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dsavarese0812(at)bellsout
Guest

Posted: Tue Jun 11, 2013 5:36 am Post subject: Air system 'stuff'

I am not suggesting this modification is for everyone.  Each owner has 

to make his or her own decision whether to keep the gear and flap 

selectors in the rear cockpit or not.  But if one decides to keep them, 

then by golly make sure you exercise them periodically.  Not exercising 

them periodically can do more harm than good.



We could create all kinds of scenarios John to justify keeping the no 

longer used components in the rear cockpit.  Then what about the rear 

brake disabling capability?  What about the instrument failure simulator 

switches?  Next question would be, do you always fly with a qualified 

pilot in the rear seat?  If you had a non-pilot in the rear seat 

(happens much more than with a qualified pilot) do you really think the 

non qualified person is going to know what to do in the first place?



Lastly, the Yak 52 can be landed gear up.    The question is, can the 

person in the back seat REALLY land the airplane?  Gear up OR gear down?



Dennis



A. Dennis Savarese

334-285-6263

334-546-8182 (mobile)

www.yak-52.com

Skype - Yakguy1



On 6/11/2013 7:55 AM, John Nolan wrote:

[quote] When removing any components from the aft cockpit I would consider the 

 possibility of pilot incapacitation in the forward cockpit with a 

 person in the back.



 Regards,



 John Nolan



 On Tue, Jun 11, 2013 at 7:55 AM, A. Dennis Savarese 

 <dsavarese0812(at)bellsouth.net <mailto:dsavarese0812(at)bellsouth.net>> wrote:



     

     <dsavarese0812(at)bellsouth.net <mailto:dsavarese0812(at)bellsouth.net>>



     Since neither the CJ nor the Yak 52, which have 100% identical

     gear and flap selectors for both front and rear cockpits, the rear

     cockpit gear and flap selectors are no longer used as was

     originally intended; as primary trainers. Therefore gear and flap

     selectors in the rear cockpit serve no functional benefit other

     than to pass the air pressure through them to the front cockpit.  

     Why not fabricate a 3 valve and 5 valve bypass 'block' which could

     replace both of these "rarely ever used" components and eliminate

     potential failures in the pneumatic system?



     This is not difficult to do.  In fact, I am pretty sure Jim

     Goolsby modified his rear gear selector and created a bypass. Thus

     he eliminated the potential failure of the unit.  I personally

     fabricated a bypass configuration for one Yak 52 and completely

     removed the rear gear selector.  Replacing a rear gear selector in

     a Yak 52 is far more difficult than on a CJ because the CJ's gear

     selector can be accessed from behind the front seat.  In the Yak

     52 you need a 10 year old skinny kid to get under the instrument

     panel.



     If you have never disassembled a rear gear selector after it has

     started leaking, you would not believe the rust and junk that

     accumulates inside this piece of equipment when it is never used.

     And many folks never even test them during the condition

     inspection.  So they just sit there and corrode over time.



     My contention is, if it is not used and can and will cause

     pneumatic system problems, why not remove it from the system and

     eliminate the potential problem once and for all.

     Dennis



     A. Dennis Savarese

     334-285-6263 <tel:334-285-6263>

     334-546-8182 <tel:334-546-8182> (mobile)

     www.yak-52.com <http://www.yak-52.com>

     Skype - Yakguy1



     On 6/10/2013 4:41 PM, doug sapp wrote:



         Mark,

         It has been my experience that 75% or more of the failures of

         QSF2A valves (3 port valves to you 52 types), and 12-5522-00

         (5 port valve) are caused not by moisture/rust but by grit and

         or pieces of rusted springs.  Years of rusty springs and poor

         maintenance has resulted in the majority of the air systems

         out there being contaminated to some degree.  To combat the

         base problem we switched to all stainless steel springs in

         most all of our valves quite some time ago.  The secondary

         problem of contaminated pneumatic problems is harder to solve

         as flushing the system out is very difficult.  We are

         experimenting with the installation of a second stainless

         steel desiccant filter installed just prior to the rear gear

         valve, if successful this should vastly extend the life of

         these expensive valves.



         Best,

         Doug



         On Mon, Jun 10, 2013 at 12:10 PM, Bitterlich, Mark G CIV

         NAVAIR, WD <mark.bitterlich(at)navy.mil

         <mailto:mark.bitterlich(at)navy.mil>

         <mailto:mark.bitterlich(at)navy.mil

         <mailto:mark.bitterlich(at)navy.mil>>> wrote:



             

         NAVAIR,

             WD" <mark.bitterlich(at)navy.mil

         <mailto:mark.bitterlich(at)navy.mil>

         <mailto:mark.bitterlich(at)navy.mil

         <mailto:mark.bitterlich(at)navy.mil>>>



             Thanks for the expert advice Doug.  I had never even

         considered that.



