Pre-purchase diligence
Airworthiness Directive status review for airlines evaluating an aircraft purchase
An airline weighing an aircraft purchase runs this review to test the seller's AD compliance claims while the price is still open. Specialists work through the AD status list in the data room, checking applicability against the actual configuration, method of compliance against each directive's terms, and accomplishment claims against task cards and logbook entries. Beyond compliance, the review measures how the aircraft's AD position fits the buying airline's fleet: which repetitive inspections it inherits and on what clock. The fleet technical team gets a verified status view, an exposure list for the negotiation, and induction inputs for its own AD management.
When this review is needed
- A purchase candidate's data room has opened and the AD status list is the seller's own export, unverified by anyone on the buy side.
- The candidate comes from a different registry and the airline needs its AD position translated into FAA or EASA terms before pricing it.
- Upcoming ADs with expensive terminating action are known in the fleet and their status on this serial number moves the deal economics.
- The airline's AD tracking system needs a clean, evidenced position to load at induction, and the data room is the one chance to build it.
The problem
A seller's AD status list answers the seller's question: is my aircraft compliant today. The buying airline has different ones. Which repetitive inspections arrive with the aircraft, and how do their intervals mesh with checks already planned. Which terminating actions were done, and which were deferred in ways the airline would not have chosen. The data room holds the answers, spread across accomplishment records the status list may summarize loosely, and the exclusivity clock limits how long anyone can dig.
What gets reviewed
- The AD status list checked line by line for applicability against the candidate's configuration, engines, and APU
- Accomplishment evidence located for complied-with and terminated items, weighted toward high-cost directives
- Method-of-compliance entries tested against what each AD permits, including AMOC validity for this serial number
- Repetitive AD intervals projected onto the airline's planned utilization and check schedule
- Open and upcoming ADs costed as induction workscope inputs
- Registry translation of the AD position where the candidate transfers from another authority
Scope this review
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Send a representative, redacted record set and we will scope the review.
What gets validated
- Directive applicability determinations match part numbers and serial numbers evidenced in the configuration records
- Each terminating-action claim traces to accomplishment paperwork, without accepting an SB status line as a proxy
- Repetitive next-due calculations use the correct interval basis and survive recomputation from the last accomplishment
- AMOCs cited on the list were approved for this aircraft or transfer with it, rather than attaching to the seller's operation
- The status list references the current revision of each AD, with superseded citations flagged
Evidence normally required
- The seller's AD status list for airframe, engines, and APU
- Configuration, modification, and engine build records from the data room
- Accomplishment evidence: task cards, work orders, logbook entries, SB records
- The airline's utilization and check-plan assumptions for the aircraft
- AMOC approvals and any authority correspondence the seller can produce
Common discrepancies
- Terminating action claimed on the strength of an SB the records show was only partially embodied
- An AD listed not-applicable based on a modification the configuration records cannot confirm
- Repetitive items whose next-due dates assume the seller's low utilization and compress sharply under airline flying
- AMOC approvals that named the previous operator and lapse at transfer
What is at stake
AD exposure missed in diligence converts into unbudgeted maintenance after delivery, at the airline's cost and on the airline's certificate. A terminating action assumed done and later found open can ground the aircraft against a compliance deadline the previous operator never faced. Price is negotiable before signing and fixed after, so every unverified AD line is a concession the airline may be making without knowing it.
How the work runs
Frame the list
Confirm the status list's scope, revision basis, and the configuration it claims to describe.
Verify the expensive lines
Trace high-cost and terminating-action items to accomplishment evidence first, then widen the sample.
Project onto airline operation
Recompute repetitive due points against planned utilization and the airline's check structure.
Report for price and induction
Deliver the exposure list to the deal team and the evidenced baseline to the CAMO.
What the buyer receives
Who uses the output
- Fleet management and the negotiation team pricing conditions and adjustments
- The airline's continuing-airworthiness organization preparing induction workscope
- Records leadership seeding the AD tracking system for day one of operation
How the work fits into the transaction or program
AD verification is one strand of pre-purchase records diligence, alongside LLP trace, release documents, and program review. It tends to move first because AD exposure is the most direct lever on price, and its evidenced baseline then shortens the CAMO's induction work once the deal closes.
Start with a single asset
Prove the review on a single tail, then scale across the fleet.
Jurisdiction-specific considerations
An aircraft moving onto the airline's registry brings its AD history with it, and the receiving authority's directives govern from transfer. FAA and EASA issue parallel but non-identical ADs against the same type, so a compliant position under one can hold open items under the other. The review maps the delta explicitly instead of assuming equivalence.
Regulatory limits
This work verifies records and quantifies exposure. It does not certify AD compliance, approve methods of compliance, or replace the determinations the airline's own CAMO and authority must make at induction.
What this review does not cover
- Physical verification of AD embodiment on the aircraft
- Performing AD compliance work or preparing engineering dispositions
- Legal drafting of purchase-agreement conditions
Specific to this review
- The cheapest moment to fix an AD evidence gap is before signing, when the seller still wants the deal; the same gap after delivery belongs to the airline alone.
- Utilization change is the quiet AD cost in airline acquisitions: repetitive inspections that were calm under a previous operator's flying can land inside the first year at airline rates.
- AMOC portability gets checked early because a non-transferable AMOC can silently convert a compliant line into an open one at the moment of registry transfer.
- Sampling depth matters more than list coverage: recomputing ten high-cost lines from source documents reveals the seller's recordkeeping quality faster than skimming three hundred.
Sources
U.S. Government (eCFR). The legal basis for issuing and enforcing Airworthiness Directives on U.S.-registered products.
U.S. Government (eCFR). Records an owner or operator must keep, including total time in service, current status of life-limited parts, and AD compliance.
European Union / EASA. Continuing airworthiness, maintenance records, CAMO responsibilities, and the airworthiness review process in the EASA system.
Frequently asked questions
How much of the AD list actually gets traced to source evidence?
All terminating actions and every line above an agreed cost threshold, plus a random sample of the rest. Full-list tracing rarely fits a diligence window, and a structured sample gives a reliable read on both the aircraft and the quality of the seller's records.
Relevant glossary terms
Related pages
Where this fits
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