< Back Engineering updates in November and December 7 Jan 2026 The following documents have been issued/updated in the Engineering 'Info Library' during November and December. Technical Leaflets : TL 2.18 Change of owner/co-owner details TL 3.12 Engines and propellers fitted to LAA aircraft TL 3.17 List of approved prototype modifications Standard modifications : SM12871 Europa fresh air rotory ventilators SM16618 Europa PTFE lined hinges SM16770 LED exernal lights (new) Continuing airworthiness information : Alert A-13-2025 Sporcruiser nose leg failures Alert A-14-2025 Eurofox fuel line disconnected in flight Alert A-15-2025 Glasair rudder pedal bearing failures MTD-04-2025 Rans control linkage rode end connector washers MTD-05-2025 Eurofox rudder pedal cracking MTD-06-2025 Europa tailplane torque tube clamp mod failure TADS: Continental engines Eurofox Ikarus C42 Jabiru engines Pioneer 300 and 300 Hawk Piper J3C/L4 Woodcomp propellers Next Previous

E10 Mogas From 1st September 2021, the government mandated that all regular grade unleaded petrol must contain up to 10% ethanol, rather than up to 5% as previously. In the autumn of 2021, most filling stations around the UK re-marked their E5 petrol pumps to show that they now supply E10 specification fuel, and started receiving tanker-loads blended with up to 10 percent ethanol content. For the automotive world this means reduced carbon dioxide emissions, which is better for the environment, and, arguably in terms of eco-desirability, a small further reduction in the reliance on fossil fuel. The automotive industry had been preparing for this change, and people with road vehicles registered after 2002 should be able to switch to E10 without noticing any difference. Unfortunately, the additional ethanol content is bad news for aviation users if we were to ignore the change and start putting E10 in our aircraft regardless. Ethanol is a powerful chemical solvent which can attack components including rubberised gaskets and fuel pipes, older lacquered carburettor floats and composite or plastic components in some newer fuel systems. The doubling of the concentration of ethanol in E10 compared to E5 makes it much more likely that problems will be experienced if these parts are not designed to be ethanol-proof. Ethanol also has an affinity for absorbing water, which over time can then become acidic, attacking metal components in the fuel system and engine. Even if there was a practical way to do so in the volumes of fuel we use in our aircraft, we cannot safely remove the ethanol content from the fuel because the ethanol acts as an octane enhancer, so the washed-out fuel would be left with a reduced octane value, likely to cause detonation problems. Another issue is that ethanol-blended fuel has a lower energy density than petrol, so to develop full power from our engines using an E10 fuel, we may need to richen the fuel/air mixture, for example using a bigger carburettor jet size. Owners of Rotax and Jabiru engines are probably already aware that many of these engines are supplied as being able to use E10 fuel – though with Jabiru engines, in particular, it’s far from straightforward because some of the earlier engines require cylinder head modifications and reduced compression ratio if they are to avoid detonation issues when using any form of Mogas. Jabiru also say that Mogas of any type should not be used in commercial flight schools and only at the owners own risk. Even with a supposedly E10-compatable engine, the chemical compatibility problems with fuel system components are such that the LAA does not at present approve the use of E10 Mogas in any LAA amateur-built or vintage aircraft. For factory-built microlights and factory-built gyroplanes, where LAA is not the approving authority but only renews the CAA’s Permits to Fly, owners need to refer to the TADS for the types for details of the approved fuel types, and monitor the service bulletins from the approved manufacturers for news of any updates. Where we need to be particularly careful in reading-across from (hopefully) a trouble-free transition to E10 in automotive use is the big difference between our petrol cars and the way our aircraft engines are configured. Our cars generally have submerged fuel pumps in their petrol tanks and a sealed fuel system. In our aircraft we have an open-vented tank and usually a fuel pump several feet away, often mounted in a hot area of the engine bay near to the engine exhaust, dragging the fuel through a fairly convoluted pipework system, a filter and fuel selector – all features encouraging a vapour lock - and then to make matters worse we want to climb up to altitude and operate in reduced atmospheric pressure. Modern petrol cars have a fuel injection systems rather than carburettors, a circulating fuel system designed to purge any vapour forming in the fuel line, and an ECU that monitors the engine’s parameters constantly and adjusts the fuel mixture strength and ignition timing to prevent damage to the engine – and if all else fails and the engine should ‘pink’, we can hear it from the driver’s seat and drop a gear to lighten the load. Because of the much higher background noise level in our aircraft, detonation cannot be heard and the pilot’s first indication of a problem may be when the first piston crown disintegrates, or a valve head departs its stem. In conclusion - E10 is presently not approved for use in any LAA aircraft. ‘Hoping for the best’ and using E10 fuel in your aircraft regardless could risk ruining the fuel system components, fibreglass tanks falling to bits, engine failure through contamination of the fuel or ruptured fuel pump diaphragms etc, or more serious engine damage. For most of our engines, UL91 Avgas is the best choice, but 97 octane E5 Super Unleaded remains an alternative to the now-obsolete E5 spec Mogas.