             By the way, there is an air filter of sorts in the YAK-50.

          It is

             located on the "T" air divider area where all the check

         valves are

             located (four of them).  It appears to be a circular

         device with

             fittings at both ends and is possibly filled with

         something like steel

             wool.  In any case, whatever was in mine came all to

         pieces and junked

             up the check valves.



             Again: Good advice on a better filter.  Hmmm.



             Mark

             --

dsavarese0812(at)bellsout
Guest

Posted: Tue Jun 11, 2013 5:51 am Post subject: Air system 'stuff'

Why in the world would you put a "less than qualified person" in the 

front seat of a Yak 52 in the first place?  Putting anyone in the front 

seat of a Yak 52, including even a high time pilot,  without proper 

aircraft-specific instruction and cockpit briefing BEFOREHAND is 

potentially an accident looking for a place to happen.



Performing aerobatic flight instruction from the rear seat in a Yak 52 

normally presumes the person in the front cockpit is a certificated 

pilot to begin with.  If not, what is that person doing in the front 

seat in the first place?  AND if an instructor is in the back seat and 

teaching aerobatics to certificated pilot, the instructor also has the 

responsibility to provide proper orientation and cockpit instruction 

long before ever having the person in the front seat push the start button.



Dennis



A. Dennis Savarese

334-285-6263

334-546-8182 (mobile)

www.yak-52.com

Skype - Yakguy1



On 6/11/2013 8:12 AM, Bitterlich, Mark G CIV NAVAIR, WD wrote:

[quote] 



 I have the same concerns when flying my YAK-50.   



 No seriously.... with a "person" in the back, or "you" in the back?  For

 those performing aerobatic flight instruction in their YAK-52's where

 they have some less than qualified person in the front seat, keeping the

 rear seat selectors and indicators working makes sense.  Of course that

 also then assumes the same folks are going to pay special attention to

 the known problems that accumulate due to this decision.



 Otherwise the less than qualified person is probably going to be in the

 rear seat anyway... and if the owner/pilot is incapacitated in the front

 seat the passenger can land it gear up.    Just thinking out loud...

 sorry.



 Mark

   



 --

johnrobertnolan(at)gmail.
Guest

Posted: Tue Jun 11, 2013 5:52 am Post subject: Air system 'stuff'

Dennis,



You are correct sir and I deffer to your superior knowledge of the 52. My post was, in general, for all to consider this possibility when disabling or keeping/enabling any system.

 



Regards,

John Nolan



On Tue, Jun 11, 2013 at 9:34 AM, A. Dennis Savarese <dsavarese0812(at)bellsouth.net (dsavarese0812(at)bellsouth.net)> wrote:

 [quote]--> Yak-List message posted by: "A. Dennis Savarese" <dsavarese0812(at)bellsouth.net (dsavarese0812(at)bellsouth.net)>

  

 I am not suggesting this modification is for everyone.  Each owner has to make his or her own decision whether to keep the gear and flap selectors in the rear cockpit or not.  But if one decides to keep them, then by golly make sure you exercise them periodically.  Not exercising them periodically can do more harm than good.

  

 We could create all kinds of scenarios John to justify keeping the no longer used components in the rear cockpit.  Then what about the rear brake disabling capability?  What about the instrument failure simulator switches?  Next question would be, do you always fly with a qualified pilot in the rear seat?  If you had a non-pilot in the rear seat (happens much more than with a qualified pilot) do you really think the non qualified person is going to know what to do in the first place?

  

 Lastly, the Yak 52 can be landed gear up.    The question is, can the person in the back seat REALLY land the airplane?  Gear up OR gear down?

 

 Dennis

 

 A. Dennis Savarese

 [url=tel:334-285-6263]334-285-6263[/url]

 [url=tel:334-546-8182]334-546-8182[/url] (mobile)

 www.yak-52.com

 Skype - Yakguy1

 

 On 6/11/2013 7:55 AM, John Nolan wrote:

 [quote] When removing any components from the aft cockpit I would consider the possibility of pilot incapacitation in the forward cockpit with a person in the back.

 

 Regards,

 

 John Nolan

 

 

 

 On Tue, Jun 11, 2013 at 7:55 AM, A. Dennis Savarese <dsavarese0812(at)bellsouth.net (dsavarese0812(at)bellsouth.net) <mailto:dsavarese0812(at)bellsouth.net (dsavarese0812(at)bellsouth.net)>> wrote:

  

     --> Yak-List message posted by: "A. Dennis Savarese"

     <dsavarese0812(at)bellsouth.net (dsavarese0812(at)bellsouth.net) <mailto:dsavarese0812(at)bellsouth.net (dsavarese0812(at)bellsouth.net)>>

  

     Since neither the CJ nor the Yak 52, which have 100% identical

     gear and flap selectors for both front and rear cockpits, the rear

     cockpit gear and flap selectors are no longer used as was

     originally intended; as primary trainers. Therefore gear and flap

     selectors in the rear cockpit serve no functional benefit other

     than to pass the air pressure through them to the front cockpit.      Why not fabricate a 3 valve and 5 valve bypass 'block' which could

     replace both of these "rarely ever used" components and eliminate

     potential failures in the pneumatic system?

