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steve2(at)sover.net
Guest

Posted: Mon Apr 07, 2008 11:25 am Post subject: Electric Hydraulic Pump Ideas

If there's a sudden worldwide rash of off-runway  excursions for Commanders for the month of April 2008, we'll know what  happened!

 [quote]   ---

aquadiver99(at)yahoo.com
Guest

Posted: Mon Apr 07, 2008 6:16 pm Post subject: Electric Hydraulic Pump Ideas

Hey there John, yes per my POH and experience the pump will Paul you down to the sump giving you only minimal braking. That is why the wise ones are pulling the breaker (everyone included).  

 

 

 Donnie Rose 

205/492-8444

  

 



 ---

aquadiver99(at)yahoo.com
Guest

Posted: Mon Apr 07, 2008 6:17 pm Post subject: Electric Hydraulic Pump Ideas

The key is it would pump down to that  

 

 

 Donnie Rose 

205/492-8444

  

 



 ---

rsrandazzo(at)precisionma
Guest

Posted: Mon Apr 07, 2008 7:02 pm Post subject: Electric Hydraulic Pump Ideas

Donnie, et al-  

   

I’m not so sure I agree with “the wise ones” who are pulling the breaker.  

   

Back in my chief piloting days we used to see “in cockpit solutions” to these types of things roll around the pilot ranks on occasion.  This has led me to believe that if we do a comparative risk analysis on the per-flight chances of landing with the breaker pulled and suffering adverse consequences- versus the chance of suffering the hydraulic failure mentioned-  we are very likely putting the airplane at a greater overall risk exposure by using a system in a manner for which it wasn’t designed.  

   

Based on my knowledge of the system, it does seem to me that the system was designed to provide positive pressure in all failure modes EXCEPT a leak condition-  but knowing how well my commander is built- I’m betting the engineers who dreamed these airplanes up were probably very comfortable with the risk level for such a failure and the ability of the pilot to handle it effectively.  

   

Other achillies heals on our commanders?  Pulling all fuel from a central tank- AND pulling all fuel from a central sump…   But again- I’m sure the designers weighed carefully the actual risk factors versus alternative design theories…  

   

I’m leaving the breaker in.     

   

Robert S. Randazzo  

   

   

       

From: owner-commander-list-server(at)matronics.com [mailto:owner-commander-list-server(at)matronics.com] On Behalf Of Donnie Rose

 Sent: Monday, April 07, 2008 7:14 PM

 To: commander-list(at)matronics.com

 Subject: Re: Electric Hydraulic Pump Ideas  

  

  

     

Hey there John, yes per my POH and experience the pump will Paul you down to the sump giving you only minimal braking. That is why the wise ones are pulling the breaker (everyone included).     



    

    

Donnie Rose 

 [b]205/492-8444[/b]  

    

   

    

     

---

dfalik(at)sbcglobal.net
Guest

Posted: Mon Apr 07, 2008 7:25 pm Post subject: Electric Hydraulic Pump Ideas

All,  

   

As I related previously, I have had 2 major hydraulic failures due to the rupture of a line (abrasion/wear) and failure of a flared fitting along a hydraulic line in a wing root.  Each time I had sufficient pressure for the brakes upon landing.  The gear extension was due to the bungies and springs for the nose gear.  

   

I don’t know where the information came from that relates to ALL the hydraulic fluid being pumped overboard in the event of a line breaking.  It didn’t happen on my 500S.  

   

I’m not pulling the breaker, I have enough to remember prior to landing.  

   

Don  

   

--

John Vormbaum

Joined: 21 Aug 2006
Posts: 273
Location: SF Bay Area, CA

Posted: Mon Apr 07, 2008 7:29 pm Post subject: Electric Hydraulic Pump Ideas

Robert,



The hydraulic system as it is set up is a solid design, but it DOES 

depend on the pilot diagnosing a leak condition before things become 

critical. At 1,000 psi, you can pump the contents of your hydraulic 

fluid reservoir overboard in seconds, down to the standpipe limit. After 

which, the aux pump will happily take a few more seconds to finish the 

job of pumping the remaining fluid out.



I agree with your assessment of "in-cockpit solutions" generally. 

However, in this case (and there has been a LOT of thought put into this 

by people who know these airplanes VERY well), there aren't any adverse 

consequences of landing with the breaker pulled. If the system is sound, 

you have 1,000 redundant psi (on the newer airframes that have a hyd. 

pump on each engine) available for brakes & steering.



If the system is unsound (leak & subsequent pressure loss), you'll know 

because the gear will hang on the locks, down a couple of inches from 

the stowed position. It makes noise. You can see it. I'm assuming this 

happens in all the Commanders after a complete loss of pressure, since 

it did in my 500B and also in a 500S I was ferrying. That should be the 

wakeup call to get ready to push the breaker in on final. If you forget, 

you're in the same boat you would have been in if you had never pulled 

the breaker.



