Ethanol-Free Mogas Please select the appropriate engine type link below where you will find information describing how to obtain clearance for an aircraft to use unleaded Mogas. For Rotax, Jabiru and VW engines, please see the E5 Mogas page. Continental Hirth 2 Stroke Lycoming Related Information Operating Information TL 2.20 Fuel Flow Checking Inspection Checks - Fuel Flow EASA Investigation on MOGAS EASA has issued the Final Report of the Safety Implications of Biofuels in Aviation (SIoBiA) This project was undertaken by the University of Aachen under a research contract to EASA. The Light Aircraft Association was represented during this project by Barr y Plumb, who was a member of the project steering committee. All aspects of t he use of Mogas containing biofuel additives were considered in the research programme and the final report from the project is now publicly available here . This is a summarised version of the SIoBia findings. Placards Cockpit Placard Fuel Filler Placard

Engineering INFO LIBRARY CONTINUING AIRWORTHINESS INFORMATION INSPECTOR ZONE FLIGHT TESTING AIRCRA FT NIGHT/ IFR REVALIDATING A PERMIT TO FLY TECHNICAL LEAFLETS OPERATING & MAINTAINING BUILDING AIRCRAFT MODIFYING & REPAIRING AIRCRAFT FIND AN INSPECTOR TADS ENGINEERING FEES DESIGNING AIRCRAFT BUYING AIRCRAFT

MAGAZINE ARCHIVE Our magazine archive is available for all members to view in the Members Area. This is an ongoing project. For our latest magazine, of course, you'll need to be a member. A previous copy of Light Aviation can be viewed by clicking on the link below Light Aviation ENGINEERING INFORMATION Light Aviation magazine keeps you informed of engineering issues to help you ensure that your aircraft is kept in tip top condition. Our 'Engineering Matters' articles will form a vital information source for future reference. Light Aviation Magazine Light Aviation magazine brings you exciting articles about what LAA members are building, restoring and flying. Also included are reports on all the major rallies and GA shows and information about new products and services. ADVERTISING, CLASSIFIED & CONTRIBUTION DETAILS If you wish to advertise in Light Aviation: For display and commercial advertising, please contact Phil Johnston to discuss your requirements. For classified ad queries please contact LAA Office . Classified ads and photos can only be accepted by e-mail . Classified ad fees can be found below. The Editor, Ed Hicks , is always keen to receive your contributions of articles, pictures, technical ideas and letters. Up to 30 words Member: £6 Non-Member: £22 31-50 words Member: £12 Non-Member: £44 Up to 50 words with a coloured photo Member: £45 Non-Member: £60

Light Aviation Magazine 2023 Click on the links below to open each issue of Light Aviation Magazine from 2023 January 2023 April 2023 July 2023 October 2023 February 2023 May 2023 August 2023 November 2023 March 2023 June 2023 September 2023 December 2023

Info Library Navigate the folders below for any document that you require, like you would on your computer. To search for a particular document, use the 'magnifying glass' symbol below on the right.

< Back Alert A-05-2025 - Alpi Pioneer 300 - Inspection of Undercarriage Components for Cracking and Corrosion 12 Jun 2025 LAA Alert A-05-2025 - Alpi Pioneer 300 - Inspection of Undercarriage Components for Cracking and Corrosion LAA Alert A-05-2025 has been published on the LAA website (and is also attached), highlighting Alpi Pioneer 300 and 300 Hawk aircraft that have suffered different malfunctions and failures of various components that make up the undercarriage. This Alert strongly recommends a close inspection of the undercarriage at 25-hour intervals for corrosion and cracking, as well as a retraction check, to verify that the retraction system components remained correctly adjusted, to avoid undercarriage collapse due to the mechanism not being adequately over-centre when extended. A-05-2025 - Alpi Pioneer 300 Landing Gear Corrosion .pdf Download PDF • 204KB Next Previous

< Back Mandatory Technical Directive issued for Rotax 914 powered Eurofox aircraft 29 May 2024 Mandatory Technical Directive, MTD-03-2024 has been issued today to introduce mandatory disabling of cabin heat on examples of the type fitted with Rotax 914 (and derivative) engines. This follows an in-service occurrence of carbon monoxide entering the cabin due to leaks from the exhaust system. The MTD must be carried out before flight on or after 5th June 2024. This MTD has been emailed to all affected owners. Next Previous

