HUMS download frequency

[verticalflight]

How ofter should the IHUMS/HUMS information should be downloaded on a large rotorcraft?

I'd like to know both what the common practice is and what the absolute minimum download frequency required by JAA/EASA is?

If this info is type specific, I'd be interested in AS332 and AW139 information.

Thanks,

verticalflight

[check]

We do it after each flight on all aircraft

[flyer43]

A question for you is "What do you want HUMS to be able to tell you? That a part of the aircraft is developing a fault or a part of the aircraft failed at a particular time because it wasn't diagnosed early enough!"
Also, it's not the data downloading that's so important but what you do with the data afterwards and how quickly.
Data collected and reviewed after every flight will significantly reduce the probability that a failure will occur during flight. Data collected weekly and reviewed whenever will only give you a cursory overview of what is happening to the monitored items.

[nodrama]

No, the question is what is the specified frequency layed down in the Company's CAME and maintenance programme, that will satisfy the EASA requirement.
The a/c type doesn't matter, it is an a/c for Public Transport (Offshore)requirement.
The card should be downloaded after every flight. Obviously, if the flight is to a location where there isn't the facility to download it....common sense prevails and the card gets downloaded at the next opportunity.

[flyer43]

Meeting EASA requirements and running any system to maximum efficiency and benefit are two entirely different things!
HUMS data should be downloaded and reviewed as often as possible to ensure maximum benefit. However, nodrama is correct in saying that there will be occasions when it is not possible to do the download or review at the end of each flight, such as when the aircraft shuts down offshore.
You should also ensure that a suitable MEL is developed and implemented for the whole HUMS system, including the ground station.

[Vibroboy]

While true a PCMCIA card can store 25 hours of data not all system function in this manner. The IHUMS system is designed to be downloaded after every flight or at a maximum 24 elapsed ( not flight ) hours. If this is exceeded data could be over written and you will only be left with the last flight.

You must also consider the exceedance monitoring function. With this in mind you should be looking at a download, and review of the data after every flight.

[nodrama]

Verticalflight: what is your interest for? Is it to satisfy the CAA and/ or customer for a new operation....or is it to reduce downtime between sorties?

My experience of Offshore HUMS downloads was after every flight, where practical, and definitely everyday as a minimum.

MEL limitation for u/s HUMS system was 25 flying hrs....as long as there was no reduced intervals in place for existing threshold exceedances.

A 'red' threshold exceedance grounded the a/c until investigated by engineering.

An 'amber' threshold exceedance initiated a reduced download interval of max 3-10 flying hrs depending on what system the threshold was for.

[verticalflight]

Hi guys,

Thanks for all your input.

I do agree with the basic principle that to maximise the benefit of the HUMS a regular download AND analysis routine should be followed. I used to operate in the North Sea and I know that, depending on the operator, the practise was to download AND analyse it either between flights or at the end of each days in the worst case scenario.

Off the top of my head, I believe that there was an MEL entry which would allow an aircraft to be flown for up to 8 flights within 72 hours since the moment that a faulty HUMS is detected (provided that the aircraft is not at base or a place where it could be repaired). However I assume that this MEL entry was dictated more by the nature of the operation, and not by the need to satisfy an EASA / JAR requirement.

Now I’m in an operation that it’s simply JAR regulated, but with a completely different culture when compared with the North Sea.

The AW139 MEL doesn´t have any entry related to the HUMS. This implies that the system must be operative. However the RFM obviously does not mentione how often this information has to be downloaded and analysed. Common sense and good practise would say that it had to be done regularly, ideally daily as you all have expressed above, however we all know that common sense is not always reflected in the way regulations are written.

Any ideas of what the minimum requirements for downloading/analysing frequency is (if there is any)? Only ‘Mitchaa’ has hinted that there was nothing ‘set out in stone by the CAA’.

Thanks for your help.

[ShyTorque]

I don't see how the CAA could give a "broad brush" mandate, bearing in mind that not every helicopter finishes the day at a maintenance base or other place where facilities exist to do it.

[nodrama]

CAP 693 was the CAA's guidance on this. All though it is 'guidance', from my experience the CAA will expect to see proceedures in place that satisfy their recommendations.....HUMS in the MEL is definitely one of them! The JAA should be no different.

I'm sure that there is something in JAR Ops 3 but can't find it.

[ShyTorque]

Not all operators (i.e. non AOC ones) have an MEL.

[verticalflight]

I've also looked for any information re this subject in JAR-OPS 3 and JAR-29, but with no luck :( . Any better idea?

Bear in mind that this operation is not in the UK, thus I'd rather have a JAR / EASA reference and not a CAA one.

