MT Prop Take Off Roll…
December 30, 2014
For those that are interested in the MT, here is a quick clip from this weekend. Nothing too mind bending as I had my Dad and didn’t want to get him nervous with the stall warning all blaring on T/O. At any rate, it was me, my Dad, full fuel (444lbs) at 2635 GW. Pretty good at just over 500′.
December 22, 2014
Well, she’s on… Was already to give her a test this weekend but was hobbled with snow and crap WX here in New England. Fingers crossed for tomorrow.
The primary reason I pulled the trigger on the MT was to save some weight and move the CG back, so I was obviously anxious about the data.
In the end, the MT spinner (with 2 coats of added single stage color) was actually 1 lb heavier than the stock Mac I removed. Total taken off was -59lbs, total added was +46lbs, so the net savings was a paltry 13lbs. For sure this was an expensive 13lbs, and we all know the folks who say “Just toss survival gear in the back.” True indeed, but the fact is oz’s = lbs, and although not the 20-25 suggested, 13lbs is 13lbs.
As for CG: The prop lives at -40″ of arm, so in the end, the loss of the 13 moved the empty CG aft 0.54″. Epic? Not really…
What happens to the A/C CG empty is merely interesting. The real marker is what happens when calculated as light as you would ever conceivably fly… single pilot, reserve fuel, rear seats, and perhaps even front pax seat removed. The “theory” people talk about is to set up the A/C as light as possible w/ the CG as legally forward as possible so you can stuff her full and never worry about busting aft.
In my case, with me behind the wheel and 11 gal of fuel (45 min of reserve at a conservative 15gph) the movement difference of CG between the stock prop and the MT is still only 0.50″.
To put that into perspective, (with the stock prop on,) I could have gotten the same effect by tossing 12 lbs in the extended baggage. The argument for the proverbial “bug-out-bag.”
The net/net…. I removed 13lbs on the nose to avoid 12 lbs in the extended baggage. A ton of cash for an otherwise easy fix, but then again, that would have meant an additional 25lbs, and 25lbs is 25lbs.
Hopefully I’ll get her up in the air tomorrow and have a better all around feeling for the swap. Fingers crossed for a performance inducing smile.
On Goes the MT…
December 8, 2014
Well, the jury is in… I hung the 2 blade MT on the scale and got the hard number. W/out oil, the 2 blade MT came in a CH above 41lbs. I didn’t weight the spinner/backing plate as I’m prepping for paint, but Im hoping its the same or just a bit lighter than the 4 lb stock.
So all in, it looks like the net savings over the 82″ McCauley 2A34C20390D is only 14lbs, which is a far cry from the 20-30 that gets kicked around the old world-wide-super-web-internet-network. Of course this is still a well needed savings at -45″ of arm so I’m not complaining yet. I will run the numbers tomorrow and see just how much the CG walks back, but all I have to say is the performance upgrade better be substantive, otherwise its gong to be an expensive 14 lbs. Fingers crossed…
Off Comes the McCauley…
December 6, 2014
Hit the 100hr mark since I started flying the wagon so it was time for the 4th oil change… Also pulled the stock prop today in prep for the MT.
I weighed the 82″ McCauley 2A34C20390D and she was lighter than the 64lbs the Flight Resources website claims. The blade w/out oil came in at 55lbs. The spinner, backing plate, and fasteners were 4lbs. I will weigh the MT and spinner tomorrow.
I was looking forward to the 18lb savings advertised, but I’m starting to think this “magical” super weight savings is a bit of hyperbole. We will see…
(flight resources advertising material)
November 3, 2014
Got the prop gov back from the shop… Pulled it as it was getting a bit wonky and as the thing hadn’t been overhauled since 99 it was about time. Figured if I’m upgrading the prop I’d better get it all perfect… Love that old Garwin!
I had Aircraft Accessories do the work in Tulsa and they really did an amazing job. p
Prop came last week… Now just gotta get the time to swap em out!
MT on the Way…
October 22, 2014
Been flying the piss out of the old girl lately, but ran into a stumbling block that has had me grounded for two weeks with a bad prop gov. Sent the old Garwin out for overhaul which got my wheels turning….
Regrettably, I fell victim to temptation…..
Which prop did I go with? The STC only covers a two blade for the stock O-470 so its the only real option, but for me, it was really the better choice anyway. The two blade pulls a bit harder, is cheaper, and is lighter than the three blade. The jury is out on exactly what the weight savings is going to be. Time will tell indeed….
Tail Up, Missing the Point…
December 13, 2012
I wrote a blog post the other day about the height off the deck of my prop when in flight attitude. The measurement was interesting with respect to how much clearance you have for a “tail up taxi.”
I also created a thread on the BCP board and the C170 board. It was interesting to see the different thread migration, but on the C170 board, there was a visceral response.
There was a lot of, “I would never,” and “this and that are stupid…” and “I don’t go outside because I’m afraid of traffic…” I guess what was disappointing was seeing the narrow mindedness of some opinions clouding point that I was trying to make. To me, as a low time tail wheel pilot, and an even LOWER back country pilot, this was interesting data. Data that would be good for all of us to keep in the backs of our heads.
When I was learning to fly tail, I did a number of high speed taxi exercises from one end of the numbers to the other. In fact I still do it. Keeps me sharp. When I started landing in the grass and was bouncing the hell all over the place, I would often cringe thinking that the wheel landing was going to bugger the prop. My instructor kept saying, “don’t worry…plenty of room.”
As the hook sunk deeper and I started aspiring to operate in the really rough, my questions again came to the surface… How much clearance did I had between bushes, bumps, berms etc… How tall was too tall?
With the C170 project, I gained quite a bit of height adding the larger tires and C180 gear. When I transferred the tires over to the Skywagon, I grabbed a before and after measurement, and in going from 6.00×6 to the 8.5x10s, I gained 5 inches over stock at the axles, with a total 3 point deck to prop clearance of 30″. But what about the wheel landing? How much clearance then?
A weight and balance on a tail dragger is a perfect time to grab this measurement. As it’s already in flight attitude, all you have to do is run the tape. In my case, leveled out as if in a perfect wheel landing, I had 18″ from deck to prop tip.
Now I know that taxiing around with the tail up could, by some, be seen as courting disaster. There are several vids on the web with guys digging holes in the tarmac with their props after showing off, but for every one of those, there are ten of a TW pilot looping his airplane simply trying to land. Net net… Flying is dangerous. But that wasn’t the point of my post. The point of the post was to open one’s mind to the outside parameters of the “safe zone.”
Getting as much data about your machine and your flying helps you become a better pilot. Thinking outside the box, at least in principle, helps us become better. And better, makes us safer, and thereby allowing us to have more fun.
And if you taxi every once and a while with your tail up and crack a bit of a smile… Well maybe that’s ok too.