In my case it was too late. I hadn't pulled the breaker in either 

circumstance (I wasn't trained to) and ended up with about a thimbleful 

of fluid left after the flight. I've added the breaker pull to my checklist.



You're right that these airplanes are exceptionally well designed.....so 

I am a bit surprised that the aux pump system is set up this way.



/John



PS: Interestingly, although I didn't try them until after the airplane 

came to a complete stop, in both failures I still had brakes...at least 

enough to get one good tromp on the pedals, anyway.



Robert S. Randazzo wrote:

[quote]

 Donnie, et al-



 I’m not so sure I agree with “the wise ones” who are pulling the breaker.



 Back in my chief piloting days we used to see “in cockpit solutions” 

 to these types of things roll around the pilot ranks on occasion. This 

 has led me to believe that if we do a comparative risk analysis on the 

 per-flight chances of landing with the breaker pulled and suffering 

 adverse consequences- versus the chance of suffering the hydraulic 

 failure mentioned- we are very likely putting the airplane at a 

 greater overall risk exposure by using a system in a manner for which 

 it wasn’t designed.



 Based on my knowledge of the system, it does seem to me that the 

 system was designed to provide positive pressure in all failure modes 

 EXCEPT a leak condition- but knowing how well my commander is built- 

 I’m betting the engineers who dreamed these airplanes up were probably 

 very comfortable with the risk level for such a failure and the 

 ability of the pilot to handle it effectively.



 Other achillies heals on our commanders? Pulling all fuel from a 

 central tank- AND pulling all fuel from a central sump… But again- I’m 

 sure the designers weighed carefully the actual risk factors versus 

 alternative design theories…



 I’m leaving the breaker in.



 Robert S. Randazzo



 *From:* owner-commander-list-server(at)matronics.com 

 [mailto:owner-commander-list-server(at)matronics.com] *On Behalf Of 

 *Donnie Rose

 *Sent:* Monday, April 07, 2008 7:14 PM

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

 *Subject:* Re: Electric Hydraulic Pump Ideas



 Hey there John, yes per my POH and experience the pump will Paul you 

 down to the sump giving you only minimal braking. That is why the wise 

 ones are pulling the breaker (everyone included).

 *Donnie Rose **

 *205/492-8444**



 ---

John Vormbaum

Joined: 21 Aug 2006
Posts: 273
Location: SF Bay Area, CA

Posted: Mon Apr 07, 2008 7:46 pm Post subject: Electric Hydraulic Pump Ideas

Don,



After reading your results and comparing them to mine, I wonder now if 

this is something the designers HAD thought of. Between you & me, we've 

had 4 complete hydraulic failures. In all cases the result was a 

non-event, essentially. In all cases we had brakes....the argument would 

then seem to be, "do we need hydraulics for flaps & gear?" We know the 

gear will come down too....so then we're just down to flaps. A no-flap 

landing isn't a big deal, if you're not flying in the bush, or into a 

900-ft. strip.



So suddenly, should I really be pulling the breaker? I might still argue 

that having an additional available system ready to come on-line might 

be cheap insurance....but now we're up to what, 4, 5, maybe 6 cases of 

hyd. failure on this list, all with safe outcomes. Not reversing myself, 

just pointing out what I'm seeing.



/John



dfalik(at)sbcglobal.net wrote:

[quote]

 All,



 As I related previously, I have had 2 major hydraulic failures due to 

 the rupture of a line (abrasion/wear) and failure of a flared fitting 

 along a hydraulic line in a wing root. Each time I had sufficient 

 pressure for the brakes upon landing. The gear extension was due to 

 the bungies and springs for the nose gear.



 I don’t know where the information came from that relates to ALL the 

 hydraulic fluid being pumped overboard in the event of a line 

 breaking. It didn’t happen on my 500S.



 I’m not pulling the breaker, I have enough to remember prior to landing.



 Don



 --

bobf(at)feldtman.com
Guest

Posted: Tue Apr 08, 2008 12:00 am Post subject: Electric Hydraulic Pump Ideas

Let me think outloud hear.  I have cleveland brakes on the 500B, and I

"think" it is a separate hydraulic system from the "hydraulics" of the flaps

and nose wheel steering. Correct me if I am wrong, but it should be no

different than the "hydraulics" on my experimental, a piper, etc. So, if

that is true. all of the comments about ailerons steering is interesting,

educational, and irrelevant for directional control if the brakes are

working.

I'm 99% sure cause once had an issue with line boy dragging the commander,

and the pilot flying had "locked" the brakes days before. I don't have a

hydraulic accumulator - and the brakes were locked when he tried to drag -

of course nothing was "on"

That should stimulate some discussion.

bobf

500B

On 4/7/08, John Vormbaum <john(at)vormbaum.com> wrote:

[quote]

 Don,

 After reading your results and comparing them to mine, I wonder now if

 this is something the designers HAD thought of. Between you & me, we've had

 4 complete hydraulic failures. In all cases the result was a non-event,

 essentially. In all cases we had brakes....the argument would then seem to

 be, "do we need hydraulics for flaps & gear?" We know the gear will come

 down too....so then we're just down to flaps. A no-flap landing isn't a big

 deal, if you're not flying in the bush, or into a 900-ft. strip.

