R44- Lycoming Service Bulletin No. 388C
 

My new helicopter is in for annual inspection. This is a 2020 new R44 Raven I with TT 105 hours. The shop asked me if I want to do above mentioned SB. The SB applies at 300 hours but the mechanic says they recommend doing at 100 hours and then 300 hours apart. This was a surprise to me. As a private part 91 owner/operator I am not required to comply. Cost is $1200.
To other R 44 owners : what is your experience with exhaust valve problems ? Are they common ?
Helicopter is flying fine and there is no roughness at anytime . I do proper warm up and cooldown of engine as per POH. Engine uses 1 QT oil / 8 hours. I am using Phillips XC 20W 50 oil with Camguard .
Apart from cost I am believer in if its not broken -dont fix it concept. When the things gets opened and closed, there is always potential of something not put together properly.
Your suggestions are appreciated

Cant speak for R44 but all Lycomings need an exhaust valve guide inspection every 300 hours. In a Schweizer 300c engine that revs at 3200 rpm way more than an R44 we find that at 900 hours they just pass, by 1200 hours they need to be replaced if that is any help

At 105 hrs that engine isn’t even broken in yet.
Unless you only do short hops that oil consumption looks to be kinda high for a new engine.
Follow their recommendations.
$1200 now but it may save you a lot later.
You need to catch problems when they start not when they’re fully developed.
(Fixed wing Lycoming experience only)
Don’t be a gringe when it gets to maintenance, at $450-$500k you’re not hurting for money.
Crude but had to be said.

What checklist is the shop using to perform the annual inspection? Is this SB included in that checklist? Seems a bit premature to comply with the SB in your case.

400hrs is just fine if you're giving the aircraft and adequate cooldown and you're not doing lots of starts for those hours. A lot of people like to do the wobble check but I believe you're better off just honing (less desirable but also adequate - reaming) the valve guide and getting rid of the carbon build up. Stuck valves are a very real thing in Lycomings (especially with earlier oils) but it would be very strange for it to occur in a 400hr old engine.

[QUOTE=B2N2;11008576]At 105 hrs that engine isn’t even broken in yet.
Unless you only do short hops that oil consumption looks to be kinda high for a new engine.

1 Qt / 8 h is high ?
this is the formula from Lycoming break in service instruction : 0.006 x BHP x 4 ÷ 7.4 = Qt./Hr.
https://www.lycoming.com/sites/defau...onsumption.pdf
Now that the max allowable oil consumption and and at that rate one will spend more time adding oil than flying. But most people I know are content with oil cons. of 1 Qt / 5-6 hours. And thats my average oil use for 40-45 hours between oil changes . I do not need to add oil for first 12-15 hours

If it was me I'd be asking the mechanic for more compelling reasons, even ask the Robinson factory if there is any benefit.

For $1,200 you can buy something like this for your Lycoming.
https://www.jpinstruments.com/shop/edm-350/
And it adds value when using it and when it's time to sell it.

Stop believing in that!! Maintenance is all about being proactive, not reactive. You wont always get the chance to fix something after its broken!

My view is that if you have a brand new heli, and this is recommended, $1200 is nothing, do it!

I noticed that SB was dated 2004 and it was obvious from the wording that Lycoming intended to fit valve guides of "an improved material", to negate the requirement. Seems strange that after 17 years the requirement is still there, at least on helicopter engines.

Lycoming air cooled piston engines do have one or two known faults - I'm sure that Robinson have considered other air cooled piston engines but what might these be ?

If "wording" you reference is the term "mandatory" you'll find that terminology was added by the legal department instead of the engineering department. What Lycoming has begun to do is to certify some of their new engine variants/models under Part 33 instead of the old CAR 13. While Part 33 requires additional documentation it also provides the path for Lycoming to create Airworthiness Limitations Sections where they have moved some of the more "popular" mandatory SB requirements. Being compliance with the ALS is a regulatory requirement owners for these new models, like the Lyco HIO-390-A1A for the Entrom TH-180, the valve/guide check and a few other checks will now truly be mandatory per the FARs.

Hi-Chrome valves were installed on engines built after around 1998, that negate the need for that SB. Unfortunately for some reason, you can't fit Hi-Chrome valves to engines installed in rotary wing, so the SB still stands.

The airworthiness limitation section is the only section in the maintenance manual that is FAA approved. That makes anything in it mandatory for all. I don't know if it is the same in other countries but it probably is in many. The reason for this is that the legislative rules for making regulation extend only to government agencies, not to manufacturers. If manufacturers could make things actually be mandatory we'd be in a world of hurt by the time their legal departments were done with the manuals. Traditionally, all overhauls of components are not listed in the ALS and thus are not mandatory unless you are operating under some form of FAA approved operations specification that specifically makes them so. Also, airworthiness limitations lists only ever get longer, never shorter. Calling a service bulletin mandatory is a misnomer but gives the manufacturer some psychological recourse in a court. If they really wanted it to be mandatory they would petition the FAA to make it an AD which I'd venture has happened but rarely.

Are you sure? I did a quick search to try and find out why, and came across this directly relevant document for this post: https://austhia.com/PDfs/AHIA-piston...ity-report.pdf

It depends on who is doing the recommending. In the OP's case, the mechanic is recommending to do an inspection 200 hours earlier than the OEM recommends. And on a new engine. Why? First, being a new engine, does it have the new type valve guides installed? If so that OEM 300 hour check gets bumped to 1000 hours or 1/2 TBO time. In this case, that would mean the OP would be performing the inspection 900 hours early. So I believe the OP has every right to question it as there's a bit more missing to the mechanics recommendation.

FYI: While the Lycoming SI covering the valve checks for cylinders with the improved guide material states it does not apply to those engines installed in rotorcraft, a call to Lycoming Support may solve that discrepancy for you. Of note, the latest Lycoming helicopter engine model, the HIO-390-A1A, provides a 1000 hour valve check (vs a 300 hr) as standard.

212 and wrench - just going by SI 1485A https://www.lycoming.com/sites/defau...0Procedure.pdf

If it is wrong, I blame Lycoming! For clarity I only have experience of maintaining Lycoming O360 in fixed wing, we have had the hi-chrome valve guides for a while now and I was able to dump the pesky wobble check,

Mandatory checks are very conservative so I think it is ridiculous doing a 300-hour check at the 100-hour mark.

Frankly as it is an SB I would recommend Tech services and QA that it should not be done unless there is an economic benefit I would not do it honestly if it was that important (and after so long) it would have been an AD along time ago it would also appear the manufacturers think the same as it should have then been incorporated in production.

This is the EASA AD relating to it, note rotorcraft are separate from fixed wing requirements.

https://ad.easa.europa.eu/blob/easa_..._2005-0023R3_1