MH EDS failures

[Philip Plane]

Hi,

I've recently had two failures of newish MH EDS oxygens systems.
The units gave the fault alarm with every breath. I checked one
on the ground on the 'N' setting and it faulted with every breath.
The other failure was intermittant over several hours.

We checked the plumbing and changed the battery. Didn't help.

Both failures 'fixed' themselves. The intermittant unit worked
fine on the next flight several days later. The unit I checked
worked on the next flight after the pilot sniffed hard a few times
to get it started.


Anyone else noticed this sort of thing? Any ideas on what is causing
it and how to prevent it.


--
Philip Plane _____
|
---------------( )---------------
Glider pilots have no visible means of support

[Eric Greenwell]

Philip Plane wrote:

> Hi,
>
> I've recently had two failures of newish MH EDS oxygens systems.
> The units gave the fault alarm with every breath. I checked one
> on the ground on the 'N' setting and it faulted with every breath.
> The other failure was intermittant over several hours.
>
> We checked the plumbing and changed the battery. Didn't help.
>
> Both failures 'fixed' themselves. The intermittant unit worked
> fine on the next flight several days later. The unit I checked
> worked on the next flight after the pilot sniffed hard a few times
> to get it started.
>
> Anyone else noticed this sort of thing? Any ideas on what is causing
> it and how to prevent it.

I suggest you contact MH by phone or email, and describe the symptoms as
carefully as possible. My guess is moisture, and if some is still
present, it could cause a real problem if the unit gets below freezing
in a wave flight. In any case, oxygen is too important to leave to
guesses, so contact MH.


--
Change "netto" to "net" to email me directly

Eric Greenwell
Washington State
USA

[Karl Striedieck]

I had the same problem. EDS knew of the situation and fixed it for free.

Karl Striedieck

"Eric Greenwell" > wrote in message
...
> Philip Plane wrote:
>
>> Hi,
>>
>> I've recently had two failures of newish MH EDS oxygens systems. The
>> units gave the fault alarm with every breath. I checked one
>> on the ground on the 'N' setting and it faulted with every breath.
>> The other failure was intermittant over several hours.
>>
>> We checked the plumbing and changed the battery. Didn't help.
>>
>> Both failures 'fixed' themselves. The intermittant unit worked
>> fine on the next flight several days later. The unit I checked
>> worked on the next flight after the pilot sniffed hard a few times to get
>> it started.
>>
>> Anyone else noticed this sort of thing? Any ideas on what is causing
>> it and how to prevent it.
>
> I suggest you contact MH by phone or email, and describe the symptoms as
> carefully as possible. My guess is moisture, and if some is still present,
> it could cause a real problem if the unit gets below freezing in a wave
> flight. In any case, oxygen is too important to leave to guesses, so
> contact MH.
>
>
> --
> Change "netto" to "net" to email me directly
>
> Eric Greenwell
> Washington State
> USA

[Tim Harrison]

Users of EDS systems should be aware of another issue - known by MH but not
advertised. Several units (quantity unknown but could be many) were
calibrated using an incorrect curve after a change in technical staff.
These units resulted in insufficient supply of oxygen with every breath and
resulted in mild to moderate hypoxia.
Sending back to the factory gets the problem resolved easily. S'funny that
there was no recall of units.....
Might be worth calling the factory to check serial numbers?


"Karl Striedieck" > wrote in message
...
>I had the same problem. EDS knew of the situation and fixed it for free.
>
> Karl Striedieck
>
> "Eric Greenwell" > wrote in message
> ...
>> Philip Plane wrote:
>>
>>> Hi,
>>>
>>> I've recently had two failures of newish MH EDS oxygens systems. The
>>> units gave the fault alarm with every breath. I checked one
>>> on the ground on the 'N' setting and it faulted with every breath.
>>> The other failure was intermittant over several hours.
>>>
>>> We checked the plumbing and changed the battery. Didn't help.
>>>
>>> Both failures 'fixed' themselves. The intermittant unit worked
>>> fine on the next flight several days later. The unit I checked
>>> worked on the next flight after the pilot sniffed hard a few times to
>>> get it started.
>>>
>>> Anyone else noticed this sort of thing? Any ideas on what is causing
>>> it and how to prevent it.
>>
>> I suggest you contact MH by phone or email, and describe the symptoms as
>> carefully as possible. My guess is moisture, and if some is still
>> present, it could cause a real problem if the unit gets below freezing in
>> a wave flight. In any case, oxygen is too important to leave to guesses,
>> so contact MH.
>>
>>
>> --
>> Change "netto" to "net" to email me directly
>>
>> Eric Greenwell
>> Washington State
>> USA
>
>

[[email protected]]

Interesting.... I wonder if the oposite has also happened. I tend to
use a lot more O2 than others using the EDS at similar altitudes; more
than different breathing patterns and/or metabolism would easily
explain. Given that these devices are calibrated by the factory prior
to shipment , and, presumably, could shift, do they ever require
checking and recalibration? For those using this device w/out
reference to an oximeter, such checking and recalibration might well be
important.

