The bulletin
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SPECIAL
AIRWORTHINESS
INFORMATION
BULLETIN
REGULATORY SUPPORT DIVISION P.O. BOX 26460 OKLAHOMA CITY, OKLAHOMA 73125-0460
U.S. Department of Transportation Federal Aviation Administration
No. NE-00-02 October 7, 1999
SAIB’s are posted on the internet at http://av-info.faa.gov This is issued for informational purposes only and any recommendation for corrective action is not mandatory.
Applicability: LOW Octane Engines Fueled With Contaminated Fuel in Chico, California.
Introduction The FAA has been alerted that Aviation Gasoline (AVGAS) delivered to Pacific Fli ght Services Inc. (PFS) of Chico, California (airport identifier CIC) was contaminated with jet fuel and was therefore not co mpliant with the applicable fuel specification (ASTM D910). The non-compliant A vgas was delivered on August 31, 1999 and sales were suspended on September 21, 1999. The recommendations in this Special Airworthiness Information Bulletin (SAIB) are applicable only to aircraft that have purchased this fuel, and that are approved for operation with fuel octane numbers less than 100. . A separate SAIB, No. NE-00-03, has been issued for aircraft identified that puchased this fuel, and that require fuel with octane numbers of 100 or greater.
Background The contamination appears to have o ccurred when a fuel delivery truck (common carrier) loaded the 100LL Avgas on top of approximately 1000 gallons of jet fuel that remained on the truck from a prior delivery. It appears that the highest concentration of jet fuel in PFS’s Avgas storage tank was 7.7% and was further diluted by subsequent deliveries of fresh (on-specification) Avgas. Therefore, the most severe impact on octane rating occurred at the initial delivery of the contaminated fuel, and this impact lessened with each subsequent delivery of on-specification Avgas.
The octane rating, or antiknock quality, of avgas is measured using laboratory engines and is expressed in terms of lean and rich ratings of the fuel. AVGAS is available w ith lean/rich ratings of: 80/87, 91/96, 100/130 and 115/145.
Laboratory studies have shown that the l ean rating is little affected by the add ition of up to about 6 volume percent jet or diesel fuel, but the rich ra ting can be adversely affected if contaminated by these fuels. If the rich rating of the resulting contaminated fuel mixture falls below the rich rating requirement of the engine, the potential for combustion knock, or detonation, exists. However, in this case, the in itial (worst case) octane rating of the AVGAS/jet fuel mixture is was estimated to be 100/115, which is sufficient to prevent detonation in engines rated for 80/87 or 91/96 AVGAS.
Recommendations
1. The recommendations in the SAIB are applicable only to aircraft that meet both the following criteria:
a. fuel requirement of 80/87or 91/96 octane
b. fueled with AVGAS supplied by Pacific Flight Services FBO, Chico, California between August 21 and September 21, 1999.
NOTE: For aircraft not meeting criteria (a) above, but m eeting criteria (b) above, please refer to SAIB NE-00-03 for recommended corrective action. However, aircraft not meeting criteria (b) are exempt from compliance with SAIB NE- 00-02 and NE-00-03.
2. These aircraft are identified in distribution listing provided below.
3. The following maintenance actions are recommended for these aircraft:
a. Perform a compression check of all cylinders. Cyli nders exhibiting low compression should be repaired in accordance with the engine manufacturer’s maintenance instructions.
b. Completely borescope inspect the interior of cylinders, giving special attention to the combustion chamber, intake valves, and piston dome. Cylinders exhibiting evidence of overtemperature conditions or unusual damage should be repaired in accordance with the engine manufacturer’s maintenance instructions.
2 NE-00-02
c. Drain the engine oil and check the oil screens. Evidence of oil contamination or metal debris should be investigated in accordance with the engine manufacturer’s maintenance instructions.
d. Completely drain the fuel tanks and the entire fuel system including the engine carburetor.
e. Flush the fuel system and carburetor with on-specification AVGAS and check for leaks.
f. Fill the tanks with the proper grade of on-specification AVGAS.
g. If the engine inspection was satisfactory, complete an engine runup check.
4. Please report evidence of engine damage due to detonati on to the FAA contact specified below by email or fax.
Include the registration number of your aircraft.
Distribution The FAA has received reports that the following aircraft m eet criteria (a) and (b) of item 1. under Recommendations.
Please see NOTE if the listed registration number does not meet both (a) and (b) criteria.
N12456 N1245S N12527 N12714 N1388S N1710Q N18697 N2043Y N20972 N2187G N23206 N2326D N2386R N2421R N2475X N251GT N288D N3093X N3411U N3660J N3690L N370DA N42279 N45316 N46198 N52562 N5624W N5653U N5719U N6134B N63297 N6713J N680JR N6825G N7566X N7716U N8372L N8387A N84635 N8515S N888CZ N9160J N92460 N92467 N9324G N964T N9854R N9994V
FOR FURTHER INFORMATION CONTACT:
Federal Aviation Administration, Mark Rumizen, ANE-110, 12 New England Executive Park, Burlington, MA 01803, Tel: (781) 238-7113, Fax: (781) 238-7199, email: mark.rumizen@faa.gov.
U.S. Department of Transportation
Federal Aviation Administration
Regulatory Support Division P.O. Box 26460 Oklahoma City, OK 73125-0460 AFS-610
Official Business Penalty for Private Use $300