97 Octane Super Unleaded Since the replacement of regular E5 Mogas at the pumps by E10, for the time being at least, Mogas users have an alternative option in the form of 97 RON Super Unleaded fuels. 97 RON Super Unleaded fuel supplied by garage forecourts is NOT necessarily ethanol-free, but its ethanol content will be capped at a maximum of 5%. 97 RON E5 Super Unleaded fuel can be used under the LAA process for E5 Mogas, as before. There’s currently no legal requirement for ethanol to be present in super unleaded petrol and in fact, quite a few members have reported that their tests have shown Super Unleaded fuel to be ethanol-free in their areas. Esso reports that “Synergy Supreme+ 99 is actually ethanol free (except, due to technical supply reasons, in Devon, Cornwall, North Wales, North England and Scotland). Legislation requires us to place E5 labels on pumps that dispense unleaded petrol with ‘up to 5% ethanol’, including those that contain no ethanol, which is why we display them on our Synergy Supreme+ 99 pumps”. Shell, BP, Tesco and other fuel suppliers don’t commit to such detail, merely stating their fuels “may contain up to 5% ethanol”. Of course, many LAA members have been using Mogas of one sort or another for many years. For many airstrip users, the prospect of having to go to an airfield to fill up with Avgas would seem at best very off-putting, and at worst totally impractical for their style of operation. Hopefully Super Unleaded will continue to be an option using the LAA’s E5 procedure. Where 97 octane E5 super unleaded can be found that’s ethanol-free, it can be used in the broader range of LAA aircraft with engines eligible for use with E0 unleaded fuel. But it is important that Mogas users take on board the fact that unlike with aviation fuels, automotive fuel specifications generally only describe the properties of the fuel blend, in terms of octane rating and other characteristics, they don’t specify the chemical make-up of the fuel. Apart from specifying broad maxima and minima for those components that the powers-that-be wish to either encourage or discourage, the specifications leave to the fuel supplier the choice of how to blend the fuel to achieve the described properties. In some cases it’s the relatively small amounts of additives that cause compatibility issues, rather than the main components of the fuel that cause the problems – and the mix of additives may vary from one batch to the next. With Mogas of any type, what you get from the pump one week may be different to what you get the week after, or got the week before. The fact that your fuel system pump diaphragms, seals, composite tanks and so on might have been unaffected by Mogas up till now does not guarantee that they will be OK with the blend that the next tanker-load brings to your garage forecourt. Unfortunately there is no simple answer to this, and the only way to mitigate this problem is by constant vigilance, and thoughtful adaption of your maintenance schedule to check for signs of problems developing before they create a safety issue – more frequent checking of filters, changing of fuel lines etc. Signs to watch out for are swelling of rubber components like diaphragms, fuel valve seals and O rings, fuel pipes hardening or developing surface cracks, fuel tank sealants wrinkling or detaching from the internal surfaces of fuel tanks. Varnishes on cork floats may go gummy, or plastic carburettor floats absorb fuel and lose buoyancy, causing a rich mixture and rough running. Watch out for discolouration of the fuel you take out as fuel samples, which may imply something dissolving somewhere in the system, and for corrosion in the bases of your carb float bowls and gascolator. Avoid letting Mogas go stale in your fuel system – drain it out before a long period of disuse. Don’t leave the tanks empty for a long period – better to fill them with Avgas which will reduce condensation, and also, particularly with plastic tanks, prevent the tank’s internals drying out which can cause problems with shrinkage, and in extreme cases, the tanks splitting open. O rings and other rubber parts are best kept submerged in fuel continuously. We’ve seen cases where composite aircraft skins have rippled apparently due to exposure to the vapours created by the break-down products in stale Mogas, after being left unattended over a single winter. Mogas is blended with the expectation that in a car it will be used within a few weeks of being supplied, so it doesn’t need to be as stable over a long period of time as an aviation fuel. If a composite or plastic fuel tank is built into your aircraft, consider carefully whether you want to run the risk of having to replace it should the tank deteriorate with Mogas exposure, with all that that implies. With an integral tank in a wet-wing Jabiru aircraft, the answer should be certainly not – but even with the embedded polyethylene fuel tank in a Europa’s fuselage, changing the fuel tank is not an operation for the faint-hearted, involving cutting out quite large parts of the fibreglass cockpit module to release the tank, and then scarfing them back again afterwards in-situ. The Europa kit was first produced in the era of four-star Mogas, a very different blend to what we find at the pumps today. Ethanol-proof rubber hoses are available. In particular SAE J30/R9 or the European equivalent DIN 7339 D3 are automotive hose standards that are widely available from auto factors, and should be used in preference to the older SAEJ30/R6 standard hose which is more permeable to fuel vapour and will more quickly harden and crack, particularly using fuel containing ethanol. The SAE spec J30/R14 is a lower pressure, more pliable version for carburettor systems. Watch out for cheap imitations – the real McCoy should come from a reputable manufacturer, be marked with the SAE number along its length and will likely cost at least £10 a metre. What can we do to help the situation ? It may be that off-the-shelf drop-in-the-tank additives can be used to mitigate some of the problems with mogas fuel, in particular, stabilisers and anti-corrosion products, just as they are routinely in the marine and race-car world. Not knowing what’s in them, we recommending steering clear of any additives that claim to boost the fuel’s octane. Definitely avoid additives that claim to actively enhance an engine’s power or fuel economy, other than just to restore proper performance by giving the carburettor jets and orifices an occasional clean-up. For most aircraft engines UL91 Avgas remains the ideal fuel, in that it is a tightly-controlled aviation-grade fuel of a guaranteed composition, blended for long-term stability and optimal volatility for aviation use. As it is in effect the familiar 100LL Avgas but supplied without its tetraethyl lead, any fuel system designed for 100LL Avgas will be unaffected by using UL91 fuel, or, if circumstances demand, by a mix of 100LL and UL91. Despite a pervasive mis-conception, UL91 fuel is NOT Mogas and suffers from none of the issues associated with Mogas use in aircraft. A list of engines suitable for use with UL91 fuel can be downloaded from the ‘operating and maintaining an LAA Aircraft’ page of the LAA’s new website. Moves are afoot to increase the number of airfields supplying UL91 fuel, with full LAA backing.

