sind. Das Druckluft kann von den Triebwerks-APU oder einem externen Luftwagen geliefert werden. Es wird auch auf die Grenzen der APU-Versorgung eingegangen, abhängig davon, ob es Strom liefert oder nicht. Emmanuel hebt hervor, dass das Druckluftsystem nicht mit dem Druckkabine- oder Klimaanlagensystem verwechselt werden sollte, da es sich um interdependente, aber separate Systeme handelt.
🔧 Betriebsweise des Druckluftsystems
In diesem Abschnitt erklärt Emmanuel die normale Funktionsweise des Systems und einige Hintergrundinformationen. Es wird auf die verschiedenen Systeme eingegangen, die vom Druckluftsystem abhängig sind, wie z.B. Klimaanlage, Druckkabine, Triebwerks- und Flügelantizeise, Triebwerksstart, Hydraulikbehälter, Wassertankdruckkabine und Stickstofferzeugungssystem. Es wird auch auf die Bedeutung der Isolationsventile hingewiesen, die das linke und rechte System trennen, und wie sie durch verschiedene Schalter und Lichter auf dem Panel gesteuert werden.
⚠️ Warnleuchten und Fehlerbehandlung
Emmanuel beschreibt die verschiedenen Warnleuchten im System, wie das 'Bleed Trip Off' und das 'Wing Body Overheat' Licht, die bei Übertemperatur oder Drucküberschreitung im System eingeschaltet werden. Er betont, dass bei der Aktivierung dieser Leuchten die entsprechenden Checklisten befolgt werden sollten, um das Problem zu beheben. Des Weiteren wird erläutert, wie das 'Dual Bleed' Licht funktioniert, das bei möglichem Druckluftruückfluss zum APU aktiviert wird, und wie man es handhaben sollte.
🛫 Startvorbereitungen und Betrieb mit externer Luftversorgung
Schließlich erklärt Emmanuel, wie man die Triebwerke mit Druckluft startet, entweder vom APU oder einer externen Luftquelle. Er zeigt, wie man die Duct-Druckanzeige verwendet, um die Mindestdruckanforderungen für den Triebwerksstart zu überprüfen. Es wird auch auf die Verwendung des 'Crossbleed' Starts eingegangen, bei dem ein laufendes Triebwerk das andere mit Druckluft versorgt, sowie auf die Bedeutung der Isolationsventile und die möglichen Duct-Druckunterschiede zwischen den beiden Systemen.
Mindmap
Keywords
💡Bleed Air System
💡APU (Auxiliary Power Unit)
💡Pressurization System
💡Engine Start
💡Isolation Valve
💡Wing Anti-Ice
💡Hydraulic Reservoir
💡Nitrogen Generation System
💡Bleed Air Valve
💡Duct Pressure
Highlights
Introduction to the Boeing 737 bleed air system by a Boeing 737 pilot and PMDG tech team member.
Bleed air can be supplied by the engine, APU, or an external air cart.
APU can provide bleed air up to 17,000 feet without electrical load and up to 10,000 feet with load.
Bleed air is crucial for systems like air conditioning, pressurization, and engine thermal anti-icing.
The bleed air system is separate from the pressurization and air conditioning systems.
Explanation of the bleed system schematic for the 600 and 700 series of Boeing 737.
Bleed air can be taken from the fifth or ninth stage of the engine's compressor section.
The engine bleed air valve is controlled by the bleeder switches on the panel.
Isolation valve operation and its impact on bleed air distribution.
External air conditioning requires specific configurations to prevent system breakdown.
The bleed trip off and wing body overheat lights indicate potential issues in the bleed air system.
Procedures for addressing issues indicated by the bleed trip off and wing body overheat lights.
Dual bleed light function and its role in preventing APU damage.
Duct pressure indicators and their importance for engine starts.
Normal operation may show a difference in duct pressure between engines.
Conclusion and acknowledgment of the importance of bleed air for engine starts.
