DIRECTORATE GENERAL OF CIVIL AVIATION AIRWORTHINESS NOTICE No. 17 Issue 1 25 October 1990 USE OF MOTOR GASOLINE (MOGAS) IN CERTAIN LIGHT AIRCRAFT 1- Introduction Because of the growing difficulties experienced in obtaining Aviation Gasoline (Avgas), particularly in small quantities, and the ready availability of Motor Gasoline (MOGAS), DGCA have been asked to consider permitting the use of motor gasoline in general aviation aircraft. As a first step it has been agreed to permit the use of MOGAS in certain defined aircraft using low compression ratio unsupercharged engines, (See Appendix, Schedule 1). In such aircraft any adverse effects of using MOGAS are likely to be minimal and, if present, are likely to become apparent over a sufficiently long period to enable them to be controlled satisfactorily by normal maintenance procedures. Accordingly, the DGCA has issued an Exemption, in the terms set out in the Appendix to this Notice, form compliance with the fuel specifications and associated limitations set out in the Official Manuals forming part of the Certificate or Airworthiness. DGCA will give Page 1 consideration to individual applications in respect of aircraft not listed in the Schedule. (See paragraph 2.3). Fuel Obtained direct from a filling station forecourt may be acceptable in accordance with the provisions of Airworthiness Notice No. 17A. CAUTION: BS 7070 (unleased) MOGAS or MOGAS of any standard other than BS 4040 is not permitted by either this Notice No. 17. or Airworthiness Notice No. 17A. 2 General 2.1 It should be noted that although DGCA is satisfied that the listed aircraft/engines may be operated with adequate safety on MOGAS, provided the limitations* are observed, DGCA takes no responsibility for infringement of manufacturer' s warranty, accelerated deterioration of the engine or airframe components, or any other long term deleterious effects. * With regard to the limitation on fuel temperature, it may be assumed that the temperature of the fuel in the tank prior to the commencement of the flight is less than 20 degrees Celsius unless the ambient temperature has been in excess of this temperature for some hours, or the aircraft has been standing in continuous direct sunshine. 2.2 Because of likely differences between MOGAS of AVGAS, the following precautions are to be taken: Page 2 (a) Use only freshly obtained supplies; avoid long storage in the aircraft fuel tank. (b) If the aircraft has been standing for 24 hours or longer, check fuel for water. (c) As carburettor icing is more likely when using MOGAS, particular attention should be paid to the use of carburettor hot air. This should include: - Making sure, during the pre-take- off checks, that a good RPM drop is obtained when hot air is selected, - intermittent selection of hot air in flight whether or not the symptoms of loss of power are experienced. (d) In the course of the daily check and other routine inspections, pay particular attention to non-metallic fuel pipes and seals for signs of leaks or deterioration. (e) After any prolonged period of `heat soak' at low fuel flow (e.g. hot day ground idling) establish the ability to maintain full power before commencing a take-off. Page 3 2.3 Applications (which must be with the owner' s written consent) for use of MOGAS in aircraft not listed in the Appendix, Schedule 1, should be made to DGCA, Airworthiness Division, P.O.Box 900, Abu Dhabi, United Arab Emirates. The DGCA will need to be satisfied on the following aspects. The application should either provide authenticated information substantiating compliance or apply for a Major Modification for which the appropriate charges will be made. (a) The engine should have been either type certificated for operation with minimum grade fuel of 80 MON or less, or test evidence should be provided establishing that engine has an adequate margin from detonation under the most adverse operating conditions. (b) There should either be positive pressure throughout the fuel system under all normal operating conditions, or testing of the system should be carried out to a schedule agreed by the DGCA, to show freedom from vapour locks. (c) Non-metallic pipes, seals, etc., in the fuel system should be unlikely to be seriously affected by MOGAS. Page 4 NOTE: Where composite materials, e.g. fiber glass, are used in the construction of fuel tanks, the DGCA will require evidence that these materials are compatible with MOGAS. (d) There should be no doubts regarding the efficacy of the protection against carburettor icing. (e) Any specific prohibition of the use of MOGAS in the aeroplane or engine manuals should e brought to the attention of the DGCA, together with a copy of the relevant page of the manual. 