Tell me all about the Grumman AA1B

Ron, you're so far off base with this AA1X thing, were not even playing the same sport.

Ether cite what makes the Grumman soo exotic and needing a guru, or step out before you dig this hole any deeper.
 
James331 said:
Ron, you're so far off base with this AA1X thing, were not even playing the same sport.

Ether cite what makes the Grumman soo exotic and needing a guru, or step out before you dig this hole any deeper.
Click to expand...
The statistics speak for themselves -- a significantly high accident rate compared to the Piper/Cessna types in the first 15 hours in type without an in-type checkout, and the fact that this difference disappears when an in-type checkout from an appropriately experienced instructor is obtained. A few people who made it through that period without such a checkout don't change the overall statistics. The same is true for many other aircraft types which don't fly like the common trainers, but there don't seem to be as many of them out there as there are Grummans, which is perhaps why folks don't get so excited about it.
 
Last edited:
Ron Levy said:
The statistics speak for themselves...
Click to expand...
These planes were bought as novelties and rented to licensed pilots who got original training in other aircraft types. The planes looked like toys and didn't command the respect they deserved. Any CFI, after an hour of self-familiarization, ought to be "checked out" enough to make sure transitioning pilots understand the planes unique characteristics. No gurus needed, just capable CFIs.

dtuuri
 
IMO, .5 to .7 doing FULL falling leaf stalls (i.e. 7k to 1500) fixes that.

I've trained plenty of folks from ZERO time in the AA1X platform.

It's just a slightly higher loaded wing and a smaller tail, any CFI worth his salt should be able to address that.

Before I logged a single minute in the AA1 I knew that Id really to do some anti-spin work with my students, just based on looking at the airframe.

Like I said, full stall series, falling leaf, accelerated, basically one lesion of just stalls will cure all of that. Any ATP/Gold Seal CFI should be more than capable of that.
 
Btw, OP, if you're still here... looking at the weights and fuel data you posted, 3/4 of the people that will fly the plane are too heavy for it. The fourth one at the upper limit, IMO. That 260 pounder can't takeoff with more than half a tank of gas. Not good. How will s/he manage that?

dtuuri
 
Ah, lovely. Back on topic from arguing. Thank you.

We're not looking for a transcontinental cruiser here. And our current aircraft is a Cessna 150. It's useful load is actually less! It doesn't seem like there is anything that will give us a remarkably higher useful load for a remarkably similar price. We don't have $20,0000 + to get something larger. So no matter what, we're not taking a full load of fuel with two people.

One of the things we're planning to do, if we decide to pursue this, is weigh the plane as part of a pre-buy. We're not small, so the real W&B really matters.
 
Last edited:
How long of a runway are you planning on flying it from? Even 3000 ft of paved runway is cutting it close at gross on a warm day. A hot day and you are flirting with disaster.
 
Pedals2Paddles said:
Ah, lovely. Back on topic from arguing. Thank you.

We're not looking for a transcontinental cruiser here. And our current aircraft is a Cessna 150. It's useful load is actually less! It doesn't seem like there is anything that will give us a remarkably higher useful load for a remarkably similar price. We don't have $20,0000 + to get something larger. So no matter what, we're not taking a full load of fuel with two people.

One of the things we're planning to do, if we decide to pursue this, is weigh the plane as part of a pre-buy. We're not small, so the real W&B really matters.
Click to expand...
A C-150 is too small also. What you want is a Cherokee 140. Lots more power and has tabs you can fuel to rather than top off or guesstimate. If you want a bargain--get a Piper Colt! Has much better useful load, is a rugged trainer and a ball to fly. Leave the right wing tank (if it has one) empty.

dtuuri
 
Really? Ok, lets go at it like this. Chances are, nowhere we go will have a density altitude greater than 3500 in the summer. What is the performance like with a DA of 3000? 2500? etc. The runway at our home base is 5200ft, with a 3600ft crosswind runway. Most places we'd ever go would be greater than 2000ft runways. We're not bush flying here.
 
Pedals2Paddles said:
Really? Ok, lets go at it like this. Chances are, nowhere we go will have a density altitude greater than 3500 in the summer. What is the performance like with a DA of 3000? 2500? etc. The runway at our home base is 5200ft, with a 3600ft crosswind runway. Most places we'd ever go would be greater than 2000ft runways. We're not bush flying here.
Click to expand...
I've got lots of time instructing in a Colt back in the 1960s and 70s. Uphill out of a 2250' paved runway with rising terrain ahead and real living trees at the end of the runway. Field elevation was 1000'. We used the Colts for all primary training because of the sturdy gear. Cessnas couldn't hack it in the summer, although I loved teaching stalls in them vs. the Colt. (Colt won't do a power-off stall unless you know how to cheat one out of it). Still have a manual upstairs, do you want me to look up anything? It has to be worth the climb, since I'm recovering from a severe ankle sprain. :sad:

dtuuri
 
Sorry, that was directed at Grum.Man regarding the AA1B, not the colt.
 
Pedals2Paddles said:
Sorry, that was directed at Grum.Man regarding the AA1B, not the colt.
Click to expand...
Not as sorry as me... I'm bored, so went and got the manuals: A 1967 C-150, a Piper Colt, an American Trainer AA-1A and an American Yankee AA-1. Anything you want to know from them?

dtuuri
 
I don't know a lot about the C150, but I will tell you this. It will tolerate an overload, or a high DA much better than the Grumman. It's not just the anemic climb rate. The Grumman has a higher wing loading, which means it has a bigger section behind the power curve. If you pull it off green(too early) they will just mush down the runway in ground effect, and pulling back more will just slow it down.