For part-built LAA projects, the new owner/builder needs to continue following the LAA amateur-build process. For already-flying LAA aircraft, the new owner simply takes on the responsibilities of the old owner for looking after the airworthiness of the aircraft. The restoration of an aircraft might range from dusting off the cobwebs and giving the engine a good service, to a full strip down to component parts and fabricating missing or damaged parts. It is also possible, in some circumstances, to import a part-built or completed aircraft from overseas. This is generally only possible where the type is already accepted by the LAA, the aircraft can be shown to have been amateur-built under a similar regime to that in the UK, and which is readily inspectable to confirm the build standard. A number of LAA types come under the heading ‘orphaned vintage types’. These are types that are no longer supported by their manufacturer and have been deemed ‘orphaned’ by the CAA (e.g. Austers). There are also some types that can elect to operate either on a Certificate of Airworthiness or on an LAA-administered Permit to Fly (e.g. Chipmunks). Buying an Aircraft Not everyone has the inclination, ability or time available to build an aircraft. The only route then is to buy a part-built aircraft for completion, a ready-flying aircraft or an aircraft in need of restoration. When buying an aircraft, the overriding message is ‘Buyer Beware!’ If you’re buying an aircraft that is already flying within the LAA system, you mainly need to satisfy yourself that it’s in an acceptable condition and meets your needs. LAA Inspectors are often happy to look over an aircraft for you to help you make a technical assessment of its condition. Another area you should consider is whether it has enough payload to take you where you want to go. When buying a partially-built aircraft or one from overseas, you need to make sure that the aircraft is eligible to hold a UK Permit to Fly and is in a configuration that the LAA can accept. It is usually a good idea to drop LAA Engineering an email to check before you part with large amounts of money. For further information, click the button below or look in the 'Classifieds' section of the LAA Magazine Click here for more information

Light Aviation Magazine 2022 Click on the links below to open each issue of Light Aviation Magazine from 2022 January 2022 April 2022 July 2022 October 2022 February 2022 May 2022 August 2022 November 2022 March 2022 June 2022 September 2022 December 2022

