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Practical aviation fuel training — instruction, guided practice, practical assessment, competence decisions and certificates, with every module traceable to its source procedure.
Determine product density accurately for identification and contamination control, by portable meter and by hydrometer.
The source wording is unclear, misspelled or uses an unverified unit. The original is kept as it stands — an authorised person confirms the final wording before the module can be published.
DENSITY IS QUANTITY/MEASUREMENT OF MASS/WEIGHT PER UNIT VOLUME OF A SUBSTANCE kg/m3
Procedure 5, line 47
Density is the mass per unit volume of a substance, in kg/l at 15 °C.
Reason The source gives the unit as kg/m³ while the limits are written in kg/l. Confirm the unit used on site.
JET FUEL LIMITS 0.775-0.840 kg/m3
Procedure 5, line 48
Jet fuel limits 0.775–0.840 kg/l at 15 °C.
Reason The source states “JET FUEL LIMITS 0.775-0.840 kg/m3”, but those values are kg/l. Confirm the unit before publishing.
Position, PPE and equipment, manual handling, risk assessment and safety awareness
Why The preparation decides how safely everything that follows can be done.
Expected Correct position, correct PPE, equipment present, hazards identified.
If it fails Correct the position or fetch the missing equipment before continuing.
Source: procedure 5, line 13 — “VEHICLE POSITION”
A control check is an appearance check plus a density determination, used to identify the product and to detect contamination.
Source: procedure 5, line 18 — “AN APPEARANCE CHECK PLUS FUEL DENSITY DETERMINATION, FOR IDENTIFICATION AND CONTAMINATION”
Select the meter or hydrometer used
An accurate temperature is critical. A density reading taken at the wrong temperature converts to the wrong figure at 15 °C.
Thermometer, alcohol or electronic, confirmed serviceable
Source: procedure 5, line 20 — “ENSURE ANY ALCOHOL OR ELECTRONIC THERMOMETER IS SERVICEABLE”
Immerse the probe into the sample without touching the container
Source: procedure 5, line 21 — “IMMERSE PROBE INTO SAMPLE, DO NOT TOUCH CONTAINER”
Allow 2–3 seconds for the temperature to stabilise, and 30 seconds before observing
Why The reading drifts until the probe reaches the temperature of the sample.
Source: procedure 5, line 19 — “ACCURATE TEMPERATURE IS CRITICAL, ALLOW 30 SECS BEFORE OBSERVING”
Sample temperature
Source: procedure 5, line 22 — “ALLOW 2-3 SECONDS FOR TEMPERATURE TO STABILISE AND RECORD”
Meter checked for serviceability and switched on
Source: procedure 5, line 24 — “CHECK METER FOR SERVICEABILITY, SWITCH ON”
After the self-test, °C flashes to indicate the meter is ready.
Source: procedure 5, line 25 — “AFTER SELF-TEST, *C WILL FLASH INDICATING READY”
Submerge the filling tube into the sample, pump and flush at least three times
Source: procedure 5, line 26 — “SUBMERGE FILLING TUBE INTO SAMPLE, PUMP AND FLUSH 3X MINIMUM”
Withdraw from the sample and pump three times to empty the sample cell
Source: procedure 5, line 27 — “WITHDRAW FROM SAMPLE AND PUMP 3X TO EMPTY SAMPLE CELL”
Submerge the filling tube, press the pump and release slowly so the cell is full with no air bubbles
Why An air bubble in the cell gives a low reading.
Expected Cell completely full, no air bubbles visible.
Source: procedure 5, line 28 — “SUBMERGE FILLING TUBE INTO SAMPLE, PRESS PUMP AND RELEASE SLOWLY ENSURE TEST TUBE CELL IS FULL, NO AIR BUBBLES”
Density from the portable meter
Expected Within the jet fuel limits.
If it fails Outside the limits — do not release the product. Inform the supervisor.