 So suddenly, should I really be pulling the breaker? I might still argue

 that having an additional available system ready to come on-line might be

 cheap insurance....but now we're up to what, 4, 5, maybe 6 cases of hyd.

 failure on this list, all with safe outcomes. Not reversing myself, just

 pointing out what I'm seeing.

 /John

 dfalik(at)sbcglobal.net wrote:

 >

 > All,

 >

 > As I related previously, I have had 2 major hydraulic failures due to

 > the rupture of a line (abrasion/wear) and failure of a flared fitting along

 > a hydraulic line in a wing root. Each time I had sufficient pressure for the

 > brakes upon landing. The gear extension was due to the bungies and springs

 > for the nose gear.

 >

 > I don't know where the information came from that relates to ALL the

 > hydraulic fluid being pumped overboard in the event of a line breaking. It

 > didn't happen on my 500S.

 >

 > I'm not pulling the breaker, I have enough to remember prior to landing

RnJThompson(at)aol.com
Guest

Posted: Tue Apr 08, 2008 4:06 am Post subject: Electric Hydraulic Pump Ideas

OOOPS. Very different from you Piper ( not knocking Pipers, I have 5 of them)  

The braking system and steering system work off the same brake valves. Hence the first bit does the steering and then the brakes. Both systems therefore rely on the hydraulic pressure from the pumps. The parking brake valve shuts the system off between the calipers and the brake/steering valves thus locking the pressure on the brakes. The accumulator has nothing to do with it. Its only function really is to stop the pressure relief valve from chattering by essentially adding a little ‘give’ in the system. Not trusting the good old park brake is the reason we pressurize the system either by hand pump or electric before we start the engines. Nothing is more entertaining than a commander starting to move before the hydraulics pressurize. Particularly good in those older models that only have one pump and its not on the engine you decided to start.  

Just a thought from Down Under.( where everything works backwards etc)  

Cheers  

Richard  

   

--

steve2(at)sover.net
Guest

Posted: Tue Apr 08, 2008 4:55 am Post subject: Electric Hydraulic Pump Ideas

My Dad relates a very funny story years ago of  having the hydraulic pressure gauge fail internally as the pumps on a 680E  happily pumped the remainder of the fluid out. I'll check with him to make sure  I've got this right...... After losing rudder authority and going very  slowly I believe he shut both engines down as he entered a giant snow bank  and gently buried the thing up to the wing roots.... I had wondered when you  would use the emergency cut-off's in anger in the 500B, and I guess this would  have been one of those times.......

  

 I too was very, very reluctant to incorporate some  "clever idea" in the cockpit.

  

 Before the electric pump was added to the  airframes, the handpump used the same arrangment of the lower  standpipe?

  

 I think I've been comfortable with the idea then  that the electric pump takes the place of the hand pump, 'when I want it to',  rather than it just sitting there and pumping the remaining fluid  overboard.

  

 As to consequences of accidentally leaving the pump  off, the only dire one I can think of is a momentary loss of braking and  steering at startup. I've tried this on the ground several times, and haven't  been able to make the ship do anything scary. Am I missing anything? An inflight  failure without the pump I believe would have been noticed by odd behavior in  the gear and flaps........

  

 Steve

 [quote]   ---

nico(at)cybersuperstore.c
Guest

Posted: Tue Apr 08, 2008 8:44 am Post subject: Electric Hydraulic Pump Ideas

That jogged my memory, Richard.

 My straight 500 a strictly left-engine-starter.  

 Once I had a young hot-shot fly a charter in her and I went  out to make sure everything was taken care of, when I briefed him on the plane's  peculiarities, such as, starting the left engine first at all times. He, of  course, fired up the right engine because it was the furthest from the door in  case they had to evacuate. Those Lyc's had no need for a second opinion when it  came to starting; they fired up right away. So, there I was pushing back on the  nose while he tried to get the left engine going. It wasn't hilarious at the  time, but we laughed about it afterwards. He had to deal with his pax for the  duration of the flight. Served him right.

  



   From: owner-commander-list-server(at)matronics.com  [mailto:owner-commander-list-server(at)matronics.com] On Behalf Of Richard  & Jacqui Thompson

Sent: Tuesday, April 08, 2008 5:04  AM

To: commander-list(at)matronics.com

Subject: RE:  Electric Hydraulic Pump Ideas

 

  

OOOPS. Very different  from you Piper ( not knocking Pipers, I have 5 of them) 

The braking system and  steering system work off the same brake valves. Hence the first bit does the  steering and then the brakes. Both systems therefore rely on the hydraulic  pressure from the pumps. The parking brake valve shuts the system off between  the calipers and the brake/steering valves thus locking the pressure on the  brakes. The accumulator has nothing to do with it. Its only function really is  to stop the pressure relief valve from chattering by essentially adding a little  ‘give’ in the system. Not trusting the good old park brake is the reason we  pressurize the system either by hand pump or electric before we start the  engines. Nothing is more entertaining than a commander starting to move before  the hydraulics pressurize. Particularly good in those older models that only  have one pump and its not on the engine you decided to start. 