< Back New LAA Inspector - James Coyne-Downhill 15 Sept 2025 We are pleased to welcome James Coyne-Downhill as a new LAA Inspector, having attended an LAA Inspector Assessment Day at Turweston recently. James started flying at the age of 14 with the Air Cadets, flew solo on his 16th birthday, and earned his Private Pilot’s Licence at 18. By day, he works on Dassault Falcon 20 business jets as part of a base maintenance team, following an aircraft engineering apprenticeship at Cobham. Outside of work, he enjoys flying and maintaining Luscombe 8As. Next Previous

< Back New LAA Inspector - Lewis Harper 18 Aug 2025 We are pleased to welcome Lewis Harper as a new LAA Inspector, having attended an LAA Inspector Assessment Day at Turweston recently. Working full-time as a CAA and EASA Licensed Aircraft Engineer, Lewis has pursued his lifelong passion for aviation since entering the industry at age 16, and have also achieved his PPL along the way. Next Previous

< Back Standard Modification for fresh air rotary ventilators added for Europa types 18 Oct 2023 A new Standard Modification (SM12871) has been uploaded to the website for Europa types. This covers the installation of rotary air vents in the forward cockpit to aid ventilation. Standard Modifications are used to enable other owners to install a modification on a given type, generally by following the instructions in the Standard Modification leaflet, having their inspector check and sign it off and letting LAA Engineering know that it's been installed. Further information on the Standard Modification process can be found in TL 3.06 Standard Modification leaflets can be found by following Engineering - Info Library - Engineering - Standard Modifictations. Technical leaflets can be found by following Engineering - Info Library - Engineering - Technical Leaflets. Next Previous

< Back Armstrong / Isaacs Bursary 2025 30 May 2025 More information can be found here . Next Previous

Light Aviation Magazine 2011 Click on the links below to open each issue of Light Aviation Magazine from 2011 January 2011 April 2011 Juky 2011 October 2011 February 2011 May 2011 August 2011 November 2011 March 2011 June 2011 September 2011 December 2011

< Back Engineering Employment Opportunity 13 Jul 2023 Want to take the next step in your Aviation Engineering career? Then join the Light Aircraft Association Engineering Team and help keep the UK’s largest fleet of vintage and light sport aircraft flying! We have vacancies for Airworthiness Engineers at all levels to be part of the LAA team based at Turweston. The successful applicants will be responsible for all aspects of continued airworthiness for the LAA-administered fleet of aircraft. Main duties will include the analysis of data from many sources to identify and communicate opportunities to improve the airworthiness of our fleet of nearly 3,000 aircraft. This will include working with manufacturers, the Air Accident Investigation Branch, LAA Inspectors and engineers and the LAA design team, as well as providing technical assistance to LAA members, writing technical articles for our own Light Aviation magazine, and assisting with Permit to Fly revalidations. The ideal applicants will demonstrate experience in all aspects of general aviation airworthiness, including a knowledge of airframes, engines and aircraft systems. A knowledge of vintage aircraft, as well as newer LAA types and modern avionics, would be advantageous. Inspired? Then we’re keen to create exciting career paths for the right individuals and will provide development, training and certification accordingly. Candidates should be IT competent with Microsoft Office, have a friendly personality and the ability to work within a small team and also independently. Excellent communication skills are required and attention to detail is essential. These are full-time posts, mainly based at LAA HQ but with potential for hybrid/remote working and site visits. Salary dependent on experience. Send your CV to [email protected] , and fly high with LAA. Next Previous

LAA are proud to announce our Rally 2025 sponsors Opening Times & Car Parking Opening Times Visitors will be asked to leave the exhibition area by 5.00 p.m. Friday: 9.30 a.m. to 5.00 p.m. Saturday: 9.30 a.m. to 5.00 p.m. Sunday: 9.30 a.m. to 4.00 p.m. Car Park Car parking remains free. Follow sign posts to visitors car park. Please do not use the Exhibitor car park. Disabled parking is available. Please note that entrance to the LAA Rally car park and exhibition site is separate from the Leicestershire Aero Club entrance (reserved for LAC members and other airfield users) How to get there Leicester Airfield , Gartree Road, Leicester, LE2 2FG Follow the Rally Car Park Signs What3words Location: rings.using.nails

