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Coy Jacob |
| This article originally appeared in the March 2002 edition of AVIATION CONSUMER and is reprinted here by permission.
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What's in a name? Or a label? When it comes to
aircraft engines, a simple label — or, more properly, a logbook notation — can
carry an impressive cache that, in reality, may not mean what you think. A case
in point is the value a buyer or owner puts on a "zero-time" engine as
opposed to a freshly overhauled powerplant from a field shop. Hands down, the
zero-time is thought to be a better engine, since it has all new parts. Except,
of course, it might not have all new parts. In some cases, a field overhaul
could have more new parts than a zero-time factory engine.
Obviously, excluding test-stand time, new recently manufactured engines are
fairly and properly termed zero-time. All the parts will be factory new.
However, the FAA also allows the original equipment manufacturers (OEMs) to
label their rebuilt engines "zero time," a minor sleight of the pen
that has some field overhaul shops fuming. We don't blame them, frankly. As far
as engine longevity, "zero time" versus "stated total time"
may make little difference in the outcome. But if you think you're getting
something you're not, the term is misleading at best.
OEMs Only, Please
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No one but the OEMs have the official, FAA-blessed right to term any engine
zero time, even if the scope of work done on the engine by a field shop is
exactly the same as the factory's rebuild process. Actually, even the OEM's own
overhaul shops can't call their overhauled engines "zero time."
Lycoming, of course, offers factory overhauls and new engines, while Continental
sells new and remanufactured engines only. A terminology note here: FAA regs
don't recognize the term "remanufactured" but use the term
"rebuilt." In this article, we have used the terms
interchangeably.
In Canada, the rules are a little different. The Canadian Aviation
Regulations don't have an equivalent to our FAR 91.421, which allows "zero
time" to be recorded for a factory rebuilt engine. So in Canada, the actual
time or the term of prior duty time is considered "total time
unknown." Only a new engine is zero time.
Even though the factory's actual remanufacturing/rebuilding process may be
functionally identical to what most competent engine shops offer on new limits
overhauled engines, buyers seem enamored with the idea that a zero-time engine
from the factory contains all new parts. That's simply not the case.
For years, field shops have complained about this practice — an
"exalted privilege granted from on-high" — as one engine shop owner
puts it. One industry activist, Bill Schmidt of Cincinnati-based Signature
Engines, believes that zero-timing is paramount to false advertising and has
officially petitioned the FAA to change the rules. He even has his own Web site
to carry the cause forward, www.stopzerotime.com.
The site includes Schmidt's petition to the FAA.
How It Works
From the FAA's point of view, the OEMs have access to the original production
drawings, thus they can theoretically attest that each engine component conforms
to new specs during the rebuilding process, whether it's a new part or one with
2000 hours of flight time. In other words, your "zero-time" crankshaft
can legally be undersize due to wear but still treated like new because the
factory allows it.
In practice, how important are these production drawings? Not very, in our
estimation. Except under the most unusual of circumstances, everything any
competent shop needs to know about how to overhaul the engine is contained in
the OEM Service and Overhaul Manuals. Having the production drawings is a nice
technicality but unconvincing as basis for building a better engine. In fact,
we're told by industry insiders that the drawings are rarely used anyway, since
the principal specifications are in the overhaul manuals, for all to see.
Drawings are, however, critical when building new engine components from
scratch.
Most reputable engine shops not only believe the term "zero time"
means nothing, but some even consider it blatant false advertising. Jimmy Broad,
of Sebring, Florida-based JB Aircraft Engines Services, says that, while the
OEMs may not admit to it, it's entirely possible for a factory zero-time rebuilt
engine to contain parts having more total time than the engine it's replacing.
Engine modifier Terry Capehart of High Performance Engines Ltd. in Mena,
Arkansas and Zephyr Engine's Charlie Mellot in Zephyrhills, Florida, say there
are instances in which internal components involved in sudden stoppages or
accidents have found their way into zero-time engines. (The same is true of
field overhauls, by the way.)
At present, there's no legal obligation for anyone turning an engine in for a
core charge to inform the factory of such abuse. The typical independent shop
may actually have a better handle on the past history of the engines they offer
than does the factory, which receives cores by the pallet load. Of course, the
factories do inspect the parts for wear and damage before reusing them, just as
overhaul shops do.