Just a thought from  Down Under.( where everything works backwards etc) 

Cheers 

Richard 

  

-----Original  Message-----

From:  owner-commander-list-server(at)matronics.com  [mailto:owner-commander-list-server(at)matronics.com] On Behalf Of Robert Feldtman

Sent: Tuesday, 8 April 2008 5:57  PM

To:  commander-list(at)matronics.com

Subject: Re: Electric  Hydraulic Pump Ideas 

   

Let me think outloud hear.  I have  cleveland brakes on the 500B, and I "think" it is a separate hydraulic system  from the "hydraulics" of the flaps and nose wheel steering. Correct me if I am  wrong, but it should be no different than the "hydraulics" on my experimental, a  piper, etc. So, if that is true. all of the comments about ailerons steering is  interesting, educational, and irrelevant for directional control if the brakes  are working. 

  

 

  

I'm 99% sure cause once had an issue with  line boy dragging the commander, and the pilot flying had "locked" the brakes  days before. I don't have a hydraulic accumulator - and the brakes were locked  when he tried to drag - of course nothing was "on"

  

 

  

That should stimulate some  discussion.

  

 

  

bobf

  

 

  

500B



 

  

On 4/7/08, John Vormbaum <john(at)vormbaum.com (john(at)vormbaum.com)>  wrote:  

-->  Commander-List message posted by: John Vormbaum <john(at)vormbaum.com (john(at)vormbaum.com)>



Don,



After  reading your results and comparing them to mine, I wonder now if this is  something the designers HAD thought of. Between you & me, we've had 4  complete hydraulic failures. In all cases the result was a non-event,  essentially. In all cases we had brakes....the argument would then seem to be,  "do we need hydraulics for flaps & gear?" We know the gear will come down  too....so then we're just down to flaps. A no-flap landing isn't a big deal, if  you're not flying in the bush, or into a 900-ft. strip.



So suddenly,  should I really be pulling the breaker? I might still argue that having an  additional available system ready to come on-line might be cheap  insurance....but now we're up to what, 4, 5, maybe 6 cases of hyd. failure on  this list, all with safe outcomes. Not reversing myself, just pointing out what  I'm seeing.



/John



dfalik(at)sbcglobal.net (dfalik(at)sbcglobal.net)  wrote: 



All,



As I related previously, I have had 2 major hydraulic failures due to  the rupture of a line (abrasion/wear) and failure of a flared fitting along a  hydraulic line in a wing root. Each time I had sufficient pressure for the  brakes upon landing. The gear extension was due to the bungies and springs for  the nose gear.



I don't know where the information  came from that relates to ALL the hydraulic fluid being pumped overboard in the  event of a line breaking. It didn't happen on my 500S.



I'm not pulling the breaker, I have enough to remember prior to  landing.



Don



--

amg3636(at)hotmail.com
Guest

Posted: Tue Apr 08, 2008 3:18 pm Post subject: Electric Hydraulic Pump Ideas

Since this thread is called "pump ideas", it looks like it  would have been a good idea to put the intake for the electric pump at the same place as the engine pump. Then saved the hand pump for the emergency. I understand my straight 500 is plumbed where the electric pump on the later models are. In case  both 

pumps ,and the electric pump went out, you could still hand pump for brakes and  flaps. Correct me if I am wrong. I fly a straight 500, and love the simplicity .

 Question for old Bob ( or anyone) . If my plane has a hose rupture, can I pump

 for brakes and flaps without pumping overboard, as long as the problem is not in

 brake or flap plumbing??

 Thanks,

 Roland Gilliam   AC 500     N6291b

[quote] Date: Mon, 7 Apr 2008 20:46:05 -0700

 From: john(at)vormbaum.com

 To: commander-list(at)matronics.com

 Subject: Re: Commander-List: Electric Hydraulic Pump Ideas

 --> Commander-List message posted by: John Vormbaum <john(at)vormbaum.com>

 Don,

 After reading your results and comparing them to mine, I wonder now if 

 this is something the designers HAD thought of. Between you & me, we've 

 had 4 complete hydraulic failures. In all cases the result was a 

 non-event, essentially. In all cases we had brakes....the argument would 

 then seem to be, "do we need hydraulics for flaps & gear?" We know the 

 gear will come down too....so then we're just down to flaps. A no-flap 

 landing isn't a big deal, if you're not flying in the bush, or into a 

 900-ft. strip.

