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atas.aeroLease methodology End-of-Lease contract review — how it works Part of our methodology
At lease return, two questions decide the handover: is the aircraft in the contracted return condition (readiness), and who owes whom for any gap (settlement). The review answers both from the lease bundle and the aircraft records — before you reach the gate.

What we read

the lease bundle — five document buckets
A

Master lease

Lease agreement and any novations — identity, definitions, the return-condition framework.

B

Redelivery schedule

The contracted target condition per system at handback.

C

Compensation schedule

Maintenance-reserve and compensation rate tables — the settlement basis.

D

Side letters

Variations and amendments that override the schedules — applied last.

E

Aircraft records

Status and shop-visit data — turns contracted targets into a live settlement figure.

When documents conflict, we resolve the governing text per topic — side letters over schedules over the lease body — and every extracted condition carries its controlling clause reference. Where no document speaks to a topic, the item is marked lease-silent: a gap to negotiate, not a zero.

What we extract

219 line items across 13 return-condition systems

Every return condition and compensation rate in the bundle is extracted, clause-referenced and organised under the thirteen systems a redelivery team actually manages:

01Aircraft identity & title
02Airframe & structures
03Engines
04APU
05Landing gear
06Components & rotables
07ADs & SBs
08Modifications & configuration
09Cabin & interiors
10Cargo systems & loading
11Records & documentation
12Reserves & compensation
13Open & deferred items

Readiness — how the score works

every line item lands in one of three states
Mapped

Target extracted, benchmark set. The lease states the return condition and we’ve captured it against its clause.

Needs actuals

Target known, awaiting records. The contracted condition is clear; engineering actuals turn it into a settlement position.

Lease-silent

No document speaks to it. A drafting or negotiation gap — surfaced and ranked, never silently defaulted.

Redelivery readiness is the mapped share of the 219 line items, with a per-system coverage heatmap and a ranked gap list weighted by settlement materiality — so the work plan starts with what moves money.

Settlement — the half-life model

the four major maintenance events

Close-out is modelled on the four events that carry the money — airframe heavy check, engine performance restoration & LLPs, landing-gear overhaul, APU restoration. For each, the life potential remaining at return is compared with the position at delivery, on the lease’s half-life or full-life basis: more potential returned than delivered and the lessor compensates the operator; less, and the operator compensates the lessor.

The reserve-rate arithmetic — illustrative
event cost ÷ interval = rate  →  $800,000 ÷ 20,000 FH = $40/FH
Rates are expressed per flight hour, cycle or month exactly as the lease states them. Engine performance restoration and LLP replacement are modelled first — they carry the largest exposure. The output aggregates gross in each direction plus an indicative net.

Clause-ambiguity flags. The review also flags lease language that moves settlements before any engineering does — for example:

  • Undefined terms — obligations hung on words like “major” with no measurable threshold.
  • Half-life applied to the wrong items — e.g. to life-limited parts, where the basis materially shifts the close-out.
  • Obligation vs condition precedent — whether a return condition blocks redelivery or merely prices it.

What you get

the tier ladder is the verification ladder
Tier 01 · Free

Indicative view

Readiness score, indicative net settlement exposure and the section heatmap. Watermarked indicative — a screen, not a citation.

Tier 02 · from £9.5k ex VAT

Expert-validated pack

Every condition expert-validated against the lease: the populated 15-tab exit tracker, redelivery memo, ranked gap list and clause-ambiguity flags.

Tier 03 · Bespoke

Campaign or programme

A hands-on redelivery campaign for one aircraft, or a lease-return programme across a fleet — live tracker through handover.

The same method runs at every tier — the tiers change how much of the evidence is verified and who works it, not the method. Open the review Our methodology
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