Night Fighters

[Rhino]

I'm just reading an account of the so-called Dam Busters Raid and it's
raised a few questions for me. I have no military experience so forgive any
questions that seem foolish.

What was the mechanical difference between a plane that was a night fighter
and one that wasn't? In other words, what equipment did a night fighter
have that made it capable of night-fighting that another plane lacked? I
know that night-vision goggles weren't invented until well after the war so
I know it can't be that.


Also, how did night fighters do their jobs in the dark? How did they
distinguish friend from foe in the dark? Given that it would be hard to see
much of anything in the dark, it must have been very challenging indeed to
tell their own compatriots from whatever enemies were in the sky. I'm
guessing that each plane had some sort of recognition light on it but I'm
assuming it was pretty small so that it couldn't be easily seen from the
ground. After all, you wouldn't want anti-aircraft batteries to be able to
see you too easily for fear that they would hit you.

--
Rhino

--- news://freenews.netfront.net/ - complaints: ***@netfront.net ---

[Rainer Pehlke]

Post by Rhino
I'm just reading an account of the so-called Dam Busters Raid and it's
raised a few questions for me. I have no military experience so forgive any
questions that seem foolish.
What was the mechanical difference between a plane that was a night fighter
and one that wasn't? In other words, what equipment did a night fighter
have that made it capable of night-fighting that another plane lacked?

The main difference was radar. As the radar equipment in these days was
huge and heavy, night fighters had to be twin engined planes with
enought carrying capacity and space.
Also a second crew member - the radio operator - was needed, who had to
direct the pilot to the target. Later an additional "Beobachter"
(scanner) was added on Ju 88 and He 219 machines.
Thirdly, much more fuel capacity was required because until the last
third of 1943 the fighters had to wait in circling areas and finding the
bombers was difficult.

[e***@yahoo.com.au]

Post by Rainer Pehlke

Post by Rhino
I'm just reading an account of the so-called Dam Busters Raid and it's
raised a few questions for me. I have no military experience so forgive any
questions that seem foolish.
What was the mechanical difference between a plane that was a night fighter
and one that wasn't? In other words, what equipment did a night fighter
have that made it capable of night-fighting that another plane lacked?

The main difference was radar.

That's what most posters have said, but the Luftwaffe opperated quite
a lot of single engined night fighters.

I would say the main difference was instrumentation for bad weather
flying and navigation. How extensive a fitout was possible on a
single engined aircraft would be interesting. Apart from an
artificial horizon the FuG 16ZY for homing onto a becon and distance
measurements would be the minimum I would immagine. Some single
engined units did get a blind landing systems as well.

The German singles could in theory carry an effective radar, the
problem was that peering into an osciliscope was not good for pilots
night vision.

I know the US navy tried Corsairs and Hellcats with radar, I can't
immagine they didn't have this problem either.






As the radar equipment in these days was

Post by Rainer Pehlke
huge and heavy, night fighters had to be twin engined planes with
enought carrying capacity and space.
Also a second crew member - the radio operator - was needed, who had to
direct the pilot to the target. Later an additional "Beobachter"
(scanner) was added on Ju 88 and He 219 machines.
Thirdly, much more fuel capacity was required because until the last
third of 1943 the fighters had to wait in circling areas and finding the
bombers was difficult.
--
Rainer Pehlke
Germany

[Don Phillipson]

. . . the Luftwaffe opperated quite
a lot of single engined night fighters.
I would say the main difference was instrumentation for bad weather
flying and navigation.

The operational difference was that (most) multi-engined night
fighters equipped with radar were controlled by ground radar
observers (in the "boxes" of the Kammhuber Line) and found
specific targets through the radar observer on board. Single-
engined single-seat fighters (usually) found their targets by eyesight
(over searchlight belts or fires.) See Zahme Sau and Wilde
Sau (respectively) in the records.

[Rich Rostrom]

Post by Rhino
I'm just reading an account of the so-called Dam Busters Raid and it's
raised a few questions for me. I have no military experience so forgive any
questions that seem foolish.
What was the mechanical difference between a plane that was a night fighter
and one that wasn't?

The primary difference was that night-fighters
were not operated as "pursuit" planes. By day,
a bomber interceptor needed maximum speed to
reach and catch its targets. By night, it was
a matter of "stalking", and then using the
moment of attack to deliver maximum fire.

Thus most night fighters were larger, slower,
and more heavily armed than day fighters. Some
were not even fighter types. For instance the
Germans used the Ju 88 and Do 17 series medium
bomber as night fighters. The British used the
Blenheim light bomber, and later the Mosquito.

While some single-seat, single-engine fighters
were used as night fighters, it was more common
to use two seat and twin-engine planes, such as
the Me 110 or Beaufighter.

