Oxygen Mask Fittings
and CRU Blocks
Like
anything else in military aviation, there are many different
items doing a similar job, but each one is specialized for specific
application. Below we will discuss 3 types of "oxygen mask
connectors" and 2 types of "oxygen blocks" as
used primarily by the Air Force.
We have
Oxygen Mask Hose Fittings and CRU Blocks available for sale:
Oxygen
Mask Hose Fittings
CRU
Chest Mounted Regulators
CRU
Harness Mounting Plate
|
Oxygen mask
connectors as shown to the left- Top:
2 Pin Friction Quick Disconnect fitting. Used
in "non-tactical" aircraft or those without ejection
seats. There have been many different styles and colors.
For instance, early ones are longer than the one shown and
aluminum silver in color- later ones are black and typically
shorter. You will see several different colored gasket seals,
the one shown is red. Used with MBU-5/P and MBU-12/P oxygen
masks in aircraft like the F-111 Aardvark. Middle:
The next fitting is a
3 Pin Quick Disconnect fitting. These are
for use in ejection seat aircraft that utilize a bailout
bottle and therefore a CRU-60 or CRU-94 oxygen block (see
more info below). This is used with the MBU-5/P, MBU-12/P,
or MBU-20/P oxygen mask and their variants in aircraft like
the A/F F-4 Phantom, F-15 Eagle, F-16 Falcon. Bottom:
The
MC-3A connector was used in quantity by the
Navy and Air Force from the end of WW2 the 1960s. They are
even used today on a special MBU-12/P variant in aircraft
like the Marine Corps OV-1 Bronco. You can find this fitting
on MS22001s, A-14s, and more. The offset elbow is for bailout
bottle attachment. The actual attachment part is the same
as the 2 Pin Friction fitting. There is a cloth loop that
snaps shut to secure the heavy connector so it does not
hit the pilot during ejection. |
When a crewmember
ejects, they need to be supplied oxygen in case egress from
the aircraft occurs at over 10,000 feet AGL. The modern
ejection seats have emergency o2 stored oxygen bottles "Bail-Out
Bottle" built into the seat. The crewmember receives the
oxygen supply during regular flight from the aircraft o2 system
(the Air Force has the regulator built into the aircraft system,
the Navy uses crew-mounted regulators [CRU-79/P, CRU-88/P] see
the MBU-12/P
vs. MBU-14/P article. The Air Force uses oxygen blocks
which have "ports" for various fittings.
|
The
CRU-60/P, seen here attached to the PCU-15ejection
torso harness (F-4 Phantom, F-15 Eagle). The CRU block (60/P
or 94/P) attaches securely to the PCU harness via the metal
CRU Bracket, seen at right. The MBU-12/P or 5/P oxygen mask
attaches to the CRU-60/P by the 3 Pin Quick Disconnect fitting.
The hose from the emergency bottle in the ejection seat
attaches to the Bail Out Bottle elbow. The aircraft oxygen
hose hooks into the friction fitting at the bottom of the
CRU-60/P. This "friction" fitting requires 5 pounds
of pull to disconnect- Upon ejection, the aircraft oxygen
hose separates from the CRU-60 and the crewmember breathes
from the bailout bottle. |
The
Combat Edge CRU-94/P oxygen block is seen here attached
via the CRU Bracket to the
PCU-15A/P ejection torso harness (used on the F-16 Fighting
Falcon). The MBU-20/P Combat Edge (CE) oxygen mask
attaches to the CRU-94/P by the 3 Pin Quick Disconnect fitting,
like the masks do above to the CRU-60/P. The only difference
between the CRU-60 and the CRU-94 is the addition of one
extra port for the CSU-17/P Counter Pressure Vest. It plugs
into the 94/P with a 4 Pin Quick Disconnect fitting. The
other bail out bottle & aircraft friction fitting works
the same as on the CRU-60/P.
Click
here! to see the article on the Air Force & Navy
Ejection Harness.
|
|
|
|