Engineering Fees Project Registration Kit-Built Aircraft - £373 Plans - Built Aircraft - £54 Initial Permit Issue Up to 450kg - £750 451-999kg - £857 1000kg & above - £964 Permit Revalidation Up to 450kg - £283 451-999kg - £336 1000kg & above - £368 Note: For FBGs - if the last Permit revalidation was not administered by the LAA, an extra fee of £160 applies Modification & Repair Application Modification & Repair Applications (except Repeat Mods) - min £107 Hourly rate beyond 2 hour's work - £59 Repeat Modification Application - £54 Hourly-rate beyond 1 hour's work - £59 STC Modification Application - £54 Transfer from CAA CofA or CAA Permit to Fly to an LAA Permit to Fly Up to 450kg - £298 451-999kg - £342 1000kg & above - £384 Category Change Group A to Microlight - £213 Microlight to Group A - £213 Change of G-registration Fee Issue of Permit to Fly documents following G-reg change - £64 Replacement Documents (ref TL 2.12 ) Lost, stolen etc (fee is per document) - £27 Endorsement of report for replacement logbook - £27 Night/IFR application Application (to be paid when requested by LAA Engineering) - £320 Payment Methods ONLINE You can pay for Engineering Services via the ONLINE SHOP BY CALLING HQ 01280 846 786 with card details BY INTERNET BANKING Account No : 26225220 Sort Code : 60-30-03 Please note, for engineering fees, you MUST quote your aircraft registration. or your payment will not be credited to the correct aircraft record. If paying from abroad, SWIFT code is : NWBKGB2L IBAN code is : GB81 NWBK 6030 0326225220

Revalidating a Permit to Fly Revalidating the Permit to Fly on your aircraft involves a simple three-step process, as outlined below: START APPLICATION HERE More detailed information is available by clicking the buttons below: Step-by-Step Video Guide TL 2.00 - Permit Revalidation Frequently Asked Questions Check Flight Form, PFRC & Inspector Crib Sheet

Avgas UL91 & UL94 UL91 has been supplied at many airfields for a number of years. UL94 (similar to UL91 but with a slightly higher octane rating) is now becoming available. These fuels are suitable, and approved, for a wide range of engines types used in LAA aircraft. With 100LL being phased out over the coming years, now is an ideal time to see if your engine is compatible and help do your bit for the environment. The LAA Airworthiness Approval Note (AAN) for use of UL91 & UL94 in appropriate LAA aircraft can be found here . It contains a list of the most popular types of engines for which the fuel is suitable. The EASA document pertaining to use of UL91 in non LAA types is available here.

Light Aviation Magazine 2020 Click on the links below to open each issue of Light Aviation Magazine from 2020 January 2020 April 2020 July 2020 October 2020 February 2020 May 2020 August 2020 November 2020 March 2020 June 2020 September 2020 December 2020

Light Aviation Magazine 2013 Click on the links below to open each issue of Light Aviation Magazine from 2013 January 2013 April 2013 July 2013 October 2013 February 2013 May 2013 August 2013 November 2013 March 2013 June 2013 September 2013 December 2013

Light Aviation Magazine 2012 Click on the links below to open each issue of Light Aviation Magazine from 2012 January 2012 April 2012 July 2012 October 2012 February 2012 May 2012 August 2012 November 2012 March 2012 June 2012 September 2012 December 2012

LAA are proud to announce our Rally 2026 sponsor Trophies & Awards A number of prestigious Trophies and Awards are judged at the Rally, recognising the many superbly built and restored aircraft that attend. If you would like to enter your aircraft for judging you can do so on arrival. The judging team will be co-located with booking-in. You can, however, download and complete the entry form beforehand. The list of the awards for 2026 can be found here . Detailed list of award can be found here . Judging guidelines can be found here . Factory built aircraft less than 35 years old are not eligible. The judging team will ensure you are in all competitions for which you are eligible. The judges sometimes have difficulty finding an aircraft. Owners are therefore urged to download the free`What3Words’ app and use it to show their aircraft’s location when registering. All pilots who wish their aircraft to be judged are asked to display to the marshallers the large J found here . They will then direct you, if possible, to a convenient parking space. Please leave the 'J' visible in the windscreen to help the judges find your aircraft. Judging takes place from 13:30 to 17:00 on the Saturday; therefore, all entries must be received by 13:00 on Saturday.

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

Light Aviation Magazine 2017 Click on the links below to open each issue of Light Aviation Magazine from 2017 January 2017 April 2017 July 2017 October 2017 February 2017 May 2017 August 2017 November 2017 March 2017 June 2017 September 2017 December 2017

< Back Alert A-10-2025 - Cracking in E-Props Carbon Propeller Hubs 28 Aug 2025 LAA Alert A-10-2025 - Cracking in E-Props Carbon Propeller Hubs A recent report of a crack appearing on an E-Props carbon composite propeller hub was received by the British Microlight Aircraft Association (BMAA). The crack was in the flange forming the periphery of the circular hub, in the close vicinity of one of the bolts in the outer ring of blade clamping bolts. Alert A-10-2025 shows photographs of the crack discovered and details required actions if cracks are found on LAA aircraft. A-10-2025 is available HERE and shown below. A_10_2025_E_Props_Propeller_Hub_Cracking_Issue_1 .pdf Download PDF • 382KB Next Previous