STOL twins

Could I safely assume that STOL mods on the Twinkie (and others) wouldn't exactly take care of accelerate-stop and single engine-climb concerns, like additional HP would? Isn't that what makes the Aztec preferable to the Twinkie (as an example) in some ways even though it is outperformed in others?
 
i never went to school for the 421 and still got insured as PIC on a pt. 135 certificate. I did have about 50 hrs of dual though from the chief pilot.
 
bbchien said:
Well, I will agree that they are DEAFENING. The TriIslander is also a vibration atrocity as you can never get all three in sync.
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Trislander? Poor man's DC-10. I've flown in one of those, too. Pretty weird - but the noisiest flying machine I've been in was one of the old (Piasecki?) "Flying Banana" helicopters. Coudn't wait to get out of that thing.

Back on the subject of STOL twins, I understand that a Beech 18 preceded the Islander where I encountered it. One of those could probably be had for the price quoted - but the operating expenses might be out of sight.

Dave
 
tonycondon said:
i never went to school for the 421 and still got insured as PIC on a pt. 135 certificate. I did have about 50 hrs of dual though from the chief pilot.
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I checked out on the 402 A-C Single Pilot 135 for my first 400 series. I didn't have to go to school either. The insurance companies seem to treat 135 different than 91. Then I started flying a 421 for a private owner. Then all o a sudden the insurance company required school for the 421. Same insurance company for both operations too.
 
A 421 might be cheap to buy, but a cheap one won't be cheap to operate.

I still say 337, turbo, with Horton STOL. Do the aft cooling mod if you're really worried about it.

The price is right, the mx reqmts are overstated.

Is there a BN that has less than 10,000 hours anywhere in the world? Talk about ridden hard and put away wet!!!
 
alaskaflyer said:
Could I safely assume that STOL mods on the Twinkie (and others) wouldn't exactly take care of accelerate-stop and single engine-climb concerns, like additional HP would? Isn't that what makes the Aztec preferable to the Twinkie (as an example) in some ways even though it is outperformed in others?
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Well, it depends on the aspect. The STOL mods will help the accelerate-stop since your accelerate is to a lower speed, and therefore your accelerate-stop roll will be shorter. The single engine climb rate probably depends on the STOL mods, but my feeling is that power is going to be more preferable there. The Twinkies may be relatively light, but still don't have much power. The Aztecs actually do have single engine climb rate, but in most piston twins if you lose an engine after takeoff you'll be hurting. To me, the real advantage is that if an engine fails at altitude, you'll be likely able to maintain altitude (although not if your MEAs are in the 12,000 ft range) and get to an airport.

The Aztec is a good enough STOL performer that it doesn't seem like there's much out there in the way of additional STOL kits. The VGs claim to reduce Vmc by 8 mph and Vs by 9 mph. I'm not sure how much of that really translates into better climb rate, especially single engine climb, and unless Vyse changes substantially you'll still need to accelerate to that speed before you get some sort of appreciable climb rate. When I'm flying my Aztec, I generally accelerate to Vyse on the takeoff roll before the wheels leave the ground. I also fly out of runways that are way longer than the Aztec needs.

I think that the Aztec would be a good performer for you, but you may want to seriously look into a turbo Aztec considering the altitudes you're planning on flying at. Even I find myself wishing that I'd bought a turbo Aztec. Actually, I really find myself wishing Piper had put the PA-41P (pressurized Aztec) into production.
 
flyersfan31 said:
A 421 might be cheap to buy, but a cheap one won't be cheap to operate.
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I also wouldn't think it to be the best short field performer with its heavy weight and high speeds.

Cheap they ain't, but they're a good value if what it does is what you need.
 
LearDriver said:
I checked out on the 402 A-C Single Pilot 135 for my first 400 series. I didn't have to go to school either. The insurance companies seem to treat 135 different than 91. Then I started flying a 421 for a private owner. Then all o a sudden the insurance company required school for the 421. Same insurance company for both operations too.
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Look at the difference in premiums, says it all.
 
