STOL twins

alaskaflyer said:
Nice. This sounds like something that might work very well for my mission, so long as I'm realistic about ifr altitudes.
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If you add turbos, that opens up a lot of possibilities. If you're looking at operating in Montana, it might be a good thing to consider.
 
A Pinto Rallye?????
:rofl::rofl::rofl::rofl:


The triumph of marketing over reality!!!!
 
Ted DuPuis said:
If you add turbos, that opens up a lot of possibilities. If you're looking at operating in Montana, it might be a good thing to consider.
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Yep - There are occasionally Turbo STOL's available. In fact, about 4 months ago there were three of them on the market - Now I don't see any.
 
flyingcheesehead said:
Yep - There are occasionally Turbo STOL's available. In fact, about 4 months ago there were three of them on the market - Now I don't see any.
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Yeah, given the area that he's looking at, I would consider turbos to be a good idea. STOL will definitely help, too.
 
alaskaflyer said:
So, what are thoughts about (relatively) affordable NA twins that have relatively good short field performance compared to others?

We can leave out the twin Otter please, and since I put NA I don't mean the King Air, which, yes, for all of its other attributes has pretty darn good short field performance. I'm talking sub-$150k aircraft that are good cross country machines...

I see stories of Seneca II's in and out of all manner of grass strips on here :lol:
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Britten-Norman Islander perhaps? I've ridden in them as a passenger, and can testify to their suitability for the role. That said, I've done the same in a Skymaster - which does quite well also. As others have said, you'd have a hard time finding more performance for your money than with a Skymaster.

Dave
 
Pilawt said:
I had one, a '72. I loved driving it ... until the head gasket blew at 35,000 miles. :(
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Sorry about the thread hijack here....GM mated an aluminum block to a cast iron head. All the engines were dead by 50,000 miles. All of 'em. Just think about the metal expansion issues with heat. The hoods rusted. The exhausts lasted about 12,000 and it sounded like a motorboat.

Those things were NOT victims of bad owners. The owners were victims of bad companies. RIP my 1972 Vega.
 
flyingcheesehead said:
Yep - There are occasionally Turbo STOL's available. In fact, about 4 months ago there were three of them on the market - Now I don't see any.
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Are most of the Turbo Twinkies modified from the original Rajay turbos?
 
bbchien said:
Aw man, I was thinking this one....
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Hey now, don't diss the Vega!

What other engine had torque specifications in in-lbs for tightening the head?

(I learned to not give your cousing the engine rebuilder the beer until AFTER he finishes the job when he overtorqued and stripped out a head bolt on my '77 Vega wagon.) Gotta love aluminum!
 
dmccormack said:
Well, maybe not most...


ford-pinto-parts.jpg
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bbchien said:
Aw man, I was thinking this one....
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As was I.

The Pacer ranks right up there, too.

1975_AMC-Pacer_Pic.jpg


along with this:

4x4yugo.jpg
 
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cessna182b said:
Britten-Norman Islander perhaps?
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Someone sent me the following recently about the Islander: :D

Undaunted by aerodynamic reality, the design team at Pilatus/Britten-Norman has announced plans for the BN2-XL (Extra Loud), promising more noise, reduced payload, a lower cruise speed, and increased pilot workload.

We spoke to Mr. Fred Gribble, former British Rail boilermaker and now Chief Project Engineer. Fred was responsible for developing many original and creative design flaws in the service of his former employer, and assures he will be incorporating these in the new BN2-XL technology under a licensing agreement.

Fred reassured BN-2 pilots however that all fundamental design flaws of the original model had been retained. Further good news is that the XL version is available as a retrofit.

Among the new measures is that of locking the ailerons in the central position, following airborne and simulator tests which showed that whilst pilots of average strength were able to achieve up to 30° of control wheel deflection, this produced no appreciable variation in the net flight path of the aircraft.

Thus the removal of costly and unnecessary linkages has been possible, and the rudder has been nominated as the primary directional control. In keeping with this new philosophy, but to retain commonality for crews transitioning to the XL, additional resistance to foot pressure has been built into the rudder pedals to prevent overcontrolling in gusty conditions (defined as those in which wind velocity exceeds 3 knots).

An outstanding feature of Islander technology has always been the adaptation of the 0-540 engine, which mounted in any other aircraft in the free world (except the Trislander) is known for its low vibration levels, so as to cause it to shake and batter the airframe, gradually crystallise the main spar, desynchronise the accompanying engine, and simulate the sound of fifty skeletons fornicating in an aluminium dustbin.

