Would like to understand the landing gear challenges

[YankeeClipper]

My apologies for poking at an old sore, but I'm trying to understand a little more about the landing gear issues that have been reported from owners and journals alike--namely that they require a greater commitment to maintenance, or are otherwise more prone to failure than a conventional twin. If helpful, I can find some links to examples of these claims but for now I'll assume that this is a familiar topic. Also, from what I gather, there was an improvement in the '73 model that simplified the system. In any case, sssuming that there is any merit to these reports, the points I'd like to hear owners comment on are:

* What commitment to maintenance (i.e. frequency & cost) is necessary to keep either the old or newer system on par with the reliability of more conventional, otherwise comparable twin?

* Did the newer system substantially improve either the reliability or performance of the system?

* Do you feel that the reports have, for some reason, overstated the cost of prevention, or likelihood of failure?

* Does the gear-door delete address one or more issues of reliability with the gear operation?

[Ernie Martin]

In over 15 years I have owned 2, a 69 and a 73, and I have NEVER had a landing gear problem except for those caused by a weak battery.

Nor do I recall any references citing the Skymaster landing gear being any more problematic than that of other twins.

And I gave my Skymasters the most routine of maintenance, namely a thorough inspection of the gear at annual. Period.

You should note that I have a Master's in Mechanical Engineering and investigated Skymasters before I bought my first one.

Ernie

[hharney]

With a good search of this forum using the search tab, you may find some of the answers you have cited. Just a suggestion as many gear related questions and situations have been discussed on the forum over the last 20 years.

First let me ask you your reason for questioning the gear system on the Skymaster? As owners and pilots of these great aircraft, we on this forum are little jumpy when folks poke at our bird especially when trying to single it out as being unique to certain "problematic systems"

The retractable landing gear system on any aircraft requires experienced and knowledgable care. All retractable landing gear systems have some unique differences that must be understood before it can be deemed airworthy, ie. after the inspection. Following the Service Manual and thoroughly understanding the system is required to maintain the system. A good, knowledgable A&P/IA is the most important part of this equation but the owner pilot must also know and understand the system. This is with any retractable gear system.

Be cautious of what you hear / are told by those "know it all's" that have not flown, studied, worked or been around these systems. For my experience I can only speak of maybe 2 or 3 systems. All three have some concerns when servicing. All three have a totally different system, ie. engine driven hydraulic, electric driven hydraulic and electric cable push pull system. There are lots more systems out there but I am only experienced in the three above. Once the owner pilot is familiar, comfortable and has some history with the system, the system is trusted with the proper maintenance. The initial fear of the system diminishes and because you understand the system you have faith in the design.

Now back to your question of the Skymaster system, let me put it this way; the system is a very stable, very strong, very reliable, trouble free system as long as the maintenance performed is correct and consistent. Other than a few mechanical failures all issues with the Skymaster gear system are related to poor maintenance or misunderstanding of the system. Even the mechanical failures can be traced back to maintenance or unknowledgable adjustments. This is the same with almost every retractable gear system out there.

As far as I know the newer electric hydraulic system did not have any substantial benefits to the system and in some cases may have negative benefits, ie: electrical failure. Some of the early engine driven systems had pumps on both engines. This is an added benefit but not entirely required. The early system had a single actuator for the main gear and the newer system used 2 independent actuators. I have never heard of one being better than the other or why they changed this, I am sure there was good reason or at least some reason.

Reliability of the system, like any retractable gear, is in the hands of the maintenance and owner. Defer potential problems and it will come back to haunt you. Have a some unqualified person give you the green light and ..................stated failures or perceived weekness' of the system will typically point back to maintenance (lack of) or misadjustment.

The gear door deletion has been one of the most popular mods for the Skymaster. All of it's benefits are justified by the designer. RT Aerospace holds the STC and can be accessed via the internet. Most everyone that I have talked to has only positive things to say about this mod. I have only heard of one comment that might be negative and I have never heard any good facts to that negative comment. This was a concern of ice, slush, snow, mud possibly trapping the gear in the up position. I have never heard of this issue but could be perceived as a negative.

You should note that I have flown my Skymaster for 39 years and I am a commercial rated pilot that flies my bird an average of 75 hours per year and performs 99% of the maintenance under the supervision of a very qualified IA that is an expert with Skymasters.

[edasmus]

In 12 years of ownership and 800+ hours of flying, I have never had significant landing gear issues. I am no where as near knowledgeable in the internal workings of the gear as Ernie and Herb but instead I pay people who are. Having someone who knows what they are doing when it comes to maintenance is the key. I wish I was an expert, but I am not and I don't pretend to be. Instead, I found an IA who remembers working on C337's when they were new. I pay for it, but it appears I'm getting what I pay for as I can honestly say in my SkyMaster experience, my heart rate has never been elevated while flying the airplane due to a maintenance issue.

When it comes to opinions on airplanes, unless someone has had long term flying and ownership experience, their opinion likely is not based on much. The SkyMaster, as any other 40+ year old high performance complex airplane is going to require a lot of maintenance. If that is done properly, as in all airplanes, likely the experience will be a good one. Costly but good!

Ed