Limit min 0.775 · max 0.84 kg/l
Source: procedure 5, line 29 — “WAIT 3 SECONDS, RECORD HIGHEST DENSITY WHEN READING STABILISES”
Empty the sample from the meter, switch it off and stow it safely
Source: procedure 5, line 30 — “EMPTY SAMPLE FROM METER, SWITCH OFF AND SAFELY STOW”
The meter may already be set to convert to 15 °C automatically — confirm before converting by hand.
Source: procedure 5, line 31 — “DMA METER MAY ALREADY BE SET TO API B @ 15* SO CONVERTS AUTOMATICALLY”
Hydrometer checked: scale markings legible, no bitumen, no damage, stored upright
Source: procedure 5, line 33 — “CHECK HYDROMETER FOR SEVICEABILITY, SCALE MARKINGS, BITUMEN, DAMAGE AND STORED UPRIGHT”
Test the sample in a clean cylinder on a flat, stable surface
Source: procedure 5, line 34 — “TEST SAMPLE IN CLEAN CYLINDER, ON FLAT STABLE SURFACE,”
No air bubbles or currents that would disrupt the reading
Source: procedure 5, line 35 — “NO AIR BUBBLES OR CURRENTS TO DISRUPT READING”
Lower the clean, dry hydrometer gently into the sample
Source: procedure 5, line 36 — “LOWER GENTLY CLEAN, DRY HYDROMETER INTO SAMPLE”
Do not wet the upper stem; spin the hydrometer to centralise it
Why Fuel on the stem changes where the surface cuts the scale.
Source: procedure 5, line 37 — “DO NOT WET UPPER STEM, SPIN TO CENTRALISE”
Allow the hydrometer to rest away from the side of the cylinder
Source: procedure 5, line 38 — “ALLOW HYDROMETER TO REST AWAY FROM CYLINDER SIDE”
Lower your eyes to just below the surface, then raise them to the level of the surface
Source: procedure 5, line 39 — “LOWER EYES TO JUST BELOW SURFACE OF SAMPLE THEN RAISE TO LEVEL OF SURFACE”
Observed hydrometer density
Source: procedure 5, line 40 — “READ HYDROMETER SCALE WHERE SURFACE OF SAMPLE CUTS ACROSS”
Observed density and thermometer reading converted to 15 °C using the charts
Why Density is only comparable at the reference temperature.
Expected Conversion carried out and the converted figure recorded.
Source: procedure 5, line 41 — “CONVERT OBSERVED HYDROMETER DENSITY AND THERMOMETER READINGS TO 15*C VIA CHARTS”
Density converted to 15 °C
Limit min 0.775 · max 0.84 kg/l
Source: procedure 5, line 41 — “CONVERT OBSERVED HYDROMETER DENSITY AND THERMOMETER READINGS TO 15*C VIA CHARTS”
Control check recorded where required: appearance, colour, water, sediment, volume, ambient temperature and density, converted
Source: procedure 5, line 42 — “RECORD RESULTS OF CONTROL CHECK WHERE REQUIRED;”
The control check is recorded on airport storage tank release certificates, on the approved form, and on the bridger receipt sample test sheet.
Source: procedure 5, line 44 — “AIRPORT STORAGE TANK RELEASE CERTIFICATES AND FORM the approved form”
Specific gravity, or relative density, is the density of the sample at the reference temperature of 15 °C divided by the density of water.
Source: procedure 5, line 46 — “SPECIFIC GRAVITY (SG) OR RELATIVE DENSITY IS DENSITY OF SAMPLE AT SELECTED REFERENCE TEMP 15* DIVIDED BY DENSITY OF WATER”
Density is the mass per unit volume of a substance.
Source: procedure 5, line 47 — “DENSITY IS QUANTITY/MEASUREMENT OF MASS/WEIGHT PER UNIT VOLUME OF A SUBSTANCE kg/m3”
What are the density limits for jet fuel?
Source: procedure 5, line 48 — “JET FUEL LIMITS 0.775-0.840 kg/m3”
The converted density is 0.851 kg/l. What do you do?
Comments and praise
Trainer observation
Trainee acknowledgement
Assessor competence decision