Part66L Theoretical Knowledge Examinations
Read this first!
Qualifying for a Part66L licence requires the candidate to demonstrate required practical experience and to pass multi-choice question examinations covering theoretical knowledge on range of topics.
The Part66L licence has sub-categories. For sailplanes, they are:
— L1C: composite sailplanes,
— L1: sailplanes,
— L2C: composite powered sailplanes and composite ELA1 aeroplanes,
— L2: powered sailplanes and ELA1 aeroplanes
The exam topics are:
1L Basic knowledge
2L Human factors
3L Aviation legislation
4L Airframe wooden, metal tube and fabric
5L Airframe composite
6L Airframe metal
7L Airframe general
8L Powerplant
12L Radio, Com, ELT, transponder, instruments
Note that not all of the exams are required to qualify for a Part66L licence:
- the minimum requirement for Part66L composite sailplanes only (an L1C sub-category rating) is a pass in 1L, 2L, 3L, 5L, 7L and 12L.
- for all un-powered sailplanes (an L1 sub-category rating), a pass is required in 1L, 2L, 3L, 4L, 5L, 6L, 7L and 12L.
- clearly 8L is additionally required for powered sailplanes.
Self-study guidance
A collated list of potential study resources (initially informed by the Netherlands gliding federation) is available here. It will be fine-tuned with experience.
A ‘primer’ document here that helps exam candidates understand the scope and depth of required relevant knowledge is available here. This is a recommended ‘must-read’.
Question topics are listed under each exam title below.
AI (e.g. Chat GPT, etc) has been used by exam candidates during studying to identify likely exam questions from the question topics below by analysing syllabi and study materials to find patterns and generate practice questions. We cannot guarantee this approach. Care is obviously needed.
Recording self-study progress
The BGA’s Part66L candidate experience logbook is a helpful method of recording progress. You can download the logbook here.
The Exams
Each exam is listed below by topic along with learning objectives. The numbers, eg 1L, refer to the exam in the Part66L requirements. The learning objectives take the reader to a link to source CAA information. The ‘question topics’ are based on experience.
1L Basic knowledge
Question topics include:
Acceleration and deceleration; degrees and minutes expressed as a decimal; elements in an oxygen atom; twisting forces; thermometer principles; resistor colour bands; volts, current and resistance; standard atmosphere; Murphy’s Law; boundary layer; extinguisher types
2L – Human factors
Question topics include:
Why study human factors; healthy BMI range; presbyopia; peer pressure; cold stress; colours most commonly affected by colour blindness; good judgement; satisfactory sleep; problems with inspecting in very bright light.
3L – Aviation legislation
3L – Aviation legislation learning objectives
Question topics include:
Scope of Part66 including aircraft groups, basis for Part66 privileges, Part66 licence invalidation, where to find pilot owner maintenance requirements, reportable occurrences, commercial aircraft CAMO/CAO use requirement, , ELA1 aircraft continuing airworthiness, where to find instructions for standard repairs, CS STAN, source of modification & repair approval, airworthiness limitations, airworthiness maintenance programme requirements, CRS requirements, continuing airworthiness limitations, where to find pilot owner maintenance requirements, reference maintenance data, maintenance programmes, status of ADs, deferring defects, responsibility for continuing airworthiness, maintenance records including back up.
4L – Airframe wooden, metal tube and fabric
Question topics include:
Welded steel tube airframes, welding, fungus infection on a wooden airframe structure, minimum acceptable gradient of grain in wood for an airframe repair, calculating the splice for a tapered beam repair, identifying a heavy landing a compression failure in a beam, stitching a repair to a fabric tear, applying dope to a polyester fabric, Oratex compared to Dacron, inspecting a possible crack in a welded airframe using dye penetrant, repairing corrosion detected on a tube, corrosion protection for the inside of a steel tube, identifying use of urea-formaldehyde glues, specification for aviation grade plywood, use of adhesive lines in plywood when scarfing fasteners, turnbuckles, nicopress swaging, L’Hotellier connections.
