Bond ground all UK EC135s

[skadi]

ASB 28A-018 FUEL SYSTEM

This actual ASB requires a fuel system check on all EC 135 within four weeks or 30 flighthours.

skadi

[cockney steve]

I would suggest the helicopter fares a lot better in unpowered flight, especially at the end.

I'd agree with tha last bit...the transition to,and execution of, unpowered flight seems to be the problem....the actual landing, less-so.
( I have tried to master a Nitro-powered model, flights tend to cost ~£50 a go in crash-damage Not as expensive as flying full-size, but vastly more twitchy and the complication of orientation , flying from an external viewpoint.
I was heartened to hear from a Pilot who flies both full-size and models, that the latter are infinitely harder! ) Plenty of youtube footage of model pilots cutting and then autoing to their feet !

@ Jim Jim 1... yes, harsh, but you are advocating an unneccessary layer of complexity. It is fallacious to assume the contents being measured, are of a tightly -controlled consistency and constituency...not so! laboratory-standard measuring-systems have no place in an industrial environment, especially when, as demonstrated, the measurement is error-prone and based on a theoretical standard of purity which is not borne out in practise.

[EPAC]

http://www.eurocopter.com/site/docs_...18-Rev0-EN.pdf

http://www.eurocopter.com/site/docs_...19-REV0-EN.pdf

[Bill4a]

I'm having a very hard time trying to imagine how the amount of water that would need to be in a fuel tank in order to give a significant 'float' based system error would get there!
Unless the drain checks haven't been carried out for a very long time, surely the amount of water present in the tanks would be minuscule?

[SASless]

It can land at 60 Knots or Zero knots (especially in hands of our ex "Nam" brethren).

Well not always......

You Tube

[ShyTorque]

SASless, moving as casually as he could, on the way to hand his notice in before the Boss found out....

[SASless]

Actually, some locals shooting at him after downing his aircraft. I would be legging it too in a style we knew as "Low Running!".

[Mechta]

Can anyone say what type of gauging system operates the red warning light?

[Fortyodd2]

Mechta,
It's a Thermal Sensor - basically, it senses whether it is in liquid - or not.

[Mechta]

Thanks Fortyodd2.

The fact that the Eurocopter technical bulletins state that the capacitance fuel probes need cleaning and that some inspected probes worked correctly after cleaning, suggests that the probes could be getting a build up of bacteria. This can cause water droplets to be retained between the probe's concentric tubes. This in turn would give an incorrect capacitance reading, an incorrect remaining fuel reading and a false sense of security for the pilot.

Fuels

Larger aircraft use multiple probes to determine the location of the fuel surface across the whole tank. An incorrect reading from one probe would show up as a fault. The Boeing 777's ultrasonic system also uses an inverted probe to look for the water/fuel interface.

In response to Bill4a's query about water in the fuel tank, this generally takes four forms that I am aware of:

1. Water pooled on the bottom of the tank below the fuel (what one is generally looking for when taking a fuel sample).
2. Water molecules sitting between the fuel molecules throughout the fuel.
3. Condensation on the tank components in the ullage (area above the fuel).
4. Water droplets free floating in the fuel due to fuel sloshing.
5. Water trapped by bacteria or by tank hardware.

If the problem is water droplets sitting between the probe tubes on a clean probe, then the very act of getting at the probe to inspect it may cause the droplets to be washed off or dislodged before the evidence can be seen.

[Bill4a]

Thanks Mechta, but I was referring to a previous post where it was posited that water in the tank was sufficient to cause a float system error. I still can't see it!