Cambridge Model 20 Issues

[B. Iten]

I am (I think) a proud owner of a model 20 which is driving me up the
wall. Yesterday, I was flying our clubs Discus B with my logger
attached under the glare shield. On my flight, after I was off of tow,
the recorder recorded what looked and was shown as engine noise. The
engine noise also showed up in flight for a couple of minutes. A
friend of mine asked if I had the gear down during my initial climb
and I did. I also dropped the gear to drain my bladder once. My logger
is translating engine noise for gear doors open. Am I the only one
with this problem? Is there a sensativity adjustment that can be done?
I have the question posted to Cambridge but they are close now so I
figured I would see if someone out there had the answer faster.
Thanks
Brian Iten
17

[Gary Evans]

Any significant noise (e.g. high speed, gear down,
spoilers) may show as engine noise on the flight log
but it's apparent to anyone reading the trace that
engine noise while sinking isn't really from a motor
on.

At 23:48 05 April 2004, B. Iten wrote:
>I am (I think) a proud owner of a model 20 which is
>driving me up the
>wall. Yesterday, I was flying our clubs Discus B with
>my logger
>attached under the glare shield. On my flight, after
>I was off of tow,
>the recorder recorded what looked and was shown as
>engine noise. The
>engine noise also showed up in flight for a couple
>of minutes. A
>friend of mine asked if I had the gear down during
>my initial climb
>and I did. I also dropped the gear to drain my bladder
>once. My logger
>is translating engine noise for gear doors open. Am
>I the only one
>with this problem? Is there a sensativity adjustment
>that can be done?
>I have the question posted to Cambridge but they are
>close now so I
>figured I would see if someone out there had the answer
>faster.
>Thanks
>Brian Iten
>17
>

[Eric Greenwell]

B. Iten wrote:

> I am (I think) a proud owner of a model 20 which is driving me up the
> wall. Yesterday, I was flying our clubs Discus B with my logger
> attached under the glare shield. On my flight, after I was off of tow,
> the recorder recorded what looked and was shown as engine noise. The
> engine noise also showed up in flight for a couple of minutes. A
> friend of mine asked if I had the gear down during my initial climb
> and I did. I also dropped the gear to drain my bladder once. My logger
> is translating engine noise for gear doors open. Am I the only one
> with this problem? Is there a sensativity adjustment that can be done?
> I have the question posted to Cambridge but they are close now so I
> figured I would see if someone out there had the answer faster.

What you describe is normal and proper operation of the recorder, unless
the values are very high. On my glider, gear down is around 40-50 units,
engine noise is over 200.

--
-----
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Eric Greenwell
Washington State
USA

[Tim Newport-Peace]

X-no-archive: yes
In article >, Eric Greenwell
> writes
>B. Iten wrote:
>
>> I am (I think) a proud owner of a model 20 which is driving me up the
>> wall. Yesterday, I was flying our clubs Discus B with my logger
>> attached under the glare shield. On my flight, after I was off of tow,
>> the recorder recorded what looked and was shown as engine noise. The
>> engine noise also showed up in flight for a couple of minutes. A
>> friend of mine asked if I had the gear down during my initial climb
>> and I did. I also dropped the gear to drain my bladder once. My logger
>> is translating engine noise for gear doors open. Am I the only one
>> with this problem? Is there a sensativity adjustment that can be done?
>> I have the question posted to Cambridge but they are close now so I
>> figured I would see if someone out there had the answer faster.
>
>What you describe is normal and proper operation of the recorder, unless
>the values are very high. On my glider, gear down is around 40-50 units,
>engine noise is over 200.
>
Are you sure about ENL of over 200?

Although the range of possible values is 0-999, on the Model 10/20/25
only values between 0 and 195 are recorded (in the .IGC file).

It would be interesting to see the .IGC file.

Best regards,

Tim Newport-Peace

"May you be cursed with a chronic anxiety about the weather."

John Burroughs (1837-1921).

[Mal]

Singing and talking also show up on the noise recorder of my vox logger.


