Researching the Luftwaffe through Prisoner Interrogations

[Bruce Dennis]

"SECRET A.D.I.(K) Report No.187/1944
THE FOLLOWING INFORMATION HAS BEEN OBTAINED FROM P/W.
AS THE STATEMENTS MADE HAVE NOT AS YET BEEN VERIFIED,
NO MENTION OF THEM SHOULD BE MADE IN INTELLIGENCE
SUMMARIES OF COMMAND OR LOWER FORMATIONS, NOR SHOULD
THEY BE ACCEPTED AS FACT UNTIL COMMENTED ON IN AIR
MINISTRY INTELLIGENCE SUMMARIES OR SPECIAL
COMMUNICATIONS.
SOME FURTHER NOTES ON G.A.F. PATHFINDER PROCEDURE.
1. Since the issue of A.D.I.(K) Report N°160/151,4, "A G.A.F.
Pathfinder Unit", the two P/W concerned have added some
further details of the Egon procedure. This information,
together with some notes on other navigational aids, is
summarised in the present report.
EGON PROCEDURE
Operation
2. It was stated to be usual for five or six aircraft from
5/K.G.66, using the Egon procedure, to take part in a
pathfinder operation. Whilst some of these would be engaged in
laying the turning point markers, others, all controlled on
one and the same frequency, would be flying at intervals to
the target to place and renew the target marking.
3. According to P/W, although one Freya would suffice for the
Egon procedure, two plotting Freyas are employed so that the
second can give undivided attention to the aircraft which is
near and over the target, whilst the first Freya plots the
aircraft up to that point.
4. When a pathfinder aircraft has released its first flares
it is usual for it to make a 180° left-hand turn and fly away
from the target, leaving its bomb-doors open and maintaining
the same height as at the time of flare release; a further
turn of 180° then brings the aircraft back to its original
course for the second run-in.
5. Freya control is maintained during this manoeuvre and
course corrections are given if necessary; should the aircraft
be in the correct position for the bombing run, the only
signals from control are those for pre-release (dash) and for
release (dot). It is stated that the latter signal may consist
of either one or three dots.
6. It frequently occurs that aircraft which have placed the
turning-point markers also proceed to the target area to help
in renewing the marker flares. In such cases the aircraft are
given new courses by control immediately after completion of
the turning-point marking; the initial new course is indicated
in this case in degrees, e.g.: "Autobahn 128".
7. Freya control of any aircraft ceases immediately after the
completion of the task of that particular aircraft.
Range and Accuracy
8. The present Egon procedure is operable up to a range of
approximately 270 km. P/W amplified his previous statement on
the accuracy of the present Egon procedure and stated that he
had been told it was accurate to 0.3 degrees in bearing and
200/250 metres in range.
Communication with Aircraft
9. The P/W from the Z6+IN was able to add further code words
and their meanings to the list given is paragraph 20 of
A.D.I.(K) 160/1944.-
W/T R/T Meaning
3 letter code group Zeppelin
Originally (Rübezahl)
Codes used for
"control"
...--... Frage Question (precedes a
codeword if a
question is asked
MAR Marie Your distance in min-
(followed by a number) utes from base is ...
NTE Ente Your distance from
(followed by a number) the target is ...
SNK Schnecke (=snail) decrease speed
EXP Express increase speed
KRS Karussel (=merry-goround)
Fly in circle
REI Reise Reise Fly on as at
present
NAL 1 Kanal 1
NAL 2 Kanal 2
(The keyed (morse
(recognition) and un-
(Keyed signals
(respectively of the
(FuGe 25A.
CCC Caruso No more evasive
action to be taken
from now (prior to
bomb release signal)
AAAMAT+/+ Autobahn+/+
Heimat
Set course for base
VVV Victor understood
SAL Trübsal Have you enough fuel
(followed by a number) for....minutes flying
KKK Ich besuche Sie
or
Ich besuche Sie nicht
mehr, bitte kommen
you are being plotted
or
control finished,
please confirm
+/+ = amendment to previous list.
10. The signals "Schnecke" and "Express" are given by control
when the aircraft in ahead of or behind schedule. When control
sees that the aircraft will arrive too early, "Schnecke",
followed by a number is signalled, meaning "at your present
speed you will arrive...... minutes too soon over the target".
"Express" is given for the opposite condition.
11. Before the pathfinder aircraft has been released by
control the only communication from the aircraft to control is
normally by manipulation of the FuGe 25A switch, although if
specially requested the aircraft will resort to R/T or W/T.
Control frames questions to the aircraft in such a way that
they only require an acknowledgement and can therefore be
answered by means of the FuGe 25A.
12. The FuGe 25A is switched to Kanal 1 to transmit the morse
recognition signal and to Kanal 2 for the unkeyed tone signal.
