View Full Version : ATR fuel gauges
Since the fuel gauges are in Kilograms and not in percentage, could someone explain how an inadvertent swap between the 42 gauges and the 72 ones lead to an incorrect amount af fuel uplifted?
Am I wrong in thinking that the 42 resistances in the tanks, if placed in the 72 tanks, would read less than actual, since the 72 tanks are longer but have the same thickness?
It's been years since I flew an ATR, so forgive any eventual BS I have wrote here.
Thankyou
LEM
too much toulouse
7th Sep 2005, 13:07
Lem,
Do you say this has happened? The difference between 42 and 72 is that of 4500 to 5000kg. Resistances imply hot-wire galvanometer, surely not? More like capacitance?
Anyway a meter reads in electrical units that have to be calculated into something useful. I suggest that this is a two-stage process. Electrical Capacitance becomes mathematically related to depth in centimetres and therefore highly correlate-able with dipping and therefore volume and therefore through specific gravity into kilograms which the gauges display.
Never mind the ATR but consider any aircraft for which multi-size tankage is an option. Do you say there is one part number for model "A" and one part number for model "B" and these measuring devices are somehow calibrated on a jig in the factory before being placed in a box? And that a maintenance engineer on replacing one reads the label and instals it without any kind of calibration check? Fit and forget?
Would it not be the case that models "A" and "B" have virtually identical components to simplify cost? One of course can suggest that in the final assemby of parts "A" and "B" that there is mechanical coding to prevent inadvertent insertion of the wrong replacement. But the final assemby could still be faulty (Murphy)on occasion and therefore it is more than prudent to have a failsafe check that readings are true.
Would it not be the case that some kind of calibration check is essential whenever a part is replaced precisely because we are all human.
If we are in the end going to "blame" the factory well I have an issue with my father and mother and god if he exists for making me such as I am. I think we are here to prevent any repetition of any accident. I wonder if that includes me?
LEM,
The FQI are also available in lbs and they too are plug compatible.
Someone will correct me if I’m wrong, but this is no different to other airframe manufacturers instrument fit options.