 

     This is not difficult to do.  In fact, I am pretty sure Jim

     Goolsby modified his rear gear selector and created a bypass. Thus

     he eliminated the potential failure of the unit.  I personally

     fabricated a bypass configuration for one Yak 52 and completely

     removed the rear gear selector.  Replacing a rear gear selector in

     a Yak 52 is far more difficult than on a CJ because the CJ's gear

     selector can be accessed from behind the front seat.  In the Yak

     52 you need a 10 year old skinny kid to get under the instrument

     panel.

 

     If you have never disassembled a rear gear selector after it has

     started leaking, you would not believe the rust and junk that

     accumulates inside this piece of equipment when it is never used.

     And many folks never even test them during the condition

     inspection.  So they just sit there and corrode over time.

 

     My contention is, if it is not used and can and will cause

     pneumatic system problems, why not remove it from the system and

     eliminate the potential problem once and for all.

     Dennis

 

     A. Dennis Savarese

     [url=tel:334-285-6263]334-285-6263[/url] <tel:[url=tel:334-285-6263]334-285-6263[/url]>

     [url=tel:334-546-8182]334-546-8182[/url] <tel:[url=tel:334-546-8182]334-546-8182[/url]> (mobile)

     www.yak-52.com <http://www.yak-52.com>

     Skype - Yakguy1

 

     On 6/10/2013 4:41 PM, doug sapp wrote:

 

         Mark,

         It has been my experience that 75% or more of the failures of

         QSF2A valves (3 port valves to you 52 types), and 12-5522-00

         (5 port valve) are caused not by moisture/rust but by grit and

         or pieces of rusted springs.  Years of rusty springs and poor

         maintenance has resulted in the majority of the air systems

         out there being contaminated to some degree.  To combat the

         base problem we switched to all stainless steel springs in

         most all of our valves quite some time ago.  The secondary

         problem of contaminated pneumatic problems is harder to solve

         as flushing the system out is very difficult.  We are

         experimenting with the installation of a second stainless

         steel desiccant filter installed just prior to the rear gear

         valve, if successful this should vastly extend the life of

         these expensive valves.

 

         Best,

         Doug

 

         On Mon, Jun 10, 2013 at 12:10 PM, Bitterlich, Mark G CIV

         NAVAIR, WD <mark.bitterlich(at)navy.mil (mark.bitterlich(at)navy.mil)

         <mailto:mark.bitterlich(at)navy.mil (mark.bitterlich(at)navy.mil)>

         <mailto:mark.bitterlich(at)navy.mil (mark.bitterlich(at)navy.mil)

         <mailto:mark.bitterlich(at)navy.mil (mark.bitterlich(at)navy.mil)>>> wrote:

 

             --> Yak-List message posted by: "Bitterlich, Mark G CIV

         NAVAIR,

             WD" <mark.bitterlich(at)navy.mil (mark.bitterlich(at)navy.mil)

         <mailto:mark.bitterlich(at)navy.mil (mark.bitterlich(at)navy.mil)>

         <mailto:mark.bitterlich(at)navy.mil (mark.bitterlich(at)navy.mil)

         <mailto:mark.bitterlich(at)navy.mil (mark.bitterlich(at)navy.mil)>>>

 

             Thanks for the expert advice Doug.  I had never even

         considered that.

 

             By the way, there is an air filter of sorts in the YAK-50.

          It is

             located on the "T" air divider area where all the check

         valves are

             located (four of them).  It appears to be a circular

         device with

             fittings at both ends and is possibly filled with

         something like steel

             wool.  In any case, whatever was in mine came all to

         pieces and junked

             up the check valves.

 

             Again: Good advice on a better filter.  Hmmm.

 

             Mark

 

 

             --

mark.bitterlich(at)navy.m
Guest

Posted: Tue Jun 11, 2013 5:59 am Post subject: Air system 'stuff'

I totally agree.  



I was playing "Devils Advocate".  



Mark Bitterlich 



p.s.  My Guy In Back is usually hanging on by a long rope.  



--

dsavarese0812(at)bellsout
Guest

Posted: Tue Jun 11, 2013 6:07 am Post subject: Air system 'stuff'

John,

I would agree with you if the airplane's mission today was for primary 

or initial flight instruction.  But since it is not, components that can 

potentially fail could be removed.  Again, that decision is always up to 

the owner.