 So suddenly, should I really be pulling the breaker? I might still argue 

 that having an additional available system ready to come on-line might 

 be cheap insurance....but now we're up to what, 4, 5, maybe 6 cases of 

 hyd. failure on this list, all with safe outcomes. Not reversing myself, 

 just pointing out what I'm seeing.

 /John

 dfalik(at)sbcglobal.net wrote:

 >

 > All,

 >

 > As I related previously, I have had 2 major hydraulic failures due to 

 > the rupture of a line (abrasion/wear) and failure of a flared fitting 

 > along a hydraulic line in a wing root. Each time I had sufficient 

 > pressure for the brakes upon landing. The gear extension was due to 

 > the bungies and springs for the nose gear.

 >

 > I don’t know where the information came from that relates to ALL the 

 > hydraulic fluid being pumped overboard in the event of a line 

 > breaking. It didn’t happen on my 500S.

 >

 > I’m not pulling the breaker, I have enough to remember prior to landing.

 >

 > Don

 >

 > --

BobsV35B(at)aol.com
Guest

Posted: Tue Apr 08, 2008 5:09 pm Post subject: Electric Hydraulic Pump Ideas

Good Evening Roland,

  

 Since it has been at least forty years since I flew an Aero Commander, I am  not qualified to make a broad and or authoritative statement concerning the  hydraulic variations of the aircraft.

  

 However, such a lack of knowledge very rarely keeps me quiet!

  

 In general, It All Depends!

  

 Depends on where the leak is located. If you can isolate the leaking system  by setting a valve in neutral, you may be able to retain the standby fluid long  enough to operate whatever is the most important at the time. Any time a  hydraulic fluid loss becomes apparent, it is good practice to isolate any  suspect system and to depressurize the entire system if that is practical.

  

 I do have one old Commander war story. 

  

 I was out one dark and stormy night when I lost the left engine. It  was Aero Commander serial number twenty-four and was still equipped  with the T-handle one shot feathering device. The one and only engine driven  hydraulic pump was on the left engine.  Fortunately for me, the landing  gear free fell as designed. I did have a copilot available who could wobble the  hand pump, but hard as he was pumping, the pressure was very slow to build. I  elected to forgo the use of flap and save what pressure was being built up to  use for the brakes.

  

 We later found out that the hand pump seals were quite badly worn. I should  have picked that up when I built up hydraulic pressure before engine start, but  that was the first and, at that time, the only Aero Commander I had ever  flown.  I thought the number of strokes needed to build up adequate  prestart pressure was normal.  Later Commanders that I flew could get  adequate prestart pressure by using only three or four strokes on the hand  pump.

  

 So  I guess the only thing I could add would be that it is important  that the hand pump be working well and that the pilot understand how to isolate  various systems.

  

 My dumb luck held out and I was able to retain braking action by my  friend's furious pumping of the handle!

  

 Happy  Skies,



Old Bob

AKA

Bob Siegfried

Ancient Aviator

628 West  86th Street

Downers Grove, IL 60516

630 985-8502 

Stearman  N3977A

Brookeridge Air Park LL22

  

  In a message dated 4/8/2008 6:19:29 P.M. Central Daylight Time,  amg3636(at)hotmail.com writes:

  	  Quote: 	
		  Question for old Bob ( or anyone) . If my plane has a hose rupture, can    I pump

for brakes and flaps without pumping overboard, as long as the    problem is not in

brake or flap    plumbing??

 

 

Thanks,

Roland Gilliam   AC    500      N6291b

	






Planning your summer road trip? Check out AOL Travel Guides.

  [quote][b]

moe-rosspistons(at)hotmai
Guest

Posted: Wed Apr 09, 2008 6:30 am Post subject: Electric Hydraulic Pump Ideas

Nico,

  

 I don't get it.  My Commander will not taxi  from a standing start on one engine, although J.B. told me that it could be done  by turning the nose wheel as far as it would go away from the running engine,  start out in a circle and slowly increase the circle diameter to a straight  line?

  

 Regards,

  

 Moe

 N680RR

 680Fp

  

  



  From: nico css (nico(at)cybersuperstore.com) 

 Sent: Tuesday, April 08, 2008 9:41 AM

 To: commander-list(at)matronics.com (commander-list(at)matronics.com)  

 Subject: RE: Electric Hydraulic Pump  Ideas

 



 That jogged my memory, Richard.

 My straight 500 a strictly left-engine-starter.  

 Once I had a young hot-shot fly a charter in her and I went  out to make sure everything was taken care of, when I briefed him on the plane's  peculiarities, such as, starting the left engine first at all times. He, of  course, fired up the right engine because it was the furthest from the door in  case they had to evacuate. Those Lyc's had no need for a second opinion when it  came to starting; they fired up right away. So, there I was pushing back on the  nose while he tried to get the left engine going. It wasn't hilarious at the  time, but we laughed about it afterwards. He had to deal with his pax for the  duration of the flight. Served him right.

