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.

Aircraft Maintenance Before accessing the maintenance documents below, please ensure you have read Technical Leaflet 2.19 - General Maintenance Schedule . Technical Leaflet 2.19 Other useful documentation is as follows: Maintenance Schedules Sample Engine Condition Monitor Blank Engine Condition Monitor AC 43.13-1B Chg 1 CAP 562: CAAIP CAP 661: MPDs Latest MPDs - not in CAP 661 CAP 747: Mandatory Requirements Breaking in an Engine Engine Pre-Oiler Schematic Forms, Checklists & Worksheets

< Back Engineering updates in December 2 Jan 2025 The following documents have been issued/updated in the Engineering 'Info Library' during December. Continuing airworthiness information: Mandatory Technical Directive 07-2024 - Eurofox trim cables Alert 03-2024 - Eurostar trim cables Alert 04-2024 - Loose Rotax engines Alert 05-2024 - Rotax 900 series engines - blocked oil spray nozzle Technical Leaflets: TL 2.22 'non-type specific MPDs' TADS : Sling 4 TSi Wishing all our members a very Happy New Year. Next Previous

Light Aviation Magazine 2021 Click on the links below to open each issue of Light Aviation Magazine from 2021 January 2021 April 2021 July 2021 October 2021 February 2021 May 2021 August 2021 November 2021 March 2021 June 2021 September 2021 December 2021

Continental Covering Letter to Owners AAN PFA 999-413 Sup 3 Approved Mogas Aircraft/Continental Engine combinations Inspection Checklist

LAA are proud to announce our Rally 2025 sponsors Entrance Fees All fly-in slot bookings for the event are available via the Eventbrite (coming soon) booking website. Member and public entrance tickets can be bought in advance via the LAA Shop. There is free car parking and provision for disabled parking on site. For those arriving by road, Leicester Airfield is easily reached from the north and southwest via J21 on the M1; A563 Sth Leicester Bypass to B582 Gartree Road. Routes from the East and South East via A47 and A6. No dogs are allowed airside BY AIR One landing fee of £10.00 covers a single landing and stay of up to three days and camping by your aircraft. Pilots and accompanying passengers will also need to purchase individual entry tickets to the Rally - available via the LAA Shop . If flying in, you will need to book a slot. PLEASE NOTE ANY FURTHER LANDINGS WILL BE CHARGED. (Local evening flying will be available and not charged) Members : INCLUDES AIRSIDE ACCESS £25 (for all 3 days) LAA, BMAA and BRA members - Please bring proof of membership by way of showing your receipt or mobile phone with membership details. More details on how to find this will be emailed to all members nearer the time. Non-Members £25 for One Day Ticket (does not include airside access) Special Offer!!! Non Member Three Day Ticket (including airside access) for £50. This offer is available until 31st July 2025. Non-Members AIRSIDE ACCESS £15 for One Day Ticket Children 16 and under go free.

Aircraft Fabric Covering Course Price Member - £206, Non-Member - £226 Duration Arrival 09:00. Finish 17:00. < Back About the Course Our covering course is presented by Chris and Alex, father and son team who run Aircraft Coverings Ltd., the UK dealer for Consolidated Aircraft Coverings products. 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! Your Instructor Chris and Alex Allen Dates New date tbc Times Arrival 09:00. Finish 17:00. Duration One day course Venue Henstridge Airfield, Somerset, BA8 0TN Price Member - £206, Non-Member - £226 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**