"Eric Greenwell" > wrote in message
...
> B. Iten wrote:
>
> > I am (I think) a proud owner of a model 20 which is driving me up the
> > wall. Yesterday, I was flying our clubs Discus B with my logger
> > attached under the glare shield. On my flight, after I was off of tow,
> > the recorder recorded what looked and was shown as engine noise. The
> > engine noise also showed up in flight for a couple of minutes. A
> > friend of mine asked if I had the gear down during my initial climb
> > and I did. I also dropped the gear to drain my bladder once. My logger
> > is translating engine noise for gear doors open. Am I the only one
> > with this problem? Is there a sensativity adjustment that can be done?
> > I have the question posted to Cambridge but they are close now so I
> > figured I would see if someone out there had the answer faster.
>
> What you describe is normal and proper operation of the recorder, unless
> the values are very high. On my glider, gear down is around 40-50 units,
> engine noise is over 200.
>
> --
> -----
> change "netto" to "net" to email me directly
>
> Eric Greenwell
> Washington State
> USA
>

[Andy Durbin]

(B. Iten) wrote in message >...
> I am (I think) a proud owner of a model 20 which is driving me up the
> wall. Yesterday, I was flying our clubs Discus B with my logger
> attached under the glare shield. On my flight, after I was off of tow,
> the recorder recorded what looked and was shown as engine noise. The
> engine noise also showed up in flight for a couple of minutes. A
> friend of mine asked if I had the gear down during my initial climb
> and I did. I also dropped the gear to drain my bladder once. My logger
> is translating engine noise for gear doors open. Am I the only one
> with this problem? Is there a sensativity adjustment that can be done?
> I have the question posted to Cambridge but they are close now so I
> figured I would see if someone out there had the answer faster.
> Thanks
> Brian Iten
> 17

Probably normal. I used to use my Model 25 ENL trace to confirm tow
release point. There was a large reduction in noise when the gear
door closed on my ASW 19. In that glider the ENL reached levels that
indicated engine run several time during a flight.


I see similar effects with my ENL 302.


Andy

[Eric Greenwell]

Tim Newport-Peace wrote:
> X-no-archive: yes
> In article >, Eric Greenwell
> > writes
>
>>B. Iten wrote:
>>
>>
>>>I am (I think) a proud owner of a model 20 which is driving me up the
>>>wall. Yesterday, I was flying our clubs Discus B with my logger
>>>attached under the glare shield. On my flight, after I was off of tow,
>>>the recorder recorded what looked and was shown as engine noise. The
>>>engine noise also showed up in flight for a couple of minutes. A
>>>friend of mine asked if I had the gear down during my initial climb
>>>and I did. I also dropped the gear to drain my bladder once. My logger
>>>is translating engine noise for gear doors open. Am I the only one
>>>with this problem? Is there a sensativity adjustment that can be done?
>>>I have the question posted to Cambridge but they are close now so I
>>>figured I would see if someone out there had the answer faster.
>>
>>What you describe is normal and proper operation of the recorder, unless
>>the values are very high. On my glider, gear down is around 40-50 units,
>>engine noise is over 200.
>>
>
> Are you sure about ENL of over 200?
>
> Although the range of possible values is 0-999, on the Model 10/20/25
> only values between 0 and 195 are recorded (in the .IGC file).
>
> It would be interesting to see the .IGC file.

I was looking at the files with the old Cambridge DOS viewer, which does
show values to 400 for both the original CAI file and the post-flight
generated IGC file. The newer viewers (Cambridge's Aero Explorer and
Seeyou) seem to rescale the values to a full scale of 195 for both file
formats. I should have asked Brian which viewer he was using, but I
didn't realize the CAI values were being rescaled.

--
-----
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Eric Greenwell
Washington State
USA

[Greg Arnold]

Brian Iten's file with the high noise reading in on the OLC site for
April 4, if anyone wants to look at it.


Eric Greenwell wrote:

> Tim Newport-Peace wrote:
>
>> X-no-archive: yes
>> In article >, Eric Greenwell
>> > writes
>>
>>> B. Iten wrote:
>>>
>>>
>>>> I am (I think) a proud owner of a model 20 which is driving me up the
>>>> wall. Yesterday, I was flying our clubs Discus B with my logger
>>>> attached under the glare shield. On my flight, after I was off of tow,
>>>> the recorder recorded what looked and was shown as engine noise. The
>>>> engine noise also showed up in flight for a couple of minutes. A
>>>> friend of mine asked if I had the gear down during my initial climb
>>>> and I did. I also dropped the gear to drain my bladder once. My logger
>>>> is translating engine noise for gear doors open. Am I the only one
>>>> with this problem? Is there a sensativity adjustment that can be done?
>>>> I have the question posted to Cambridge but they are close now so I
>>>> figured I would see if someone out there had the answer faster.
>>>
>>>
>>> What you describe is normal and proper operation of the recorder,
>>> unless the values are very high. On my glider, gear down is around
>>> 40-50 units, engine noise is over 200.
>>>
>>
>> Are you sure about ENL of over 200?
>>
>> Although the range of possible values is 0-999, on the Model 10/20/25
>> only values between 0 and 195 are recorded (in the .IGC file).
>>
>> It would be interesting to see the .IGC file.
>
>
> I was looking at the files with the old Cambridge DOS viewer, which does
> show values to 400 for both the original CAI file and the post-flight
> generated IGC file. The newer viewers (Cambridge's Aero Explorer and
> Seeyou) seem to rescale the values to a full scale of 195 for both file
> formats. I should have asked Brian which viewer he was using, but I
> didn't realize the CAI values were being rescaled.
>