Britten-Norman will not disclose the technology they applied in enhancing this effect in the XL, but Mr. Gribble assures us it will be perpetuated in later models and sees it as a strong selling point; "After all, the Concorde makes a lot of noise," he said, "and look how fast it goes."

However, design documents clandestinely recovered from the Britten-Norman shredder have solved a question that has puzzled aerodynamicists and pilots for many years, disclosing that it is actually noise which causes the BN-2 to fly. The vibration set up by the engines and amplified by the airframe, in turn causes the air molecules above the wing to oscillate at atomic frequency, reducing their density and causing lift. This can be demonstrated by sudden closure of the throttles, which causes the aircraft to fall from the sky. As a result, lift is proportional to noise rather than speed, explaining amongst other things the aircraft's remarkable takeoff performance. In the driver's cab (as Gribble describes it), ergonomic measures will ensure that long-term PBN pilots' deafness does not cause inflight dozing. Orthopaedic surgeons have designed a cockpit layout and seat to maximise backache, enroute insomnia, chronic irritability, and terminal (post-flight) lethargy. Redesigned 'bullworker' elastic aileron cables, now disconnected from the control surfaces, increase pilot workload and fitness.

Special noise retention cabin lining is an innovation on the XL, and it is hoped in later models to develop cabin noise to a level which will enable pilots to relate ear pain directly to engine power, eliminating the need for engine instruments altogether.

We were offered an opportunity to fly the XL at Britten-Normans' developmental facility, adjacent to the Britrail tea rooms at Little Chortling. (The flight was originally to have been conducted at the Pilatus plant, but aircraft of Britten-Norman design are now prohibited from operating in Swiss airspace during the avalanche season).
For our mission profile, the XL was loaded with fossil fuel for a standard 100 nm with Britrail reserves, carrying one pilot and nine passengers to maximise discomfort.

Passenger loading is unchanged, the normal under-wing protrusions inflicting serious lacerations on 71% of boarding passengers, and there was the usual entertaining confusion in selecting a door appropriate to the allocated seat.

The facility for the clothing of embarking passengers to remove oil slicks from engine cowls during loading has also been thoughtfully retained.
Startup is standard, and taxying, as in the BN-2, is accomplished by brute force. Takeoff calculations called for a 250 decibel power setting, and the rotation force for the (neutral) C of G was calculated as 180ft/lbs of back pressure.

Initial warning of an engine failure during takeoff is provided by a reduction in flight instrument panel vibration. Complete seizure of one engine is indicated by the momentary illusion that the engines have suddenly and inexplicably become synchronised. Otherwise, identification of the failed engine is achieved by comparing the vibration levels of the windows on either side of the cabin. (Relative passenger pallor has been found to be an unreliable guide on many BN-2 routes because of ethnic considerations).

Shortly after takeoff the XL's chief test pilot, Capt. "Muscles" Mulligan, demonstrated the extent to which modem aeronautical design has left the BN-2 untouched; he simulated pilot incapacitation by slumping forward onto the control column, simultaneously applying full right rudder and bleeding from the ears. The XL, like its predecessor, demonstrated total control rigidity and continued undisturbed.

Power was then reduced to 249 decibels for cruise, and we carried out some comparisons of actual flight performance with graph predictions.
At 5000' and ISA, we achieved a vibration amplitude of 500 CPS and 240 decibels, for a fuel flow of 210 lb/hr, making the BN-2 XL the most efficient converter of fuel to noise since the Titan rocket.

Exploring the constant noise-variable speed and constant speed-variable noise concepts, we found that in a VNE dive, vibration reached its design maximum at 1000 CPS, at which point the limiting factor is the emulsification of human tissue. The catatonic condition of long term BN-2 pilots is attributed to this syndrome, which commences in the cerebral cortex and spreads outwards.

We asked Capt. Mulligan what he considered the outstanding features of the XL. He cupped his hand behind his car and shouted. "Whazzat?"
We returned to Britten-Norman field convinced that the XL model retains the marque's most memorable features, while showing some significant and worthwhile regressions.

Pilatus/Britten-Norman are however not resting on their laurels. Plans are already advanced for the three-engined Trislander XL, and noise tunnel testing has commenced. The basis of preliminary design and performance specifications is that lift increases as the square of noise, and as the principle of acoustic lift is further developed, a later five-engined vertical takeoff model is another possibility.
 
