Flying a new aircraft type: what differences training actually requires
Before you fly an unfamiliar aircraft, EASA requires differences training for certain class changes. Here is what the regulation says, what counts as differences training, and how to log it.
Pilots move between aircraft types all the time — from a Cessna 172 to a Piper PA-28, or from a fixed-gear SEP to a retractable. Sometimes this is completely unrestricted. Sometimes it requires formal differences training. Knowing which is which before you fly is not optional.
The distinction: differences training vs familiarisation
EASA Part-FCL FCL.710 establishes two categories:
Differences training — formal training from a qualified instructor, with a logbook entry or certificate. Required for certain specific changes within a class rating.
Familiarisation — self-study of the aircraft's Pilot Operating Handbook. No instructor, no logbook entry required. Sufficient for minor variations within the same type.
Whether you need differences training or familiarisation (or nothing at all) depends on what kind of aircraft you are stepping into.
When differences training is required under FCL.710
Differences training is required when the new aircraft has one or more of these features that your current type experience does not cover:
- Variable pitch (VP) propeller
- Retractable undercarriage (RU)
- Turbo- or supercharged engine
- Constant speed unit (CSU)
- Tail wheel (tail-dragger)
- Floatplane or amphibian
- Pressurised aircraft
If you have never flown a retractable-gear SEP before and you are about to hire a Piper Arrow, you need differences training logged for retractable undercarriage before you fly it as PIC. Similarly, a CSU endorsement is required before PIC on an aircraft with a constant-speed prop if you have only flown fixed-pitch types.
What differences training involves
There is no fixed hour requirement for differences training in FCL.710 — the duration is at the instructor's discretion based on your background. Typically:
- A VP/CSU endorsement: 1–2 hours dual with an instructor familiarising you with propeller management procedures
- Retractable undercarriage: 1–2 hours dual covering normal ops, abnormal gear indications, circuit work
- Tailwheel: often 3–5 hours given the significant handling difference; some schools require a check to solo standard
The instructor confirms completion by entering it in your logbook and, depending on the national authority's implementation, by issuing a brief written endorsement or signing a declaration.
What does NOT require differences training
- Switching between aircraft of the same variant (Cessna 172M to Cessna 172S) — familiarisation with the POH is sufficient
- Moving between different fixed-gear, fixed-pitch SEP types (most C150s, PA-28-161, Robin DR400) — familiarisation only, no instructor required
- Changing from one manufacturer's brand to another within the same configuration
If in doubt, check with your flying school. They will know whether the aircraft you want to fly has equipment your licence does not currently cover.
Logging differences training
Differences training flights are logged as dual (your instructor is acting as instructor in command). The logbook entry should record:
- Date
- Aircraft registration and type
- Dual time
- Nature of the training (e.g. "VP/CSU differences training" or "retractable undercarriage endorsement")
- Instructor's signature
Some pilots keep a separate endorsements page or section; others log it inline with a clear remarks column entry. Either is acceptable as long as the record is clear.
Building a complete endorsement picture
If you fly several different types, your logbook should make it easy to answer the question: "what endorsements do I hold?" For differences training, the evidence is typically in individual flight entries. For class ratings (MEP, etc.) it is in your licence document.
Before checking out in an unfamiliar aircraft at a new club or school, the check-in process will often ask you to demonstrate your relevant endorsements. Having them clearly logged — with dates, instructor names, and the type flown — makes this a two-minute exercise rather than a search through old entries.
The bottom line
Most SEP-to-SEP transitions are unrestricted beyond reading the POH. But if the new aircraft has a retractable undercarriage, VP prop, CSU, or tailwheel and you have never been trained on these features, FCL.710 requires formal differences training before you fly it as PIC. Get the training, log it clearly, and move on.