Invitation for viewers to support the channel through donations.
Transcripts
hello everyone and welcome to the
channel i'm emmanuel i'm a boeing 737
pilot and a member of pmdg's tech team
in today's video let's talk a little bit
about the bleed air system of the boeing
737 i've seen quite a couple of
questions in my channel about it and so
let's have a look at it
in a little bit more detail
so
the boeing 737
bleeder system is not all that
complicated however be aware that
everything that's set in this video is
only for entertainment purposes and not
for
any real aviation study purposes
all right so let's go for it um
air for the bleeder system can be
supplied by the engine's apu or an
external air cart
and the apu or external aircard supplies
air to the bleed air duct prior to
engine start and after engine start the
engine bleed air system is normally used
now the apu is able to provide bleed air
as well up to 17 000 feet
if it is not providing electrical load
and up to 10 000 feet if the apu has to
provide both electrical and bleed air
now for the purpose of today's video
let's talk about the normal operation of
the system and how it actually works as
well as a little bit of the system
backgrounds
it is very important not to confuse the
bleeder system with the pressurization
system or the air conditioning system
which are basically reliant on one
another but independent systems
so for today we'll focus only on this
panel that we see on screen over here
and what the different switches and
lights are doing and how the overall
system works
you can see i've already
got up the bleed system schematic of the
600 and 700 on the left hand side here
as well as of the 800 and 900 which are
basically
very similar similar to one another the
only real difference is you have an
additional recirculation fan on the
panel up here
now let's focus on the 600 and 700 since
those are released at the time of
recording
the following systems do rely on the
bleed system for operation that's air
conditioning and pressurization wing and
engine thermal anti-icing engine
starting hydraulic reservoir
pressurization water tank pressurization
and if installed on the aircraft the
nitrogen generation system
now pmdg does not have the nitrogen
generation system installed on the
aircraft but you
would simply have to imagine an
additional um
source over here in the system schematic
where it says two hydraulic reservoir
and two water tank there would be
another one two nitrogen generation
system
so
this looks pretty complicated doesn't it
all right
it's not all that problematic first of
all we have a simplified look of the
system available on the
panel itself so we can see over here the
left hand side is basically fat from the
left engine bleed and from the apu bleed
which we can see in the schematic down
here
so we have our engine
and we have our apu providing bleed air
into the system
and then the right-hand system is fed by
the right engine
and they are separated by the isolation
valve
now let's have a quick look in the
system description and see which path
the bleed air is basically flowing
bleed air can be taken from the fifth
and from the ninth stage of the
compressor section in the engine the
fifth stage basically is the low
pressure stage and the ninth stage is
the high pressure stage
and
basically the fifth stage is usually
used to obtain bleed air
from the engine and that is sufficient
during
pretty much all operation in takeoff
climb in most cruising conditions
and ninth stage air is then only needed
when you are in low thrust situations
for example
during descent
that's why in here we can see our
check valve
letting
air flow from the fifth stage into the
system and not back into the opposite
while at the ninth stage down here we do
have a high
stage valve
that opens and closes as required
from here the bleed air is basically
going straight away to the engine cowl
ntis
so cow thermal anti-icing basically is
the engine anti-ice
and you can see that this is basically
always available as long as there is air
coming from the fifth or the ninth stage
from here on next up is the bleed trip
sensors where we have two around the
engine bleed air valve
now the engine bleed air valve is the
valve which we are operating with the
bleeder switches like this
so that's the valve we are controlling
here
from there on
the airflow is continuing
we half away to the engine start valve
up here
and then to the
wing thermal anti-icing
from there air is fed into the bleed air
duct and to the water tank and hydraulic
reservoir and the nitrogen generation
system as applicable
and then it's fed directly to the pack
valve
so that is basically the flow that we
see on the actual panel over here where
you have air from either the
engine number
one or the apu bleed air and then we can
see by following the schematic that it's
going to the wing ntis
