Sennheiser 502399 User manual

Instruction manual
HMEC 26

1
Safety instructions
yPlease read these instructions carefully and
completely before using the headset.
yMake these instructions easily accessible to all users
at all times.
yAlways include these instructions when passing the
headset on to third parties.
yDuring flight operation, do not use the headset for
telephone calls.
yWith the NoiseGard™ active noise compensation
switched on, typical aircraft sounds (for example,
those from engines, propellers, warning alarms, etc.)
may sound different to you. Before operating any
aircraft, make sure that, with NoiseGard™ switched
on, you can hear and recognize these sounds. Set the
volume to safe levels that do not interfere with your
ability to hear informational sounds and warning
alarms.
yThe headset is capable of producing sound pressure
levels exceeding 85 dB(A). In many countries 85 dB(A)
is the maximum legally permissible level for
continuous noise exposure during the working day.
Exposure to sounds of higher volume levels or for
longer durations can permanently damage your
hearing!
yNever repair or attempt to repair a defective headset
yourself. Contact your Sennheiser agent or the
Sennheiser Service Department.

2
yOnly replace those parts of the headset whose
replacement is described in this manual. All other
parts of the headset must be replaced by your
Sennheiser agent.
yProtect the headset from humidity. Use only a slightly
damp cloth to clean the headset. For information on
how to clean the headset, contact your Sennheiser
agent.
Intended use of the headset
Intended use includes:
• having read this instruction manual especially the
chapter “Safety instructions”.
• using the headset in jet aircraft and within the
operating conditions as described in this instruction
manual.
Improper use
Improper use means using the headset other than as
described in this instruction manual, or under operating
conditions which differ from those described herein.

3
The HMEC 26 headset
The HMEC 26 headset with NoiseGard™ active noise
compensation features dynamic, closed headphones. The
noise-compensating condenser microphone ensures
excellent speech transmission even in noisy
environments. Designed for use in aircraft cockpits.
Features
yNoiseGard™ active noise compensation reduces
ambient noise by up to 18 dB – consequently the radio
volume can be decreased
yLightweight
yExtremely comfortable to wear due to the patented
two-piece automatic headband and soft earpads
yPeak level protection (cannot be switched off)
safeguards you from volume peaks above 110 dB
y“Flip-away” headphone allows single-sided listening
yFlexible microphone boom, can be worn on either left
or right-hand side
yNoise-compensating condenser microphone ensures
excellent speech transmission
ySingle-sided cable, easy to replace
yWith NoiseGard™ switched off, the headset can be
used as a conventional headset
yPower supply for NoiseGard™ from aircraft DC power
supply system (on suitably equipped aircraft) or
batteries/rechargeable batteries
y“Auto shut-off” extends battery life
yTalkThrough function (HMEC 26-T only)

4
yETSO approval C57a/C58a
Delivery includes
y1 HMEC 26 headset
y1 cable clip
y1 wind and pop screen
y1 instruction manual
y1 carry bag
y1 EASA Form 1
Operation
Turning the microphone boom
The microphone boom can be rotated. This allows the
headset to be worn with the microphone boom positioned
on either the left or right-hand side of the head.

5
Putting on the headset
When putting on the headset, the patented two-piece
headband adjusts automatically.
Positioning the microphone
Bend the flexible microphone boom so that the micro-
phone is placed at the corner of the mouth. Maintain a
distance of approx. 2 cm between microphone and mouth.
Always use the supplied wind and pop screen.

6
Flipping away one earcup
The headset features a “flip-away” earcup for single-
sided listening.
Adjusting the volume directly on the audio system
Connect the headset to the corresponding sockets of your
audio system. Adjust the volume directly on the audio
system.
Hearing damage due to high volumes!
This headset is capable of producing high
sound pressure levels. Higher volumes or
longer durations can damage your hearing!
Set the volume to a medium level. Make sure
that you can hear critical sounds such as
warning alarms.
CAUTION!