Dennis



A. Dennis Savarese

334-285-6263

334-546-8182 (mobile)

www.yak-52.com

Skype - Yakguy1



On 6/11/2013 8:50 AM, John Nolan wrote:

[quote] Dennis,



 You are correct sir and I deffer to your superior knowledge of the 52. 

 My post was, in general, for all to consider this possibility when 

 disabling or keeping/enabling any system.



 Regards,



 John Nolan

 On Tue, Jun 11, 2013 at 9:34 AM, A. Dennis Savarese 

 <dsavarese0812(at)bellsouth.net <mailto:dsavarese0812(at)bellsouth.net>> wrote:



     

     <dsavarese0812(at)bellsouth.net <mailto:dsavarese0812(at)bellsouth.net>>



     I am not suggesting this modification is for everyone.  Each owner

     has to make his or her own decision whether to keep the gear and

     flap selectors in the rear cockpit or not.  But if one decides to

     keep them, then by golly make sure you exercise them periodically.

      Not exercising them periodically can do more harm than good.



     We could create all kinds of scenarios John to justify keeping the

     no longer used components in the rear cockpit.  Then what about

     the rear brake disabling capability?  What about the instrument

     failure simulator switches?  Next question would be, do you always

     fly with a qualified pilot in the rear seat?  If you had a

     non-pilot in the rear seat (happens much more than with a

     qualified pilot) do you really think the non qualified person is

     going to know what to do in the first place?



     Lastly, the Yak 52 can be landed gear up.    The question is, can

     the person in the back seat REALLY land the airplane?  Gear up OR

     gear down?



     Dennis



     A. Dennis Savarese

     334-285-6263 <tel:334-285-6263>

     334-546-8182 <tel:334-546-8182> (mobile)

     www.yak-52.com <http://www.yak-52.com>

     Skype - Yakguy1



     On 6/11/2013 7:55 AM, John Nolan wrote:



         When removing any components from the aft cockpit I would

         consider the possibility of pilot incapacitation in the

         forward cockpit with a person in the back.



         Regards,



         John Nolan



         On Tue, Jun 11, 2013 at 7:55 AM, A. Dennis Savarese

         <dsavarese0812(at)bellsouth.net

         <mailto:dsavarese0812(at)bellsouth.net>

         <mailto:dsavarese0812(at)bellsouth.net

         <mailto:dsavarese0812(at)bellsouth.net>>> wrote:



             

             <dsavarese0812(at)bellsouth.net

         <mailto:dsavarese0812(at)bellsouth.net>

         <mailto:dsavarese0812(at)bellsouth.net

         <mailto:dsavarese0812(at)bellsouth.net>>>



             Since neither the CJ nor the Yak 52, which have 100% identical

             gear and flap selectors for both front and rear cockpits,

         the rear

             cockpit gear and flap selectors are no longer used as was

             originally intended; as primary trainers. Therefore gear

         and flap

             selectors in the rear cockpit serve no functional benefit

         other

             than to pass the air pressure through them to the front

         cockpit.      Why not fabricate a 3 valve and 5 valve bypass

         'block' which could

             replace both of these "rarely ever used" components and

         eliminate

             potential failures in the pneumatic system?



             This is not difficult to do.  In fact, I am pretty sure Jim

             Goolsby modified his rear gear selector and created a

         bypass. Thus

             he eliminated the potential failure of the unit.  I personally

             fabricated a bypass configuration for one Yak 52 and

         completely

             removed the rear gear selector.  Replacing a rear gear

         selector in

             a Yak 52 is far more difficult than on a CJ because the

         CJ's gear

             selector can be accessed from behind the front seat.  In

         the Yak

             52 you need a 10 year old skinny kid to get under the

         instrument

             panel.



             If you have never disassembled a rear gear selector after

         it has

             started leaking, you would not believe the rust and junk that

             accumulates inside this piece of equipment when it is

         never used.

             And many folks never even test them during the condition

             inspection.  So they just sit there and corrode over time.



             My contention is, if it is not used and can and will cause

             pneumatic system problems, why not remove it from the

         system and

             eliminate the potential problem once and for all.