(One should distinguish here between true night
fighters, and day fighters shifted to night duty
using different tactics. This was tried by the
Germans under the name "Wildesau" (Wild boar);
Wildesau fighters attacked by visual contact on
full-moon nights and with the aid of searchlights.)

Another aspect was the configuration of the
armament. The Germans equipped many of their
night fighters with "Schrage Musik guns.
(Literally "slant music"; the German slang for
jazz.) These guns were mounted behind the pilot,
firing up and forward. This allowed the night
fighter to attack the bomber from underneath.

The most important difference was the provision
of airborne intercept (AI) radar. This of course
was not available until the middle of the war;
both sides equipped nightfighters with it. It
was of course easier to mount radar sets and
antennas on larger aircraft, and to have a
second seat for the radar operator. However,
a few Hurricanes were equipped with AI radar.

Me 262 trainers (which had two seats) were
equipped with AI radar and Schrage Musik
guns - they could be quite effective.

Prior to AI radar, nightfighters found their
targets by visual contact; they were sometimes
vectored to targets by ground-based radar
controllers.

One feature of nightfighters was "glare panels"
which concealed any flames coming out of the
engine exhausts, in particular to screen them
from the view of the pilots or other crew and
preserve their night vision.

Post by Rhino
night-vision goggles weren't invented until well after the war...

Actually, Germany did develop some infrared
equipment during the war. It was not very effective
though. One attempt to use it on Do 17 nightfighters
was a failure.

Post by Rhino
I know it can't be that.
Also, how did night fighters do their jobs in the dark? How
did they distinguish friend from foe in the dark?

With difficulty. There were lots of "friendly
fire" incidents - some of them fatal. It helped
if one side had aircraft that were totally unlike
anything the enemy had in the area. For instance
Japanese nightfighters in 1945 were not likely
to mistake one another for a B-24 or B-29; but
for a British pilot in 1941, distinguishing a
Beaufighter from a Ju 88 was much harder.

[Don Phillipson]

I'm just reading an account of the so-called Dam Busters Raid . . .
What was the mechanical difference between a plane that was a night fighter
and one that wasn't? In other words, what equipment did a night fighter
have that made it capable of night-fighting that another plane lacked?

1. Ground control: German night defence was the "Kammhuber Belt"
of 30-mile boxes over land on the continent, each of which could
track enemy bombers and direct one fighter to bring it near. There
were also over German territory (inside the belt) "Wild Boar" fighters,
looking for bombers by eyesight (via searchlights etc.)

2. AI (Airborne Interception) radar aboard aircraft, i.e. short-range
radar sets capable of tracking another aircraft within (say) 5 miles
so that the pilot could be directed close enough to see it. AI equipment
required carrying a radar observer to operate it.

3. Weapons, preferably cannons firing explosive shells rather
than solid shot (because one accurate cannon strike could
destroy or cripple an aircraft, which a single rifle bullet would
be unlikely to do.) Some German fighters (typically twin-engined
Junkers and Messerschmitt types) also had special Jazz Music
canons that fired 30 or 40 degrees upward, instead of straight
ahead, so as to hit aircraft from their blind spots below and behind.
The bigger aircraft cannons (British and German) were loaded
from magazines (not rounds linked in a belt) which during combat
the radar observer might have to replace to reload.

There is a good description of these methods in Night Fighter by
C.F. Rawnsley, an RAF radar observer since 1941 (and pioneer
in the early development of British AI.)

[Bradipus]

Post by Rhino
I'm just reading an account of the so-called Dam Busters Raid
and it's raised a few questions for me. I have no military
experience so forgive any questions that seem foolish.
What was the mechanical difference between a plane that was a
night fighter and one that wasn't? In other words, what
equipment did a night fighter have that made it capable of
night-fighting that another plane lacked? I know that
night-vision goggles weren't invented until well after the war
so I know it can't be that.
Also, how did night fighters do their jobs in the dark? How
did they distinguish friend from foe in the dark? Given that
it would be hard to see much of anything in the dark, it must
have been very challenging indeed to tell their own
compatriots from whatever enemies were in the sky. I'm
guessing that each plane had some sort of recognition light on
it but I'm assuming it was pretty small so that it couldn't be
easily seen from the ground. After all, you wouldn't want
anti-aircraft batteries to be able to see you too easily for
fear that they would hit you.

Another problem is that during the night airfields have to turn
lights on to let airplanes take off and land.

Also, pilots cannot see the ground so how do they manage to go
back to their airport?

[j***@cix.compulink.co.uk]

Post by Bradipus

How did they distinguish friend from foe in the dark?

Darkness is rarely total: silhouettes are usually visible against the
sky to the dark-adapted eye. It was hard to tell friend from foe, but
some things helped: the Germans had no four-engine aircraft flying at
night, so if a German were sure an aircraft had four engines, it was
pretty definitely enemy.