7
Adjusting the microphone sensitivity
The microphone sensitivity has been factory pre-set to
80 mV/Pa as per RTCA DO-214. You can change the
microphone sensitivity by turning a small screwdriver in
the direction of the arrow.
+
–

8
The operating controls of the HMEC 26
Operating control I
Volume controls
LED
NoiseGard™ ON/OFF
switch
Mono/stereo switch
BOOM switch L/R
3.5 mm jack socket
Battery compartment
2.5 mm jack socket
Headset with
operating
control I
Operating element

HMEC26-BV-K xxxxxxxx
HMEC26-BV-KP xxxxxxxx
HMEC 26-BV-CP x x x x x
HMEC 26-B-K x x x
HMEC 26-B-CP x x x
HMEC26-V-KP xxxxx
HMEC26-V-RP xxxxx
HMEC 26-V-CP x x x x
HMEC26-V-KX xxxxx















9
Operating control II
LED
NoiseGard™ ON/OFF
switch
Headset with
operating
control II
Operating element

HMEC 26-CP x x
HMEC 26-KP x x
HMEC 26-NP x x



10
Using the headset
Switching NoiseGard™ on/off
The NoiseGard™ ON/OFF switch allows you to switch
the NoiseGard™ active noise compensation on or off. With
NoiseGard™ switched off, the headset can be used as a
conventional headset.
왘Set the NoiseGard™ ON/OFF switch to the desired
position:
ON: NoiseGard™ is switched on. The LED lights up,
indicating the battery charge status (see
page 11) or power supply via the aircraft DC
power supply system.
OFF: NoiseGard™ is switched off. The LED is off.
Adjusting the volume
The two slide volume controls allow you to adjust the
volume for the left and right channel separately.
왘Use the two volume controls  to adjust the desired
volume.
Hearing damage due to high volumes!
This headset is capable of producing high
sound pressure levels. Higher volumes or
longer durations can damage your hearing!
Set the volume to a medium level. Make sure
that you can hear critical sounds such as
warning alarms.
CAUTION!

11
Switching between mono and stereo mode
The mono/stereo switch allows you to switch between
mono () and stereo () mode, depending on the
audio system.
왘Set the mono/stereo switch to the desired
position: mono () or stereo ().
Changing the left and right stereo channel
The position “R” or “L” of the BOOM switch 
corresponds to the position of the microphone on the left
or right side of the mouth. When the microphone boom is
rotated to permit left or right side microphone
orientation, the BOOM switch allows you to correctly
assign the audio channels (L/R) to the appropriate
headphone sides. This enables the correct orientation of
the volume controls and any stereo audio signals. To
move the BOOM switch, use a pointed tool.
Powering NoiseGard™ via two (rechargeable) batteries
왘Insert two 1.5 V AA alkaline batteries (IEC LR 6) or
two 1.2 V AA rechargeable batteries (IEC LR 6).
Observe correct polarity when inserting the batteries.

12
The operating time with batteries/rechargeable batteries
is approx. 60 hours.
With NoiseGard™ switched on (see page 10), the LED 
provides information on the remaining battery/
rechargeable battery capacity.
LED lights up yellow: The battery capacity is
sufficient.
LED lights up red: The batteries are flat.
Replace the batteries.
Activating the “auto shut-off” function
The battery-saving “auto shut-off” function automatical-
ly switches the NoiseGard™ electronics off when the
headset is disconnected from the audio system or when
the aircraft avionics are switched off. The headset is de-
livered ex-works with the function deactivated. You can
activate “auto shut-off” as follows:
왘Set the switch to the position ASO.

13
Switching the TalkThrough function on/off
(HMEC 26-T only)
The headset provides excellent attenuation of ambient
noise. In order to allow you to communicate undisturbed
with your surroundings while wearing the headset, the
HMEC 26-T features a TalkThrough function.
왘Press the TalkThrough button to switch the
TalkThrough function on. The LED lights up. Press
the TalkThrough button again to switch TalkThrough
off.
Note:
The TalkThrough function can only be used when the
NoiseGard™ active noise compensation is switched
on.



