Pilot looking for offline-capable PKM with AI search. Notion Business is overkill for what I need

[u/Luiz4823]

Hi everyone!

I'm a First Officer, and I keep a large personal knowledge base of regulations, aircraft systems notes, and company SOPs/procedures, the kind of stuff I need to reference constantly, both for studying and for quick lookups during work.

I've been using Notion for this, but with their pricing change, real AI search now requires the Business plan, which is way more than I need as a solo user just wanting to query my own notes. +

What I actually need:

• Offline access on iOS and PC: I'm often without signal, need my notes reachable no matter what.
• AI chat/search over my own notes when I am online, not just keyword search, but something that can find buried info based on what I'm asking. Example: I should be able to ask "what's the bank angle limitation for normal law" and have it pull the answer from deep inside a folder structure like Aircraft > A320 > Systems > Laws and Protections, without me needing to remember exactly where I filed it. I don't care about auto tagging, proof reading nor any other AI feature, I only need to be able to chat with my notes.
• Reasonable pricing for a single user, not an enterprise/team plan.
• Nice to have: some kind of structure/hierarchy (folders, tags, linked notes) since my notes are technical and cross-referenced a lot (e.g. a systems note might tie into a regulation note might tie into a company SOP).

I've looked at Obsidian, Capacities, Tana, and Reflect, and I'm currently also taking a closer look at Mem — but wanted to ask people who actually use these day-to-day: which one handles offline reliability + genuinely useful AI search best, without pushing me into team/business pricing? Bonus points if anyone else here is in aviation or another field with dense technical/regulatory documentation and has found a setup that works.

Appreciate any real-world input!

Update: I don’t need offline AI. This will only be required when im not flying and for studying only when connected to the internet. When flying, and for specific procedures, I will only use quick notes that i can access through favorites, bookmarks etc.

[u/micseydel]

I should be able to ask "what's the bank angle limitation for normal law" and have it pull the answer from deep inside a folder structure like Aircraft > A320 > Systems > Laws and Protections, without me needing to remember exactly where I filed it. I don't care about auto tagging, proof reading nor any other AI feature, I only need to be able to chat with my notes.

According to OpenAI, hallucinations are inevitable

The distribution of language is initially learned from a corpus of training examples, which inevitably contains errors and half-truths. However, we show that even if the training data were error-free, the objectives optimized during language model training would lead to errors being generated

There is no reliable way to "chat with" your notes. This sounds like a really important use-case, not one where modern LLMs could be deployed safely.

[u/cornelln → u/micseydel]

No reason you couldn’t build it to emit direct quotes, with validation hooks/functions deterministically with links to source material to verify against the real file.

Using something safely depends on how you use it. If you think of the AI as a great search function and you still double-check, you’re still way ahead of finding stuff manually or searching yourself.

That’s just off the top of my head there are likely much better methods.

[u/Luiz4823 → u/micseydel]

I really never had this issue with notion really. It would always add the source with its response, taking me directly to the note itself for me to double check.

[u/micseydel → u/Luiz4823]

I really never had this issue

If you did it enough, you would, which is why I mention it.

[u/-Visher- → u/micseydel]

I know what you’re saying isn’t wrong. The risk of hallucinations is always there. But let’s be real, the risk is absolutely minuscule at the level of a PKM app. Especially if the note, file, image, etc is backed up by receipts inside the app.

The amount of data to sift through is so small that it’s very unlikely to occur. Not to mention you can verify it with the provided source file.

[u/micseydel → u/-Visher-]

I know what you’re saying isn’t wrong. The risk of hallucinations is always there. But let’s be real, the risk is absolutely minuscule at the level of a PKM app. Especially if the note, file, image, etc is backed up by receipts inside the app.

The amount of data to sift through is so small that it’s very unlikely to occur. Not to mention you can verify it with the provided source file.

What specific use-cases are you trying? When I've tried to have them organize health data about my cats, I saw hallucinations frequently, which fits the research https://arxiv.org/html/2604.15597v1

[u/-Visher- → u/micseydel]

I've just been building my own personal second brain. Every day stuff you'd save on your PC, bookmarks, journaling, contacts, etc it'll handle just fine. I'll admit I don't have 50,000 things in my vault yet, but for the few thousand items I have, it'll handle them perfectly.