[Brian Iten]

Thanks for posting where to see the file at Greg. I guess the next
question to this issue will be what will happen if during a badge or
record flight, you drop the gear to water the desert? With the engine
noise being recorded, will this affect your claim?
Brian
17

[Eric Greenwell]

Brian Iten wrote:

> Thanks for posting where to see the file at Greg. I guess the next
> question to this issue will be what will happen if during a badge or
> record flight, you drop the gear to water the desert? With the engine
> noise being recorded, will this affect your claim?
> Brian

It's not an issue unless you are flying a motorglider, then the flight
evaluators must determine if it was caused by the engine or other
sources. Generally, this isn't hard to do.

Just be sure your Official Observer can tell the difference between a
Discus B and a Discus BT!

--
-----
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Eric Greenwell
Washington State
USA

[Eric Greenwell]

Greg Arnold wrote:

> Brian Iten's file with the high noise reading in on the OLC site for
> April 4, if anyone wants to look at it.

I think we need the original file (.cai format) from the logger. The
noise recordings look much too high for gear down noise. What program
was used to produce the IGC file from the CAI file? If it was the
cai2igc.exe, perhaps that program does not rescale the engine noise
level to the IGC values?
--
-----
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Eric Greenwell
Washington State
USA

[Brian Iten]

Eric,
I used the cai2igc program as I didn't know at the
time that I could do it in SeeYou. I will email you
the original CAI file tonight.
Brian


What program
>was used to produce the IGC file from the CAI file?
>If it was the
>cai2igc.exe, perhaps that program does not rescale
>the engine noise
>level to the IGC values?
>--
>-----
>change 'netto' to 'net' to email me directly
>
>Eric Greenwell
>Washington State
>USA
>
>

[Tim Newport-Peace]

X-no-archive: yes
In article >, Eric Greenwell
> writes
>Greg Arnold wrote:
>
>> Brian Iten's file with the high noise reading in on the OLC site for
>> April 4, if anyone wants to look at it.
>
>I think we need the original file (.cai format) from the logger. The
>noise recordings look much too high for gear down noise. What program
>was used to produce the IGC file from the CAI file? If it was the
>cai2igc.exe, perhaps that program does not rescale the engine noise
>level to the IGC values?

I have has a look at Brian's .IGC file and it show maximum values of
195, which suggests that any rescaling is being done by the viewing
program and not on conversion to .IGC format. The download was done
using SeeYou.

What I do see is that the maximum value of 195 (equivalent to 999 on any
other recorder, and top-of-scale for Cambridge 10/20/25) is reached and
sustained (flat tops to ENL graph) during both Take-off/Tow and final
stage of flight to landing (presumably when the wheel was down), as well
as occasionally during what I take to be urination.

The ENL on this recorder is abnormally high. A new design of recorder
showing these characteristics would not get IGC approval.

I would guess that the ENL system on this recorder is in need of
adjustment/repair.

Best regards,

Tim Newport-Peace.
Technical Advisor to
Global Navigation Satellite System
Flight Recorder Approval Committee (GFAC)
of the International Gliding Commission
of the Federation Aeronautique Internationale

[Brian Iten]

I have emailed Cambridge about this and they informed
me that it was normal for engine noise detection when
the gear is down. I would love to see a trace with
a model 20 inside of a 1-26,2-33 or Blanik..... The
logger would probably self destruct from the noise......LOL
Brian
17
>
>I would guess that the ENL system on this recorder
>is in need of
>adjustment/repair.
>
>Best regards,
>
>Tim Newport-Peace.
>Technical Advisor to
>Global Navigation Satellite System
>Flight Recorder Approval Committee (GFAC)
>of the International Gliding Commission
>of the Federation Aeronautique Internationale
>

>

[Brian Iten]

I have emailed Cambridge about this and they informed
me that it was normal for engine noise detection when
the gear is down. I would love to see a trace with
a model 20 inside of a 1-26,2-33 or Blanik..... The
logger would probably self destruct from the noise......LOL
Brian
17
>
>I would guess that the ENL system on this recorder
>is in need of
>adjustment/repair.
>
>Best regards,
>
>Tim Newport-Peace.
>Technical Advisor to
>Global Navigation Satellite System
>Flight Recorder Approval Committee (GFAC)
>of the International Gliding Commission
>of the Federation Aeronautique Internationale
>

