Differences Training and Familiarization (FCL.710)

Differences Training and Familiarisation (FCL.710)

A class rating such as SEP(land) covers many aircraft that can differ considerably — a Cessna 152 and a turbocharged, retractable-gear Piper are both "SEP". Before you fly a different variant within your rating, Part-FCL requires either simple familiarisation or formal differences training with an instructor. Examiners like to test which changes trigger which level.

Legal basis

ICAO Annex 1 distinguishes class and type ratings; differences within a class are bridged by training rather than by a new rating. In the EU, FCL.710 of Regulation (EU) No 1178/2011 (Part-FCL), together with AMC1 FCL.710, defines two levels of conversion to a variant within the same class or type rating.

Level 1 — Familiarisation

Familiarisation is sufficient when the new aircraft is a similar variant with no significantly different equipment or handling.

• May be acquired by self-study: reading the AFM/POH and, where helpful, a cockpit briefing.
• No instructor and no licence endorsement required; a logbook note is good practice.

Level 2 — Differences training

Differences training is required when moving to a variant with significantly different equipment, systems or procedures within the same class or type rating.

• Must be completed with an authorised instructor (CRI or FI).
• Comprises theoretical instruction plus practical training on the differing elements (aircraft or suitable training device).
• Must be entered in the pilot's logbook and signed by the instructor — this entry is the proof you produce when asked.
• Recency: if a variant has not been flown within 2 years after the differences training, further differences training or a proficiency check in that variant is required (this does not apply to variants within the SEP and TMG class ratings).

What typically triggers differences training?

• Carburettor → fuel injection
• Fixed-pitch → variable-pitch / constant-speed propeller
• Normally aspirated → turbocharged/supercharged engine
• Nose wheel → tailwheel (conventional) undercarriage
• Fixed → retractable undercarriage
• Analogue instruments → EFIS / glass cockpit (e.g. Garmin G1000)
• Unpressurised → pressurised cabin
• Aircraft with anti-icing / de-icing equipment

Worked examples

Germany

EU law applies directly. In case of doubt, ATOs/DTOs (flight schools) clarify with the LBA which variants require which training level; national practice strictly follows FCL.710 and AMC1 FCL.710.

Exam essentials

• Familiarisation (similar variant): self-study of the AFM/POH is sufficient — no instructor required.
• Differences training (significantly different variant): must be conducted by a CRI or FI and covers theory plus practical training.
• Differences training must be entered in the logbook and signed by the instructor.
• Typical triggers: variable-pitch propeller, retractable gear, turbocharger, tailwheel, EFIS, pressurised cabin, fuel injection, ice protection.
• If the variant has not been flown for 2 years after the differences training, further differences training or a proficiency check is required (not applicable within SEP/TMG class ratings).
• Neither level creates a new rating — both take place within the existing class or type rating.