Ray Warshaw
1LK

[Eric Greenwell]

wrote:
> Interesting.... I wonder if the oposite has also happened. I tend to
> use a lot more O2 than others using the EDS at similar altitudes; more
> than different breathing patterns and/or metabolism would easily
> explain.

The EDS depends on the regulator supplying the correct pressure (15
psi). If the pressure is higher, you will consume more oxygen, and vice
versa. This was the case for a friend of mind (20 psi, I think), and MH
replaced the regulator free. The outlet pressure is easy to measure with
any gauge that can measure 15 psi accurately. I've used a good car tire
gauge.

> Given that these devices are calibrated by the factory prior
> to shipment , and, presumably, could shift, do they ever require
> checking and recalibration?

I had this done by MH when I visited their facility. It took only a few
minutes to check the electronic functions and oxygen delivery. I believe
MH will do this for free, if you send your unit to them, but you might
have to pay for the shipping both ways. Contact them - it's been a few
years since I asked.

> For those using this device w/out
> reference to an oximeter, such checking and recalibration might well be
> important.

I agree, but with suitable oximeters costing only $200, there is little
reason to do without one. At least, talk your buddy into buying one so
you can borrow it, or casually mention to his wife that it makes a great
Christmas present! "Deviousness in the pursuit of safety is readily
excused" - author unknown.

--
Change "netto" to "net" to email me directly

Eric Greenwell
Washington State
USA

[[email protected]]

I am a US Dealer for Mountain High Oxygen System (Craggy Aero
www.craggyaero.com) and have found their products and support
excellent. I infomed the factory of the above post. They forwarded
me the response to Tim Harrison.

Tim...your E-mail was forwarded to me and I would like to give you some
facts based on the MH EDS units.

Your statement that "Several units (quantity unknown but could be many)
were calibrated using an incorrect curve after a change in technical
staff" is incorrect and based on false information. I have no idea
where you came up with that absurdity but where ever you got your
information it would require further corroboration before making such a
general false statement.

There never has been an EDS unit shipped that has not been completely
tested for function as well as quality. That is why MH can give each
unit a lifetime warranty.

We have thousands of the units being used worldwide under a variety of
conditions and no one --NOT ONE--has ever indicated a problem of your
nature.

There is no "Recall" and your statement about mild to moderate hypoxia
can only lead me to believe that you have other problems.

Each unit is tested for proper oxygen pulses at altitudes based on
standards through stringent testing at established University and
Military test sites. We know what we are talking about. If anything,
the profiles are scheduled richer than they need to be to compensate
that the average pilot is not twenty-five years of age.

However, about 3 years ago, in an effort to help persons with
cyne-stokes like breathing issues at altitude, the EDS had an addition
alert added that detected inspiration efforts that did not follow
through to the end of the delivery pulse at higher altitudes. Some of
these units were sold in N.Z. as well as Europe. We know where they are
by our records and they were was found not suitable for all types (of
persons). It resulted in having the alert go off with almost every
inspiration effort which caused concern with many. Because this alert
issue was an individual issue, we decided it did not warrant any type
of a recall., rather a reprogramming to disable the alert. Therefore,
any and all who found the alarm a problem simply had to contact us and
send the unit in where we disabled it by reprogramming it. Furthermore,
all new units at this point do not have this post-flow alert and is so
noted with a new firmware version.

It may be interesting to note however, that with chamber testing, we
can verify that the EDS unit is scheduled to deliver about 2.5 times
more than is needed for a typical person at altitude. This, we found,
more accurately reflected the condition of the real flying population.
Therefore, if you feel that the unit is indeed not operating properly,
please send it back to us for a check-up, at no cost to you.

We at MH take great pride in the quality of our products and our
customer service. If in the future you have a problem, we are the ones
to help you with it. Please do not hesitate to call, fax or E-mail.
Best regards,
Robert Jamieson
CEO


Richard Pfiffner
Craggy Aero
www.craggyaero.com