Topics in Category: Rolls-Royce Spey - Rotate.Aero Sat, 30 May 2020 11:20:34 +0000 MYOB /media/kunena/images/icons/rss.png Topics in Category: Rolls-Royce Spey - Rotate.Aero en-gb ATA 80, Start Valve Indication - by: Mark D Francis
I grabbed a stick pin and started poking my why up the insulation until I found power. Putting holes in a wire is a BAD idea. In this case that whole section was replaced during the repair.

A wire that has been stuck, especially one exposed to the elements, will break down and fail "very" quickly. Even with the knowledge that this aircraft is heading to the bone yard within two years, I would not of left that wire in that condition.

I should of isolated the problem "to" the engine by disconnecting the firewall plug first. I got lazy and lucky with this problem.

Using stick pins is not a recommended troubleshooting practice.]]>
ATA 80 Engine Start Sun, 30 Oct 2016 18:31:09 +0000
Engine Sync - by: Mark D Francis

Proper actuator operation verification can be accomplished by jumping power to the actuator plug. This can be done with the drive cable attached or disconnected. “Bumping” power to pins “A” or “B” will cause actuator movement of about 1/8 rotation per voltage input.

Maintenance Manual rigging requires that both the plunger assembly and actuator be at their respective centers before being connected. Plunger rigging is accomplished by halving the total number of cable rotations. Actuator rigging is done by halving the total number of rotation “clicks.” Although not mentioned in the manual; by pulsing power to pin “D”, the actuator will find its electrical center.

Ship’s power will work to pulse actuator. A Dewalt 18 volt battery will also.

A Woodward troubleshooting manual can be found below.

GII ATA 76-01-00
AMM 76-01-00
AWM 76-10-00
ATA 76 Engine Control Tue, 16 Dec 2014 12:42:31 +0000
ATA 79-02, Engine Oil Temp/Pressure Indication - by: Mark D Francis (This entry also applies to engine fuel temp indication.)

There is a very simple way of isolating a control unit, indicator, or sensor failure when troubleshooting GIII "vertical bar" indicators for fuel temperature, oil temperature, and oil pressure. These systems are manufactured by Intercontinental Dynamics Corporation. The cost of these units can be quite prohibitive, so isolation of the problem to the actual fault is essential.

When looking at the control box from the plug receptacle sides, it can be noted that the plugs have the same "key" pattern. The only difference is that they are mounted 180 degrees "out" from each other.

System power and sensor inputs use the plugs on one side of the unit. Indicator outputs use the opposite side's plugs.

The oil temperature, oil pressure, and fuel temperature control boxes have their plugs configured in the same fashion. The fuel tank temperature control box does not have the same configuration. It needs to be troubleshot by alternate methods.

This particular aircraft had a problem with the left indication pegged out high. The control box was removed from its mount and turned over. When the plugs were reconnected the problem had moved to the right. In this case, the control box was at fault.

A box flip will verify a control box failure. The plugs can be swapped on one side to isolate a sensor/power input problem. The opposite side plugs can be swapped to cross-feed the indicator. The indicator itself only has one input plug, so indicator troubleshooting must be be done at the box.

If the problem remains "on side" after all the troubleshooting steps have been taken, then the most likely cause is a wiring issue on the indicator output side. ( A broken wire to the left indication will always remain on the left.)

A sensor failure will follow a plug swap, but normal troubleshooting would entail hanging a new one on the engine before pulling the entry floor up to gain access to the control boxes.

GIII ATA 79-02-00 and 73-05-00]]>
ATA 79 Engine Oil Mon, 04 Aug 2014 23:55:49 +0000