Reminder: Air Data System Best Practices
Effectivity: All Challenger series aircraft
ATA: 34-11
By: Eriva Randriamanjatosoa, Technical ServicesThis is a good reminder about Air Data System faults that you may encounter during rainy seasons. Faults like “ALT” and/or “IAS” red flags on left/right PFD ‘s or on the EISI, along with other faults or “EFIS MISCOMPARE”, “YAW DAMPER FAIL”, “STALL PROTECT FAIL”, as well as other flight deck effects may or may not be observed on the ground before departure. These conditions can be attributed to water contamination in the Pitot-Static lines or by cracked Pitot-Static visual drains.
To prevent experiencing the above conditions and prevent unnecessary LRU removals, it is a good practice to check your water drain indicators more often, especially after flying in humid environments or parking your aircraft overnight in the rain, even with the pitot/static probe covers installed. Before departure, make sure there is no water in the Pitot-Static visual drains as it may freeze and cause cracking. Perform AMM task 34-11-09-616-801 servicing the pitot-static visual drains and/or 34-11-00-100-801 pitot-static system purging. That will save you missed trips and/or unnecessary delays.
Bombardier also introduced a larger drain bottles installation via Service Bulletins listed in the references below, however the above maintenance practice recommendations also apply to the aircraft equipped with the larger drain bottles.
References:
AW600-34-2389 Basic Issue for CL6XX
SB 604-34-065 Rev.02 for CL604
SB 605-34-027 Rev.02 for CL605
SB 100-34-22 Basic Issue and SB100-34-25 Rev.01 for CL300
SB 350-34-005 Basic Issue for CL350