There were plenty of mistakes, mind you. There weren't any recognition
lights, since they would made planes far too obvious. The night skies
over Germany were the birthplace of modern ECM, ECCM, and so on.
Sometimes this could be very effective: for a while many British bombers
had a low-powered rear-facing radar called "Monica" which was meant to
alter the crew to the approach of night-fighters. it was little use,
since it went off all the time in the steam formations used for mass
raids. The Germans also built a homing receiver for its signals, which
helped them find targets that they could be reasonably sure were British.

The number of bombers in an area was usually vastly in excess of the
number of night-fighters.

Post by Bradipus
Also, pilots cannot see the ground so how do they manage to go
back to their airport?

Aerial navigation was not usually done by following landmarks at the
time of WWII. The Germans had a system of radio homing beacons and
receivers in the night-fighters - another piece of electronics that day
fighters usually lacked - that let them find the general area of
airfields.

Post by Bradipus
Another problem is that during the night airfields have to turn
lights on to let airplanes take off and land.

Yes. But electric lights can be turned on and off really quite quickly.
Radio communications let them be turned on briefly for takeoffs and
landings.

[Michele]

Post by Bradipus
Another problem is that during the night airfields have to turn
lights on to let airplanes take off and land.

Yes. But since ground control is talking with the radio operator of the
night fighter, the lights can be turned on when needed and not before.

Post by Bradipus
Also, pilots cannot see the ground so how do they manage to go
back to their airport?

Again, ground control, radar, and radios. By "radios" here I mean both the
ground control having the fighter on their radar screen and telling the
pilot "come to 180°" on the radio, and also the radio beacon systems
installed as navigation aids on some aircraft types.
Note many fighters, including daylight ones, had IFF devices so ground
control knew who was where.

[Alan Meyer]

... How did they distinguish friend from foe in the dark? Given
that it would be hard to see much of anything in the dark, it
must have been very challenging indeed to tell their own
compatriots from whatever enemies were in the sky. I'm guessing
that each plane had some sort of recognition light on it but
I'm assuming it was pretty small so that it couldn't be easily
seen from the ground. After all, you wouldn't want
anti-aircraft batteries to be able to see you too easily for
fear that they would hit you.

One tool used by both sides was "Identification Friend or Foe"
(IFF). I've sometimes seen the acronym interpreted as
"Interrogate Friend or Foe".

The idea was to place a radio transponder in the tail of the
airplane. When it received a certain signal on a pre-selected
frequency it would respond with a return signal. The German air
defenses used this to distinguish their own night fighters in a
stream of Allied bombers, and I believe the British also used it
to enable their night fighters to distinguish, well, friend from
foe.

As with the rest of the electronic systems during the war, there
was steady development on both sides with new capabilities and
new counter measures. I believe that at one point, the British
were able to equip night fighters with a device that would send
the signal to the German night fighters that caused them to
respond. That would allow British fighters to find and shoot
down the German fighters. So the very device intended to save
you from being destroyed by your friends could cause you to be
shot down by your foes.

Alan

[Jim H.]

On Mar 13, 3:30 pm, Rhino <***@example.com>
wrote:.............

Post by Rhino
What was the mechanical difference between a plane that was a night fighter
and one that wasn't? In other words, what equipment did a night fighter
have that made it capable of night-fighting that another plane lacked?............

.................

In addition to the other items mentioned, I think some (most?) also
had flash hiders / flash suppressors on the muzzles of their
weapons... AFAIK, these were just simple cones of sheet metal added
beyond the muzzle. They were there to prevent ruining the pilot's
night-adapted vision when firing, and to make the night fighter less
visible to other aircraft.

Jim H.

[Geoffrey Sinclair]

Post by Rhino
I'm just reading an account of the so-called Dam Busters Raid and it's
raised a few questions for me. I have no military experience so forgive any
questions that seem foolish.
What was the mechanical difference between a plane that was a night fighter
and one that wasn't?

Not a lot if you mean WWII ones, most night fighters were versions of
aircraft designed for other purposes.

Ideally aircraft flying at night have better low speed and landing
performances, to decrease the accident rates.

The early WWII ideas about night fighters assumed twin engines for
range and firepower considerations. Though the pre war German fighter
units used Bf109s. The addition of a radar set initially meant the need
for a second crew member, the size of the sets tended to dictate a
larger aircraft as well. Twin engines mean the radar could be nose
mounted.

That did not stop the appearance of radar equipped Defiants in the
RAF and later radar equipped Hellcats, Corsairs and Fw190s
and others.

Post by Rhino
In other words, what equipment did a night fighter
have that made it capable of night-fighting that another plane lacked?

Generally an on board radar set. Things like flame dampeners for
exhausts were also employed.