  



   From: owner-commander-list-server(at)matronics.com  [mailto:owner-commander-list-server(at)matronics.com] On Behalf Of Richard  & Jacqui Thompson

Sent: Tuesday, April 08, 2008 5:04  AM

To: commander-list(at)matronics.com

Subject: RE:  Electric Hydraulic Pump Ideas

 

  

OOOPS. Very different  from you Piper ( not knocking Pipers, I have 5 of them) 

The braking system and  steering system work off the same brake valves. Hence the first bit does the  steering and then the brakes. Both systems therefore rely on the hydraulic  pressure from the pumps. The parking brake valve shuts the system off between  the calipers and the brake/steering valves thus locking the pressure on the  brakes. The accumulator has nothing to do with it. Its only function really is  to stop the pressure relief valve from chattering by essentially adding a little  ‘give’ in the system. Not trusting the good old park brake is the reason we  pressurize the system either by hand pump or electric before we start the  engines. Nothing is more entertaining than a commander starting to move before  the hydraulics pressurize. Particularly good in those older models that only  have one pump and its not on the engine you decided to start. 

Just a thought from  Down Under.( where everything works backwards etc) 

Cheers 

Richard 

  

-----Original  Message-----

From:  owner-commander-list-server(at)matronics.com  [mailto:owner-commander-list-server(at)matronics.com] On Behalf Of Robert Feldtman

Sent: Tuesday, 8 April 2008 5:57  PM

To:  commander-list(at)matronics.com

Subject: Re: Electric  Hydraulic Pump Ideas 

   

Let me think outloud hear.  I have  cleveland brakes on the 500B, and I "think" it is a separate hydraulic system  from the "hydraulics" of the flaps and nose wheel steering. Correct me if I am  wrong, but it should be no different than the "hydraulics" on my experimental, a  piper, etc. So, if that is true. all of the comments about ailerons steering is  interesting, educational, and irrelevant for directional control if the brakes  are working. 

  

 

  

I'm 99% sure cause once had an issue with  line boy dragging the commander, and the pilot flying had "locked" the brakes  days before. I don't have a hydraulic accumulator - and the brakes were locked  when he tried to drag - of course nothing was "on"

  

 

  

That should stimulate some  discussion.

  

 

  

bobf

  

 

  

500B



 

  

On 4/7/08, John Vormbaum <john(at)vormbaum.com (john(at)vormbaum.com)>  wrote:  

-->  Commander-List message posted by: John Vormbaum <john(at)vormbaum.com (john(at)vormbaum.com)>



Don,



After  reading your results and comparing them to mine, I wonder now if this is  something the designers HAD thought of. Between you & me, we've had 4  complete hydraulic failures. In all cases the result was a non-event,  essentially. In all cases we had brakes....the argument would then seem to be,  "do we need hydraulics for flaps & gear?" We know the gear will come down  too....so then we're just down to flaps. A no-flap landing isn't a big deal, if  you're not flying in the bush, or into a 900-ft. strip.



So suddenly,  should I really be pulling the breaker? I might still argue that having an  additional available system ready to come on-line might be cheap  insurance....but now we're up to what, 4, 5, maybe 6 cases of hyd. failure on  this list, all with safe outcomes. Not reversing myself, just pointing out what  I'm seeing.



/John



dfalik(at)sbcglobal.net (dfalik(at)sbcglobal.net)  wrote: 



All,



As I related previously, I have had 2 major hydraulic failures due to  the rupture of a line (abrasion/wear) and failure of a flared fitting along a  hydraulic line in a wing root. Each time I had sufficient pressure for the  brakes upon landing. The gear extension was due to the bungies and springs for  the nose gear.



I don't know where the information  came from that relates to ALL the hydraulic fluid being pumped overboard in the  event of a line breaking. It didn't happen on my 500S.



I'm not pulling the breaker, I have enough to remember prior to  landing.



Don



--

cloudcraft(at)aol.com
Guest

Posted: Wed Apr 09, 2008 7:00 am Post subject: Electric Hydraulic Pump Ideas

--

nico(at)cybersuperstore.c
Guest

Posted: Wed Apr 09, 2008 10:01 am Post subject: Electric Hydraulic Pump Ideas

J.B. is exactly right. The nose wheel was turned to the  left and it was a slight decline in that direction, too.  

   From: owner-commander-list-server(at)matronics.com  [mailto:owner-commander-list-server(at)matronics.com] On Behalf Of  Moe-rosspistons

Sent: Wednesday, April 09, 2008 7:28  AM

To: commander-list(at)matronics.com

Subject: Re:  Electric Hydraulic Pump Ideas

 Nico,

 I don't get it.  My Commander will not taxi  from a standing start on one engine, although J.B. told me that it could be done  by turning the nose wheel as far as it would go away from the running engine,  start out in a circle and slowly increase the circle diameter to a straight  line?