             Dennis



             A. Dennis Savarese

         334-285-6263 <tel:334-285-6263> <tel:334-285-6263

         <tel:334-285-6263>>

         334-546-8182 <tel:334-546-8182> <tel:334-546-8182

         <tel:334-546-8182>> (mobile)

         www.yak-52.com <http://www.yak-52.com> <http://www.yak-52.com>

             Skype - Yakguy1



             On 6/10/2013 4:41 PM, doug sapp wrote:



                 Mark,

                 It has been my experience that 75% or more of the

         failures of

                 QSF2A valves (3 port valves to you 52 types), and

         12-5522-00

                 (5 port valve) are caused not by moisture/rust but by

         grit and

                 or pieces of rusted springs.  Years of rusty springs

         and poor

                 maintenance has resulted in the majority of the air

         systems

                 out there being contaminated to some degree.  To

         combat the

                 base problem we switched to all stainless steel springs in

                 most all of our valves quite some time ago.  The secondary

                 problem of contaminated pneumatic problems is harder

         to solve

                 as flushing the system out is very difficult.  We are

                 experimenting with the installation of a second stainless

                 steel desiccant filter installed just prior to the

         rear gear

                 valve, if successful this should vastly extend the life of

                 these expensive valves.



                 Best,

                 Doug



                 On Mon, Jun 10, 2013 at 12:10 PM, Bitterlich, Mark G CIV

                 NAVAIR, WD <mark.bitterlich(at)navy.mil

         <mailto:mark.bitterlich(at)navy.mil>

                 <mailto:mark.bitterlich(at)navy.mil

         <mailto:mark.bitterlich(at)navy.mil>>

                 <mailto:mark.bitterlich(at)navy.mil

         <mailto:mark.bitterlich(at)navy.mil>

                 <mailto:mark.bitterlich(at)navy.mil

         <mailto:mark.bitterlich(at)navy.mil>>>> wrote:



                     

         G CIV

                 NAVAIR,

                     WD" <mark.bitterlich(at)navy.mil

         <mailto:mark.bitterlich(at)navy.mil>

                 <mailto:mark.bitterlich(at)navy.mil

         <mailto:mark.bitterlich(at)navy.mil>>

                 <mailto:mark.bitterlich(at)navy.mil

         <mailto:mark.bitterlich(at)navy.mil>

                 <mailto:mark.bitterlich(at)navy.mil

         <mailto:mark.bitterlich(at)navy.mil>>>>



                     Thanks for the expert advice Doug.  I had never even

                 considered that.



                     By the way, there is an air filter of sorts in the

         YAK-50.

                  It is

                     located on the "T" air divider area where all the

         check

                 valves are

                     located (four of them).  It appears to be a circular

                 device with

                     fittings at both ends and is possibly filled with

                 something like steel

                     wool.  In any case, whatever was in mine came all to

                 pieces and junked

                     up the check valves.



                     Again: Good advice on a better filter.  Hmmm.



                     Mark

                     --

markdavis(at)wbsnet.org
Guest

Posted: Tue Jun 11, 2013 6:22 am Post subject: Air system 'stuff'

The good news with a YAK-52 is that if you kill the  mags and land flaps up you likely will do very little damage to the aircraft in  a gear up landing.  This of course would depend on a GIB that understands  this concept and actually gives a s#%t at the time!

  

 Mark Davis

 N44YK

  

  

 [quote]   ---

bwade154(at)yahoo.com
Guest

Posted: Tue Jun 11, 2013 6:52 am Post subject: Air system 'stuff'

As were talking about air system stuff 

Does any one know if the air start valve solenoid is polarity sensitive? The wire plug connector can be attached both ways. Took it out cleaned it now it doesn't work I have voltage at the wire when start button is pushed, valve works when the lever is pushed down? Just ordered new Batteries.

Bill Wade



     

   From: Mark Davis <markdavis(at)wbsnet.org>

 To: yak-list(at)matronics.com 

 Sent: Tuesday, June 11, 2013 10:20 AM

 Subject: Re: Air system 'stuff'

  

 

         The good news with a YAK-52 is that if you kill the  mags and land flaps up you likely will do very little damage to the aircraft in  a gear up landing.  This of course would depend on a GIB that understands  this concept and actually gives a s#%t at the time!

  

 Mark Davis

 N44YK

  

  

 [quote]   ---

dsavarese0812(at)bellsout
Guest

Posted: Tue Jun 11, 2013 7:28 am Post subject: Air system 'stuff'

Bill,

If I am not mistaken, a Cannon plug without a key-way indicates it can 

be connected either way.  Since it is nothing more than a solenoid with 

power and ground being applied, it should work either way.



You can easily test it though with a 24 volt battery and some leads.  

Connect them both ways and see if the solenoid engages or not.



Battery voltage has a significant effect on whether the solenoid engages 

or not.  Less than about 22 volts on the battery voltage instrument may 

not engage the solenoid.

Dennis



A. Dennis Savarese

334-285-6263

334-546-8182 (mobile)

www.yak-52.com

Skype - Yakguy1



On 6/11/2013 9:50 AM, bill wade wrote:

[quote] As were talking about air system stuff

 Does any one know if the air start valve solenoid is polarity 

 sensitive? The wire plug connector can be attached both ways. Took it 

 out cleaned it now it doesn't work I have voltage at the wire when 

 start button is pushed, valve works when the lever is pushed down? 