Post by Rhino
I
know that night-vision goggles weren't invented until well after the war so
I know it can't be that.

The allied night fighters at least carried night binoculars, to enable them
to identify what aircraft they were attacking. Radar was the primary
search tool, the Germans tried an infra red system but radar was much
better.

Post by Rhino
Also, how did night fighters do their jobs in the dark?

With much assistance from ground based radars. The allied on board
radars had better range than the Germans but nothing like that of the
ground based units. Hence the efforts made to jam the ground based
radars as well as the communications to the pilots.

There was also homing on any transmissions aircraft made, like their
radars, or their IFF sets.

Post by Rhino
How did they
distinguish friend from foe in the dark?

Visual identification. Night is rarely truly dark. Especially above most
of the clouds, there is some starlight or even a lighter horizon.

Post by Rhino
Given that it would be hard to see
much of anything in the dark, it must have been very challenging indeed to
tell their own compatriots from whatever enemies were in the sky.

Correct.

Post by Rhino
I'm
guessing that each plane had some sort of recognition light on it

Over friendly territory with no alarms about hostile intruders, otherwise
it was electronic, IFF systems were in place early in WWII, they grew
up alongside the radar chains. One method was to try and trigger your
opponents IFF, in a bomber formation only one needed to fail to switch
off their IFF to enable the formation to be tracked.

Post by Rhino
but I'm
assuming it was pretty small so that it couldn't be easily seen from the
ground. After all, you wouldn't want anti-aircraft batteries to be able
to
see you too easily for fear that they would hit you.

Think of it like aircraft markings, the compromise between being clear
to friends while not being so clear to opponents. There is no right answer.

Geoffrey Sinclair
Remove the nb for email.

[e***@yahoo.com.au]

Post by Rhino
I'm just reading an account of the so-called Dam Busters Raid and it's
raised a few questions for me. I have no military experience so forgive any
questions that seem foolish.
What was the mechanical difference between a plane that was a night fighter
and one that wasn't? In other words, what equipment did a night fighter
have that made it capable of night-fighting that another plane lacked? I
know that night-vision goggles weren't invented until well after the war so
I know it can't be that.
Also, how did night fighters do their jobs in the dark? How did they
distinguish friend from foe in the dark?

IFF identify friend of foe. The German system was called "Erstling",
it was designed by the builders and designers of the Freya radar
called GEMA.
A device called a transponder on the aircraft reacted to an
interrogation signal from the ground control radar and sent out pulse
on a different frequency.

The transponder on the German aircraft was called the FuG 25a. It
was triggered by a frequency slightly of the standard Freya
frequeny and would react by sending back a slightly delayed pulse on a
different frequency. It would also send back a 2 letter morse code.
On the radar screen the radar opperator would suddenly see two
slightly seperated pulses when he interrrogated.

Since a transponder response was more powerfull than a reflected radar
echoe the range was quite long: 270km.

An Eralier system called Zwilling (twin) also desginated FuG 25 was
developed by Telefunken and triggered by the Wurzubug radar
switching from a pulse repetion frequency of about 3250Hz to 5000Hz.
It was a failure as the radar function was so disrupted tracking and
ranging
was lost and the morse code could not be assigne. The solution was to
mount a seperate set of dipoles on the Wuraburg dish with an
interrogator.

One weakness of the Ersling/FuG 25a system is that it did not opperate
from night fighters but only ground stations. In general however
for German night fighter pilots the rule was that if it had 4 engines
shoot it down because its allied, if it had two it probably was not
allied.

German Ground Control Stations would typically have:
1 One Freya radar for long range detection with an integral IFF
abillity.
2 two Wurzburg-Riesse (Wurzbug giant with 7.5m dia dish) supposedly
one for tracking the fighter and the other the bomber
3 two Freya-Erstling, basically a Freya without the radar and only the
abillity to track friendly fighters viat their FuG 25a.
Thus two enemy bombers could be tracked and two interceptors guided to
them.

The Freya using addtions to its lobe switching circuitry could
accurately track the friendly fighter and the
enemy bomber very accurately so long as they were within 6 degrees of
each other, so in good circumstances three
intercepts presumably could be guided.

A boosted verstion of the Freya Erstling FuG 25a also was the basis of
EGON I, EGON II which were blind bombing systems. EGON II worked much
like Oboe.

Post by Rhino
Given that it would be hard to see
much of anything in the dark, it must have been very challenging indeed to
tell their own compatriots from whatever enemies were in the sky.

Somewhat of a problem for the Germans since they didn't have airborn
IFF.

The FuG 25a Erstling was supposed to be replaced by the FuG 226
"Neuling" which had multiple
freuquencies and was to be for both blind bombing and interception as
well as IFF. Nueling did have
airborn IFF abillity, had variants for naval use and an advanced
development FuG 229 "Frishling".