 Regards,

 Moe

 N680RR

 680Fp

  From: nico css (nico(at)cybersuperstore.com) 

 Sent: Tuesday, April 08, 2008 9:41 AM

 To: commander-list(at)matronics.com (commander-list(at)matronics.com)  

 Subject: RE: Electric Hydraulic Pump  Ideas

 That jogged my memory, Richard.

 My straight 500 a strictly left-engine-starter.  

 Once I had a young hot-shot fly a charter in her and I went  out to make sure everything was taken care of, when I briefed him on the plane's  peculiarities, such as, starting the left engine first at all times. He, of  course, fired up the right engine because it was the furthest from the door in  case they had to evacuate. Those Lyc's had no need for a second opinion when it  came to starting; they fired up right away. So, there I was pushing back on the  nose while he tried to get the left engine going. It wasn't hilarious at the  time, but we laughed about it afterwards. He had to deal with his pax for the  duration of the flight. Served him right.

   From: owner-commander-list-server(at)matronics.com  [mailto:owner-commander-list-server(at)matronics.com] On Behalf Of Richard  & Jacqui Thompson

Sent: Tuesday, April 08, 2008 5:04  AM

To: commander-list(at)matronics.com

Subject: RE:  Electric Hydraulic Pump Ideas

OOOPS. Very different  from you Piper ( not knocking Pipers, I have 5 of them) 

The braking system and  steering system work off the same brake valves. Hence the first bit does the  steering and then the brakes. Both systems therefore rely on the hydraulic  pressure from the pumps. The parking brake valve shuts the system off between  the calipers and the brake/steering valves thus locking the pressure on the  brakes. The accumulator has nothing to do with it. Its only function really is  to stop the pressure relief valve from chattering by essentially adding a little  ‘give’ in the system. Not trusting the good old park brake is the reason we  pressurize the system either by hand pump or electric before we start the  engines. Nothing is more entertaining than a commander starting to move before  the hydraulics pressurize. Particularly good in those older models that only  have one pump and its not on the engine you decided to start. 

Just a thought from  Down Under.( where everything works backwards etc) 

Cheers 

Richard 

-----Original  Message-----

From:  owner-commander-list-server(at)matronics.com  [mailto:owner-commander-list-server(at)matronics.com] On Behalf Of Robert Feldtman

Sent: Tuesday, 8 April 2008 5:57  PM

To:  commander-list(at)matronics.com

Subject: Re: Electric  Hydraulic Pump Ideas 

Let me think outloud hear.  I have  cleveland brakes on the 500B, and I "think" it is a separate hydraulic system  from the "hydraulics" of the flaps and nose wheel steering. Correct me if I am  wrong, but it should be no different than the "hydraulics" on my experimental, a  piper, etc. So, if that is true. all of the comments about ailerons steering is  interesting, educational, and irrelevant for directional control if the brakes  are working. 

I'm 99% sure cause once had an issue with  line boy dragging the commander, and the pilot flying had "locked" the brakes  days before. I don't have a hydraulic accumulator - and the brakes were locked  when he tried to drag - of course nothing was "on"

That should stimulate some  discussion.

bobf

500B

On 4/7/08, John Vormbaum <john(at)vormbaum.com (john(at)vormbaum.com)>  wrote:  

-->  Commander-List message posted by: John Vormbaum <john(at)vormbaum.com (john(at)vormbaum.com)>

Don,

After  reading your results and comparing them to mine, I wonder now if this is  something the designers HAD thought of. Between you & me, we've had 4  complete hydraulic failures. In all cases the result was a non-event,  essentially. In all cases we had brakes....the argument would then seem to be,  "do we need hydraulics for flaps & gear?" We know the gear will come down  too....so then we're just down to flaps. A no-flap landing isn't a big deal, if  you're not flying in the bush, or into a 900-ft. strip.

So suddenly,  should I really be pulling the breaker? I might still argue that having an  additional available system ready to come on-line might be cheap  insurance....but now we're up to what, 4, 5, maybe 6 cases of hyd. failure on  this list, all with safe outcomes. Not reversing myself, just pointing out what  I'm seeing.

/John

dfalik(at)sbcglobal.net (dfalik(at)sbcglobal.net)  wrote: 

All,

As I related previously, I have had 2 major hydraulic failures due to  the rupture of a line (abrasion/wear) and failure of a flared fitting along a  hydraulic line in a wing root. Each time I had sufficient pressure for the  brakes upon landing. The gear extension was due to the bungies and springs for  the nose gear.

I don't know where the information  came from that relates to ALL the hydraulic fluid being pumped overboard in the  event of a line breaking. It didn't happen on my 500S.

I'm not pulling the breaker, I have enough to remember prior to  landing.

Don

--

amg3636(at)hotmail.com
Guest

Posted: Wed Apr 09, 2008 2:15 pm Post subject: Electric Hydraulic Pump Ideas

Thanks much Keith for taking the time to explain it. It is as I thought, but nice to know I understood  correctly.

