Regional Jet 200 ER/LR (CRJ200)
Maintenance Airframe; Maintenance Powerplant
Time Pressure; Situational Awareness; Distraction; Communication Breakdown; Workload
Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural FAR; Deviation / Discrepancy - Procedural Published Material / Policy
Aircraft Aircraft Damaged; General Maintenance Action
Procedure; Human Factors; Manuals
Early evening; September 2013; at our ZZZ Company X Maintenance Hangar; I was assigned to a Main Landing Gear (MLG) change on a CRJ-200 aircraft. I installed the two hydraulic brake swivel lines incorrectly. When the aircraft landed in ZZZ1 two days later; both Outboard (O/B) Tires had blown because the Antiskid was not reading right [correctly] and caused the brakes to lock-up. I failed to correctly read my Aircraft Maintenance Manual (AMM) reference to ensure that I fully complied with AMM 32-11-20. The swivel [coupling] easily fit into position; so I did not think that it was being installed incorrectly. I incorrectly performed the Operational Check of the Anti-Skid Brake Test System. The hydraulic lines had been installed opposite from what they should have been. The lines were operating the wrong brakes which caused them to lock-up. The CRJ-200 was immediately taken out of service when it landed in ZZZ1. Recommend a couple things that I could have done to prevent this incident are:   1)-Always look at and read my reference to whatever my task pertains to   2)-Never Assume anything. Always ensure that if I install something or remove something; to be sure that I did it correctly and within limits of the Manuals.3)-Double check my work. Get someone else if they have the time to look at my work so I can have a second opinion; then go back and triple check my work to be absolutely sure!Complacency and time pressures [were contributors].  Aircraft damage [occurred].
Reporter stated that all four Main Landing Gear (MLG) tires on the CRJ-200 had blown on landing. He had cross-connected the two stainless steel hydraulic brake lines at the Forward [Outer] and Aft [Inner] couplings on the Right MLG Swivel Coupling Assembly valve; which is located at the top of both Main Landing Gears (MLG) at the forward trunnion. Both hydraulic lines were easy to attach. Another Mechanic had misread the Aircraft Maintenance Manual (AMM) reference material and cross-connected the hydraulic lines on the Left MLG.Reporter stated the Outboard (O/B) MLG brakes use Number 2 Hydraulic System and the Inboard (I/B) MLG brakes use Number 3 Hydraulic System fluid. If they had done the full Brake Check per the (AMM); they would have seen the I/B and O/B brakes were operating when they should not be; because part of the Brake Check procedures require operating the I/B and O/B brakes separately. Instead; they just checked to see that both I/B and O/B set of brakes worked at the same time when they pressurized the Number 2 and Number 3 Hydraulic Systems. The RII Inspector also missed the cross-connected hydraulic lines.  He doesn't know what actually triggered the incident when all four brakes locked-up and blew the four MLG tires; because the aircraft had flown several legs without any discrepancies after the MLGs were changed and the brake lines had been cross-connected.
An Aircraft Maintenance Technician (AMT) was informed that a CRJ-200 aircraft had blown all four Main Landing Gear (MLG) tires on landing. He had inadvertently cross-connected the Number 2 and Number 3 Hydraulic System brake lines at the MLG Swivel Coupling Assembly during a MLG change. The Anti-Skid Brake Test was also  performed incorrectly.