Kanal 1 is employed until the aircraft is within 50 km of the
target, Kanal 2 being used whilst the aircraft is near and
over the target and under control of Freya No.2. The latter
Kanal enables the bearing of the aircraft to be read more
accurately.
13. Each signal passed by control to the aircraft must be
acknowledged on the FuGe 25A, either on Kanal 1 or 2. In
practice, however, crews often forget to acknowledge signals
and control therefore requests "Kanal Quittung" and awaits the
appropriate reply.
14. When control of an aircraft is being withdrawn, control
signals "Ich besuche Sie nicht mehr, bitte kommen" (I have
finished with you, please confirm).
Communication Frequencies
15. As an example of R/T and W/T frequencies employed on a
pathfinder operation, P/W quoted those used on the night of
24/25th March 1944. These were 40.5 mc/s on FuGe 16 and 4848
kc/s on FuGe 10, besides the 583 kcs of the broadcasting
station Calais I.
New Egon Procedure
16. It was stated that certain crews of 5/K.G. 66 had been
sent to Königsberg/Neumark for practice with the new Egon
procedure.
17. whilst P/W had little to add to his original description
of the Egon attachment which will be introduced into
operations at some future date, he believed that the
presentation apparatus of the ground-control equipment is
divided up into sectors in a similar manner to the airborne
apparatus.
18. He did not know details of the frequency, other than that
it is V.H.F. and crystal controlled.
OTHER NAVIGATIONAL AIDS Bernhardiner Gerät
19. The present P/W were able to add a few small details on
this subject to those given in A.D I.(K) 108/1944 paragraphs
37 - 39.
20. In October 1943, 5/K.G. 66 had a Do. 217M equipped with
the Bernhardiner Gerät, manufactured by Telefunken.
Oberleutnant Grotz and a civilian technician named Menzel or
Wenzel conducted some experiments but came to the conclusion
that the apparatus was not sufficiently accurate for
pathfinder work. It was thought to be accurate enough for the
use of bomber units, however, and at that time it was proposed
to pass the equipment over to K.G. 6.
21. P/W later overheard the Gruppenkommandeur saying that the
project might have been abandoned as work on the ground
installations had ceased.
22. One Bernhard (ground station) was known to P/W near
Chartres; the apparatus was about 30 metres high and was
mounted on a turntable some 40 metres in diameter. Each ground
transmitter was to work on a different frequency so that dross
bearings could be taken.
23. The aircraft equipment included a Hellschreiber
(teleprinter) some 40 cm. square. A paper tape appeared in a
window of about 30 cm. in length in the front panel, and every
30 to 60 seconds the true bearing of the aircraft and the time
of the bearing appeared on the tape. This equipment, which was
thought by P/W to work through the E.B.L.3., is remarkably
reminiscent of the Drehelektra described by P/W of the old
Gruppe 106 in May 1942 (A.D.I.(K) 104/1942 paragraphs 8 - 15)
and later by other P/W of the same unit (A.D.I.(K) 244/1942
paragraphs 11 - 16).
24. The range of the Bernhard was said to have been about 400
km. under ideal conditions.
Erika Gerät
25. Experiments in this navigational aid were conducted in
K.G. 66 under the direction of a civilian technician by the
name of Voss. The system was abandoned as being too open to
enemy countermeasure, and the instruments were withdrawn from
the unit. P/W knew no details of how the Erika Gerät
functioned.
Y-Gerät
26. P/W stated that 1/K.G. 66 used the 'Y' system as a
navigational aid; he had seen the switch for the FuGe. 28A in
one of the aircraft of that Staffel.
"X" Clock
27. Early in 1943 P/W saw a number of "X" clocks, of both the
larger and the new smaller types, in the technical section of
the Staffel. He understood that these were to be employed in
conjunction with Hohentwiel for attacking ships. He had heard
nothing more of this, however, and recently the "X" clocks
were no not to be seen.
Jamming of Knickebein
28. One of the present P/W stated that it was possible for an
experienced operator to read through British jamming of
Knickebein; he said that the genuine dots and dashes were more
pronounced than those produced by the countermeasures.
29. Another type of interference which P/W had experienced
with Knickebein took the form of rising and falling wail.
German Jamming of R/T
30. P/W could not enlarge on his previous account of the
activities of 3/K.G.66, to which he was attached for six
months at Cormeilles-en-Vexin, since during that period the
Staffel was still only under training for investigation and
countermeasure flights. He stated, however, that the aircraft
were equipped with a fixed wire aerial about 1.20 metres in
length fitted under the fuselage, and he believed that this
aerial was used in conjunction with the Viktor R/T jamming
set.
A.D.I.(K) S. D. Felkin
25/Apr/44 Wing Commander"