  

 Roland   AC 500 N6291B

 [quote]  To: commander-list(at)matronics.com

Subject: Re: Electric Hydraulic Pump Ideas

Date: Wed, 9 Apr 2008 10:57:01 -0400

From: cloudcraft(at)aol.com



--

amg3636(at)hotmail.com
Guest

Posted: Wed Apr 09, 2008 2:25 pm Post subject: Electric Hydraulic Pump Ideas

Thanks for the reply Bob, as always they are welcome. How many pumps would you guess it shoulds take to get the complete system up to 1000 psi? Mine takes about 40 ( for the complete system). and pressure stays up for a bout 2 days.

  

 Thanks again,

  

 Roland  AC500  N6291B

  	  Quote: 	
		    From: BobsV35B(at)aol.com

Date: Tue, 8 Apr 2008 21:07:23 -0400

Subject: Re: Electric Hydraulic Pump Ideas

To: commander-list(at)matronics.com



  Good Evening Roland,

  

 Since it has been at least forty years since I flew an Aero Commander, I am not qualified to make a broad and or authoritative statement concerning the hydraulic variations of the aircraft.

  

 However, such a lack of knowledge very rarely keeps me quiet!

  

 In general, It All Depends!

  

 Depends on where the leak is located. If you can isolate the leaking system by setting a valve in neutral, you may be able to retain the standby fluid long enough to operate whatever is the most important at the time. Any time a hydraulic fluid loss becomes apparent, it is good practice to isolate any suspect system and to depressurize the entire system if that is practical.

  

 I do have one old Commander war story. 

  

 I was out one dark and stormy night when I lost the left engine. It was Aero Commander serial number twenty-four and was still equipped with the T-handle one shot feathering device. The one and only engine driven hydraulic pump was on the left engine.  Fortunately for me, the landing gear free fell as designed. I did have a copilot available who could wobble the hand pump, but hard as he was pumping, the pressure was very slow to build. I elected to forgo the use of flap and save what pressure was being built up to use for the brakes.

  

 We later found out that the hand pump seals were quite badly worn. I should have picked that up when I built up hydraulic pressure before engine start, but that was the first and, at that time, the only Aero Commander I had ever flown.  I thought the number of strokes needed to build up adequate prestart pressure was normal.  Later Commanders that I flew could get adequate prestart pressure by using only three or four strokes on the hand pump.

  

 So  I guess the only thing I could add would be that it is important that the hand pump be working well and that the pilot understand how to isolate various systems.

  

 My dumb luck held out and I was able to retain braking action by my friend's furious pumping of the handle!

  

 Happy Skies,



Old Bob

AKA

Bob Siegfried

Ancient Aviator

628 West 86th Street

Downers Grove, IL 60516

630 985-8502 

Stearman N3977A

Brookeridge Air Park LL22

  

  In a message dated 4/8/2008 6:19:29 P.M. Central Daylight Time, amg3636(at)hotmail.com writes:

  	  Quote: 	
		  Question for old Bob ( or anyone) . If my plane has a hose rupture, can I pump

for brakes and flaps without pumping overboard, as long as the problem is not in

brake or flap plumbing??

 

 

Thanks,

Roland Gilliam   AC 500     N6291b

	






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BobsV35B(at)aol.com
Guest

Posted: Wed Apr 09, 2008 3:11 pm Post subject: Electric Hydraulic Pump Ideas

Good Evening Roland,

  

 That seems high to me, but as I said before, it is at least forty years  since I flew any Aero Commander and my memory just isn't that good. I would try  to inquire of more current pilots because forty pumps seems like a lot to me if  no component is being actuated other than the brakes.  My recollection is  that it only took a few pumps when the system was tight. Maybe half a dozen at  most, but you know, I am getting senile!

  

 Happy  Skies,



Old Bob

AKA

Bob Siegfried

Ancient Aviator

628 West  86th Street

Downers Grove, IL 60516

630 985-8502 

Stearman  N3977A

Brookeridge Air Park LL22

  

  In a message dated 4/9/2008 5:26:07 P.M. Central Daylight Time,  amg3636(at)hotmail.com writes:

  	  Quote: 	
		  Thanks    for the reply Bob, as always they are welcome. How many pumps would you guess    it shoulds take to get the complete system up to 1000 psi? Mine takes about 40    ( for the complete system). and pressure stays up for about 2    days.

 

Thanks again,

 

Roland  AC500     N6291B

	






Planning your summer road trip? Check out AOL Travel Guides.

  [quote][b]

dongirod

Joined: 11 Dec 2006
Posts: 140

Posted: Wed Apr 09, 2008 3:39 pm Post subject: Electric Hydraulic Pump Ideas

Moe;

  

 Makes you wonder how AeroCommander did its famous  one engine ferry from OK. to Washington to demonstrate its ability to fly one on  one engine doesn't it.

  

 Don

 [quote]   ---

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