lml@lancaironline.net Mailing List Archive

Just so, although each Lancair is built according to an individual's ideas. In my mind switches on the gear doors are a good way to ensure the gear is up. Years ago I patented an indicator system that among other things displayed gear up as well as down- nowadays I'm not so sure I'd want lights shining all the time. Complexity is subjective- there's tradeoffs involved. If you want to fly you can't get much simpler than a J-3 Cub. Anything more than that adds capability but also additional systems. A hydraulic gauge serves a purpose for me but it doesn't have to be for everyone. BTW, I'd use 5052 tubing instead of a hose- simpler, lighter, cheaper. -Bill Wade -----Original Message----- From: John Barrett Sent: Friday, March 16, 2012 8:13 AM To: lml@lancaironline.net Subject: [LML] Re: hydraulic pressure gauges Most IV's have gear indicators. Up and Down. If you don't have one or the other it would mean the gear is in transit. John Barrett -----Original Message----- From: Lancair Mailing List [mailto:lml@lancaironline.net] On Behalf Of Bill Wade Sent: Thursday, March 15, 2012 12:44 PM To: lml@lancaironline.net Subject: [LML] Re: hydraulic pressure gauges Good point, although in the IV it appears that continuous pressure is needed to keep the gear up. Not sure how other models are but I'd guess they're similar. You might get some warning of low pressure from a pump or pressure switch malfunction if you had switches on the gear doors. Or if speed started to decay. Navions have an engine-driven pump with a controllable pressure/ dump valve. I'm used to checking the gauge prior to taxi to make sure the system is up and running. It's not a bad idea to make sure there's pressure even with over-center links and locking pins. -Bill Wade -----Original Message----- From: jeffrey liegner Sent: Thursday, March 15, 2012 8:34 AM To: lml@lancaironline.net Subject: [LML] Re: hydraulic pressure gauges After reviewing the options for tapping into the hydraulics, the plumbing and the gauge, rather than having a gauge on the panel somewhere, I'm now actually thinking I will place a transducer off the hydraulic distribution manifold in the gear well. Then I would make this an annual option (or periodic option), connecting a display gauge to read the high-low. I'm thinking that I don't need immediate and continuous monitoring of the pressure. If the flaps or gear transit time slows, I will know this. If the pressure is suddenly lost (catastrophic loss of hydraulics), having the gauge won't tell me more than what I already know...gear won't go down, flaps don't work. And having another high pressure hose behind the panel invites a new leak. Thoughts? Jeff L On the IV-P I'm planning to tee a mechanical gauge in the Pressure line going to the control valve assembly. That'd show me what's available for use and there's no need for any external power source. That could be in addition to transponders monitoring pressure at other points in the system. -Bill Wade I just finished installing 2 hydraulic gages. I was replacing all flex hyd lines with new, so it wasn't hard to include a T in the up line and down line located under the passenger seat. Made an aluminum add on mini panel that goes between pilot's legs and straddles my flap switch. Ran 2 four foot lines to back of gages. All works great on several gear swings, but no operational/environmental experience yet. I definitely wanted the gages where I could see them for any diagnosis, and the panel was full of 1000 steam gages already. Gages are number 9780T221 from McMaster-Carr for a low $21.48 each. These are liquid filled with silicon (-40 deg F to 158deg F). Entire operation cost less than $100. I'll forward a picture in day or so. Jack Addison jraddison@msn.com IO360 high comp -----Original Message----- From: jeffrey liegner [mailto:liegner@ptd.net] Sent: Monday, March 12, 2012 6:56 AM To: lml@lancaironline.net Subject: Suggested Pressure Gauge for Hydraulic Monitoring (LIVP) Any suggestions on which small hydraulic pressure gauge would be a good choice to display hydraulic pressure, either during preflight (ex, in wheel well) or inside the cockpit (for monitoring)? Analogue or electric display? Best location to T the gauge into the system? Thanks. Jeff Liegner Sparta, NJ -- For archives and unsub http://mail.lancaironline.net:81/lists/lml/List.html -- For archives and unsub http://mail.lancaironline.net:81/lists/lml/List.html -- For archives and unsub http://mail.lancaironline.net:81/lists/lml/List.html