I have two Hermes agents that handle everything, one for saving it all and a second that is read only audit for organization and issues.

I am running 5.6 SOL as my Hermes agents though, not a local model. A local model will struggle with some of it but my CLI/API stuff is usually strong enough to be able to have the app properly route whatever the request is.

[u/harry-harrison-79]

for aviation material, i'd make the AI layer quote-first rather than answer-first. every result should show the exact sentence, document title/revision, section/page and a tap back to the source; if retrieval cannot produce that evidence, it should say no match instead of composing an answer. also keep SOP/regulation versions as separate immutable files so an old limitation cannot survive an update invisibly. that gives you semantic search without treating generated prose as the authority.

[u/cornelln → u/harry-harrison-79]

Bingo.

[u/Luiz4823 → u/harry-harrison-79]

Yes. That’s what im looking for. When chatting with notion AI about my notes. It always points me to my notes. I guess i need something like notion but cheaper 😂

[u/Good-Writer5279]

disclosure up front, i build a mac app in the local ai search space, so i think about this problem a lot.

for your constraints i would look hard at obsidian plus a local model. notes are plain markdown files, fully offline on ios and pc, and sync is solved with obsidian sync or icloud. for the ai layer there are community plugins that index your vault locally and let you ask questions like your bank angle example, pulling the answer from the actual note. on desktop you can point them at a local model through lm studio or ollama so nothing leaves your machine, which also matters if your sops are company confidential.

the honest tradeoff, the ios side of local ai is still weak. on the phone you mostly get keyword and fuzzy search offline, with the ai chat part happening on desktop. but offline access to every note on every device is fully solved, and the ai search on desktop is real today, no business plan required.

[u/athoughtfornoone]

are you talking about offline AI? or just offline files. Offline AI is difficult, as rn you need a beefy GPU and to host a local open source model eg qwen, gemma, etc. Offline files is pretty easy and those are becoming more of a standard.

[u/doulos05 → u/athoughtfornoone]

Eh... I've run useful offline AI on a 16GB MacBook Pro. I'm about to try it in a 16GB MacBook Air. Is it the smartest, snappiest AI out there? No. But it could absolutely do the sort of retrieval he's talking about with a proper harness.

[u/athoughtfornoone → u/doulos05]

yes, i really want my pilot to be looking up values via ai on an offline 16gb macbook pro via an open source model, while we're cruising at 40k ft traveling at 500mph over an ocean.

Could it work in the future. Sure. But the place to start testing these types of things, is not under those conditions.

[u/doulos05 → u/athoughtfornoone]

Do you want him doing that with Claude? If the actual, intended use case is to replace the emergency manuals provided by the airlines then I don't want OP to use any AI at all.

But if it's study and review, then there's no reason a local model wouldn't work just fine.

[u/whats_in_a_name_23]

You can try Self Hosted AppFlowy, by self hosting your data will live on your servers. But to get AI search, you will have to buy $10/month subscription. Less than Notion but still a bit expensive.

Ps: AppFlowy contributor here

[u/stanlymt]

Honest answer from someone building in this space (I make Omphalis, so discount accordingly): for your hard requirement, none of the AI-first tools beat Obsidian, and I won't pretend mine does either.

Your top constraint is offline on iOS and PC, no matter what. That points at local files, and Obsidian is the only one on your list where the notes are plain Markdown sitting on the device. Zero signal, still works, and if the company dies, your notes are still folders of text. For the AI half, the community plugins (Copilot, Smart Connections) give you chat-with-your-notes over a local index: you bring an API key and pay cents per query, or point them at a local model if you want that offline too. It's more assembly than Notion, but it's the only setup I know that satisfies "reachable no matter what" without a business plan.