>

[Brian Iten]

I have emailed Cambridge about this and they informed
me that it was normal for engine noise detection when
the gear is down. I would love to see a trace with
a model 20 inside of a 1-26,2-33 or Blanik..... The
logger would probably self destruct from the noise......LOL
Brian
17
>
>I would guess that the ENL system on this recorder
>is in need of
>adjustment/repair.
>
>Best regards,
>
>Tim Newport-Peace.
>Technical Advisor to
>Global Navigation Satellite System
>Flight Recorder Approval Committee (GFAC)
>of the International Gliding Commission
>of the Federation Aeronautique Internationale
>

>

[Brian Iten]

I have emailed Cambridge about this and they informed
me that it was normal for engine noise detection when
the gear is down. I would love to see a trace with
a model 20 inside of a 1-26,2-33 or Blanik..... The
logger would probably self destruct from the noise......LOL
Brian
17
>
>I would guess that the ENL system on this recorder
>is in need of
>adjustment/repair.
>
>Best regards,
>
>Tim Newport-Peace.
>Technical Advisor to
>Global Navigation Satellite System
>Flight Recorder Approval Committee (GFAC)
>of the International Gliding Commission
>of the Federation Aeronautique Internationale
>

>

[Brian Iten]

I have emailed Cambridge about this and they informed
me that it was normal for engine noise detection when
the gear is down. I would love to see a trace with
a model 20 inside of a 1-26,2-33 or Blanik..... The
logger would probably self destruct from the noise......LOL
Brian
17
>
>I would guess that the ENL system on this recorder
>is in need of
>adjustment/repair.
>
>Best regards,
>
>Tim Newport-Peace.
>Technical Advisor to
>Global Navigation Satellite System
>Flight Recorder Approval Committee (GFAC)
>of the International Gliding Commission
>of the Federation Aeronautique Internationale
>

>

[Tim Newport-Peace]

X-no-archive: yes
In article >, Brian Iten
> writes
>I have emailed Cambridge about this and they informed
>me that it was normal for engine noise detection when
>the gear is down. I would love to see a trace with
>a model 20 inside of a 1-26,2-33 or Blanik..... The
>logger would probably self destruct from the noise......LOL
>Brian
>17

Some noise yes, but I would not expect it to be a maximum value.

I have a trace from a Ventus using a legacy Cambridge which gives much
more reasonable values.

Best regards,

Tim.
--

>>
>>I would guess that the ENL system on this recorder
>>is in need of
>>adjustment/repair.
>>
>>Best regards,
>>
>>Tim Newport-Peace.
>>Technical Advisor to
>>Global Navigation Satellite System
>>Flight Recorder Approval Committee (GFAC)
>>of the International Gliding Commission
>>of the Federation Aeronautique Internationale
>>

>>
>
>

[Rory O'Conor]

Brian


I have looked at your IGC file.
The issue for me is: what is the fully scale ENL level?

If it is 195, then you have a problem with the logger.
If it is 400 or 1000, then the logger may be recording entirely normally.
The higher ENL values also occur in both the circuits, suggesting that they
represent "wheel-down".
The highest glide of 100 knots only gives a reading of 40.

I would have expected to see a higher value at touchdown. I see no evidence
of a touchdown spike. Maybe you grease the glider onto a smooth runway! I
would also have expected a higher value at 100 knots.

I would recommend the following tests:
Put the logger into the tug plane and seem what ENL level is recorded -
expect over 800, if 195 then problems.
Try putting the logger somewhere else in the glider, such as the luggage
shelf, which should be more noise-sensitive than the top of the instrument
panel.

If you have neither Turbo nor SLMG then the ENL is not vital.

------------------------------------------------

I fly a DG800 SLMG with LX20 logger.
The ENL recording is between 0-1000.
I tend to review my flights using SeeYou with Map, Altitude and ENL windows.
This allows ENL noise to be reviewed and interpreted.

My values are:
Engine running - never less than 800, normally about 900.
There is sometimes an after effect following the engine run and this seems
to take some minutes to return to normal levels, but not of the same order
as your noise levels. The engine noise also dips to 800 at the start of the
takeoff roll! I have not studied the post-engine run noise because it is
normally not very noticeable.

Touchdown spike 800
Winch launches 500-600.
Spins 600-800.
Engine up 500-700.
Normal flying 0-400.
High speed glides - 80kts 400, 90kts 550, 100kts 600, 120kts 800.
I can find a record of 600 at only 80kts.
I cannot tell from the ENL if the wheel is down, but it is colder and sounds
noisier in the cockpit. I have checked at least one "wheel down" flight.



Rory