and then right towards the pack
now next up is the isolation valve that
is located just next uh to it and the
isolation valve is
operated by a ac power
and there is basically a very easy way
to know how the isolation valve is
positioned when the switch is in auto
so i'm putting it into auto now and
basically
when the rest of the panel is configured
as normal then the isolation valve is
closed so with the bleeder switches on
and the pack switch is in auto the
isolation valve is going to be closed
the the same accounts with the pack
switches in high by the way
now
if you turn any of these switches so
either a pack switch
or an engine bleeder switch into off
then the isolation valve is
automatically going to open
when the switch is in the auto position
the apu bleeder switch does not affect
the automatic positioning of the
isolation valve
the isolation valve itself as you can
see on the
system schematic here is separating the
left side of the bleeder system from the
right side
and do note that external air
conditioning is flowing in from the
right hand side of the system over here
so in order for the external air
conditioning to be able to provide air
to the left pack
the oscillation valve has to be open
the good news about that is when
external air conditioning is connected
the pilot needs to
turn off the packs manually in order to
um
provide in order to protect the system
from uh
basically from breaking down due to
external air coming in
and remember what i just said with the
packs and off and the isolation of an
auto it is going to open up
automatically
now for operation on the ground the
isolation valve is always going to be
open anyway
as uh part of the normal procedures
where you would open the isolation valve
after engine shutdown and then only set
it back to auto after engine start has
commenced
so external air is always available for
both sides with the normal system
configuration as you would do it
following the normal procedures
now going on from here
we have a couple of warning lights
available on the system
the pack check trip of light is not all
that interesting for the bleed air
system for us that's why we are not
going to talk about that one
but the other two are
we have the bleed trip off and the wing
body overheat
the bleed trip of
light is going to be triggered when the
bleed trip sensors sense
either
an excessive temperature
or an exceedance of a predefined
pressure limit inside the
engine bleed air system
and what's happening then is the bleed
air valve is going to close
automatically
and the bleed trip of light is going to
illuminate when this happens
now
when that happens to you
pull up the quick reference handbook run
the bleed trip of non-normal checklist
and it is going to give you directions
on how to fix the problem
the next one is a little bit more
serious that's the wing body overheat
light
basically we have
several sensors installed along critical
parts of the engine bleeder system
which are
measuring if there is any hot air coming
from the engine bleeds leaking out of
the system
and
keep in mind we have the bleed air lines
running along some very sensitive
systems there in the aircraft so if you
get some couple hundred degrees
hot air leaking out in positions where
it's not supposed to be that can be a
pretty serious issue
again if the wing body overheat light
illuminates then
run the associated non-normal checklist
and it is going to direct you to isolate
the problem and
basically configure the airplane for
flight with a single bleed air system
only
note that this does come with some
pretty
severe
uh limitations
so
that is not a failure to take lightly
we can have a look at the distribution
of the um
wing body overheat ducts if we go on in
the afghan we can see this down here
basically from the left hand side
of the left sensor
are located on the left engine strut the
left leading
edge inbound so that's the one we see
over here
the left hand air conditioning bay
the keel beam and the bleed duct from
the apu
so
here again the apu is part of the left
hand side of the system so as we can see
in the schematic anything that is
leaking coming from the apu and the keel
beam as well as anything from the
left-hand engine here is going to cause
the left wing body overheat light to
illuminate and then basically on the
right hand side we have sensors in the
right engine strut the right inboard
wing leading edge and the right hand air
conditioning bay that might cause these
to illuminate
then going on a little bit in the system
we have the dual bleed light the one
located up here
and the dual bleed light is going to
illuminate whenever apu bleeder valve is
open and the position of the engine
bleeder switches and isolation valve
would permit a possible back pressure of
air towards the apu
and frost has to be limited to idle when
the dual bleed light is illuminated