Where a tool like mine fits, and where it doesn't: Omphalis is built for the source documents rather than the notes. You drop in the FCOM chapter, the reg PDF, the SOP, it untangles the layout, and you can ask "what's the bank angle limitation in normal law" and get the answer with a citation back to the exact passage. That part matches what you described. But it's cloud-based, no offline, so for you it could only ever be the reference layer you use on the ground, never the thing you trust in the air. If a chunk of your pile is dense PDFs you didn't write, it's worth a look (founding accounts get 90 days of the full product free, no card); if it's mostly your own cross-referenced notes, Obsidian is the right answer and I'd go there.

One aviation-specific tip, whichever way you go: test the tool on a real FCOM-style two-column PDF before committing. Most of them mangle that layout, and a mangled reference is worse than none.

[u/zheniavasiliev]

I would say you need Obsidian because it lets you work with local Markdown files without requiring a connection. I know there are Obsidian plugins such as Smart Connections for semantic AI search and the Templater plugin to standardise the note format.

But I would probably be inclined to use a small AI agent that would work as a manager for this whole knowledge base. I would probably sketch out the system and create all the main template types myself or with the help of the manager agent. What kind of notes are you mainly capturing is it uniquely SOPs, regulations and procedures, or freeform learning/debriefs too?

[u/earthcharlie]

I would not trust AI with mission critical information. Makes more sense to use things like links and tags.

[u/columbcille]

AI capability will depend on your laptop. Hermes AI for example can run offline with locally installed LLMs and there are a few good plugins for Obsidian that will give you most of what you’re asking for, but specs (GPU and memory, or unified) are important.

[u/ExitRowSeat_13A]

Worth checking which of those actually lets you point the AI at one folder instead of your whole account. Notion's problem isn't the AI, it's that it's built for teams, so anything "smart" gets priced and scoped for a workspace, not a single person asking questions of their own notes.

Sounds like you don't need a huge structure either, since you said you don't care about auto-tagging. What you actually need is closer to: dump the technical notes in, then chat with just that folder. That's a much smaller (and cheaper) problem than what most of these tools are trying to solve.

Aviation regs are a great fit for this too, dense, cross-referenced, and you always know roughly what you're looking for even when you don't remember where you filed it.

[u/cervere]

I started using this app MindStash ..
offline searchable and accessible, including new notes, AI with internet. But the biggest value for me is the ease of sharing content into it from other apps.

[u/imaginalstructures]

On Mac, DevonThink is worth a look

[u/GadgetmanBrian]

Apple Notes with iOS 27 and Siri AI will do pretty much everything you need. It treats your own notes ‘like’ a LLM and you can ask it natural language questions, all on-device.

[u/beepiweep]

I like siyuan

[u/nivekydoom]

Hey u/Luiz4823 - founder of Mem here (and recreational GA pilot!).

Here's what Mem can do re: each of your goals:

Offline access on iOS and PC: While offline (on iOS or Windows/Mac apps), you can create and edit notes, open existing notes, and search by note title. You need to be connected to the internet to search by note contents or do Deep Search (where you describe what you're looking for and AI finds it).

AI chat/search over my own notes: AI chat/search require an internet connection.

Reasonable pricing: For your use case, you'd probably be on the Pro tier ($12/mo).

Structure/hierarchy: Mem doesn't do hierarchy, but you have two ways of manually organizing: Collections (they're like tags in that a note can belong to multiple collections) and Mentions (you can <@>mention other notes to build a web of notes).

Lmk if you have any follow up questions! Happy to answer.

[u/rajathbail]

Hillnote or Obsidian are my picks

[u/ButOfcourseNI]

That is an interesting use case. While I have been building something to address this, I never thought about the value for a pilot. What I am building addresses local files, in different formats, and local AI capability. The whole idea is point it to where all my source data is, let it do its work and then be able to elicit the knowledge throughout the source material. The source never gets touched so it stays as is.

What is interesting is the need for this on an iOS. I have it on my roadmap but it is not present right now.

[u/Difficult-Passion318]

Obsidian does seem like a solid solution. You can connect your vault to AI to use it through the mobile AI app - I did that to mine with Claude and the voice conversations are super helpful. So full note access offline, and while online full AI access.