Aircraft Lease Review – Landing Gear Life Limited Parts
Landing Gear SLI or Safe Life Items are better known as LLP or “Life Limited Parts”. These parts are those that have a defined life that is usually measured in cycles or hours of operation or even calendar days. When an LLP reaches that limit it is destroyed and cannot be used further.
We need a status summary detailing the Life Limited Parts on the landing gear so we can determine both their serviceability and remaining life and so can compare then to the lease hand back conditions.
On the status sheet which must be on company letter headed paper for the LLP parts installed you should have for each leg i.e. RH MLG (Main Landing Gear), LH MLG or NLG (Nose Landing gear):
Aircraft Make/Model & MSN (Manufactures Serial Number)
Landing Gear Position and Installed Date
Aircraft Hours and Cycles at installation date (AC HRS/AC CYC)
Landing Gear Part Number and Serial Number
Landing Gear Total Time (Hours) and Total Cycles commonly referred to as TT and TC at time of installation
Defined LLP limit in Hours/Cycles/Calendar days (FH/FC/Days)
Status of the part; Time since New (TSN); Cycles since New (CSN); Time since Overhaul (TSO); Cycles since Overhaul (CSO)
Remaining Life of the LLP in Hours/Cycles/Calendar days (FH/FC/Days)
Next Overhaul due in: Remaining Hours/Cycles/Calendar days (FH/FC/Days)
Signed by either CAMO personnel or a Quality Team Member
To determine if the component meets the required lease agreements refer to the return off lease conditions in the lease agreement. It will detail the remaining life required for the landing gear to be in acceptable return conditions.
You need to know the current status of the LLP items on the landing gear; how many Flight Hours/Cycles and how many calendar days they have been installed.
Then you need to determine the number of Flight Hours/Cycles and how many calendar days BEFORE another overhaul is required
Determine the LLP (Life Limited Part) limitation for each LLP item. What is the limiting factor again look for Flight Hours/Cycles or calendar days. (Cycles would be the most common limiting factor)
The limiting factor is the lowest limit LLP or reason that a component requires Overhaul or Replacement.
Compare the lowest life LLP or limiting factor to the lease to determine if the lease return conditions are met.
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