Ted DuPuis said:
Well, it depends on the aspect. The STOL mods will help the accelerate-stop since your accelerate is to a lower speed, and therefore your accelerate-stop roll will be shorter.
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Ted, think again. Accelerate-stop is to Vyse, no matter what the mods do.

Do the mods lower Vyse?
 
bbchien said:
Ted, think again. Accelerate-stop is to Vyse, no matter what the mods do.

Do the mods lower Vyse?
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Oops, you're right. I was thinking in terms of the speed you'd lift off if the mods changed that.

As I said, I accelerate to Vyse before liftoff, but on a 2200 ft strip at 4000 DA, I wonder about that being possible.
 
Ted DuPuis said:
I also wouldn't think it to be the best short field performer with its heavy weight and high speeds.

Cheap they ain't, but they're a good value if what it does is what you need.
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STOL and Cessna 421 don't really belong in the same sentence. I never like operating off less than 4000 feet.
 
tonycondon said:
STOL and Cessna 421 don't really belong in the same sentence. I never like operating off less than 4000 feet.
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Now if only you could strip out a couple thousand pounds of weight and put a STOL kit on it, that 750 hp would probably work out pretty nicely. :)
 
Ted DuPuis said:
Now if only you could strip out a couple thousand pounds of weight and put a STOL kit on it, that 750 hp would probably work out pretty nicely. :)
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or just bolt the GTSIOs to your aztec. you are coming up on TBO, right?? :)
 
tonycondon said:
or just bolt the GTSIOs to your aztec. you are coming up on TBO, right?? :)
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Yeah, left engine will need a top soon and the right engine is 350 from TBO. Hmm... :D
 
Ted DuPuis said:
Also, as far as I'm aware, the "factory" setup was factory from Piper, not Lycoming. Piper did this in a few cases, buying engines and then bolting on the turbos.
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Yup, and it was actually an STC even if it was done at the (Piper) factory. Cirrus is the same way today.

Agreed. I'm a fan of the manual wastegates personally, but you do have to remember which levers to move. For cruise purposes, I'd probably run the engines around 24" normally, so figure above 6,000 ft you're moving the wastegates and not the throttles. To get your 30" for takeoff at 4,000 ft you'd need to have them going a bit, and that could get a bit confusing.
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Agreed - That's why I would just fly it as if it were normally aspirated for takeoff whenever the runway was long enough. Otherwise you'd pretty much need to stop it on the runway, go to full throttle, set the turbos, and then release the brakes. Your props won't like you. :nono:
 
bbchien said:
Ted, think again. Accelerate-stop is to Vyse, no matter what the mods do.

Do the mods lower Vyse?
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Yes, in the case of the Twin Comanche at least. With the R/STOL kit, the Twinkie's Vyse is reduced from 110mph to 95mph, and Vmc is reduced from 90mph (or 80 if it has counter-rotating engines) to 75mph.
 
flyingcheesehead said:
Agreed - That's why I would just fly it as if it were normally aspirated for takeoff whenever the runway was long enough. Otherwise you'd pretty much need to stop it on the runway, go to full throttle, set the turbos, and then release the brakes. Your props won't like you. :nono:
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I would suspect that if you flew a plane in and out of ceratin conditions regularly, you could figure out a rough location that would give you what you needed, and just leave the wastegate levers there. Then put the props forward and, if you had to, pull them back a bit to prevent overboost. So in practice it probably wouldn't be too big of a problem. Still, definitely not ideal, and I was not previously aware of the booststrapping issue that Lance mentioned.
 
I don't know why anyone would prefer a manual wastegate. :dunno:
 
I guess we can throw levers in there with buttons. :D
 

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tonycondon said:
more levers
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+1000

My favorite thing about a twin: I have 6 levers plus flaps and gear to manipulate. The only thing better would be having 8 levers, flaps, gear, slats...
 
