Date: 201706
Local time of day: 1201-1800
Location: ZZZ.Airport, US
Light: Daylight
Aircraft: B767-300 and 300 ER
Operator: Air Carrier
Operating under: Part 121
Mission: Passenger
Flight phase: Parked
Aircraft component: Speedbrake/Spoiler
Component problem: Improperly Operated
Reporter organization: Air Carrier
Reporter function: Technician
Human factors: Training / Qualification
Anomaly: Deviation / Discrepancy - Procedural Maintenance; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Maintenance
When detected: Routine Inspection
Result: General Maintenance Action
Contributing factors: Aircraft; Human Factors; Manuals; Procedure; Chart Or Publication
Primary problem: Chart Or Publication

Narrative: While I was performing a test of the VOR accuracy; Systems mechanics started the process of locking out the spoilers on both wings as part of the normal docking procedures. This procedure involves 3 mechanics; 1 mechanic on each wing and 1 mechanic in the flight deck responsible to run all 3 hydraulics systems at the same time and moving the flight controls to the needed positions. The mechanic in the flight deck is there as a safety measure to secure the flight controls so they will not be inadvertently moved. The mechanics on each wing wait for the Spoilers/Speed Brakes on each wing to hydraulically move to the full up position and then they install locks on the mechanisms to prevent them from coming to the down and stowed position.I was sitting in the captain's seat going through of my work card which involves aligning the IRUs (Inertial Reference Unit) but does not require hydraulics when the Systems mechanic assigned to the flight deck entered; sat in the first observer's seat and announced to me what he was preparing to do. He asked if their assigned duties would interfere with mine; since no hydraulics were required on my work card; I said it was OK for them to do theirs in conjunction with mine.After getting the proper clearance; he pressurized all 3 hydraulics systems and moved the Speed Brake handle to the full up position and sat there securing the flight controls while the other 2 mechanics were on both wings installing the lockout devices. About 10 minutes later; I finished my work card and the 2 mechanics on the wings were up under the Ailerons on each wing installing the locks.The last step on my work card stated to remove power from the IRUs. I asked if this would affect his task and we could find nothing to indicate this would be an issue. After I turned off the last of the 3 IRU switches; the Speed Brake handle automatically moved all the way to the down and locked position. This un-commanded flight control movement happened while 2 mechanics were working on each wing in an extremely dangerous area and had no warning. This was a near miss not an injury.Causes:1. Work Cards need to have warnings about un-commanded flight control movement.2. Add a step to Work Cards to tag out the Auto Speed Brake breaker G11 on the pilots overhead (P11) panel. This breaker disables the Auto Brake Actuator ensuring the Speed brakes will not move unless manually commanded to do so.3. Add a step to the Aircraft Maintenance Manual procedure to say 'Open Auto Speed Brake breaker G11 on the P11 Panel.When Work Cards are being assigned on all 767 aircraft; there is a possibility of uncommanded flight control movement anytime the aircraft is put into air mode and pulling the G11 breaker is a proactive measure to ensure the workers safety.




Synopsis: B767 Maintenance Technician reported that when the last of the 3 IRU switches were turned off the spoilers were un-commanded to the down position while maintenance personnel were installing up-locks to the spoilers.