Modifying & Repairing Aircraft One of the main features of the LAA system is that modifications and repairs can be approved with significantly reduced costs compared with aircraft on Certificates of Airworthiness, where applicants would need to deal with the CAA or EASA. Since the engineering team are all ‘little aircraft’ experts, it is usually a straight-forward job to approve many types of change. Of course, with many of our members being so creative, sometimes the job takes a little more time and thought to approve! View current mod/repair application queue Modifcation Type Description Further Details Application Form Application Fee Category Changes Applications to change an aircraft’s category from a microlight to a ‘Group A’ aircraft (and vice versa) are allocated a modification number to record the change. If an engine or propeller change is required at the same time, then an application must be made as noted above. N/A LAA/ MOD 10 £206 Engine & Propeller Changes These are treated as Prototype or Repeat modifications, unless they appear on the PTL list for the type. Technical Leaflet TL 3.02 LAA/MOD 4 and LAA/MOD 5 * See below Avionics Installations These are not considered modifications, but in order to fulfil their legal obligations, owners are required to keep LAA up-to-date should radio details alter. A special system exists for the approval of radio changes that is separate from other modifications. Technical Leaflet TL 3.03 LAA/MOD 7 No charge for radio/transponder installations, but a £31 fee is chargeable for certified ADS-B Out applications STCs Where a change has previously been approved by means of a Supplemental Type Certificate (STC), an LAA Inspector can sign off the change. Technical Leaflet TL 3.29 N/A N/A The Trivial Change Sometimes a change is so trivial that no application is required and there is no need to inform the Engineering department. Technical Leaflet TL 3.10 N/A N/A Manufacturers' Modifications Kit manufacturers and plans suppliers often have long lists of optional modifications that can be fitted and during the lifetime of a type product improvements are introduced. Generally, LAA-accepted optional items are listed on the TADS for the type. N/A N/A N/A The Standard Modification This is a modification that is very well defined and is applicable to a particular aircraft or engine type or types. Members may nominate new Standard Modifications using form LAA/MOD 9; however, LAA Engineering may choose to convert popular Repeat modifications into Standard Modifications. Technical Leaflet TL 3.06 LAA/MOD 1 Variable, see individual mods for details The Repeat Modification A modification that has already been approved on one aircraft as a Prototype modification. Note that a Repeat modification must identically replicate the original Prototype modification including fasteners and positions of parts and should generally be on the same aircraft type as the original. Technical Leaflet TL 3.07 and TL 3.17 LAA/MOD 11 * See below The Prototype ("normal") Modification This is a normal modification application made in the usual way and is applicable only to the aircraft for which the application is made. Technical Leaflet TL 3.01 LAA/MOD 2 and LAA/MOD3 * See below * All prototype modifications (including engine and propeller changes) attract a minimum fee of £103 which covers up to two hours' work; all repeat modifications (including engine and propeller changes) attract a minimum fee of £52 which covers up to one hour's work. Thereafter, work is charged at £57/hour in either case. See the relevant Technical Leaflet for the type of modification for further details. To access the Technical Leaflets, MOD forms and Standard Modifications described above, click one of the buttons below: Technical Leaflets on Modifications & Repairs LAA MOD Forms Standard Modifications

Light Aviation Magazine 2015 Click on the links below to open each issue of Light Aviation Magazine from 2015 January 2015 April 2015 July 2015 October 2015 February 2015 May 2015 August 2015 November 2015 March 2015 June 2015 September 2015 December 2015

E5 Mogas Inspection Checklists for Jabiru 2200A, Jabiru 3300A, Rotax 2 Stroke, Rotax 4 Stroke, VW and VW-based engines can be found at the link below Inspection Checklists Other useful documentation is as follows: TL 2.26 Procedures for E5 Mogas use TL 2.20 Fuel Flow Checking Inspection Checks - Fuel Flow Rotax Service Instruction for 912/914 Rotax Service Instruction for 2-strokes Jabiru Service Letter Buy Mogas Placards Cockpit Placard Fuel Filler Placard

