Terms of use

By using KeepBlueUp you agree to these terms. If you do not agree with them, do not use the tools. If you are using KeepBlueUp on behalf of an organisation, you confirm you are authorised to accept these terms for it.

Your use is also subject to our privacy policy.

KeepBlueUp is a free set of web-based flight calculators: weight and balance with a centre-of-gravity envelope, an E6B (wind triangle, density altitude, true airspeed, time and fuel), and a METAR decoder. There is no account, no charge, and no contract for a paid service.

Every calculation runs in your browser. Apart from loading the site itself, two kinds of request reach our server: an airport's ICAO code - when its weather is looked up by that code, and after a METAR decode, to fetch its runways - and our own cookieless usage events, which carry no identifier and none of your numbers. What each one carries is set out in the privacy policy, section 4 and section 5.

KeepBlueUp is a planning, training and cross-checking aid. It is not:

• an electronic flight bag;
• an approved or certified aeronautical product. It holds no airworthiness or operational approval from EASA, the FAA or any other authority, and none is claimed;
• a source of official aeronautical information;
• a weather briefing service;
• a substitute for the POH or AFM for the aircraft you are flying.

No output from KeepBlueUp authorises a flight, clears an aircraft for dispatch, or discharges any regulatory obligation.

The aircraft profiles supplied with KeepBlueUp are illustrative defaults for a representative airframe, derived from published handbook data. They are not your aircraft.

Empty weight, empty-weight arm and moment, equipment fit, and any supplement or supplemental type certificate differ from serial number to serial number and change over an aircraft's life. The empty weight and empty-weight arm that the tool prefills are documented placeholders, not measurements of any real aeroplane.

You must take those values from the current weight-and-balance record of the aircraft you are actually flying, and confirm every limit against the POH or AFM applicable to that serial number.

Weather text is relayed from the US National Weather Service Aviation Weather Center. The raw observation is displayed unmodified; the plain-English decode is ours and is not official. NOAA and the National Weather Service do not endorse KeepBlueUp.

Data may be stale, incomplete or unavailable. Using it does not constitute preflight action under 14 CFR 91.103 or any equivalent rule. Get an official briefing before you fly.

You confirm that you will independently verify every figure produced by KeepBlueUp against official sources before relying on it, and that as pilot in command you remain solely responsible for the safe conduct of every flight, including all airworthiness, loading, performance and dispatch decisions. See 14 CFR 91.3 and 91.103, and EASA Part-NCO.

KeepBlueUp is intended for private and recreational operations. If you use it in connection with commercial air transport, flight instruction for reward, or any operation that requires an approved performance or mass-and-balance application, you do so on your own responsibility.

Please do not:

• automate bulk requests against the airport-lookup endpoint, or use it as a general weather feed - it is rate-limited and shared with everyone else;
• present KeepBlueUp output as official, approved or certified data, or redistribute it as if it were;
• attempt to break, overload or gain unauthorised access to the service.

You are welcome to use the tools for instruction, for a club, or to show a student - that is what they are for.

KeepBlueUp is provided free and on a best-efforts basis. We may change, suspend or discontinue any part of it, including the airport-lookup endpoint, at any time and without notice. Offline use is a convenience feature, not a guarantee: a cached page can be out of date.

Nothing on this site is a promise that a given aircraft profile, formula or data source will be kept current. Where a source changes, we will update it if and when we can.

The KeepBlueUp name, the site, its text and its code belong to Gaperi Consult S.R.L. You may use the tools and quote or screenshot results (for example in a lesson or a club briefing) with attribution. You may not copy the site wholesale or present it as your own product.

Aircraft handbook figures used in the profiles - station arms, limits and envelope breakpoints - are facts, cited to their published source. We do not reproduce or host any manufacturer manual, chart, table or page.

Cessna and Skyhawk are trademarks of Textron Aviation Inc.; other aircraft names are trademarks of their respective owners, used only to identify the aircraft a profile describes. KeepBlueUp is an independent tool and is not affiliated with, endorsed, sponsored or approved by any aircraft manufacturer or aviation authority.

