Auto retract failure

[Jamie Halstead]

Hi All, I am fairly new to operating my Arcus M, 100hrs/48launches in 12 months and have had my first failure, on switching off ignition the auto retract failed with the 'brake' warning and alarm, manually retracted engine no problem, have read previous threads on subject and have cleaned/ adjusted sensors, amber LED's appear to be working as they should fault hasn't cleared, tried both front and rear controllers with no change. Looking for advice on what to try next??. Thanks in advance. Jamie Halstead, Blenheim, New Zealand.

[Mark Zivley]

Jamie,

You've come to a good place as there are several folks here who share good info.

  

What year-ish is your Arcus?   Since you didn't mention it, you don't have the propeller stopper that flips out?

My manual may be older, but page 7.3.31 covers the conditions necessary for automatic retraction.

It is also possible to test on the ground without running the engine.  I know this works for the early Ilec controller.  Not sure about the newer color screen unit.

Obviously, be extra careful to ensure the ignition is off when you move the prop.

1.  Extend with mast by turning on the ignition switch.  After it's fully extended wait about 5 seconds and then turn it back OFF.

(if it tries to retract, use the manual extend and move the prop backwards and then cycle the ignition on and then back off)

2.  Manually rotate the propeller backwards about 30 degrees so that neither of the proximity switches are active.

3.  Expect to see "Brake?" on the display.  Acknowledge with the white menu button.

4.  Slowly advance the propeller by hand.

5.  When the first proximity sensor detects the propeller the brake will engage for 3 seconds and you should feel the resistance to advancement.

6.  The brake should then pulse about once a second and during that time keep light forward pressure on the prop.  It will advance in small increments until the second sensor engages.

7.  With both sensors engaged the automatic retraction will start.   You can cancel by using the manual switch on the ilec.

I've had a couple instances where it was just bad luck in that the engine advanced somewhat suddenly as a result of the engine passing through the top of the compression stroke and it went past the first limit switch far enough that it "missed" and I had to let the prop go another 1/2 turn to try again.   I can't remember, but that may also activate the buzzer and the "brake?" alarm.

On a separate note, it's kinda mentioned in the manual, but until you've seen it done it may not be obvious what is happening.

After you have run the motor (I believe it has to run for a couple seconds first OR the prop has to be rotated back wards so the sensors are not active) and you shut off the motor by turning the ignition switch "OFF", you can manually advance the propeller by using the starter button on the stick.   This is an entirely different mode that is available and it's NOT like when you are starting the engine.  When you press the starter, you'll hear a somewhat scary "whine" and the starter will then turn over VERY slowly.  This can be used to advance the prop much faster than waiting for the windmilling effect to advance the propeller.   This mode will disable as soon as the 1st sensor detects the propeller.  If the prop is almost lined up when it stops naturally, it's not worth doing, but if it needs to go most of a 1/2 turn it's a nice feature.  Especially if the system "missed" a catch and you want to bring the prop around for a 2nd try.

Mark

[Mark B]

I have had repeated failure to retract automatically twice. Once required new prop position sensors. The other time just required adjustment of the position sensor gaps. I found that the gap specified in the maintenance manual (5.5.5.3 in my 2012 maintenance manual) did not work, but changing the gap to 50/1000 restored correct function. Good luck and let us know what happens.

Checking was obviously a 2 person job, operating the mechanism repeatedly as described by Mark Zivley above.