I was in SoCal when I flew ours, and I think when at gross we had a rule of 3500' runway up to 3000' DA. Maybe I got that backwards, but the key is to get the little thing really moving before pulling it off the ground. Which also means your accel-stop distance goes up dramatically.

It's a hard thing to explain until you experience it. You'll be flying along, everything is fine, then one afternoon when it's +90F, and you fill up with fuel, then do your 'normal' take off, things just won't seem right. The plane will be sitting there, about 20' just chewing up runway, not accelerating and not climbing, and you wonder; 'hmmmm, never seen this before.' The other issue that contributes to this situation is if the nose gear is suffering from any kind of shimmy(common), because the natural tendency is to hold the nose up on the takeoff run which will tend to put the wing in that reverse command region. Once the mains leave the ground early, that dog just won't hunt as we say.

The cure is to push forward and let it gain some flying speed so the wing is happier. It's counter-intuitive, but you gotta do it, or it'll just motor along until you run out of airport, and you're trucking across the marsh at about 70mph, and 20 feet. I think there's a video of this happening in an AA-5, but I haven't seen it forever.
 
dtuuri said:
Not as sorry as me... I'm bored, so went and got the manuals: A 1967 C-150, a Piper Colt, an American Trainer AA-1A and an American Yankee AA-1. Anything you want to know from them?
Click to expand...
Wow you are bored! Takeoff performance at say 3000ft DA would be lovely.
 
Last edited:
dtuuri said:
....., 3/4 of the people that will fly the plane are too heavy for it. The fourth one at the upper limit, IMO. That 260 pounder can't takeoff with more than half a tank of gas. Not good. How will s/he manage that?

dtuuri
Click to expand...

IMO 260lbs is barely considered human, unless the guy is over 7' tall.

A normal adult male human should be 6' 180lbs or less.

If you're over that, stop eating.

:dunno:
 
Pedals2Paddles said:
Wow you are bored! Takeoff performance at say 3000ft DA would be lovely.
Click to expand...
Well, the Colt takeoff distance chart looks like something is terribly wrong with it. The density altitudes aren't correct for the pressure altitude vs temperature resulting in way too much distance. So, I just gave you the Mfg stated values for SL instead. Also, the useful loads. You can use a Koch chart to predict the effect of density altitude.

TO dist to 50' @ Sea level (useful load) :
C-150.........1385 (595-Trainer)
Colt............1500 (710)
Yankee........1615 (493)
Trainer........1400 (493)​
dtuuri
 
dtuuri said:
These planes were bought as novelties and rented to licensed pilots who got original training in other aircraft types. The planes looked like toys and didn't command the respect they deserved.
Click to expand...
You're assuming facts not in evidence, and not supported by the decades of experience since then, because we're still seeing this happening with new pilots with no checkout/experience in type.
Any CFI, after an hour of self-familiarization, ought to be "checked out" enough to make sure transitioning pilots understand the planes unique characteristics. No gurus needed, just capable CFIs.
Click to expand...
"Capable" I agree with. "No experience in type" I would not, and "an hour of self-familiarization" won't do. For teaching enough to get around the pattern safely? Maybe. But for teaching a new owner/pilot everything s/he needs to know about owning and flying his/her new plane? Not a chance.
 
Last edited:
dtuuri said:
Well, the Colt takeoff distance chart looks like something is terribly wrong with it. The density altitudes aren't correct for the pressure altitude vs temperature resulting in way too much distance.
Click to expand...
I found a copy of the Owner's Manual to show what I mean. Makes me wonder how many others are also wrong (see page 35):

http://learnandfly.com/download/Piper PA-22-108 Colt - Owner's Handbook.pdf

Notice that if you enter at 84°F & 1000' PA the takeoff distance should be the same as for a DA of 3000' (see http://www.aeroplanner.com/calculators/avcalcden.cfm), but if you look left to the STD line--it's showing less than 2000'. This results in an excessive TO distance if you go the other way and enter at a DA of 3000'. :confused: I wonder if anybody ever crashed because of this? :dunno: Or maybe I'm missing something here?

dtuuri
 
Ron Levy said:
You're assuming facts not in evidence, and not supported by the decades of experience since then, because we're still seeing this happening with new pilots with no checkout/experience in type...
Click to expand...

Okay Ron, why don't you give us a link to these accident statistics that show what type of "checkout" the pilot had :dunno:
 
Pedals2Paddles said:
Really? Ok, lets go at it like this. Chances are, nowhere we go will have a density altitude greater than 3500 in the summer. What is the performance like with a DA of 3000? 2500? etc. The runway at our home base is 5200ft, with a 3600ft crosswind runway. Most places we'd ever go would be greater than 2000ft runways. We're not bush flying here.
Click to expand...

I will put it this way. In mine a couple months back I was loaded with me (185 lbs) my friend (200 lbs maybe a little more) half fuel, and a few light things in the baggage area like foldable chairs. In my AA1 we used majority of a 7,000 ft grass runway to clear the trees. There might have been 1,000 ft to spare but that would have been cutting it close. The density altitude was 3600 ft.

That morning with a density altitude of 1,000 ft. and almost full tanks we departed a 3,000 ft paved runway pretty comfortably. The AA1B should be better especially if it has a climb prop. Mine has a cruise propeller and since I fly mostly solo I never miss the climb.

Keep in mind, the climb rate of the grumman is pretty much the same as a Cessna 150 or any other 0-235 trainer. The difference is that you are covering a lot more ground at that rate. Best angle climb speed in mine is 78 mph and best rate is 89 mph. That's compared to about 55 mph and 64 mph for a 152.
 
You must log in or register to reply here.
Back
Top