KeepBlueUp is provided "as is" and "as available". To the fullest extent permitted by law we disclaim all warranties, express or implied, including merchantability, fitness for a particular purpose, accuracy, currency, completeness, uninterrupted availability, and non-infringement.

If you are a consumer, nothing in this section affects statutory rights that cannot be excluded under the law of your country of habitual residence.

As of the date at the top of this page, KeepBlueUp carries no advertising and no affiliate links, and we have no commercial relationship with any aviation retailer, training provider or equipment manufacturer. Nothing on the site is a paid placement. This section states the policy that will apply if that ever changes, so the rules are set before there is any money on the table.

The rules we are committing to

• Disclosure at the link, not in the footer. Any link that could earn us a commission will be labelled as such immediately next to it, in plain language, visible without expanding or scrolling past it. This is what the US FTC endorsement guides (16 CFR Part 255) require, and our audience is largely in the United States.
• Never inside a result. No advertisement or affiliate link will be placed inside, or immediately adjacent to, a weight-and-balance verdict, a centre-of-gravity plot, a density-altitude figure or the safety notice. A commercial message next to a go or no-go number is not acceptable on a safety-adjacent tool.
• No influence on the maths. No commercial relationship will ever change a calculation, a limit, a warning, or which result we show. If a partner asked for that, we would decline the money.
• No recommendation we do not stand behind. We will only link to equipment or training we would use ourselves, and we will say when we have not used something.
• Consent first. Advertising and affiliate scripts set or read information on your device, so they would be loaded only after you consent. The tools would keep working in full if you decline. See section 12 of the privacy policy.
• The tools stay free. Calculating a result will not be gated behind an advertisement or a consent choice.

What we do not limit, and do not pretend to

Nothing in these terms limits or excludes our liability for: death or personal injury caused by our negligence; fraud or fraudulent misrepresentation; gross negligence or wilful misconduct; liability under national law implementing Directive (EU) 2024/2853 on liability for defective products; or any other liability that cannot lawfully be limited or excluded.

We want to be straight about this rather than write a clause that sounds stronger than it is. Under EU law a term excluding a trader's liability for a consumer's death or personal injury is presumptively unfair and does not bind the consumer (Annex 1(a) to Directive 93/13/EEC), and the new Product Liability Directive treats software as a product and does not allow that liability to be limited by contract. A disclaimer is not a shield against that, and we do not present it as one. What the safety notice on this site is actually for is to make sure you know what these tools are before you rely on them.

What we do limit

Subject to the paragraphs above and to the fullest extent permitted by law, we are not liable for: loss of or damage to any aircraft; loss of profit, revenue, business, contracts or anticipated savings; loss or corruption of data; regulatory or certificate action; loss of insurance cover or the denial of an insurance claim; or any indirect or consequential loss, arising out of or in connection with your use of, or reliance on, KeepBlueUp.

Subject to the paragraphs above, our total aggregate liability arising out of or in connection with KeepBlueUp in any twelve-month period is limited to EUR 100. We have deliberately not written the usual "limited to what you paid us" cap: KeepBlueUp is free, so that cap would be zero, which is an exclusion wearing a cap's clothing.

If you are a consumer, these limits apply only so far as the mandatory law of your country of habitual residence allows. Where that law gives you more than this section does, that law wins.

These terms are governed by Romanian law, and the courts of Romania have jurisdiction.

Honestly stated: if you are a consumer habitually resident in the EU, that sentence does not take away the protection of the mandatory rules of your own country, and you may bring proceedings in the courts of your own domicile (Article 6 of the Rome I Regulation; Articles 17 to 19 of the Brussels Ia Regulation). We are not going to argue otherwise.

Tell us first - contact@keepblueup.com. We would much rather fix a wrong number than argue about a clause, and a report that a formula or a limit is wrong goes to the top of the queue.

Consumers in Romania may also contact ANPC, the national consumer protection authority. The EU online dispute resolution platform closed on 20 July 2025, so there is no link to it here.

We may update these terms. The date at the top always shows the current version, and a change that materially affects you will be flagged in the product rather than slipped in quietly.

Gaperi Consult S.R.L., Brasov, Romania. contact@keepblueup.com.