Which oxygen system is right for me?

An oxygen system consists of a cylinder, regulator, oxygen delivery unit and a cannula or mask. Below we have tried to provide answers to some of the most common questions.

Oxygen delivery unit - EDS vs. constant flow


Constant flow

Uses less oxygen as more efficient

Lower cost

Auto adjust for flow with altitude – lower workload

Does not require batteries

Audible warnings for loss of oxygen supply



Cylinder and regulator types


Default regulator

Diameter x length (cm)

Recommended for glider types:

AL – 180

with gauge


no gauge

8.1 x 30

Ideal for moving between multiple glider types + small cockpits e.g JS3, Ventus 2A, Discus 2A.

AL – 248

with gauge


no gauge

11.1 x 27

Early JS1s

AL – 415

with gauge


no gauge

11.1 x 41

Large cockpit single seaters (e.g Std. Cirrus, Nimbus)

AL – 682

with gauge


no gauge

11.1 x 65

Large pure two-seaters (e.g Duo Discus, Nimbus, ASH25).

CFF – 480

with gauge


no gauge

11.4 x 36.5

Many modern Schempp-Hirth including Ventus 3M, Arcus T and M, Duo Discus XLT

KF – 011

with gauge


no gauge

9.3 x 48.5

DG, LS, Schleichers, Glasflugel – a light-weight alternative to the Steel 3L

Steel 3L

no gauge


with gauge

10 x 58

Perfect fit for most pure DG, LS, PIK and Glasflugel gliders.

Steel 2L

no gauge


with gauge

10.5 x 44

Ventus 3T + 3F



For mounting the EDS unit or constant flow flowmeter – we usually recommend heavy duty Velcro to affix the unit to the side of the cockpit. It should be in view and accessible to the pilot in flight and should not obstruct the pilot from moving any controls in the cockpit. In some gliders it is possible to achieve this with the unit in a cockpit’s side pocket.

For mounting your cylinder, you ideally want to make seeing the gauge on the cylinder easy so that the oxygen level can be observed in flight or at the very least, just before take-off. You also ideally want to be able to operate the cut-off valve easily in flight. Again if not possible to achieve, you should be able to easily access the valve pre-take off.

Many gliders already have mounting solutions present. In most DG, LS, Schleicher, PIKs and Glasflugel gliders, the holder for the cylinder is present but you may need to mount a securing/locking mechanism. In older Schempp-Hirth gliders, there can be a variety of different mounting positions. Some may have a hole in a bulkhead designed to take a cylinder, usually in the fuselage, aft of the cockpit. Often Schempp-Hirth gliders will need mounting brackets to secure the cylinder. JS gliders usually have an obvious mounting position for the cylinder and a locking mechanism provided from factory. Modern two-seaters with engines may have a mounting position in the rear cockpit foot-well.


Filling adapters and other accessories

Once you have the kit setup in the glider, you need to consider how you will get the cylinder re-filled. If you fly regularly at most established wave sites in the UK or abroad, they will likely have filling facilities on site which should suit either the CGA540 or DIN477 threads. Alternatively, you may be able to fill the cylinder at your local dive-shop. It is very unlikely the dive-shop will have fittings to fill your cylinder and so for this reason we sell dive-shop filling adapters.

If your glider is owned by a syndicate or is a two-seater, you may require extra cannulas or masks (masks should be used when flying above 18,000ft.



What comes in the kits?

The EDS kit includes:

  • O2D1 (single person) or O2D2 (dual person) EDS unit
  • Standard cannula
  • Flare tip cannula (increased sensitivity for those who find that using the standard cannula does not reliably induce a pulse from the EDS unit)
  • EDS face mask – for use above 18000ft
  • Carry bag
  • Batteries for the EDS unit
  • 2 X hygiene wipes

The constant flow kit includes:

  • MH4 Flowmeter
  • Oximiser - oxygen conserving cannula,
  • Constant flow face mask
  • Carry bag


Can I use my existing cylinder with a Mountain High oxygen delivery system?

Possibly, however many cylinders found in gliders have BSP threads. Unfortunately we can only source Mountain High regulators with a CGA540 or DIN477 thread and as the cylinder is usually the lowest cost element of the whole oxygen system, it is usually more economical to replace an old cylinder.


Can Navboys help me with installation of an oxygen system into my glider?

Yes we can - please make an enquiry using our contact form here.