Permit Aircraft Electrics - Advanced Course Price Member - £216, Non-Member - £236 (includes printed course material) Duration Arrival 09:00. Finish 17:00. < Back About the Course The Basics course covers simple DC theory and concentrates on the practical aspects of installing a basic permit aircraft electrical system. The course explains how to interpret a ‘typical’ permit aircraft electrical systems diagram and for every element, explains how to size, select and source components and then how to practically install them. This Advanced course builds on the Basics course by providing more detail about component selection and options and the use of integrated power management systems within permit aircraft. The course takes the simple systems design introduced in the Basics course and explores options for creating more complex electrical systems including the use of dual and essential system bus bars. The course introduces fault tolerant design considerations, thus allowing attendees to consider safety and fault analysis in their own designs. As a tool for understanding this aspect of the course, it will take an introductory look into the requirements of electrical systems for those wishing to fly their aircraft under IFR. What this course will try to do is: Explain power generation and distribution options in a light aircraft More advanced consisderations into component selection Discuss circuit protection devices and systems Explain failure modes and reliability issues Introduce interference and EMC issues Show correct grounding and screening techniques Provide you with the knowledge to plan an installation and create the necessary documentation Warn about the ‘gotcha’ areas and the things to look out for What the course will not do is: Turn you overnight into an expert Enable you to fault find on an undocumented aircraft installation Delve inside avionics boxes It will be useful, but not essential, for people to have previously attended the Basic course. In order to make the best of this course, if you have not attended the basics course, you will need to understand basic DC theory; Ohms Law and the Power Law. Please note that this course is primarily a classroom based course, as you will already have the practical skills you need, which are covered in the basics course. Your Instructor Mark Castle-Smith Dates 9 November 2025, 8 February 2026 Times Arrival 09:00. Finish 17:00. Duration One day course Venue LAA HQ, Turweston Aerodrome, NN13 5YD Price Member - £216, Non-Member - £236 (includes printed course material) 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**

Rotax Fuel Injected 912 iS / 915 iS Installation & Operation Price Member - £216, Non-Member - £236 Duration Arrival 09:30. Finish 17:00. < Back About the Course With the growth of interest in the fuel-injected Rotax 912 and 915 iS series engines, it has become apparent that there is a lot of confusion and misunderstanding about the installation and operation of these engines and the way that the latest built-in systems work. Electronics and Rotax iRMT certified engineer, John Barrott, was an early installer of a 912iS and found it difficult to find accurate information on best practice. Working with UK Rotax agents CFS and LAA Engineering, John has built up a comprehensive understanding of the iS engines and has developed a course around this to provide help and advice on the installation and operation of this new generation of aero engines. The course is classroom (not workshop) based. Your Instructor John Barrott Dates Saturday 21 February 2026 Times Arrival 09:30. Finish 17:00. Duration One day course Venue LAA HQ, Turweston Aerodrome, NN13 5YD Price Member - £216, Non-Member - £236 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**

< Back Alert A-12-2025 - Aeroprakt windscreens 14 Oct 2025 LAA Engineering has issued Alert A-12-2025 to highlight the recent issue of a series of Aeroprakt service bulletins that require older style windscreens to be replaced at certain intervals, with the Vne of the aircraft being temporarily reduced in certain circumstances. A-12-2025 - Aeroprakt windscreens issue 1 .pdf Download PDF • 231KB Next Previous

< Back Engineering updates in August and September 1 Oct 2024 The following documents have been issued/updated in the Engineering 'Info Library' during August and September. Standard modifications: Europa SM12871 cockpit fresh air rotary ventilators issue 2 Propeller type lists PTL-1 : Aeronca 7-series Kitfox mk1-mk3 Next Previous

< Back New LAA Inspector - Ed Stinton 27 Mar 2024 The LAA is pleased to welcome Ed Stinton as a new LAA Inspector. Ed came to an Assessment Day at LAA HQ at the start of March. Ed has restored two crash-damaged Avid flyers and one crash-damaged MW7. He also restored a barn-find ARV Super2, including Rotax engine conversion. He has been involved with numerous RV builds, including his own Harmon Rocket (modified RV4). Ed has held CAA approvals for welding carbon steels. He is experienced with fabric, wood and composites, Wankel Rotary and Lycoming engines. Ed has worked with both two-stroke and four-stroke Rotax engines. He has worked for MidWest engines, Diamond Aircraft and numerous maintenance organisations. Next Previous