Lost Steering on my 1850

[woodlandfarms]

Ken,

I believe you are correct on capping the steering lines, but I have never done that. but that cap should pressurize the other cylinder (one gets the pressure then the other gets the pressure, at least on mine)

But no guarantees. I still struggle with the flow direction on the steering system we have...

 

[J_J]

I don't know what your first move is, but if the steering valve is bad and is just recirculating fluid back to tank, except when you lift or tilt, it will be difficult to test the steering. You need good pressure down to the steering cylinders, and you can get that using the aux circuit. I believe there is a priority valve in the steering circuit. If the steering wheel is not turning, the fluid is available to the lift and tilt circuits. Since you have lift and tilt, you can also use the lines from the lift valve to connect to the steering cyl, and if you tee in a gage in that circuit, you will know if you have a good cylinder, if you extend or retract the rod. It should read some pressure, but will only see relief pressure at the stops.

 

[Marks481]

So two cylinders for steering means half the reliability? Since if one fails, you loose steering?

Sort of like a twin engine plane, when one engine fails, the other just carrier you to the crash site? So you are twice as likely to crash.

Of course, you are less likely to rip a chunk of you frame out, like happens occasionally with the single piston PT422. That reminds me, time to lift the floorboard and inspect the pivot point on my steering for cracks... Someday, when I am better at welding and will do more good then bad, I will add some reinforcements and get rid of that poorly placed drain hole.

 

[J_J]

Carl,

Both of the cylinders should get pressure at the same time. One cylinder is extending and the other is retracting. More fluid is going to the extending cylinder.

 

[J_J]

So two cylinders for steering means half the reliability? Since if one fails, you loose steering?

Sort of like a twin engine plane, when one engine fails, the other just carrier you to the crash site? So you are twice as likely to crash.

Of course, you are less likely to rip a chunk of you frame out, like happens occasionally with the single piston PT422. That reminds me, time to lift the floorboard and inspect the pivot point on my steering for cracks... Someday, when I am better at welding and will do more good then bad, I will add some reinforcements and get rid of that poorly placed drain hole.

On the airplane comment, not true. While in the Navy, flying in the Lockheed P3, with four engines, we regularly shut down one engine, and sometimes two to extend the range. I was told that plane could fly on just one engine, if it had to. We dumped fuel many times to lighten the load when we had to return home for some emergency.

I believe one cylinder could turn the PT, but the brackets would have to be reinforced. One of the smaller PT's only uses one cylinder.

 

[MossRoad]

On the airplane comment, not true. While in the Navy, flying in the Lockheed P3, with four engines, we regularly shut down one engine, and sometimes two to extend the range. I was told that plane could fly on just one engine, if it had to. We dumped fuel many times to lighten the load when we had to return home for some emergency. .

The P3 is one of THE most overpowered monsters in the sky!

Now take the popular nicknames for the SWEARINGEN METROLINER on one engine: Death Pencil / Kerozen Crowbar / San Antonio Sewerpipe / Swetro / Terror Tube / Texas Lawn Dart / Texas Sewer Pipe / Window Maker

 

[J_J]

They only have 4500 HP per engine. In that crash out in California, many years ago, the P3 was taking off, and a 727 landed on it as it went down the runway, and the P3 lifted the 727 for a short distance, but they both crashed and burned.

 

[Marks481]

While in the Navy, flying in the Lockheed P3, with four engines, we regularly shut down one engine, and sometimes two to extend the range.

True. But I was talking about loosing one of two (not four), leading to very assymmetric thrust. Did you ever shut down two engines on the same side, other then in a controlled training exercise?

But most light twins do not perform well under SE conditions, and have a very limited SE ceiling and minimal climb capability. As long as the pilot does what he is trained to do, loss of an engine shouldn't actually result in a crash... although it occasionally does.

http://www.avweb.com/news/usedacft/182809-1.html
The overall accident rates of high-performance singles (like Bonanzas or 210s or Mooneys) and light twins (like Aerostars or Barons or Commanders or Cessna 310s) are astonishingly close. Twins have a slightly higher accident rate per 100 aircraft and a slightly lower accident rate per 100,000 hours, but for all practical purposes the accident rates are the same.

A single is about two-and-a-half times more likely to have an accident due to engine/prop failure than a twin (8% versus 3%). And if we assume that a twin is twice as likely to have an engine/prop failure (since it has twice as many to fail), then we can conclude that an engine/prop failure in a single is five times more likely to result in an accident than an engine/prop failure in a twin.

But it makes for a funny application of probabilistic risk assessment...

 

[Sedgewood]

So, if i disconnect one cylinder, plug the lines and cap the cylinder connections and try operating it, does that tell me anything? These cylinders are double acting, aren't they. So if the bad cylinder is capped and the lines plugged, the system should pressurize and the tractor turn. If the good cylinder is capped, the system should not work. If both are bad, nothing would happen. If both are good and the steering valve is bad, nothing would happen. Sound right?

Sounds right. And you can steer with just one cylinder working to get you home.

Sedgewood

 

[woodlandfarms]

Carl,

Both of the cylinders should get pressure at the same time. One cylinder is extending and the other is retracting. More fluid is going to the extending cylinder.

When I ripped the cylinder free the oddest thing happened. One cylinder would expand then the other one would contract (Not at the same time). Now, as I freaked out that my PT would be stuck in the woods forever, I never paid full amount of attention to the intricacies. But basically I would have to spin the wheel and get the rippedcylinder to its long or short position before the other piston would take over.... Maybe because there was no backpressure?