5L – Airframe composite
Question topics include:
Resins, fillers, inspecting spar root and end fittings, joining two halves of a wing, preparing a hole for repair, effecting repair of a puncture/impact damage less than 5cm close to the main spar near the spar, inspecting a fuselage after a heavy landing using a tap test, use of hand tools when sanding a repair, repairing an FRP balsa sandwich panel which has a puncture penetrating both skins, FRP balsa sandwich panel core repair, balsa use and repair, moulds, gel coat and polyurethan paint, resonance frequency test, turnbuckles, nicopress swaging, L’Hotellier connections.
6L – Airframe metal
Question topics include:
Use of dural rivets, rivet clearance, use of lower spec rivets, dimpling, doubler plates, bending, identifying corrosion, dissimilar metal corrosion, nitriding components, cadmium plating, welding, fasteners.
7L – Airframe general
Question topics include:
Light for inspections, turbulator tapes, interconnected controls, e.g. flap and airbrake, static balance after control surface repair, control cables inc tension checking, mylar seals, cockpit control colour coding, pitch trim systems, checking control range of movement, adjusting a drum brake, location of back release hook, functional checks of hooks, removing oily residue from acrylic transparency, brake fluids, seat harness condition, L’Hotellier checking, turnbuckle locking, checking swages, use of locking plates, wirelocking, wedekind sleeves, placard cockpit seat limits, weighing, inc forward and aft reference datums, seat upholstery, pneumatic instruments including fault finding of ASI, variometer and altimeter, TE systems, FLARM firmware updates, gyro instruments, compass correction cards, instrument panel electrics, batteries including Li-on, circuit breakers, CS22 G limits, exhaust leak checking, propellers inc refinishing, defects, maintenance, braking, retraction/extension systems, light operated digital tacho checking, wheels and tyres and bearings, control deflection checks, cable tensions, torquing nuts and bolts, heavy landing inspection
8L – Powerplant
Question topics include:
Noise certificate requirements, Wankel engines, sailplane folding and retractable propellers and systems, propeller pitch change mechanisms (mechanical and electrical), fuel tanks and fuel level transmitters, fuel consumed quantity indication system, rubber hose life, magnetos including adjustment, thyristor ignition system, spark plugs including testing, engine bay fire protection, exhaust component inspection, Avgas 100LL, unleaded fuel, ignition timing and issues, pinking, detonating, back-firing, lubricating oil types, release documents eg 8130-3 and EASA form 1, on-deviation and on-condition lifing of engines, sliding piston, float and and diaphragm carburettors, decompressor valve, ground running engines, engine static timing, strobe checking engine rpm, procedure following propeller installation, 4-stroke engines inc gas scavenging, 2-stroke engines, electronic control unit troubleshooting, FADEC system, v-belt tension testing, safety when maintaining a sailplane with retractable engine pylon, lithium-ion batteries and FES, lubrication of sailplane jet engines, inspecting and repairing jet engine compressor blades.
12L – Radio, Com, ELT, transponder, instruments
Question topics include:
VHF frequency ranges, VHF reception fault finding, 25KHz radio v 8.33 KHz radio, VHF whip antennae lengths, VHF emergency frequency, ELT requirements, ELT transmission freqs, transponder frequencies, 24-bit codes and portable transponders, transponder modes A, C and S, transponder functionality i.e. how it works, altimeter fault finding, lithium iron phosphate batteries, dry-fit batteries.
Exam testing
The Part66L examinations are only available online. Please note that the CAA are responsible for the content of their exams.
CAA published Part66L e-exams and module information
The first step is for the candidate to register for the CAA customer portal. Once registered, the candidate can then engage with e-examination process. This candidate user guide explains in detail. The training organisation is BGA and the reference number is GBR.DTO.0007.
Booked examinations are managed and overseen by BGA invigilators who have been specifically approved by the CAA. Candidates are encouraged to contact the BGA office or an invigilator in good time. Candidates are advised to only book exams once they feel fully prepared. The BGA Part66L invigilators are:
Kate Byrne (based Portmoak) katefbyrne@gmail.com
Ron Smith (based Lasham) rsmith@lasham.org.uk
Ian Mitchell (based North Hill) m1txh@btinternet.com
Pete Stratten (based BGA office) office@gliding.co.uk
Steve Wilkinson (based Pocklington) swglider@aol.com
Your BGA invigilator will guide you through the online exam taking process on the day that you arrange between you.