3 Recording Use of MOGAS All operating times with fuel containing 25% or more of MOGAS must be recorded in the airframe log book, and block records must be transferred at appropriate intervals into the engine log book(s). MOHAMED YAHYA AL-SUWEIDI Assistant Undersecretary For Finance, Administration and Civil Aviation Page 5 APPENDIX TO AIRWORTHINESS NOTICE No. 17 Exemption 1 The DGCA, in exercise of its powers, hereby exempts the aircraft set out in schedule 1 hereto, with engines as listed therein, to the extent necessary to enable them to fly using four star Motor Gasoline to BSI specification BS 4040 : 1988. Unless it is known, on a particular flight that the proportion of Motor Gasoline in the aircraft' s fuel is less than 25%, the aircraft shall be deemed for the purpose of this Exemption to be using Motor Gasoline. 2 This Exemption is subject to the following conditions: (a) No Motor Gasoline fuel shall be used for flight unless it has been proved to comply with BS 4040 : 1988 and Schedule 2 of this Notice No. 17. (b) No flight shall be made pursuant to this exemption unless either: (i) the temperature of the fuel in the tank prior to the commencement of the flight may reasonably be assumed to be less than 20 degrees Celsius and the aircraft is flown below a pressure altitude of 6000 ft, or 7 (ii) the written permission of the DGCA has been obtained to operate to different limitations and that the terms of the permission are complied with. (c) No flight shall be made pursuant to this Exemption unless the limitations pursuant to sub-paragraph (b) above due to the use of Motor Gasoline are set out on a placard which is affixed in a conspicuous position in the flight crew compartment of the aircraft. (d) In respect of every flight pursuant to this Exemption, there shall be endorsed in the aircraft log book maintained in respect of the aircraft, a statement that the flight was undertaken pursuant to this Exemption. Block records must be transferred to the engine log book at appropriate intervals. 3- This Exemption shall have effect from the date hereof until revoked. MOHAMED YAHYA AL-SUWEIDI Assistant Undersecretary For Finance, Administration And Civil Aviation 8 SCHEDULE 1 25 October 1990 The following aircraft may use four star Motor Gasoline to BSI specification BS 4040 : 1988 in accordance with Airworthiness Notice No. 17. AIRCRAFT ENGINE Adam Loisir .. .. Continental A65 Aeronca C3 .. .. JAP 100 J99 Aeronca 100 .. .. JAP 100 J99 Aeronca L16 .. .. Continental C85 Aeronca 7BCM .. .. Continental C85 Aeronca 7AC .. .. Continental A65 or A75 Aeronca 11 AC .. .. Continental A65 Aeronca 7FC .. .. Continental A75 Aeronca 11CC .. .. Continental C85 Andreasson BA4B .. .. Continental 0-200-Arrow Sport A2 .. .. Le Blond 90 Auster 3 .. .. Gipsy Major 1 Auster 4 .. .. Lycoming 0-290 Auster 5 .. .. Lycoming 0-290-3,0-320 Auster 5D .. .. Gipsy Major 1 or 1F Auster 5J1 Autocraft .. .. Cirrus Minor 1 Auster 5J1 B Aiglet .. .. Gipsy Major 1 Auster 5J2 Arrow .. .. Continental C75 Auster 5 J4 .. .. Cirrus Minor 1 Auster 5 J4/100 .. .. Continental 0-200-A Auster 6A .. .. Gipsy Major 10 (All variants of Mk.1) Auster D4/108 .. .. Lycoming 0-235-C Auster D5/J2 .. .. Continental A75, Cirrus Minor 1 9 Auster D5/JSA .. .. Continental A75, Cirrus Minor 1 Auster J1N .. .. Gipsy Major 1C or 1F Auster J5B Autocraft .. .. Gipsy Major 1 Auster J5F Aiglet Trainer .. Gipsy Major 1 or 1F Auster J5G .. .. Blackburn Cirrus Major 3 Auster J5L .. .. Gipsy Major 10 Mk. 2 Auster J5P .. .. Gipsy Major 10 Mk. 2 Auster J5Q Alpine .. .. Gipsy Major 1 Auster J5V .. .. Lycoming 0-320-B Auster D6-180 .. .. Lycoming 0-320-A Avions Mudry CAP 10B .. Lycoming AE10-360-B Baby Lakes .. .. Continental A65-8 Beagle A61 Series 2 .. .. DH Gipsy Major 10 Mk. 1-1 Beagle A109 Airedale.. .. Lycoming 0-360-A Beagle Auster D5-180 .. Lycoming 0-360-A Beagle Pup 100 .. .. Continental 0-200-A Beagle Pup B121/2 .. .. Lycoming 0-320-A Beagle Terrier A61 .. .. Gipsy Major 10 (All variants of Mk. 1 and Mk. 2) Bensen B8 .. .. VW Bolkow Junior .. .. Continental 0-200A BA Swallow .. .. Pobjoy, Niagara, Cateract Bell 47G-2 .. .. Lycoming VO-435-AID Bell 47G4-A .. .. Lycoming VO-540-B Bell 47J-2A .. .. Lycoming VO-540-B Bellanca Citabria .. .. Lycoming 0-320-A Bellanca 8GCBC .. .. Lycoming 0-360-C Benes Sokol .. .. Walter Minor Boeing Stearman A75N1 .. Continental W670 6A Brochet M B84 .. .. Contnental A65 Brooklands Mosquito .. .. VW 10 Cadet Motor Glider .. .. VW Campbell Cricket .. .. VW Cassutt Racer 111 M .. .. Continental C90 Cessna 120 .. .. Continental C90 Continental C85 Cessna 140 .. .. Continental C85 Cessna 150 .. .. Continental 0-200-A Cessna 150M .. .. Continental 0-200-A Cessna F150 .. .. Continental 0-200-A Cessna F150H .. .. Continental 0-200-A Cessna F150K .. .. Continental 0-200-A Cessna F150L .. .. Continental 0-200-A Cessna F150M .. .. Continental 0-200-A Cessna FA150K .. .. Continental 0-200-A Cessna FRA-150L .. .. Continental 0-240-A Cessna 152 .