[HeliComparator]

verticalflight

There does seem to be a paucity of information out there about download frequency. I think CAP693 is no longer valide since the AAD was withdrawn. There is CAP 753, but even that does not give much info on dowload frequency, however it does mention that the system should ideally be able to support rotors-running downloads. There is not much in EASA land, that is because EASA retain a degree of ludditism for HUMS. In FAA land there is something called AC29-2c-MG15 but I couldn't find it.

But there can be no doubt that best practice is to download every time the aircraft visits a base where there are download facilities. Just like the fuel in the bowser and the runway behind you, there is little more useless than the HUMS data still on the card.

HC

[Brilliant Stuff]

Just to add my two pennies.

In my last company our base downloaded the hums after every shutdown and crew change but within the same company but different base they would only download after the days flying had stopped.

[zalt]

HC

Do you not know that AC29 is harmonised between EASA & FAA so CS29's advisory material is in AC29?

This may help:
Managing a Successful HUMS Operation: http://dspace.dsto.defence.gov.au/dspace/bitstream/1947/3734/1/DSTO-GD-0348.pdf

[HeliComparator]

zalt - yes I do know they are harmonised (though not quite identical). The difference is that the FAA advisory material seems much easier to find on the internet (though I couldn't find the MG15 bit during the short time I looked, and have to admit that I don't know what the MG bits are at all) - I think you have to pay for EASA's advisory material.

HC

[zalt]

HC

You have missed my point. There is NO seperate EASA advisory for CS29 - it IS AC29!

And EASA do not charge for their advisory material (Executive Decisions) as JAA did.

Perhaps you need to talk to someone who knows about certification!

[nodrama]

Post #13


Bear in mind that this operation is not in the UK, thus I'd rather have a JAR / EASA reference and not a CAA one.


......So not CHC and no easy solution I'm afraid.

[steve_oc]

For info UK CAA has just published CAA Paper 2008/05: HUMS Extension to Rotor Health Monitoring. Doesn't help with download frequency but contains a lot of other interesting info.

CAA Paper 2008/05: HUMS Extension to Rotor Health Monitoring | Publications | CAA (http://www.caa.co.uk/application.aspx?catid=33&pagetype=65&appid=11&mode=detail&id=3391)

[HeliComparator]

zalt

Yes, now I know why I can't find the advisory material for CS29 on the EASA website - it doesn't exist! Regarding your point about EASA not charging for advisory material, that is an easy decision when they do not provide any advisory material!

But back to the original point, since you are the expert on certification what is in the MG15 bit of AC29-2C that I have seen references to?

HC

[zalt]

HC

Chill out man - you'll give yourself heart burn and some people might stop being helpful.

Plenty of free EASA certification guidance here (only 27 & 29 link to an FAA AC) - the advisory is helfully behind the rule:
Agency Measures | Certification specifications (http://www.easa.eu.int/ws_prod/g/rg_certspecs.php)

To quote direct fron CS29:

CS–29 BOOK 2
2–1
AMC 29 General
1. The AMC to CS–29 consists of FAA AC 292C
Change 2 dated 25 April 2006 with the
changes/additions given in this BOOK 2 of CS–29.
[Amdt 29/2]
2. The primary reference for each of these AMCs is the CS–29 paragraph. Where there is an
appropriate paragraph in FAA AC 292C
Change 2 dated 25 April 2006 this is added as a secondary
reference.
[Amdt 29/2]

AC29 is at:

http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgAdvisoryCircular.nsf/0/29e440234b4cc27586256e4300597dd7/$FILE/AC-29-2Cincorporated.pdf

All the MGs are in Chapter 3.

If you actually want an expert ask one of these guys who are updating MG15:

http://www.easa.eu.int/doc/Rulemaking/TORs2/GC%2027&29.019.pdf

AUBOURG, Piere-Antoine Eurocopter
CUEVAS, Ed FAA
EVANS, Andy Bristow Group Inc.
HEALEY, Alastair EASA, Certification Directorate
LARDER, Brian GE Aviation
NEKSÅ, Knut Vidar CAA - Norway
PIPE, Kenneth
WENDELSDORF, Joseph Bell Helicopter Textron
HADDON, David EASA Rulemaking Directorate

But you will not find a time period there.

[verticalflight]

Thanks a lot!

You´ve given me heaps of useful information.

Yes, I used to fly for CHC in the UK, but now I'm not either with CHC nor in the UK. I've contacted the HUMS guys in CHC and they had plenty of company guidlines and policies there. However I needed some EASA material since now I'm in another European country.

You all have given me plenty of ammunition to load my guns with.

Thanks a lot,

verticalflight