LAA Courses 2025 Jabiru Engine Course This course aims to give pilots sufficient knowledge to be confident that their engines are serviceable, inc. detailing common weaknesses & the important Jabiru modifications, primarily focusing on the 4 & 6 cylinder generation 1-3 engines. Read More An Introduction to Permit Aircraft Avionics The course starts with explaining the LAA rules and guidance regarding avionics fit, discusses how to plan and install your avionics (inc. panel design) and explains how modern avionics connect with each other. Read More Aircraft Fabric Covering Course This is a hands-on course, not a lecture, so you will be working with the tools and materials, learning the required skills and you will undoubtedly surprise yourself by how quickly you begin to pick things up! Read More Caring for your Gipsy Major - Basic Course The course will explain the ins and outs of these deHavilland vintage aircraft engines and how to solve those starting difficulties, with comprehensive course notes to take away. Read More Permit Aircraft Electrics - Advanced Course The premise of this course is that it will help the owner/builder create the system design and circuit diagram, including covering electrical theory, failure modes, reliability issues and planning an installation. Read More Permit Aircraft Electrics - Basic Course An introductory course on electrical wiring, featuring minimal electrical theory, instead concentrating on the installation practices with practical wiring experience and fault finding. Read More Aircraft Carpentry Workshop - Basic Course A perfect course for the would-be aircraft builder, who may be nervous about cutting the first piece of spruce, or anyone contemplating repairing a classic wooden aircraft. Read More Air to Ground Radio Operator's Course A course to achieve your Radio Operator's Certificate of Competence (ROCC) in order to operate a Ground Radio Station running AGCS (Air-Ground-Communication-Service). This is not to be confused with a FRTOL. Read More Rotax Fuel Injected 912 iS / 915 iS Installation & Operation A course providing information and advice on installation and operational procedures for Rotax Fuel Injected 912iS/915iS aero engines. This course is run by a Rotax iRMT certified engineer. Read More Rotax Carburetted 912/914 Installation & Operation The course covers everything those who own/operate a carburetted Rotax 912 (UL, ULS and 914 turbocharged) engine need to know about getting the best out of these very popular engines! Read More

Working with Aluminium - Basic Course Price Member - £255, Non-Member - £275 (includes toolbox) Duration Arrival 09:00. Finish 17:00. < Back About the Course The 'Working in Aluminium' courses have proved immensely popular, as so many of the popular kits today use this medium. Our tutors will guide you through the construction of a Van’s toolbox. The build process is specifically designed to teach you drilling, de-burring, dimpling and riveting by various methods, and by the end of the day you will have a useful ‘apprentice piece’ to take home with you. The course syllabus will include: measuring and marking, cutting and drilling, deburring, fluting and straightening, countersinking and dimpling, and, the bit you’ve been waiting for, riveting; in fact, all you need to know to get you started on your aluminium aircraft project. These subjects will be covered by description, demonstration, and practice as you construct a Van’s toolbox kit. We will also discuss workshop practice and safety, the technical rationale behind many common build techniques, such as de-burring and priming, and provide guidance on further tools and techniques required. Aluminium is a clean material and no special clothes are required, nor will be provided. Overalls, lab coats, etc. are not necessary, but by all means bring them if you wish. Some safety equipment is necessary, however. Please bring suitable eye protection (glasses, goggles), ear protection (muffs, plugs), and hand protection (gloves). All the tools required to assemble the box will be provided by the LAA, but if you have your own air drill (PCL air connection) or pneumatic rivet gun then please feel free to bring them along (suitably identified). Your Instructor Gary Smith Dates Date TBC Times Arrival 09:00. Finish 17:00. Duration One day course Venue LAA HQ, Turweston Aerodrome, NN13 5YD Price Member - £255, Non-Member - £275 (includes toolbox) Booking Pls call the LAA on 01280 846 786 to enquire/book or email [email protected] . *Please note that payment is required when booking, to confirm your place. NO place will be held without confirmed payment* **Please note that your booking payment is non-refundable unless we can fill your place timeously or there are exceptional circumstances**