 Just ordered new Batteries.

 Bill Wade



 *From:* Mark Davis <markdavis(at)wbsnet.org>

 *To:* yak-list(at)matronics.com

 *Sent:* Tuesday, June 11, 2013 10:20 AM

 *Subject:* Re: Air system 'stuff'



 The good news with a YAK-52 is that if you kill the mags and land 

 flaps up you likely will do very little damage to the aircraft in a 

 gear up landing.  This of course would depend on a GIB that 

 understands this concept and actually gives a s#%t at the time!

 Mark Davis

 N44YK



     ---

mark.bitterlich(at)navy.m
Guest

Posted: Tue Jun 11, 2013 7:32 am Post subject: Air system 'stuff'

Yes, it should be polarity sensitive even though I have never tested it

to that effect.  We are talking DC here, so if we reverse the polarity,

the magnetic field will reverse as well.  I never realized that the plug

could be connected both ways.  Hmmm.  



Connect an ohm-meter to the two pins on the solenoid and check to at

least see that you do not have an open, meaning make sure coil is not

dead.  



Check cockpit volt meter and make sure when you press the start button

that you are not dropping voltage below say ... 20 volts minimum...

actually should stay up around 23 VDC or so, but even 20 volts (when

pushing the start button) should open the valve.  



You checked for voltage to one pin on the feed plug, but did you check

the other pin with an ohm-meter and make sure it has a good reading to

ground?  If you really want to be sure, connect about a 20 watt (or so)

light bulb across the two pins in the plug and make sure it lights when

you hit start.  Realize that when you check for power on a plug like you

just did, it is being checked with zero load (no current flow).  So if

you have a ton of resistance in the wire, it will still read the exact

voltage that you want to see.  Meaning, voltage drop equals current

times resistance.  So if E=IR and you have zero current ... zero times

anything is zero, so you will have no voltage drop.  This rarely is a

concern because wires normally just fail open.  But once in awhile it

can really bite you in the tail if you are not aware of it.  



In any case, putting a light bulb across the two pins on the feed plug

puts a load on the wires. If the bulb lights up bright, you have good

wiring, if it glows dimly, you have high resistance somewhere.  Simple.

Did you take it out and clean it because you were already having a

problem?  Or just because .....  Usually problems of this nature are not

with the aircraft wiring, but with the device itself.  A lot has already

been writing about these things.. you might want to check the archives.



Mark



p.s. Doug Sapp has new ones.  



--

bwade154(at)yahoo.com
Guest

Posted: Tue Jun 11, 2013 1:18 pm Post subject: Air system 'stuff'

Actually Mark I've been having problem's building air and a friend cleaned his air starter and reported very good results on higher RPM when starting so I thought as I'm messing with the air system and I've read it should be cleaned periodically (first time in 13 years) I would take a look, falls under if it isn't broke don't fix it! actually it was very clean. As for the building air seems to be from the pump to the check valve and still chasing it, looking for a flex hose from the pump to the snot valve. I will try the bulb thing and check for an open in solenoid. Thanks

Bill Wade

   From: "Bitterlich, Mark G CIV NAVAIR, WD" <mark.bitterlich(at)navy.mil>

 To: yak-list(at)matronics.com 

 Sent: Tuesday, June 11, 2013 11:29 AM

 Subject: RE: Air system 'stuff'

--> Yak-List message posted by: "Bitterlich, Mark G CIV NAVAIR, WD" <mark.bitterlich(at)navy.mil (mark.bitterlich(at)navy.mil)>

Yes, it should be polarity sensitive even though I have never tested it

to that effect.  We are  talking DC here, so if we reverse the polarity,

the magnetic field will reverse as well.  I never realized that the plug

could be connected both ways.  Hmmm.  

Connect an ohm-meter to the two pins on the solenoid and check to at

least see that you do not have an open, meaning make sure coil is not

dead.  

Check cockpit volt meter and make sure when you press the start button

that you are not dropping voltage below say ... 20 volts minimum...

actually should stay up around 23 VDC or so, but even 20 volts (when

pushing the start button) should open the valve.  

You checked for voltage to one pin on the feed plug, but did you check

the other pin with an ohm-meter and make sure it has a good reading to

ground?  If you really want to be sure, connect about a 20 watt (or so)

light bulb across the two pins in the plug and make sure it lights when

you hit start.  Realize  that when you check for power on a plug like you

just did, it is being checked with zero load (no current flow).  So if

you have a ton of resistance in the wire, it will still read the exact

voltage that you want to see.  Meaning, voltage drop equals current

times resistance.  So if E=IR and you have zero current ... zero times

anything is zero, so you will have no voltage drop.  This rarely is a

concern because wires normally just fail open.  But once in awhile it

can really bite you in the tail if you are not aware of it.  