Night IFR Certain LAA types can be cleared for flight at night and/or under IMC (instrument meteorlogical conditions) - commonly referred to as 'Night/IFR' for convenience. The special Night/IFR requirements and process are detailed in technical leaflets TL 2.27 and 2.28, linked below, which are additional to the standard requirements applicable to any LAA aircraft. The special requirements involve the aircraft being of a type that demonstrates flight handling broadly in accordance with CS-23 subpart B (some types, including the RV-6 and RV-7, have a restricted aft cg limit to meet the pitch stability requirements), and each individual example must have a special IFR flight test to confirm it matches the first one tested. For a night clearance, the aircraft must also undergo a night test to check its lighting and general suitability for night flight. The aircraft must have accumulated enough flying hours in VFR to prove its reliability, and it must have an engine of a type accepted as being likely to be as reliable as a certified engine (for example we accept ‘clone’ Lycomings even though not certified). The propeller must be rain-proof, i.e. have hardened leading edges, and the aircraft must have an effective carb ice prevention system. The aircraft’s panel must have at least two independent attitude indicators, with either separate power sources or back-up internal power. If two EFIS are used to provide attitude information, with no other attitude instrument, then the two EFIS must be of different manufacturers so as to avoid the risk of simultaneous failures. There must be pitot heat, an alternative static and an OAT gauge. If the essential systems are relying on electrical power, the electrics must be designed to avoid being vulnerable to any single component failure, and if there is a single alternator there must be enough battery capacity to keep the essential systems running for an adequate time (at least 30 mins) before the battery goes flat. If two radios are fitted, they must not be both vulnerable to failure if any single component fails (e.g. must not be both fed through a single avionics master switch with no back-up power available). LAA does not specify what navigation or radio equipment is fitted, but as with a certified aircraft, the equipment fit determines what type of airspace can be used. An autopilot is not required, but certainly helps reduce pilot workload in sustained instrument flight. Non-certified equipment, including EFIS and autopilots, alternators, etc, are permitted, subject to the usual LAA checks. The aircraft has to be inspected initially and annually by an inspector with a special ‘night/IFR’ endorsement on their LAA inspector approval, and the aircraft is checked to have been built to an appropriate level of quality for a night/IFR aircraft. For example, quality of its instrument wiring, electrical power supply wiring, etc, are checked which are much more critical than in an aircraft only flying day VFR. The ASI and altimeter must be regularly calibrated, the battery must have a regular capacity check and the radios checked regularly by a qualified radio engineer. The aircraft must have an accepted pilot’s operating handbook and an acceptable maintenance schedule, and be maintained to that schedule. The application process involves not only a night/IFR inspector but also a night/IFR assessor who is one of a small band of LAA volunteers qualified to assess the design aspects of the aircraft’s systems and who compiles a technical report about the aircraft and if he is happy with it, includes a recommendation to remove the day-VFR only restriction. The report includes details of the aircraft’s systems, the special flight test reports, inspection reports, maintenance schedule and POH, a photo of the instrument panel and an electrical load analysis. This report is sent to LAA Engineering who checks through it and all being well, issues the aircraft new paperwork with the day and/or VFR restriction removed and replaced by limitations allowing IFR and/or night flight. All LAA night/IFR aircraft are restricted to not fly in the vicinity of thunderstorms and, for IFR cleared aircraft, take-off and landing in visibility less than 1500m is prohibited. The aircraft may not be operated in IMC below 500 ft agl for a precision approach, or 600 ft for a non-precision approach, or approach system limits, whichever is the greater. The pilot qualification for flying an LAA night/IFR aircraft at night or in IFR is the same as for flying a certified light aircraft at night or IFR. Aircraft types that have been successfully cleared for night/IFR flight include the RV-6, -7, -8, -9 and -10 (nosewheel and tailwheel variants – some with cg range restrictions), Europa and Cozy. Several of the modern lightweight 600 kg types have failed to comply due to low stability margins making them OK for day VFR flight but not suitable instrument platforms for night or IFR. Whilst a very few Rotax powered aircraft have been be to be cleared, most of the thirty or so LAA aircraft that have successfully transitioned are powered by Lycoming or Lycoming-clone engines. PROCESS SUMMARY LIST OF TYPES PERMIT IFR FEES NIGHT IFR INSPECTORS FAQs POH LITE TEMPLATE (PowerPoint File) NIGHT IFR PILOTS ACCEPTED INSTRUMENTS TL 2.27 - PROCEDURE FOR APPROVAL & TL 2.28 - ASSESSMENT OF AIRCRAFT LAA/MOD15 APPLICATION FORM

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.