The AOG Email That Takes 45 Minutes Too Long

An aircraft is on the ground. The part is failed. The maintenance controller fires off an email to three suppliers. And then — nothing happens. Not because the suppliers are slow. Not because the part doesn’t exist. Because the email that was supposed to start the clock was missing half the information the supplier needed to act.

What follows is predictable. A reply asking for the part number. Another asking for the condition requirement. A third requesting the aircraft registration and delivery location. The original sender is now dealing with a different aircraft. The thread sits. Forty-five minutes pass before the request is fully specified — and by then, the part that was available has been allocated to someone whose first email arrived complete.

The AOG clock doesn’t start when the part fails. It starts when the supplier can act. And the supplier can’t act on an incomplete email.

The Same Six Missing Details

Talk to anyone on a parts desk, an AOG desk, or a supplier’s quotes team, and they’ll tell you the same thing. The missing details aren’t random. They’re the same six items, missing from different senders, every single day.

Part number — sometimes approximate, sometimes a description instead of a number, sometimes the wrong revision. Condition requirement — new, serviceable, overhauled, or as-removed — left blank or assumed. Aircraft registration or MSN — critical for traceability, often omitted entirely. Required-by date — “ASAP” is not a date. Delivery location — especially on AOG where the aircraft might not be at the operator’s home base. Contact details — a direct phone number for the person who can approve the purchase, not a generic team inbox.

None of this is obscure. Every MRO professional knows these details matter. But under pressure — at 2am, mid-shift, juggling three aircraft — the email that goes out is whatever gets typed fastest. The thinking is “they’ll know what I mean.” The reality is they won’t, and now two people are spending time clarifying what one person could have specified in the first message.

Speed Shops Can Turn Parts in 72 Hours. The Email Takes Longer.

The manufacturing side of MRO is getting genuinely fast. Speed shops — specialist manufacturers who produce certified structural components on demand — can now turn parts in 24 to 72 hours. That’s a remarkable capability for operators who need a replacement panel, bracket, or fitting and can’t wait for the OEM backlog to clear.

But that turnaround collapses the moment the AOG request arrives without the damage description, part revision status, or applicable drawing number. The shop can’t start manufacturing until the specification is confirmed. If the first email is vague — “need a replacement panel for a 737, AOG” — the back-and-forth to establish exactly which panel, which dash number, which configuration, and what the damage looks like can take longer than the manufacturing itself.

The industry has invested heavily in reducing manufacturing lead times. Nobody is investing in reducing the communication lead time that precedes it.

Component Capacity Is Tightening. Clarity Wins the Allocation.

When supply was abundant, an incomplete email was an inconvenience. The supplier would chase the details, fill the gaps, and ship the part. There was margin for error because there was margin in inventory.

That margin is disappearing. OEMs are prioritising production commitments over aftermarket supply. Component capacity is tightening across the MRO sector. When multiple operators are chasing the same part from the same supplier at the same time, the allocation doesn’t go to the biggest customer or the longest relationship. It goes to whoever sent a request the supplier could act on immediately.

First-come-first-served sounds fair. In practice, it’s first-complete-first-served. The operator whose email arrived with the right part number, the right condition requirement, the right delivery location, and a direct contact number gets the part. The operator whose email arrived first but needed three follow-ups doesn’t.

In a constrained parts market, email quality isn’t an administrative detail. It’s a procurement strategy.

The Ground Time Nobody Measures

Airlines track turnaround time. They track parts availability. They track supplier performance. But almost nobody tracks the time between a maintenance event and the moment the supplier has enough information to act.

Proudfoot’s operational research consistently finds that planning failures, not technical complexity, drive blown turnaround times. The specific planning failure that sits at the start of every AOG event is the first outbound email. When it’s incomplete, everything downstream is delayed — but the delay gets attributed to the supplier, or to parts availability, or to logistics. The communication gap that caused it is invisible in every metric the operation tracks.

Consider the numbers. A maintenance controller sends an incomplete AOG request at 01:15. The supplier responds at 01:40 asking for clarification. The controller is now working a different aircraft. They reply at 02:00. The supplier confirms availability at 02:10 and ships. Officially, the supplier responded in 55 minutes. In reality, 45 of those minutes were communication overhead — and the part was available the entire time.

Multiply that across every AOG event, every RFQ, every work scope request, every day. The cumulative cost in aircraft ground time, technician idle time, and parts desk labour is significant — and entirely preventable.

Scale Makes It Worse

Every industry trend is amplifying this problem. MRO providers are expanding capability — adding engine types, airframe variants, and component lines. More capability means more variants in inbound requests, more specialist detail required, and more opportunities for the first email to be wrong.

Acquisitions are consolidating the industry — larger networks, more bases, more personnel who haven’t worked together before. When West Star Aviation became the world’s largest independent AOG network through acquisition, they gained 250 technicians and five new bases overnight. They solved coverage. But every AOG request now routes through a larger, more complex communication chain where the sender and receiver may never have exchanged an email before.

New MRO partnerships create the same challenge. When StandardAero signed a GTA with AviLease covering LEAP and CFM56 engines, the contract was done in a boardroom. The day-one communication layer between 53 airline customers and a new MRO partner started from scratch. Neither side knows the other’s part number conventions, escalation paths, or turnaround expectations.

Partnerships are signed in boardrooms. They succeed or fail in the inbox.

The Fix Is Upstream

The MRO industry has poured investment into what happens after the email — inventory systems, logistics platforms, predictive analytics, AI-driven demand forecasting. All valuable. But all of it depends on the information arriving correctly in the first place.

The intervention that moves the needle isn’t downstream. It’s at the point of origin: the moment a human being types an email under pressure and hits send. If that email contains the six details a supplier needs to act — part number, condition, registration, required-by date, delivery location, contact — the entire chain accelerates. If it doesn’t, no amount of downstream technology compensates for the 45 minutes lost to clarification.

The industry talks about digital transformation as if it’s a systems problem. For most MRO operations, the transformation that would have the most immediate impact isn’t a new platform. It’s fixing what goes into the emails that connect the platforms they already have.

What’s the most common detail missing from the AOG requests you receive?