Post by Rhino
I'm
guessing that each plane had some sort of recognition light

Forgetting to turn this off could get you killed.


The Germans also opperated ground based equipement to track allied
emisions. Freya-Flamme was able to trigger allied IFF.

The story behined this is interesting. Freya radar opperated at
around 2.4 meters. However many opperated at a wide range of other
frequencies from 5m to about 1.5m to burdern allied jamming efforts

This latter 1.5m frequency was chosen to coiniced with British Chain
Home Low radar since the British would be reluctant to Jam their own
radar close to the coast.

One of these sets due to a defect triggered Allied IFF. The Germnans
were able to consistantly track allied movements both US and British
throughtout the war.

Even in the Post was opperation "post mortom" in which hundreds of
allied bombers flew over the intack
German defenses over Denmark with German opperators aircraft forgot to
turn of their IFF.

Post by Rhino
on it but I'm
assuming it was pretty small so that it couldn't be easily seen from the
ground. After all, you wouldn't want anti-aircraft batteries to be able to
see you too easily for fear that they would hit you.
--
Rhino

Its worth looking at some of the standard equipment of the mid war
luftwaffe night fighter.

The aircraft would certainly have had the following 'standard'
equipment:
1 Artificial Horizon for blind flying in bad weather.
2 Flourescent radium based instuments.
3 FuG 10 radio
4 FuG 16ZY directional becon, which could also provide distance to
becon as well for guided interceptions.
5 FuG 25a IFF which provided not only IFF but a transponder for
versions of the freay radar set up to only track the night fighter for
use by ground control.
6 FuG 101a radar altimeter accurate to about 1m.
7 Fub 2L F, a runway line up becon for blind landings.
8 A radar eg the FuG 202B/C or FuG 212 Litchtenstein, FuG 220 SN2 or
Fug 218 Neptune radar. Some versions of the latter two offered a tail
warning mode as well.

Also the FuG 125 Hermine for a combination of navigation, blind
approaches and reception of ground reports.

These 'lobe' switching radar would pick up everything within 60
degrees, give their range and a good indicaton if the target was
higher, lower, left or right or dead ahead.

Fairly common was
FuG 350 Naxos to home onto H2S or 9cm radar. FuG 350ZX for 3cm radar.
(rarer)
FuG 351 Korfu, a far more sensitive radar homer with greater
directional accuracy and range characterised by being specifically
tunable to a specific radar so as to home onto a specific aircraft.
FuG 221 Freya Halbe for tracking allied aircraft emiting Jamming on
Freya frequencies. FuG 221a Rosendal Halbe for indications of Monica
tail warning emissions.

FuG 227 Flensburg was to home onto a vaiatly of meter wave amisions
including ASV but by the time it came in the move to centimetric radar
was in full swing.

FuSAn 724/725 "Bernhard" UKW-Richtstrahl-Drehfunkfeuer were already in
operation around 1942. The system consisted of a
very large antenna which rotated 360 dg. twice a minute. The receiver
in the aircraft
(FuG 120 "Bernhardine") displayed the bearing to the station on a
narrow paper strip. The system was modified to
transmit a very abbreviated Reportage Lage consisting of the height of
the Bomber Stream, the position,
heading and strength. The system worked on 30 - 33,3 Mhz, was high
powered, directional and hence very
difficult to jam. By switching between 2 stations the radio operator
could obtain a fix every 1 minute and
he did not have to work 2 radios to find a jamming free frequency.


The radar wasn't that neccesary, a ground guided interception was
possible relying on the pilots eysight fot the last 200m.


There was a lot happening and this mostly required 3 crew. However
the Germans did test Fw 190 and Me 109 with Naxos passive radar and
also FuG 217 radar.

In General it was found that after quarter of an hour staring into an
cathode ray tube that the pilots precious night vision was gone.


The equipment was only getting more diverse: FuG 280 was a fairly
effective infrared homing system.
It was found that sound locators, when mounted on a jet could track a
4 engined piston bombers out to several kilometers.

Blind firing computers to fire guns or rockets in single high speed
high ofset passes were also close to becoming standard.

[Geoffrey Sinclair]

Post by e***@yahoo.com.au

Post by Rhino
I'm just reading an account of the so-called Dam Busters Raid and it's
raised a few questions for me. I have no military experience so forgive any
questions that seem foolish.
What was the mechanical difference between a plane that was a night fighter
and one that wasn't? In other words, what equipment did a night fighter
have that made it capable of night-fighting that another plane lacked? I
know that night-vision goggles weren't invented until well after the war so
I know it can't be that.
Also, how did night fighters do their jobs in the dark? How did they
distinguish friend from foe in the dark?

