From: prang@ssc-vax.boeing.com (Ron Wanttaja)
Newsgroups: rec.aviation
Subject: Re: kitplanes (glasair, adventure air)
Keywords: kitplanes, new plane
Date: 14 Apr 92 05:49:36 GMT
Distribution: usa
Organization: Boeing Defense and Space Group, Seattle WA

In article <1992Apr11.205458.9678@dartvax.dartmouth.edu>, springs@wings.dartmouth.edu (David Fisher) writes:
> 
> Hi.  I am, for the second time in two years, trying desperately to convince  
> myself that I don't want to buy a plane kit.  (*major* smiley here...) 
> Anyway, I was doing just great, until I read in two different mags about an  
> amphibious airplane from Adventure Air, and about the Glasair series.
>
> So, on to the questions:
> 
> 1)  Does anyone have information on Adventure Air other than that in Feb. 92  
> issue of Kitplanes?  Are they for real?  The kit sounds almost too  
> good to be true.

Must have been some other rag, since my Feb '92 issue of Kitplanes doesn't
have anything on them.   I'll second Bret Marquis' recent comment:  If you
have any doubts about your ability to build an airplane, wait until a
half-dozen or so *owner-built* models are flying.

>2) This is probably obvious, but is there an STC available for autogas on the  
> Lycoming 320-E series?  Both the Glasair and Adventurer recommend that engine.

If you're installing the engine in a homebuilt, you can legally run the
engine on anything.  No STC is required.  However, you'll want to pick one
of the O-320 models that are designed for 80 octane rather than 100LL.

> 3) To any people out there who use amphibians, what are the "hidden" costs  
> involved with owning/operating an amphibious airplane? 

I know a couple of guys with homebuilt amphibs... here's what I gather:

1.  Beware the "recommended" engine.  My friend with an Osprey has a
quandary... he installed the O-320 the designer recommends.  Yet he can't
strike a compromise between water and air performance.  He's been through a
number of props.  Those that give him decent (i.e., anywhere near book)
cruise speeds won't get him off the water.  Those that get him off the
water won't let him cruise.

What he *really* needs is a constant-speed prop... highly unlikely, for a
pusher.  He probably should have installed an O-360.  But the book says an
O-320 will do just fine...  

Note that that Osprey has a lower gross weight than the Adventurer.  And
the same engine.  Have them show you the performance before you buy.

Rumor has it that the Sea Hawker suffers from the same problem.  If I were
building an amphibian I would plan on using the largest engine allowed.

Besides, the Adventurer is a new design.  Take a look at the number of 
homebuilts that eventually upgraded their engines.  In most cases, the
designer initially picks a small engine to try get more bang for the buck.
But usually they end up upgrading to get decent performance.  Here's a 
few examples:

Aircraft            Original Engine          Current Standard
---------           ---------------          ----------------
Glasair              115 Lyc                  150-180
Lancair                 "                        "
Avid Flyer           40 HP Cuyuna             65-80 HP Rotax
Kitfox               40 HP Pong Dragon            "
Vari-Eze             50 HP VW                 100 HP Cont/115 HP Lyc
Quickie (2 seat)     50 HP VW                 100 HP Cont.
Zenair Zodiac        50 HP VW                 80 HP Rotax
Protech PT-2         50 HP VW                 150 HP Lyc (!)
Murphy Rebel         65 HP Rotax              115-150 Lyc 

You get the idea.  Some engines were upgraded as better ones come along...
the Rotax 912, to be exact.  But in every case, the horsepower was upped as
well.

So if you go with their initial "recommended" engine, you may end up
underpowered.

2.  To paraphrase Ben Johnson, "Flight testing an amphibian has all the
pitfalls of flight testing any homebuilt, with the additional prospect of
drowning."

Groundloop an RV-4 and you'll get embarrased and maybe ding a wingtip.
Waterloop an amphibian, and (if you live) you'll soon be fishing for it
with a grappling hook.

3.  On a related note, the insurance premiums for amphibians are REAL
steep.

4.  You may not be able to land where you want... many lakes ban aircraft.
And you'll probably still end up flying to the regular airports to buy
gas.

I've got nothing against amphibians.  But there are enough drawbacks to
make one consider.  Make sure you really *want* one before expending years
and $$$ building one.

                                          Ron Wanttaja
					  prang@ssc-bee
					  ...rutgers!uw-beaver!ssc-bee!prang
                                          prang@ssc-bee.boeing.com