Out of curiosity, how many MANDATORY service bulletins do you get from your engine suppliers??

I don't recall in my 35 years of driving, more than 2 or 3 mandatory recalls on any of my vehicules. It seems that as soon as you introduce a 3rd dimension (wheels off the ground ..-:) ) there seems to be a flud of maintenance bulletins. Since I've been reading on aircraft engines and talking with people that maintain their own engines Jabiru, continental and especially Rotax. Why so many issues that need MANDATORY servicing?

Aren't they exagerating a bit??  It seems like every couple of months Rotax issues a Mandatory service bulletin. i've just seen one on Jabiru 220 as well.

Is that Marketing's way of getting you back intheir shops to buy more parts?

It's crazy. 

it would be very interesting in a buying process to see in a graphical mode, what supplier issues the most Mandatory Service Bulletins.

I understand it's safer to know about them than not...but there is a limit to the # of those recalls.


What do you guys think?

Are you seeing what I'm seeing?

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They should publish a TBMSB  (time between Mandatory Service Bulletin)     TBO=2000 hours  TBMSB=3 months




With respect Andre, aircraft and their engines are sold in very small quantities compared to automobiles. That means that the money available for testing and development of aircraft and their equipment is but a tiny fraction of what the car makers would spend on developing and testing, say, a new car engine, yet there are still recalls every year on various cars.


To put it another way, even Boeing has the occasionally mandatory inspection and modification to their aircraft, so you are in good company :)

You are probably right Geoff -:)  point well taken.

I guess when we leave the ground with our aircraft....the meaning of a maintenance bulletin has much more impact if we comply or not ...hahaha


A car engine maintenance recall  probably has a much lower life threatening probability than an aircraft one.

Point well taken as to the number of aircraft engines compared to cars ( therefore the higher price for aircraft engines). That's one of the main reason one can get a Viking(Honda) engine for $13,000. But once you take that same Viking(as an example...not picking on that one particularly) up in the air,  it's a different story isn't it.

In a car, you get in, turn the key and you go. In an aircraft.....we think about carb heat, fuel mixture, walk arounds etc...   Quite a different world!!  hahaha  and pulling on the side of the road doesnt require a MAYDAY call.





The difference is automakers have a policy of denial. That way they are not forced to recall or pay for repairs to hundreds of thousands...even a million or more repairs. FORD sells around 900,000+ F150 trucks / yr. so even the "mandatory" replacement of a $5 part has costs of 5 million $ + labour. That is a big hit to the bottom line. Remember that anytime your vehicle breaks down and the dealers claims "First time we have ever seen that happen". Remember Toyota's issues with stuck throttles? The opposite is true with aircraft engines, these manufactures seek to avoid any liability in your injury or death by notifying owners of any potential issue Even look at an NGK sparkplug box and notice the red circle crossed out over the picture of the ultralight.... and that is just a sparkplug ! 

In the last year that I've been around aircraft builders/owners, and from my own eyes I've seen things done to engines by so called competent aircraft mechanics that really raise concerns in my mind!! .....it's scary to take flight while trusting them blindly. Just last week, an engine was delivered to a flight school....the pilot took off for a lesson just to land straight ahead......forced landing. The carbs weren't secured properly. 

Lessons learned....stay close by when they have an open heart surgery on your engine....I know I will.

Now, keeping informed of all the maintenance bulletins will become a responsibility of mine and not necessarly counting on the mechanic.




About 25 years ago, when liability lawsuits on aircraft were flying left and right, aircraft and aircraft engine and parts manufacturers started flinging mandatory service bulletins left and right, evidently hoping to protect themselves in the courtroom. Some were downright silly. Technically, a service bulletin is not mandatory unless it becomes an AD.


The problem with this is, the courts are beginning to say that if service bulletins aren't complied with, whatever happens is the fault of the owner, or the person maintaining the aircraft. I know in the IA seminar I attend for renewal each year, we are being advised to get owners to sign a release on any service bulletin not complied with.


And, yes, if you put a certified product in an experimental aircraft, the FAA is beginning to say that you must comply with ADs, and treat it as though it were in a certificated aircraft.


I don't think this is either right, or that it makes sense, but that seems to be what is coming down.

I am seeing somwething pretty standard in aviation.  YOu cant pull over a plane cruising at 10,000 ft over to fix a problem.

I may misunderstand your point, but I see two problems:


1) The national airworthiness organization (the FAA here in the US) is acting as something of a moderator, and turning really important service bulletins into ADs. Those service bulletins that are not as critical, and may in some cases have originated in the legal department of the manufacturer, probably should not be mandatory.


2) For experimental aircraft, which (again in the US) is the category most of our Zenith's fit in, there really are very limited standards. We can modify a car engine and put it on our aircraft, if we so chose. In that instance, there will never be any service bulletins or ADs.


Why then, logically, should we be forced to modify certificated engines that we install? Locally, if you install a certificated engine on an experimental aircraft, the data plate will get a big "X" stamped on it, to show it is not necessarily being maintained to the manufacturer's standards. It already is outside the manufacturer's system, and outside the FAA's airworthiness system for that engine.


I'm sure we want to know what the manufacturer thinks, and we will probably want to do many of these bulletins. But not all, and that should be our option.


I hammered on engines here, but the same idea seems applicable to me on all the certificated items that we integrate into our aircraft.

Auto makers only have a limited time to worry about there auto and you. They are not going to think about you 1973  p/u exploding if the points arent the right ones for it. Aircraft, engine, and avionic makers have to proctect you and them forever.

On the other hand when they do have a (recall) AD, the auto manufactures pay for them and the aircraft manufactures make us pay.

Rembember the sky is just a big hole to throw money into, and it hasen't filled up yet.

The only ones who do make any money in avaition are Lawers.


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