14
Connecting a mobile telephone
The 2.5 mm jack socket allows you to connect a mobile
telephone. For this purpose, the NoiseGard™ active noise
compensation must be switched on and the microphone
connector must be connected to the aircraft radio/audio.
A suitable adapter for your mobile telephone with
2.5 mm jack socket is available from your Sennheiser
agent.
왘Connect the audio cable to the 2.5 mm jack socket 
on the operating control Iand to the corresponding
jack socket on your mobile telephone.
You can adjust the volume of the mobile telephone via
the headset’s operating control. However, the functions
of the mobile telephone cannot be controlled via the
headset’s operating control.
왘Operate your mobile telephone as usual and observe
the instructions of the manufacturer.
The latest information on cell phone compatibility is
available on the internet site at www.sennheiser.com.
왘Search under “Products”, “Aviation” and “more info
…”.
Danger of accident due to reduced attention!
Making telephone calls or operating the
mobile telephone limits your attention and
may cause accidents.
During flight operation, do not use the
headset for telephone calls!
CAUTION!

15
Connecting an additional audio player
The 3.5 mm jack socket allows you to connect and
listen to an audio player (not supplied) through the
headset. For this purpose, the NoiseGard™ active noise
compensation must be switched on.
왘Connect the audio cable to the 3.5 mm jack socket 
on the operating control Iand to the corresponding
jack socket on your audio player.
Danger of accident due to reduced attention!
Listening to music or operating an audio
device limits your attention and may cause
accidents.
During flight operation, do not use the
headset for listening to additional audio
sources!
Hearing damage due to high volumes!
This headset is capable of producing high
sound pressure levels. Higher volumes or
longer durations can damage your hearing!
Set the volume to a medium level. Make sure
that you can hear critical sounds such as
warning alarms.
CAUTION!
CAUTION!

16
Care and maintenance
Cleaning the headset
Use a soft, slightly damp cloth to clean the headset from
time to time. If the headset is very dirty, use a cloth
dampened with mild, soapy water. Do not use any
solvents or cleansing agents.
Replacing the earpads
For reasons of hygiene, the earpads should be replaced
from time to time.
왘Grasp the edge of the earpad and pull sharply.
왘Attach the new earpad to the earcup by pressing
firmly around the earpad until you hear all 12 latches
lock into place.
Danger of short-circuit due to the ingress of
water!
Water entering the housing of the headset
can cause a short-circuit and damage the
electronics.
CAUTION!

17
Accessories and spare parts
By changing the cables, you can simply retrofit different
operating controls (see page 8 and 9) or connectors (see
page 19) to your headset.
yCable -CP Cat. No. 500852
yCable -V-CP Cat. No. 500846
yCable -B-CP Cat. No. 500837
yCable -BV-CP Cat. No. 500838
yCable -KP Cat. No. 500842
yCable -V-KP Cat. No. 500848
yCable -B-K Cat. No. 502183
yCable -BV-K Cat. No. 500839
yCable -BV-KP Cat. No. 504030
yCable -NP Cat. No. 500855
yCable -V-RP Cat. No. 500853
yCable -V-KX Cat. No. 502437
yAudio cable, length 0.6 m,
with two 3.5 mm stereo jack plugs Cat. No. 520316
yAudio cable, length 0.6 m,
with two 2.5 mm jack plugs Cat. No. 520317
yHeadband padding, 1 pair Cat. No. 515629
yEarpads, leatherette, 1 pair Cat. No. 529766
yEarpads, leatherette, 100 pairs Cat. No. 529767
yHygiene pads HZH 26, 200 pairs Cat. No. 502595
yWind and pop screen, 1 item Cat. No. 515297
yWind and pop screen, any quantity Cat. No. 514127
yCarry bag Cat. No. 077408

18
yCable clip MZQ 2002 Cat. No. 044740
yCable clip HZC 08 Cat. No. 525787
Cable clips
HZC 08 MZQ 2002
(for round or flat cable)(for round cable only)