PA-28-200R Landing gear

[Illini Pilot]

The PA-28-200 has the engine mounted slightly off center, a higher AOI on the left wing, and a twisted vertical stabilizer, all to help counter left-turning tendencies (mainly torque)...where to find this i have no clue though, but if you stand in front of the airplane and look closely you can definately see the engine offset to the left. Can't really see the different AOIs or angled stabilizer though.

 

[Tinstaafl]

Engine offset on various types I'm familiar with. It's the differential mainplane incidence that I'm querying. I'm not sure that there is sufficient torque on these low powered types to warrant it. If it's there then it would be noticeable as a roll to the right in a power off glide but I've never seen it. As far as I'm aware the rigger's incidence is the same from left to right wing on these types - that's why I was interested in the source of this asymmetric incidence information.

 

[Foxcow]

B.Microswitch on the throttle quadrant. (Activates horn Below 14" MP with gear up.)

I've heard that the most but I've also heard that its not actually 14" MP but rather a position in the quadrant. What do you guys think?

 

[Illini Pilot]

I've heard that the most but I've also heard that its not actually 14" MP but rather a position in the quadrant. What do you guys think?

thats correct, in our fleet of arrows, there are some that will give you the horn at 16-17" and some that you need full idle to get the horn. usually it will get written up once it is very obvious and mx will change the setting on the throttle quadrant. it is a lot cheaper and easier to put the microswitch in this manner rather than figure out some fancy gadget that will run off the actual MP to sense <14"

 

[IrishFlyer]

Hi,

Thanks for all the interesting responses. Quick question:

"a higher AOI on the left wing"

I understand what the AOI is but can someone explain how this helps to counteract left turning tendencies.

"engine mounted slightly off center"

I presume it is mounted off to the right if looking from the rear of the aircraft?

"and a twisted vertical stabilizer"

Again I presume it is twisted off to the right, correct?

Sorry for being persistent I simply dont want to start telling the examiner a load of bs in the oral.

Thanks again,

IF

 

[cessna_driver2]

P-28R-200 has
A.squatswich on left main gear.(disables gear operation on ground)
B.Microswitch on the throttle quadrant. (Activates horn Below 14" MP with gear up.)
C.Microswitch on flaps. (Activates horn beyond 10 degrees flaps with gear up.)
D You have three down-limit switches and obviously three up-limit switches.
These basically tell the hydraulic pump when to stop pumping hydraulic fluid to the actuator cylinders on all three gears.

One small problem with the up limit switch. On the arrow's the uplimt switch does not turn off the hydraulic pump. The Pump will maintain a positive pressure then shut off around 1500 PSI & maintains it. The up limit switchs turn off the Gear unsafe light. If for one reason the hydraulic system looses pressure, the gear will fall, Deactivating the Up limit switch & illuminating the gear unsafe light.

 

[JRSLim]

One small problem with the up limit switch. On the arrow's the uplimt switch does not turn off the hydraulic pump. The Pump will maintain a positive pressure then shut off around 1500 PSI & maintains it. The up limit switchs turn off the Gear unsafe light. If for one reason the hydraulic system looses pressure, the gear will fall, Deactivating the Up limit switch & illuminating the gear unsafe light.

OK, I dug out the Arrow manual, because I was thinking the same thing (about the motor pressure switch)
Referencing the Electrical Schematic in the Arrow Manual we have:
3 up limit switches.
3 down limit swiches
1 squat switch
1 pressure switch for the motor
1 throttle quadrant switch
On certain models, 1 switch for the Automatic Gear Down Actuator.
On certain models without the above AGDA switch, 1 flap switch that sounds the horn with 10 degrees flap and gear still up.

As a matter of interest -- during flight the gear may drop a little as the system loses pressure -- this trips the pressure motor switch which pumps the gear back up

 

[JonJohn82]

I'm just making sure I understand this correctly. The three "down" microswitches will stop the pump when the gear is down and locked. They will also cause the gear position indicator lights to show illuminate. The gear "up" microswitches do not stop the pump. The pump stops itself at a certain PSI. Is that correct?

 

[pilotmyf]

P-28R-200 has
A.squatswich on left main gear.(disables gear operation on ground)
B.Microswitch on the throttle quadrant. (Activates horn Below 14" MP with gear up.)
C.Microswitch on flaps. (Activates horn beyond 10 degrees flaps with gear up.)
D You have three down-limit switches and obviously three up-limit switches.
These basically tell the hydraulic pump when to stop pumping hydraulic fluid to the actuator cylinders on all three gears.

I've heard of the vertical stabilizer thing. Whether it's found on the Arrow? I don't know.

I've also heard mounting the engine at a slight angle off-sets torque.
Which manufacturers do this? I don't know.

Stand 10 feet back from the spinner and look at the spacing in relation to the cowling. The engine is obviously offset a bit.

 

[cessna_driver2]

I'm just making sure I understand this correctly. The three "down" microswitches will stop the pump when the gear is down and locked. They will also cause the gear position indicator lights to show illuminate. The gear "up" microswitches do not stop the pump. The pump stops itself at a certain PSI. Is that correct?

Ok direct from pa28r-200 information manual for s/n 28r-7435001 - 28r-7635545.

Some a/c incorporate a pressure sensing device in the system whech lowers the gear regardless of gear selector position, depending upond airspeed & engine power.

Now, if the pressure sensor notices a loss of pressure, it should activate the pump to increase the pressure. Positive pressure keeps the gear up. The sensor should notice a drop in pressure before there is enough movement in the gear to deactivate the micro switch.

So you are correct. The gear up switch does not shut the hydraulic power pack off.