IFF identify friend of foe. The German system was called "Erstling",
it was designed by the builders and designers of the Freya radar
called GEMA.
A device called a transponder on the aircraft reacted to an
interrogation signal from the ground control radar and sent out pulse
on a different frequency.
The transponder on the German aircraft was called the FuG 25a. It
was triggered by a frequency slightly of the standard Freya
frequeny and would react by sending back a slightly delayed pulse on a
different frequency. It would also send back a 2 letter morse code.
On the radar screen the radar opperator would suddenly see two
slightly seperated pulses when he interrrogated.
Since a transponder response was more powerfull than a reflected radar
echoe the range was quite long: 270km.

Provided of course the aircraft was high enough.

Post by e***@yahoo.com.au
An Eralier system called Zwilling (twin) also desginated FuG 25 was
developed by Telefunken and triggered by the Wurzubug radar
switching from a pulse repetion frequency of about 3250Hz to 5000Hz.
It was a failure as the radar function was so disrupted tracking and
ranging
was lost and the morse code could not be assigne. The solution was to
mount a seperate set of dipoles on the Wuraburg dish with an
interrogator.

The Germans developed different IFF sets for the Freya and Wurzburg,
Stichling was the Wurzburg system, modified to the Zwilling system in
1941, a report on them concluded "completely unusable" the sets were
later cannibalised to make Erstling sets, which were fitted to both radar
types. Meaning German aircraft finally only needed one IFF set, the
first Wurzburg/Erstling set was introduced on 9 July 1942.

Post by e***@yahoo.com.au
One weakness of the Ersling/FuG 25a system is that it did not opperate
from night fighters but only ground stations.

No what the fighters needed to do was carry the relevant interrogators,
the allies managed this quite easily.

Post by e***@yahoo.com.au
In general however
for German night fighter pilots the rule was that if it had 4 engines
shoot it down because its allied, if it had two it probably was not
allied.

This is the night raids in 1944, the last Wellingtons bombing raid was
on 8 October, the last loss from a front line unit was on 20 February
1944 on a mine laying sortie. Leaflet operations continued until
France was liberated, and some flew on support and diversion
operations until the final quarter of 1944.

The Mosquito was distinctive enough thanks to its altitude and speed.

Post by e***@yahoo.com.au
1 One Freya radar for long range detection with an integral IFF
abillity.
2 two Wurzburg-Riesse (Wurzbug giant with 7.5m dia dish) supposedly
one for tracking the fighter and the other the bomber
3 two Freya-Erstling, basically a Freya without the radar and only the
abillity to track friendly fighters viat their FuG 25a.
Thus two enemy bombers could be tracked and two interceptors guided to
them.

The set up was one Freya for distant warning, one Wurzburg to
track the hostile, one to track the friendly, the idea the IFF is
attached to non radars is simply wrong. One intercept at a time,
and the night fighters were not carrying IFF before July 1943.

Post by e***@yahoo.com.au
The Freya using addtions to its lobe switching circuitry could
accurately track the friendly fighter and the
enemy bomber very accurately so long as they were within 6 degrees of
each other, so in good circumstances three
intercepts presumably could be guided.

Simply put the above is an exaggeration.

Note Lobe Switching means using half the antenna capacity at a time,
with the corresponding reduction in range and of course such D/F
work interferes with all round tracking.

Post by e***@yahoo.com.au
A boosted verstion of the Freya Erstling FuG 25a also was the basis of
EGON I, EGON II which were blind bombing systems. EGON II worked
much like Oboe.

Egon used the radar/IFF idea. Oboe used the dots and dashes radio
beams idea.

Oboe was used extensively from 1943 onwards, Egon appears to have
maybe been used by one staffel during some of the 1944 Baby Blitz.

Post by e***@yahoo.com.au

Post by Rhino
Given that it would be hard to see
much of anything in the dark, it must have been very challenging indeed to
tell their own compatriots from whatever enemies were in the sky.

Somewhat of a problem for the Germans since they didn't have airborn
IFF.

They did not have IFF interrogators on their night fighters.

Post by e***@yahoo.com.au
The FuG 25a Erstling was supposed to be replaced by the FuG 226
"Neuling" which had multiple
freuquencies and was to be for both blind bombing and interception as
well as IFF. Nueling did have
airborn IFF abillity, had variants for naval use and an advanced
development FuG 229 "Frishling".

The reality is the Neuling had some prototypes in 1945.

Post by e***@yahoo.com.au

Post by Rhino
I'm
guessing that each plane had some sort of recognition light

Forgetting to turn this off could get you killed.

Actually leaving the IFF transmitting aircraft alone was the better
idea, that way you kept the track.

Leaving your flying lights on was usually obvious to the crew.