otherwise you can significantly damage
your apu
now basically as we can see in the
system schematics over here
there is a check valve that's supposed
to
prevent air from flowing back towards
the apu however
with um
strong pressure
being in the system as in the
bleeder valves being open and a high
thrust setting
or even any thrust setting higher than
idle
this may break down and you can actually
completely break the apu with this
now you might be a little bit surprised
that modern aircrafts
does not have an automatic protection
against this but that's how it is
and that's why we have the dual bleed
lights to prevent this from happening
so it is normal to see the dual bleed
light come on
in a normal operation so if i'm just
going to turn off the um
light test switch over here
as soon as the apu bleed
is turned on and the left engine bleed
is turned on the dual bleed guide is
going to illuminate
and provided that the isolation valve is
open
the same goes for the right engine
bleeder switch
so
as we can see over here if the isolation
valve is closed
then the dual bleed light is going to
shut off because right now
the right hand
or the number two engine bleed is going
to
provide
bleed out just towards the right pack
and the right wing anti-ice but the
isolation valve is stopping it from
flowing into the left hand side of the
system where the apu bleed would be
located
all right so
then we have our duck pressure
indicators up here
right now we have our apu running
and
let's use that in order to have a look
at the duct pressures
with the apu bleed
air being switched on and the isolation
valve being open we are getting pressure
into both systems
now in order to start the engines you
want to have a dock pressure of
approximately 30 psi at least
so as you can see right now with the
packs operating in auto the apu is not
able to supply sufficient bleed air for
the engines to start but when we turn
the packs off
then we can now see that um
duct pressure is actually reducing up
here but it is now available for engine
start
if you were to conduct an engine
crossbleed start
then basically what you would be doing
is um
to configure the airplane with the apu
bleed off of course
and
now you would increase engine thrust in
order for the duct pressure needles to
increase to 30
psi and at 30 psi you would have
sufficient duct pressure to start the
other engine
for an engine cross bleed start
it is normal to see the duct pressure
needles separate from one another
so
in normal operation
it might happen that one engine is
providing a little bit more pressure
than the other and since in normal
operation the isolation valve is going
to be closed with the engines running
it can happen that one needle is showing
a higher or lower pressure than the
other
now
as we can see on the system schematic up
here
this is what it looks like
and basically
a split of like
10 15 psi can happen and it's something
that
doesn't have to be recorded in the tech
lock if it doesn't become excessive so
if one system would provide for example
10 psi and the other 60 that's
definitely something to note
but for the rest of it there are certain
limitations of how big the split can be
in the engineering manuals so that's
something that the engineers could take
care of
if required but in most cases based on
my personal experience when you see a
duck pressure difference of for example
10 psi you tell the engineer after the
flight and they are going to look up if
that's normal or not and in the vast
majority of cases
a certain split is absolutely normal and
can be tolerated
so this basically concludes our look at
the engine bleed air system already
so
keep in mind
for you in order to start the engines
you have to have
bleed air available this can come either
from the apu or from an external
unit and
as we can see on the system schematics
here there is no valve that would
prevent any
air to go right to the starter valve
however
a procedure is available in the
supplementary procedures engine section
in the f-com that is going to provide
you with guidance on how to start the
engines with
an external air source
so
this concludes a look at the bleed air
system i would like to thank you very
much for being with us if you found this
one interesting i would appreciate a
small donation through the behind me a
coffee link that you can find in the
video description below
until then thank you very much for
joining and i'm looking forward to see
you all in the virtual skies
Посмотреть больше похожих видео
COSA DICE LA FISICA? Cybertruck vs. Porsche 911
Unsere Lymphe: So bedeutsam ist die Lymphflüssigkeit - Störungen führen zu Lymphödem & dicken Beinen
Turning Notion Into Your Automated CRM system
Konjunktiv einfach erklärt I musstewissen Deutsch
Rembrandtlicht setzen wie ein Profi
How we Learn: Baddeley's Working Memory, Part 1
5.0 / 5 (0 votes)