Just why did the FAA allow this practice to get started? Probably because,
until about the late 1980s when new airplane production was less anemic than it
is now, the engine makers only built new engines. They left overhauls to field
shops. When the new engine business declined, the factories went after the
overhaul business with two distinct advantages: the economy of scale conferred
by volume and the cache of holding the engines' birthright. In other words, with
minimal FAA oversight, the factories declared the standard and passed it down to
the field shops doing overhauls.
When the factories began overhauling and remanufacturing, exchange engines
were returned to the factory, disassembled and parts inspected, sorted and put
into bins of identical parts to be reassembled later. Similar parts were then
sorted as being within OEM new specs, serviceable, or outright junk, which was
discarded. Because any future re-assembly into engines could actually be
somewhat of a mix of used and new parts, the end result would bear little
resemblance to any specific run-out engine from whence the parts came.
Major components such as crankshafts, cases, gears and so on are typically
re-used if they meet specs. However, the OEMs claim they can't keep track of
every used component's total time in service, nor do they typically make any
effort to do so. In fact, as exchange cores are passed through the rebuilding
process, individual engine components are typically not kept together as a
functioning parts group.
Volume, Numbers
From a volume/manufacturing standpoint, this makes sense. Keeping a group of
non-serial numbered parts together can be a logistical nightmare and, even if
you could do it, how would you log the time for each component and what meaning
would that have? The part total time designation loses its value unless all the
components are kept together as one functioning engine, sans those components
replaced by new parts.
This, too, is logical, given the sloppy state of paperwork that passes for
logging these days. Our audits of engine and airframe logbooks turn up all kinds
or errors, great and small. It's not uncommon to see gaps of thousands of hours
in an aircraft's history.
That said, if you opt to have your engine overhauled by Lycoming and you
specifically decline an exchange, you'll get your own serviceable core parts
back, plus any new parts installed during the overhaul. If you opt for an
exchange overhaul from Lycoming, the engine could be composed of used core parts
of widely varying times.
Continental doesn't overhaul, per se. It sells new and remanufactured engines
or, in FAA parlance, rebuilt. As we've reported, Continental bought Mattituck
Aviation Corp., a respected overhaul shop, in 1999. Mattituck does sell
overhauls and, in that sense, is no different than any other field shop.
What the Factories Say
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For the OEM view, we contacted Continental and Lycoming, both of whom
obviously have a different take on the zero-time issue. For its part, Lycoming
says the company does enjoy advantages over overhaul shops. Lycoming's VP and
Chief Engineer Rick Moffit argues that, in general aviation recips, the notion
of time-limited parts doesn't exist, although manufacturers do publish
recommended TBOs which are mandatory only for for-hire operations.
Lycoming doesn't serialize the majority of its parts, thus there's no
mechanism in place to keep track of the duty times of internal parts. This means
that while the "parts bin" argument may have had some merit in
influencing the FAA some years ago, the need to track duty time of reinstalled
components is neither necessary nor perhaps meaningful.
Although it wasn't mentioned specifically in our conversations, we're sure
the lawyers have some stake in the "zero-time" argument as well,
especially as it relates to the factories' publishing minimum/maximum time
specifications for certain parts. Were they to publish specific accepted minimum
times for components, field shops might then be able to call their engines
"zero time." But this might also increase the company's liability
exposure. In effect, any part that failed before the replacement time could be
construed as being officially okayed by the factory.
Teledyne Continental's chief engineer John Barton and Jay Wickham, who
oversees the Mattituck operation, support the view that having production
drawings gives the factories a meaningful advantage. And while it's true that
the drawing themselves aren't always on the factory floor, TCM says the drawing
requirements are increasingly controlled by a computer system called CAPPS for
computer aided process planning system.
This system makes dimensions and requirements readily available in the
factory to a level of detail not included in overhaul manuals. Further, the
CAPPS system contains the latest drawing revisions, which overhaul manuals may
not.
Indeed, say Wickham and Barton, it's not unusual to find factory overhaul
manuals not in evidence at an overhaul shop, a way of work that may be effective
for shops but would prohibit Continental from factory authorizing such a shop.
Of more material import, says TCM, is that parts used in zero-time engines are
subjected to the rigorous requirements of factory new components. For example,
reworked crankshafts are examined and undergo the same 40-hour nitriding process
that all factory new crankshafts get. If field overhaul shops provide this
service, says TCM, it's not likely to be the same process the factory uses.