Post by e***@yahoo.com.au
The Germans also opperated ground based equipement to track allied
emisions. Freya-Flamme was able to trigger allied IFF.

Actually the code flame was used for triggering allied IFF.

Post by e***@yahoo.com.au
The story behined this is interesting. Freya radar opperated at
around 2.4 meters. However many opperated at a wide range of other
frequencies from 5m to about 1.5m to burdern allied jamming efforts

The short answer here is no, the many is simply incorrect. The 5 metre
devices appear to have been experimental for example.

Post by e***@yahoo.com.au
This latter 1.5m frequency was chosen to coiniced with British Chain
Home Low radar since the British would be reluctant to Jam their own
radar close to the coast.

The simple answer here was the jamming of Freya did happen, the
allies worked out ways around their own jamming, and in any case
the jamming aircraft were closer to the German sets.

Post by e***@yahoo.com.au
One of these sets due to a defect triggered Allied IFF. The Germnans
were able to consistantly track allied movements both US and British
throughtout the war.

It goes like this, until the use of window/chaff in July 1943 and the
subsequent introduction of active jamming the Germans had no
need to built devices to track allied emissions. That changed in the
second half of 1943.

The Germans had plenty of allied IFF sets to study and understand
how they worked and therefore how to trigger them if required.

The Germans began using devices to trigger allied IFF sets, and to
track/home in on any active emitters, the H2S sets and the Monica tail
warning radar once the allied jamming started. Another idea was to
use the chain home transmissions.

It only took one bomber to leave its IFF set on to give the tracking
system an idea of raid position. This did not matter during the
day as the USAAF was only interested in jamming the flak gun
fire control radars, but it clearly was important at night. The
landing of a Ju88G in July 1944 provided the solid proof of how
dangerous any radio or radar emissions were. So more vigorous
orders were issued about turning IFF off, Monica was removed and
the H2S sets were not used until around the German border. The
policy was helped by the allies gaining control of France, it meant the
jamming of the older GEE system did not become a problem until the
German border plus of course the allies could provide other navigation
aids if required from ground stations.

Post by e***@yahoo.com.au
Even in the Post was opperation "post mortom" in which hundreds of
allied bombers flew over the intack German defenses over Denmark
with German opperators aircraft forgot to turn of their IFF.

Or alternatively left them on to see what the tracking system could
do with the information.

Operation Post Mortem.

Post by e***@yahoo.com.au

Post by Rhino
on it but I'm
assuming it was pretty small so that it couldn't be easily seen from the
ground. After all, you wouldn't want anti-aircraft batteries to be able to
see you too easily for fear that they would hit you.

Its worth looking at some of the standard equipment of the mid war
luftwaffe night fighter.

Mid war is of course technically July 1942.

Post by e***@yahoo.com.au
The aircraft would certainly have had the following 'standard'
1 Artificial Horizon for blind flying in bad weather.

This would be standard pre war.

Post by e***@yahoo.com.au
2 Flourescent radium based instuments.

Again pre war and these should have been a backup, since you cannot
adjust intensity, and they faded with time, unlike a standard instrument
panel light.

Post by e***@yahoo.com.au
3 FuG 10 radio

Fitted as standard from 1939.

Post by e***@yahoo.com.au
4 FuG 16ZY directional becon, which could also provide distance to
becon as well for guided interceptions.

The Y refers to the Y Gerat system used by bombers in attacks on
England in 1940/41 and 1944. This was not fitted on night fighters
until post July 1943, when freelance tactics were adopted with the
corresponding need for navigation aids.

It was standard equipment by around the end of 1943 or more
probably early 1944.

Post by e***@yahoo.com.au
5 FuG 25a IFF which provided not only IFF but a transponder for
versions of the freay radar set up to only track the night fighter for
use by ground control.

Again not fitted to night fighters until after July 1943 as part of the
freelancing tactics, since the set was in serial production for bombers
it seems to have been fitted earlier than Y systems.

Post by e***@yahoo.com.au
6 FuG 101a radar altimeter accurate to about 1m.

Accuracy over stated,

www.dornier24.com/pages/equipment/FuG101.html

Post by e***@yahoo.com.au
7 Fub 2L F, a runway line up becon for blind landings.

FuBl 2F

Something from 1944, This was fitted to the mid 1944 He219A-7
version for example and on the captured Ju88G. It was not fitted
to the He219A-6 as built.

Post by e***@yahoo.com.au
8 A radar eg the FuG 202B/C or FuG 212 Litchtenstein, FuG 220 SN2 or
Fug 218 Neptune radar. Some versions of the latter two offered a tail
warning mode as well.

As of mid 1943 some 20% of German night fighters did not carry
radar due to a lack of production. One reason some were used as
day fighters.

The jamming forced the change over from the older Lichtenstein to
SN-2 in the period second half of 1943 to early 1944.

