Lycoming TBO/extension.Who Decides?

[MrAverage]

I've had 3 different answers as to the TBO for an AEIO360/200hp and whether or not a 10% or 20% extension is possible on Public Cat. It's a non EASA A/C. Who decides? Is it Lycoming or the CAA or the engineer concerned. As you can imagine I'm not an engineer!

[matkat]

Very simple answer and it is this. The state of registration would have approved the maintenance programme which would have the agreed maintenance extensions contained within the manual/programme normally it is 10%.

[ericferret]

Go to the CAA website and go to publications, look in airworthiness for CAP747 and in Section 5 Appendix 1 Generic Requirements GR 24.

Its 20%.

Thats the authority to extend. The actual application of the extension rests with your maintenance provider.

[Flyingplanner]

It is definitely 20% and that applies to your engine TBO (1800hrs?) and 12 years since zero timed.

[MrAverage]

Thanks everyone, but who decides the TBO? Is it that which is on the Lycoming website or is it decided by someone else?

[Paradism]

MrAverage

You don't say what your interest is in this discussion, however, a few points to note from a QA viewpoint.

1. Whatever the AMO might say, it is the responsibility of the operator to ensure that all maintenance is properly performed, on-time and correctly recorded.

2. In order to assist you when asking for this sort of assistance, always request that primary source documents are identified. In this instance the most important is Lycoming Service Instruction Number 1009. Make sure that you ascertain that your AMO provides a copy of the latest Issue. I am now retired but the last issue I saw was 1009AS in 2006. Read the document very carefully as the type of operation can affect the final TBO figure.

3. Once you have established the Lycoming figure, you can then refer to other documents, e.g. if you have a UK AOC, then CAP 747 will guide you. It is available on line to download for free from the CAA.

4. Normally, a TBO like this will have to be specified in your maintenance programme because it is "variable" according to your type of operation. Where a Lycoming life is extendable, CAP 747 normally specifies additional maintenance at 100 hour intervals once the "normal" TBO has been reached and surpassed.

Note:
One final thought and an important one. Some organisations wish to run their engines well beyond the normall permitted TBO's. This, as I am sure everyone will agree, can only be done with the approval of both Lycoming and the relevant authority. The big risk with this is that the operator becomes legally responsible and has no means of off-loading any responsibility in the event of a major incident or accident. Not normally an issue because the effort involved in increasing a TBO, as opposed to an extension, must be more trouble than it is worth.

[horizon flyer]

An IO360 200hp injected engine has a 2000 hour TBO the 12 years is only a recomendation.
Have heard of 360s running for 30 years but a bit over the top.

Lycoming do say it needs to be run 40 hours a month to make this TBO.

Pre 72 engines had narrow cam widths and only had a 1400 hour TBO.

Valve guides wear and a need wobbe test every 400 hours, unless you have the new hardened guides, good for over 2000hours.

Once passed TBO it's on condition, have heard of engines run up to 2800 hours.

Cam lobe wear is common, only indication is a slow reduction in power over time.

Old CAA C/A climb test is good to catch this.

Creeps up on you when the trees at the end of the strip seem to get taller.

[Von Klinkerhoffen]

Link to Lycoming SI1009AT below......

http://www.lycoming.textron.com/support/publications/service-instructions/pdfs/SI1009AT.pdf

200hp AEIO-360's have a max TBO of 1400hrs but please read note 6 of said SI !!

Link to CAP747 on the CAA website below.....

http://www.caa.co.uk/docs/33/CAP747.PDF you need G.R.24 in appendix 1

On Public Transport or Aerial Work , at the discretion of your maintenance provider/LAE , you may extend TBO 20% to 1680hrs.But please don't think this is your right to run the engine to this TBO , if you aerobat your aircraft regularly , your engine has a very hard life indeed . The constant alternating high/low power settings,accelerations/decelerations,momentary overspeeds,oil pressure fluctuations(even with an inverted oil system) and the nature of aerobatic flights(tend to be short trips , so hence many cylces) take a terrible toll on your donkey.In my experience most AEIO engines do not make TBO..........hope this helps,good luck !:ok:

VK

[MrAverage]

VK

My understanding of the rules reaches the same conclusion as you. However the engineer concerned maintains the TBO is 1800 + 20% by virtue of a type specific AIC which extends the original 1400 hours in the UK.. Since there is no search engine on the NATS/AIS website I have been singularly unable to find this document. Since I need to be sure of my facts before I spoil the owner's day - and that of the engineer - I guess I'll just have to bite the bullet and phone the big grey building at Gatwick.

[Von Klinkerhoffen]

Are you able to name the aircraft type/engine model on here or is that giving the game away too much ! Regardless , what does the approved maintenance schedule for this aircraft say about engine TBO or O/H periods in general ? What is the approved maintenance schedule ??

I have no idea what NATS or their AIS have to do with Lycoming TBO's or even if Aeronautical Information Circulars are even legally binding or are approved data....get the said engineer to produce this type specific AIC and go from there !

VK