Well, I will agree that they are DEAFENING. The TriIslander is also a vibration atrocity as you can never get all three in sync.
 
wsuffa said:
As was I.

The Pacer ranks right up there, too.

1975_AMC-Pacer_Pic.jpg


along with this:

4x4yugo.jpg
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Jeez, ya'all were never in the car biz... The Pacer was also a great car. They were fat people specials as the pax door was 6" longer and 4" taller (wrapping into the roof) for ease of entry and exit from the back seat. I had one traded in and when it rolled up, 1500lbs of human flesh rolled out of it and that car had over 200,000 miles on it. The seats were in bad shape, but we sealed the doors and hatch with Liquid Nails, cut a hole in the roof, put the ignition switch under the hood and drove that car around with our scuba gear filled with water and 300 goldfish. The windows never blew out or anything. That car could take more weight than an F-250 and had no blind spots. It was so good in fact that Porsche copied it and built the 928 which was inferior in nearly every aspect.

The Yugo, what can you say about a car you could buy new for under $4000? The closest new econobox competitor was near twice that. Mine made 120,000 miles with no service (I never even change oil) except 3 sets of tires and got over 40mpg (figure avg price of gas back then was $1.00 gal, although it was a bit less). Insurance for me at 20 yrs old was $200 a year in CA, (again, much cheaper than anything else I could buy for $4k by several hundred dollars a year) and I flogged that car for near 3 years. I operated that car in the late 80s-early 90s for less than 6 cents a mile all in. Name me another car that could touch those numbers.... I'm brutal on cars and it made >120,000 miles of hard driving in SoCal and several cross countries including Death Valley mid summer mid day and crossing the Rockies and was running when I got rid of it for $200. As far as a company, Yugo sponsored the US Olympic Volleyball team in 88 when no US company would.
 
TMetzinger said:
Hey now, don't diss the Vega!

What other engine had torque specifications in in-lbs for tightening the head?

(I learned to not give your cousing the engine rebuilder the beer until AFTER he finishes the job when he overtorqued and stripped out a head bolt on my '77 Vega wagon.) Gotta love aluminum!
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We used to buy Vegas at the auction by the load for $20 a piece, steel sleeve and ring them and mill .040 off the head and they were some runners we'd sell for $750 each making $600 a piece off them for 3 days worth of work. When I'd get a GT with a good body, Don Hardy would get a call and a chassis kit would be ordered and another V-8 Vega would be born. The best deal I had was a '75 Cosworth Vega rolled into the auction line and the wheels caught my eye. Nobody else looked at it, I opened the hood just far enough to peak in and see the DOHC head and set it back down. The bidding started at $200 with no bidders and went down to $50 when I bid on it, and I was the only bidder (they were rare enough that most people didn't know the Cosworth Vega even existed and by the late 70's most dealers didn't want anything to do with a Vega) so got it. I advertised in Hemmings for $8500 (you could buy a new Caddy for that back then) and drove it until it sold 3 weeks later for $7700.
 
alaskaflyer said:
Are most of the Turbo Twinkies modified from the original Rajay turbos?
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No. Both the factory and aftermarket turbos are the Rajays with manual wastegate controlled via vernier knobs underneath the throttle quadrant. I would suggest doing takeoffs without the turbos if it can be done safely, and feeding them in slowly as you climb out.

The nice thing with the separately controlled manual wastegates is that you can effectively leave the turbos "off" if your'e going to be doing engine-out practice or the like. Also, since power reductions are done by opening the wastegates (turning "off" the turbos) first, while still at full throttle, and then reducing the throttles, when you land the turbos should already be cooled down and you can shut down right away.

The disadvantage: You can kill your engine(s) in very short order if you screw up - There is no overboost protection. However, I don't think it's something you'd be able to screw up very easily. A Seneca with its fixed wastegate would be a LOT easier to screw up!
 
flyingcheesehead said:
No. Both the factory and aftermarket turbos are the Rajays with manual wastegate controlled via vernier knobs underneath the throttle quadrant. I would suggest doing takeoffs without the turbos if it can be done safely, and feeding them in slowly as you climb out.
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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.

The nice thing with the separately controlled manual wastegates is that you can effectively leave the turbos "off" if your'e going to be doing engine-out practice or the like. Also, since power reductions are done by opening the wastegates (turning "off" the turbos) first, while still at full throttle, and then reducing the throttles, when you land the turbos should already be cooled down and you can shut down right away.

