Climb and maintain vs climb to — US vs UK/Europe phraseology

Published 3 June 2026Reference article

FAA controllers say climb and maintain. Controllers working to UK CAP 413, EASA SERA, or the Transport Canada AIM say climb to. The phrasing is mutually intelligible and means the same thing in operation, but a pilot crossing between regions can read back the wrong verb under load and sound out of place to a controller who notices.

FAA — “climb and maintain”

Under US procedures the controller issues altitude clearances using the verb pair climb and maintain or descend and maintain:

“N534CT, climb and maintain Flight Level 240.”

The pilot reads back with the same construct:

“Climb and maintain Flight Level 240, N534CT.”

The and maintain half is load-bearing: it stops the clearance from being misread as “climb at least to FL240, keep going.” Level off at the assigned altitude unless a further clearance changes it.

Source: FAA AIM Para 4-4-10 (Adherence to Clearance); FAA Order JO 7110.65, Chapter 4.

UK CAA, EASA, Transport Canada — “climb to”

Every framework outside the US uses the ICAO-aligned construct climb to or descend to, followed by the altitude or flight level:

“G-PILT, climb to Flight Level 240.”

Readback mirrors the verb. The same wording appears in CAP 413 for the UK, in SERA across the EU, and in the Transport Canada AIM. ICAO Annex 10 is the shared parent.

Source: CAP 413 Edition 24.1, Chapter 7; SERA Annex Section 14 (August 2025 revision, © European Union); TC AIM 2026-1, RAC Chapter 7.

Why the divergence exists

The FAA and maintain phrasing predates the ICAO standardisation that drove the rest of the world toward climb to. The US never harmonised because the existing wording was unambiguous, deeply embedded in controller training, and the additional safety benefit of harmonisation was judged marginal against the cost of retraining. The result is that every other regulator uses one construct and the FAA uses a different one for the same instruction.

What it sounds like on the radio

Both constructs work. A FAA controller hearing a pilot read back “climb to FL240” will understand it perfectly; a UK controller hearing “climb and maintain FL240” the same. The signal a pilot sends by using the local construct is competence and familiarity — you have flown here before, you know which framework you are inside. Network controllers on VATSIM and IVAO notice it the way native speakers notice an accent: not as a problem, but as information.

Common pitfalls in readback

Reading back without the unit.

“Six thousand” alone could mean 6,000 feet MSL or FL060. Include the prefix.

Starting the climb before reading back.

The clearance is valid on issue, but the readback should not lag the manoeuvre. Read back first, then commence.

Misinterpreting “expedite”.

Expedite means climb or descend at greater than the normal rate. It does not authorise exceeding maximum operating speed or violating published restrictions.

Continuing past the cleared altitude.

“Climb maintain 10,000” means level off at 10,000, not “climb to at least 10,000.”

Online network implications

VATSIM, IVAO, and PilotEdge controllers work to the framework of the airspace they are controlling, not to a universal compromise. A VATSIM controller staffing London Control will issue climb to; the same pilot calling Boston Center thirty minutes later will hear climb and maintain. The pilot is expected to switch with the airspace. Reading back in the regional construct is a small but real marker of a pilot who has done the homework — and it costs nothing.