Everskyward said:
I don't know why anyone would prefer a manual wastegate. :dunno:
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I guess they'd look pretty good to this guy...

ernpopboilers.jpg



Trapper John
 
So that's why your jet only has two levers... now it makes sense!

I got in a plane with two knobs the other day. I kept on asking where the other four engine controls were, plus the gear.
 
flyersfan31 said:
A Pinto Rallye?????
:rofl::rofl::rofl::rofl:


The triumph of marketing over reality!!!!
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Off topic, but: You can add the Yugo to that list as well. Malcom Bricklin did an incredible job of selling dealers, and the American public, a bill of goods.

Fascinating story in the book The Yugo: The Rise and Fall of the Worst Car in History by Jason Vuic.
 
Ted DuPuis said:
So that's why your jet only has two levers... now it makes sense!
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Exactly. And the Sovereign which is a "modern" plane has many fewer switches to manipulate than either the Lear or the Hawker. Of course there is also more programming to do...
 
flyingcheesehead said:
Yes, in the case of the Twin Comanche at least. With the R/STOL kit, the Twinkie's Vyse is reduced from 110mph to 95mph, and Vmc is reduced from 90mph (or 80 if it has counter-rotating engines) to 75mph.
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Now that's worth something!
 
tonycondon said:
or just bolt the GTSIOs to your aztec. you are coming up on TBO, right?? :)
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Hah, I know where there's a couple of low time GTSIOs that might not be missed for a long time if you can pull them off in the dark when nobody's looking.:D
 
Everskyward said:
I don't know why anyone would prefer a manual wastegate. :dunno:
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See post 58. :yes: ;)

The Seneca's fixed wastegate scares the crap out of me. One botched go-around or engine-out drill and you're buying new engines. :hairraise: It's quite possible to trash engines on fixed gates as well, but not nearly as easy IMHO.
 
gismo said:
Hah, I know where there's a couple of low time GTSIOs that might not be missed for a long time if you can pull them off in the dark when nobody's looking.:D
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Hey, that'd work! I'd even take a couple of TIO-541s or TIGO-541s. 425 hp a side on an Aztec... yummy...
 
flyingcheesehead said:
See post 58. :yes: ;)

The Seneca's fixed wastegate scares the crap out of me. One botched go-around or engine-out drill and you're buying new engines. :hairraise: It's quite possible to trash engines on fixed gates as well, but not nearly as easy IMHO.
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I wasn't comparing a manual wastegate to a fixed wastegate but to an automatic one.
 
flyingcheesehead said:
See post 58. :yes: ;)

The Seneca's fixed wastegate scares the crap out of me. One botched go-around or engine-out drill and you're buying new engines. :hairraise: It's quite possible to trash engines on fixed gates as well, but not nearly as easy IMHO.
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Only if you have ham fists. I'm on my third and fourth engines, which made TBO. NOT GOOD ON A RENTAL LINE, though!!
 
Everskyward said:
I wasn't comparing a manual wastegate to a fixed wastegate but to an automatic one.
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I'm not as familiar with the automatic ones, but would you be able to effectively "turn them off" like you can with the manual ones? That seems to me to be the principal advantage of manual. Well, that and the manliness of having eight knobs on your throttle quadrant. ;)

bbchien said:
Only if you have ham fists. I'm on my third and fourth engines, which made TBO. NOT GOOD ON A RENTAL LINE, though!!
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Yep - If I owned a Seneca, I could probably get used to it. But I don't, so I'm gonna continue to be a bit apprehensive about pushing the throttles in the PA-34. You saw that firsthand. ;)
 
flyingcheesehead said:
I'm not as familiar with the automatic ones, but would you be able to effectively "turn them off" like you can with the manual ones? That seems to me to be the principal advantage of manual. Well, that and the manliness of having eight knobs on your throttle quadrant. ;)
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Why would you want to "turn them off"? You need to be somewhat careful about not advancing the throttle too quickly and you might not end up with it all the way in to the stop, but otherwise it's no problem at all.
 
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