The disadvantage: You can kill your engine(s) in very short order if you screw up - There is no overboost protection. However, I don't think it's something you'd be able to screw up very easily. A Seneca with its fixed wastegate would be a LOT easier to screw up!
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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.
 
The problem with the pusher planes configured like the Angel is rocks on the props once you leave paved runways... And if you only fly off paved runways what do you need a stol twin for?

denny-o
 
Dr. O said:
The problem with the pusher planes configured like the Angel is rocks on the props once you leave paved runways... And if you only fly off paved runways what do you need a stol twin for?

denny-o
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Really short paved runways?:yesnod:
 
LearDriver said:
The 421 gets a bad rap due to bad pilot behavior. Flown right that can be a very reliable engine. However, an owner that owns any of those airplanes has to be prepared to properly maintain them.
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There's a 421 that's been sitting on the ramp at my airport, unused, out of annual (for two years), and AFaIK not being flown at all. What's really unusual is that the plane had a recent gorgeous paint and interior job, expensive avionics upgrade and relatively recent engines. The owner can't fly it and just leaves it outside in the elements. Seems almost criminal.
 
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.



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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Ted, besides the significant potential for abuse (typical is a descent and approach to landing with the wastegates closed followed by a full throttle go around or a takeoff after landing with the pilot forgetting about the turbos... instant mega overboost), the manual wastegates have a serious problem with bootstrapping. Operating LOP is virtually impossible and even ROP it can be darn near impossible to achieve stable engine operation up high.
 
gismo said:
Ted, besides the significant potential for abuse (typical is a descent and approach to landing with the wastegates closed followed by a full throttle go around or a takeoff after landing with the pilot forgetting about the turbos... instant mega overboost), the manual wastegates have a serious problem with bootstrapping. Operating LOP is virtually impossible and even ROP it can be darn near impossible to achieve stable engine operation up high.
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Thanks, Lance, interesting info. I will rephrase, then:

"I'm a fan of the CONCEPT of manual wastegates." :)

That's more accurate having zero experience with them.
 
gismo said:
There's a 421 that's been sitting on the ramp at my airport, unused, out of annual (for two years), and AFaIK not being flown at all. What's really unusual is that the plane had a recent gorgeous paint and interior job, expensive avionics upgrade and relatively recent engines. The owner can't fly it and just leaves it outside in the elements. Seems almost criminal.
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I'll fly it around for him!!! I'll even do it for free!! :D

That is a shame though, it hurts to see so many planes rotting at the airport.
 
LearDriver said:
Don't be a whore. Never fly for free. Have some self respect, you're better than that.
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Legally he's a private pilot, so he has to pay to fly it around.
 
LearDriver said:
Don't be a whore. Never fly for free. Have some self respect, you're better than that.
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Give me a break, he's not offering to do a job for free. I'm pretty sure Bigred is not a commercial pilot and is only indulging in a pleasant fantasy.
 
WheelDetail.jpg


Dr. O said:
The problem with the pusher planes configured like the Angel is rocks on the props once you leave paved runways... And if you only fly off paved runways what do you need a stol twin for?

denny-o
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LearDriver said:
Don't be a whore. Never fly for free. Have some self respect, you're better than that.
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I fail to see the difference between flying for "free" and flying for peanuts. I'd be perfectly happy flying a few trips as PIC in that 421 or SIC in most any airplane that burns Jet A (successfully) without any compensation beyond the experience, and certainly for a whole lot less than I charge for my (non aviation) services because it would be worth it to ME. Tell me you've never considered a flying job paying less than your're really worth (which pretty much describes any flying job except a high seniority major airline pilot). Who's the whore now?:D
 
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Ahem :incazzato:

Anyway,

gismo said:
...the manual wastegates have a serious problem with bootstrapping. Operating LOP is virtually impossible and even ROP it can be darn near impossible to achieve stable engine operation up high.
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OK, I'll bite. Could you elaborate?
 
alaskaflyer said:
Ahem :incazzato:

