Grumman AA5 series....facts versus fiction question

On Nov 15, 6:22*pm, Mark wrote:
On Nov 11, 12:37*pm, pgonzalez52 wrote:



Hi folks,

I was in the process of purchasing an AA-5A cheetah this week and
spoke with the owner about it. Pictures looked good and the specs were
reasonable for the price. Then I inquire about damage and use. NDH,
great. But then came the bombshell. I asked and he said that he sees
around 112-115 KTAS in cruise at a 23-2400ish power settings. My jaw
dropped to the floor. I asked if he had a Traveler instead of a
cheetah, he assured me a cheetah is what he has. Something is not
adding up. He was candid enough and asserted he could see me getting
120KTAS if you fly the thing wide open and he sure as heck has never
seen the book number of 127.

My question is this. I understand there is usually a difference
between stated book numbers and real numbers, but he confidently (I
appreciated his sincerity) asserted he would barely make 120KTAS with
the thing wide open, which for the purposes of this discussion was
validated by his GPS groundspeed with nominally no-wind. That is a 7-8
KTS difference from the book, more along the lines of what I would
expect to see out of a traveler, which killed *off the deal, and
formally has me even reconsidering the Grumman line.

So what's the scoop from those in the know? Are Grumman book numbers
just outright bunk? Because I know I can get 115KTAS out of a 150HP
172, been there done that. Usually a 150HP 172 will stabilize in the
112KTS range, I can take than number to the bank. That is within 3
KTAS of the book, not bad for 30 yo spam cans. But when the cheetah
book advertises 127 and you're struggling to keep 120 something is not
right.

ANybody have any experiences with the cheetah. I was looking for a
125KTAS/150HP aircraft, which is the only airspeed/engine combination
that makes it worthwhile upgrading from the capital and operating cost
of my runout 95KTAS/100HP flaking paint Cessna 150. If I wanted a
115KTAS I could go with a 150HP 172 and have more wide service support
for the same money, yet it's not worth spending 2.5x the money to get
an additional 15kts. I was considering the Traveler line, but if the
cheetah numbers are so skewed, that means the traveler is really a
105KTAS aircraft, meh..

Thanks for the feedback

Probably that is performance specific to that
individual plane, due to any number of reasons.

Only gathering data from numerous other individuals
with identical craft could give you a real picture.

Buyer beware.

---
Mark

Which is why I walked away from that aircraft. My concern is that
those numbers are all too low for the RPM and altitude he stated
(2400/ 4500') when compared to the book figures. Since I am unfamiliar
with the performance of the AA-5X lines but have more extensive
experience in the C-1/2XX and PA-28(x)-xxx arena, my experience is
that the piper and cessna numbers are usually less than book for the
majority of aircraft out there, to account for things like engine
compression and wheel/airframe fairings missing, but never by more
than 4-5KTAS. To have an aircraft true in excess of 10 KTAS below book
for a given power setting (60% in this case, with a cruise prop no
less) is cause for skepticism. I read somewhere a traveler owner with
a freshly overhauled engine was getting 108ktas at 75% power, that's
12ktas below book number. On a lighter note, it's as if the good folks
at Grumman mislabeled their MPH charts in KTAS.

If anybody has any experience with AA-5 and wouldn't mind posting some
numbers I'd appreciate it. Also, I'd like to open up the scope of the
question and get some feedback on what you all would consider the best
bang for the buck for my mission profile, which is: beating up the
pattern weekly/local buzz flying, and for trips 2 people onboard total
and bags to 200nm radius, and once or twice a year a trip of no more
than 600nm radius.

I'd like to spare the insurance and cost expense of retracts and
constant speed props, so I rather stick with fixed gear. Would also
like to take advantage of lower operating costs of a o-320 versus an
o-360 (unless I've overestimated the cost differential) and the
ability to use 87 octane mogas (biggest price differential when
compared to 96/100 octane mogas or 100LL avgas).

My C-150 fills the local flying quite well but the cross countries
with the wife are painful. 200nm are OK but in any kind of weather it
gets beaten around too much, rather flimsy for even the lightest IFR
use, specially compared with the sturdy 172s and pa-28-140/160/180s I
used during my instrument training days. So i've looked at the cessna
172 ($$$), the pa-28-140 (one door, cramped, 110TAS), and the grumman
lines (nobody can give me a straight answer on their true cruising
numbers). If there's anything there I've missed I'd love to hear about
it. Also any further plugs for the aforementioned models that I've
mentioned is welcome. Thanks!