Neptun was developed for single seater fighters and deployed in
mid 1944. By that stage the majority of the single engined night
fighter units were now all weather day fighters. The remaining
aircraft were mainly meant as Mosquito hunters.

Post by e***@yahoo.com.au
Also the FuG 125 Hermine for a combination of navigation, blind
approaches and reception of ground reports.

By the looks of things a few sets were built in 1945 and used on
the Fw190 and Bf109.

Post by e***@yahoo.com.au
These 'lobe' switching radar would pick up everything within 60
degrees, give their range and a good indicaton if the target was
higher, lower, left or right or dead ahead.

Out to a distance that depended on the height of the night fighter,
thanks to the ground returns, take off around 500 metres from
the height as a rule of thumb.

Lichtenstein search angle was 24 degrees, maximum range 4,000
metres.

SN-2 could search an arc of 120 degrees, maximum range 6,500
metres.

Post by e***@yahoo.com.au
Fairly common was
FuG 350 Naxos to home onto H2S or 9cm radar.

Again not deployed until early 1944, for the same reasons as above.

Post by e***@yahoo.com.au
FuG 350ZX for 3cm radar.
(rarer)

Very rare and late war www.cdvandt.org/Naxos95nw.pdf

Post by e***@yahoo.com.au
FuG 351 Korfu, a far more sensitive radar homer with greater
directional accuracy and range characterised by being specifically
tunable to a specific radar so as to home onto a specific aircraft.

Again something from 1945 and the capabilities are being exaggerated.

Post by e***@yahoo.com.au
FuG 221 Freya Halbe for tracking allied aircraft emiting Jamming on
Freya frequencies.

Small numbers produced in 1944/45.

Post by e***@yahoo.com.au
FuG 221a Rosendal Halbe for indications of Monica
tail warning emissions.

Another test system, no mass production.

Post by e***@yahoo.com.au
FuG 227 Flensburg was to home onto a vaiatly of meter wave amisions
including ASV but by the time it came in the move to centimetric radar
was in full swing.

Actually this was the Monica tail warning radar tracker, maybe 250
sets built.

The following seems to have been copied from,

http://www.gyges.dk/luftwaffe_bernhard.htm

The bit missing from the Eunometic text is "A small number of"

Post by e***@yahoo.com.au
FuSAn 724/725 "Bernhard" UKW-Richtstrahl-Drehfunkfeuer were already in
operation around 1942. The system consisted of a
very large antenna which rotated 360 dg. twice a minute. The receiver
in the aircraft
(FuG 120 "Bernhardine") displayed the bearing to the station on a
narrow paper strip.

Basically a modified radio beacon, used for operations over the North
Sea, a way around the RAF jamming and "bending".

Post by e***@yahoo.com.au
The system was modified to
transmit a very abbreviated Reportage Lage consisting of the height of
the Bomber Stream, the position,
heading and strength. The system worked on 30 - 33,3 Mhz, was high
powered, directional and hence very
difficult to jam. By switching between 2 stations the radio operator
could obtain a fix every 1 minute and
he did not have to work 2 radios to find a jamming free frequency.

The bit missing from the Eunometic text is "in January 1945".

Post by e***@yahoo.com.au
The radar wasn't that neccesary, a ground guided interception was
possible relying on the pilots eysight fot the last 200m.

This would come as a surprise to the night fighter pilots and is
contradicted by the results as the night fighters were fitted with
radar. The radar sets cost performance, if they were truly no
that necessary they would have been removed.

Post by e***@yahoo.com.au
There was a lot happening and this mostly required 3 crew. However
the Germans did test Fw 190 and Me 109 with Naxos passive radar and
also FuG 217 radar.

Naxos was not passive radar, it was a radar detector.

Post by e***@yahoo.com.au
In General it was found that after quarter of an hour staring into an
cathode ray tube that the pilots precious night vision was gone.

In other words, if correct, have ground control put you onto the tail
of the bomber so your radar is only used for the last few minutes.

As can be seen from above the Eunometic definition of "mid war" is
rather flexible.

Post by e***@yahoo.com.au
The equipment was only getting more diverse: FuG 280 was a fairly
effective infrared homing system.

Fairly effective is a Eunometic term meaning German, rather than a
performance measure, a few of the devices built in 1945.

Post by e***@yahoo.com.au
It was found that sound locators, when mounted on a jet could track a
4 engined piston bombers out to several kilometers.

It would be interesting to see the reality of this idea given the results
from pre war, large, ground based sound locators.

Post by e***@yahoo.com.au
Blind firing computers to fire guns or rockets in single high speed
high ofset passes were also close to becoming standard.

Translation, ideas were being thought up, test designs being
considered, prototypes being built.

Geoffrey Sinclair
Remove the nb for email.