In any case, putting a light bulb across the two pins on the feed plug

puts a load on the wires. If the bulb lights up bright, you have good

wiring, if it glows dimly, you have high resistance somewhere.  Simple.

Did you take it out and clean it because you were already having a

problem?  Or just because .....  Usually problems of this  nature are not

with the aircraft wiring, but with the device itself.  A lot has already

been writing about these things.. you might want to check the archives.

Mark

p.s. Doug Sapp has new ones.  

--

dsavarese0812(at)bellsout
Guest

Posted: Tue Jun 11, 2013 1:32 pm Post subject: Air system 'stuff'

Doug Sapp has the flexible hose from the compressor output check valve banjo fitting to the snot bottle.

Dennis

From: bill wade <bwade154(at)yahoo.com>

To: "yak-list(at)matronics.com" <yak-list(at)matronics.com>

Sent: Tue, June 11, 2013 4:19:32 PM

Subject: Re: Air system 'stuff'

Actually Mark I've been having problem's building air and a friend cleaned his air starter and reported very good results on higher RPM when starting so I thought as I'm messing with the air system and I've read it should be cleaned periodically (first time in 13 years) I would take a look, falls under if it isn't broke don't fix it! actually it was very clean. As for the building air seems to be from the pump to the check valve and still chasing it, looking for a flex hose from the pump to the snot valve. I will try the bulb thing and check for an open in solenoid. Thanks

Bill Wade

   From: "Bitterlich, Mark G CIV NAVAIR, WD" <mark.bitterlich(at)navy.mil>

 To: yak-list(at)matronics.com 

 Sent: Tuesday, June 11, 2013 11:29 AM

 Subject: RE: Air system 'stuff'

--> Yak-List message posted by: "Bitterlich, Mark G CIV NAVAIR, WD" <mark.bitterlich(at)navy.mil (mark.bitterlich(at)navy.mil)>

Yes, it should be polarity sensitive even though I have never tested it

to that effect.  We are  talking DC here, so if we reverse the polarity,

the magnetic field will reverse as well.  I never realized that the plug

could be connected both ways.  Hmmm.  

Connect an ohm-meter to the two pins on the solenoid and check to at

least see that you do not have an open, meaning make sure coil is not

dead.  

Check cockpit volt meter and make sure when you press the start button

that you are not dropping voltage below say ... 20 volts minimum...

actually should stay up around 23 VDC or so, but even 20 volts (when

pushing the start button) should open the valve.  

You checked for voltage to one pin on the feed plug, but did you check

the other pin with an ohm-meter and make sure it has a good reading to

ground?  If you really want to be sure, connect about a 20 watt (or so)

light bulb across the two pins in the plug and make sure it lights when

you hit start.  Realize  that when you check for power on a plug like you

just did, it is being checked with zero load (no current flow).  So if

you have a ton of resistance in the wire, it will still read the exact

voltage that you want to see.  Meaning, voltage drop equals current

times resistance.  So if E=IR and you have zero current ... zero times

anything is zero, so you will have no voltage drop.  This rarely is a

concern because wires normally just fail open.  But once in awhile it

can really bite you in the tail if you are not aware of it.  

In any case, putting a light bulb across the two pins on the feed plug

puts a load on the wires. If the bulb lights up bright, you have good

wiring, if it glows dimly, you have high resistance somewhere.  Simple.

Did you take it out and clean it because you were already having a

problem?  Or just because .....  Usually problems of this  nature are not

with the aircraft wiring, but with the device itself.  A lot has already

been writing about these things.. you might want to check the archives.

Mark

p.s. Doug Sapp has new ones.  

--

Rob Rowe

Joined: 10 Jan 2006
Posts: 124
Location: Berkshire, UK

Posted: Wed Jun 12, 2013 2:38 am Post subject: Re: Air system 'stuff'

 	  mark.bitterlich(at)navy.m wrote: 	
		  Yes, it should be polarity sensitive even though I have never tested it

to that effect.  We are talking DC here, so if we reverse the polarity,

the magnetic field will reverse as well.  I never realized that the plug

could be connected both ways.  Hmmm.  

	




Mark



Beg to differ here, standard solenoids are inherently NOT polarity sensitive. 



Yes reversing the polarity does reverse the magnetic field, but the induced polarity of the soft iron plunger core also reverses - so the direction of force remains unchanged.



Now if the soft iron core plunger is replaced with a magnetised version then you'll get a polarised solenoid ... and it will be marked accordingly.



You will also find polarity marked terminals on more modern solenoids/relays too, designed to work with electronic drivers versus mostly electro-mechanical systems in Yaks/CJs (where the bus battery effectively absorbs the bulk of any transient energy generated).