Anyway,




OK, I'll bite. Could you elaborate?
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With an automatic wastegate, the controller will maintain a constant pressure ahead of the throttle (or in the more sophisticated versions a constant pressure drop across the throttle). With a fixed or manually adjusted wastegate the output of the compressor varies with the power produced by the engine. Unfortunately whenever something causes the power to increase that makes the turbo pump more air into the engine which makes the engine produce more power, leading to more air,, more power,, more air... The opposite happens if the engine power decreases (less power -> less air -> less power...) This is what's called "bootstrapping" in a turbocharged engine. In addition to the direct effect of the turbo, there's an indirect effect from the varying mixture as the airflow through the engine changes. Typically with TCM injection which provides the same amount of fuel regardless of the airflow a fixed wastegate is fairly stable although it can make setting the mixture a PITA because the mixture control itself affects power and turbo output which then affects the mixture. Some systems have an aneroid on the fuel pump that adjusts output with the pressure output of the turbo which helps but I doubt that most of the aftermarket manually controlled setups have that. IIRC, with the Bendix injection used on Lycomings airflow does adjust the fuel proportionately so the problem with adjusting the mixture is probably less, and that was my experience when I played with a Travel Air that had manually controlled Rajays (although I must admit I didn't understand these systems all that well back then). And if you go lean of peak the turbo output picks up very steeply with a decrease in airflow on a TCM injection system. BTW, all automatic wastegate turbo systems operate in a "fixed" mode if you go high enough that the wastegate becomes fully closed, but for some airplanes this "critical altitude" doesn't occur below the maximum altitude under normal conditions.
 
If your using the the manual waste gates to "normalize" the engine @ altitude can you still get into the bootstrap mode? In otherwords no boost until your @ WOT w/MP decreasing.

marc
 
Mxfarm said:
If your using the the manual waste gates to "normalize" the engine @ altitude can you still get into the bootstrap mode? In otherwords no boost until your @ WOT w/MP decreasing.

marc
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With an automatic wastegate controller, bootstrapping issues don't occur until you reach the "critical altitude" where the controller has fully closed the wastegate because the turbo cannot produce the airflow being called for. But with a manually controlled wastegate bootstrapping can occur at any altitude as long as you have the gate at least partially closed since there's no regulation of induction pressure. I suspect but do not know that the further you close the wastegate the more pronounced the effect can be. That could be when boosting an ambient altitude of 12k to sea level or 20k to 8k etc.
 
gismo said:
I fail to see the difference between flying for "free" and flying for peanuts. I'd be perfectly happy flying a few trips as PIC in that 421 or SIC in most any airplane that burns Jet A (successfully) without any compensation beyond the experience, and certainly for a whole lot less than I charge for my (non aviation) services because it would be worth it to ME. Tell me you've never considered a flying job paying less than your're really worth (which pretty much describes any flying job except a high seniority major airline pilot). Who's the whore now?:D
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The feds consider flying it because its worth it to you as compensation in some cases. Whether or not money changes hands is not the only criteria to determine if it was for compensation or hire. So be careful just how loudly you advertise your opportunities. It makes a good case to get the commercial added once you get 250 hours.

Getting PIC in a 421 or turbine is going to require school, high performance and a high altitude endorsement. Whichever applies. Otherwise you would never have a shot at getting insurance.

What you think you are worth and what the market place deems you as being worth are two different things altogether.
 
LearDriver said:
The feds consider flying it because its worth it to you as compensation in some cases. Whether or not money changes hands is not the only criteria to determine if it was for compensation or hire. So be careful just how loudly you advertise your opportunities. It makes a good case to get the commercial added once you get 250 hours.

Getting PIC in a 421 or turbine is going to require school, high performance and a high altitude endorsement. Whichever applies. Otherwise you would never have a shot at getting insurance.
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I'm guessing you don't know Lance's qualifications. Since he already has his commercial multi then there's no problem with what he said he'd be willing to do, and I would suspect that with the amount of time he's put on his Baron (and other planes) that he'd be a good candidate for transitioning to a 421. For that matter, even I'm insurable in a 421 (at least, that's what the insurance companies have told me) with far fewer hours and fewer qualifications. Of course the SimCom and dual is required. Either way, there's no reason why he or I couldn't tag along on a Part 91 operation and try to get some time on dead heading legs.

What you think you are worth and what the market place deems you as being worth are two different things altogether.
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That seems hypocritical. Ironic that you tell a private pilot not to be a whore and fly for free (which he can't do legally anyway) but then tell a commercial pilot that he pretty much can't get something that's perfectly attainable. You're right, though, and I have a similar attitude towards Lance on what I'll fly for free. Basically, you have to pay me to fly anything that I'm already fully qualified to fly and insurable in (or things that I just don't want to fly). I'll fly things that I want/need to build hours in for free. That's basically getting free education and insurance qualifications, so that's worth it.
 
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