TCM says that during its rebuilding process, it routinely destroys all
cylinders and many other components that might otherwise find their way into
overhauled engines, legally or not. Many rejected parts may in fact meet service
limits overhaul requirements but not new requirements. Continental says one of
its rebuilt engines is likely to contain more new parts than a field overhaul.
The confusion — and to a degree, the deception, is there for the taking by
all parties — over the "zero-time" issue. TCM's Wickham notes that
many facilities that compete with Continental use intentional "factory
disparagement" to create favorable buyer impression of their products.
Since the factory doesn't sell direct, it relies on distributors and shops with
potentially conflicting sales interests to sell its products, thus a detailed
understanding of what goes into a zero-time engine is not necessarily conveyed
to the potential buyer.
The PMA Market
Gary Garvins, CEO of Engine Components, Inc., a major PMA house, sees both
sides of the argument. He agrees with the Lycoming line of reasoning but he also
agrees with shop owners who believe the zero-time claim is misleading at best,
false advertising at worst. But, says Garvins, the zero-time privilege for the
factories was set in stone four decades ago and it would take an act of Congress
to change it. (One engine shop owner told us, "if the FAA could drop the
zero-time issue without un uproar, it would.") What Garvins and engine
shops object to is that OEMs are essentially allowed to "throw away the
logbooks" on used but serviceable components and then to use the zero-time
claim in advertising, which gives them a distinct advantage in the minds of
buyers.
Tim Archer, who is senior vice president for Superior Air Parts, another big
PMA supplier, says there are more issues at stake than just the zero-time claim.
Archer, by the way, worked for Continental for years, so he has seen the
argument from both sides of the fence. He says the real issue shouldn't be the
logbook verbiage but what it implies. In other words, do you want to know the
history of all the parts used in building up your rebuilt/overhauled engine or
not?
The OEM's would have us believe that they're the only ones who can accurately
determine if the used parts should be reused and that they have unique
inspection ability. But is that true in the real world? Archer says no. He says
there are many quality engine shops fully capable of assembling engines equal to
or better than anything turned out by the factories. In fact, says Archer, the
"one man, one engine" build-up method used by field shops has the
advantage of allowing closer inspection and checking of each phase of the
overhaul.
Zephyr's Mellot argues simply for more truth in advertising: "My
suggestion would be to allow the factory to use the term 'zero-time since
remanufacture' due to the fact that they're the only ones with the proprietary
manufacturing drawings. After all, these are their drawings and I can't blame
them for not wanting to release them."
This would alert the buyer to the fact that the engine is not zero time since
new but contains used parts. To some buyers, it's important to know this. Our
view is that many buyers don't make the distinction.
What It All Means
Even though engine shops chaff at the advantage enjoyed by the OEMs and Bill
Schmidt is trying to get his Zero-Time Coalition off the ground, don't look for
anything to change soon. In researching this article, we sensed that this issue
is a hot potato that the OEMs and the FAA would very much like to ignore.
The engine factories, like the airframers, are struggling to retain
profitability and we doubt the FAA is going to propose rulemaking to make the
job any harder. To be fair, the engine factories do retain the mother lode of
detailed information on the engines they build and are often the only source of
information critical to overhauling an engine correctly. Both Lycoming and
Continental rightly point out that their factory drawings contain information
not found in overhaul manuals. On the other hand, the best field shops have been
doing nothing but overhauls for decades and we know from experience that they
know tricks the factories don't, because building an engine is not the same as
overhauling one.
It is true that a zero-time engine is different from an overhauled engine,
but only by a degree determined by how many new parts it might have and, as TCM
says, additional inspection processes. Both engines will have used or
reconditioned parts. The cold reality is that, in terms of durability, safety
and value, there's little difference between a zero-time overhaul from the
factory and an overhaul from a reputable field shop. To us, the more critical
factor is how the builder supports its work with warranty performance.
Given the product recalls from the factories — mostly recently on Lycoming
crankshafts — we don't think either OEM is in a position to claim the high
ground on superior quality control.
The bottom line? When you see a logbook with a claim of a zero-time engine,
know that, unless it's a factory-new engine, it contains used parts. Perhaps
many used parts of unknown service history.
This isn't a bad thing; nor does it mean the engine is blemished. But if you
buy an engine labeled "zero time" and expect to get all new parts, you
won't. If all new parts are important, buy a new engine.
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