This is not for their basic function, but because they have an integral back-emf protection diode in parallel with the coil to suppress the (potentially several hundred volt) negative spike produced as the coil field collapses when the solenoid is turned off.



Hence the terminal polarity is essential to prevent this protection diode from being destroyed through continuous forward conduction, rather then a brief spike.



Hope this helps.



Brgds, Rob

mark.bitterlich(at)navy.m
Guest

Posted: Wed Jun 12, 2013 6:44 am Post subject: Air system 'stuff'

Contact me with personal email if you still have problems. 



Problems with building air.  Lots already written on that subject as

well.  You're on the right track.  I replaced the compressor to snot

valve hard line years ago in my 50 (and a friends 52) with a Russian

flexible line.  Sukhoi's have them, but darn if I know the part numbers.

Exact fit.  At one time I believe Doug Sapp or someone else was making

them?  Can't remember.  That line cracks and leaks all the time.  Also

the banjo fitting on the compressor.  Well known "gets dirty and doesn't

work right" item.  Be aware it needs crush washers to repair properly.  



This is the short version. 



Good luck. 



Mark

--

mark.bitterlich(at)navy.m
Guest

Posted: Wed Jun 12, 2013 6:59 am Post subject: Air system 'stuff'

Rob said:



 	  Quote: 	
		   Beg to differ here, standard solenoids are inherently NOT polarity

sensitive. 
	




Rob's dead right.  I was dead wrong.  Did not think it through, sorry

folks. 



 	  Quote: 	
		   Yes reversing the polarity does reverse the magnetic field, but the

induced polarity of the soft iron plunger core also reverses - so the
	


direction of force remains unchanged.



Yep, he's right again.  



 	  Quote: 	
		   This is not for their basic function, but because they have an

integral back-emf protection diode in parallel with the coil to suppress
	


the (potentially several hundred volt) negative spike produced as the

coil field collapses when the solenoid is turned off.



I doubt many on this list are familiar with reverse EMF caused by a

collapsing magnetic field, but you're right yet *AGAIN*. 



Anyone reading this needs to take note of just whom I am speaking to:

Rob Rowe [yak-list(at)robrowe.plus.com]



I've not met too many people that know more than I do about YAK

Electrical systems.  This gent is one of them.  



Thanks Rob for the (polite) correction.  Hey, when you're wrong, you're

wrong... and I was here!   



Take care, 



Mark

Rob Rowe

Joined: 10 Jan 2006
Posts: 124
Location: Berkshire, UK

Posted: Wed Jun 12, 2013 8:18 am Post subject: Re: Air system 'stuff'

Kind words Mark but you're the real hands-on expert, I'm just the theorist!



Reminds us though that the Yak/CJ electrical bus can be a hard place for modern hi-tech avionics to survive, where your best friends are well maintained batteries that help absorb electrical noise.



While the hi-tech kit will have transorbs and other protection devices fitted, they're designed for occasional transients. 



If your batteries are in poor shape then you could be subjecting the bus to frequent transients from a couple of dozen relays & solenoids, let alone the shower of sparks & carbon pile regulator.



So a small investment in looking after your batteries will help look after your big investment in sophisticated avionics kit.



Cheers, Rob

mark.bitterlich(at)navy.m
Guest

Posted: Wed Jun 12, 2013 3:48 pm Post subject: Air system 'stuff'

Boy is that the understatement of the year!   A lot of folks in the aerobatic world put really small mini batteries in the Sukhoi's to save weight.  Works great!   For a little while.   Sometimes less than a year.  Then because they are constantly over-charged and otherwise "abused", they sag. Of course then they droop.  Then they fail to absorb spikes.  Then crap starts blowing up all over the airplane.  

  

 Add an electric smoke pump, and radios and transponders bite the dust.  

  

 As I said, you need to listen tot his guy.  

  

 Mark

  



 

  From: Rob Rowe

Sent: Wed 6/12/2013 12:18 PM

To: yak-list(at)matronics.com

Subject: Yak-List: Re: Air system 'stuff'

 [quote]--> Yak-List message posted by: "Rob Rowe" <yak-list(at)robrowe.plus.com>



Kind words Mark but you're the real hands-on expert, I'm just the theorist!



Reminds us though that the Yak/CJ electrical bus can be a hard place for modern hi-tech avionics to survive, where your best friends are well maintained batteries that help absorb electrical noise.



While the hi-tech kit will have transorbs and other protection devices fitted, they're designed for occasional transients. 



If your batteries are in poor shape then you could be subjecting the bus to frequent transients from a couple of dozen relays & solenoids, let alone the shower of sparks & carbon pile regulator.



So a small investment in looking after your batteries will help look after your big investment in sophisticated avionics kit.



Cheers, Rob





Read this topic online here:



http://forums.matronics.com/viewtopic.php?p=402558#402558





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