Not necessarily. It turned out that twin-engine redundancy was only operative as long as the pilot was willing to maintain proficiency and practice single-engine techniques on a regular basis.

Accident statistics soon revealed that most pilots weren't so disposed. After they had earned the multi-engine rating, pilots sometimes ignored the obvious fact that the relative incidence of engine failures with a twin was twice as high as with a single. Worse still, the AOPA Air Safety Institute discovered many years later that the most common phase of flight for an engine problem in a twin was cruise, not the more obvious takeoff mode. In other words, a pilot could lose one engine on a twin in the most benign phase of flight and still not be able to bring the airplane to a safe landing.

Statistically, more pilots come to grief after losing an engine in a twin than in a single. Perhaps perversely, the very reliability of general aviation engines convinced many that there was little need to maintain proficiency during single-engine operations, since the myth was that piston engines run properly almost never failed.

The problem was that little word, "almost". Nearly all piston twins utilized engines mounted on the wings, so loss of power on one side resulted in asymmetric thrust and an obvious control problem.

The emergence of the single-engine turboprop was a logical development that improved safety and side-stepped much of the cost and operating expense of a twin. Never mind that the last, true corporate twin went out of production in the late 1980s.

Swiss Turboprop
The acknowledged top of the jetprop class, not only in price and size but in carrying capacity, is the current Swiss Pilatus PC-12NG. Introduced in 1994, the basic PC-12 has been updated and improved progressively to the current NG (Next Generation) configuration that incorporates all the innovations and technology gained from 20 years of production.

At $4,556,000 (2014 pricing), the PC-12NG comes standard with Honeywell Apex avionics, synthetic vision and a BMW eight-seat interior, but may be configured for up to 11 seats, bumping it up to the entry-level King Air class in seating capacity. The Pilatus offers cruise speeds of 280 knots and a max operating altitude of FL300 when RVSM equipped.

The PC-12NG is indeed a large aircraft. In size, it dwarfs both the TBM 900 and the Piper Meridian. Wingspan is a wide 53½ feet with Pilatus' high-lift winglets on each tip. That's also roughly three feet greater span that a twin turboprop C90 King Air. Gross weight is nearly 10,500 pounds, but Pilatus mounts a huge P&W PT6A-67P rated for 1,200 shp that can more than manage the load. The four-blade Hartzell aluminum prop is nearly nine feet in diameter to convert the Pratt's horsepower to thrust.

The PC-12 sits tall on the ramp, but the airplane's forward-left airstair door is beautifully balanced, so virtually anyone can handle it. The entry door also allows the pilot to close and lock the aft 48-inch-wide cargo door from the outside before entry. The cargo entry is designed to be loaded with a fork lift and makes it possible to carry such items as dirt bikes, kayaks and other items that won't fit in any other turboprop.

With a total capacity of 11 seats, there are a myriad of interior configurations that can accommodate forward and aft-facing seats of six to nine passengers or a quick-change arrangement that allows the airplane to be converted to pure cargo space in a half hour. The PC-12's cabin is approximately 10% larger than that of the King Air 200.

Pressurization is 5.75 psi, adequate for an 8,000-foot cabin at FL250 or a 10,000 foot atmosphere at the airplane's maximum altitude of FL300.

The PC-12NG is single-pilot approved, and most of the fleet is owner flown rather than professionally operated. That's partially because the Pilatus is almost ridiculously easy to fly. Obviously, turbine systems like the Honeywell Apex are more complex, but the basic flying of the airplane is little more complex than a Bonanza.

Range with the maximum 11 seats full at high cruise is over 1,500 nm, and max range is 1,800 nm. Fuel burn is a relatively frugal 54 gph, and with tanks topped at 400 gallons, the airplane has an endurance of more than 6.5 hours at max cruise, nine hours at long-range power settings.

The airplane perches high on a sturdy trailing beam gear system that absorbs pilot misdeeds and allows the Pilatus to land and depart again from unobstructed runways as short as 1,500 feet. Part of the reason for the airplane's minimal runway use is the unusually low stall speed, 67 knots. That's primarily a function of the huge 70% span. Fowler flaps translate aft as the trailing edge deflects down, effectively increasing the wing chord in the process. In addition, full flaps offer an impressive 47 degrees of travel.

Though the PC-12 would be an expensive bushbird, I've seen the type operating out of some unlikely strips in high Colorado (I once flew an air-to-air session out of Leadville, Colo., elevation 9,927 feet MSL). The type also is popular in Alaska and northern Canada, as well as the Australian Outback.

Super Versatile Jet
Not content to simply build one of the world's most versatile single-engine turboprops, Pilatus recently decided to enter the mid-sized twin-jet market. Last August 1, the company rolled out the prototype of the Pilatus PC-24 at its production headquarters in Stans, Switzerland.

To help emphasize the utilitarian mission of the new aircraft, and highlight its workhorse flight and loading characteristics, Pilatus had the aircraft towed out onto the Stans airport ramp using a team of 24 horses. In keeping with the penchant for using abbreviations to summarize jet capabilities, Pilatus is calling the airplane a Super Versatile Jet or SVJ.

The new Pilatus PC-24 was announced at the 2013 European Business Aircraft Conference and Exhibition (EBACE) in Geneva. The PC-24 will incorporate many of the most desirable features of the existing PC-12NG turboprop on a twin-jet platform.

Jet power for the PC-24 will be provided by a pair of new-generation Williams FJ-44-4A turbofans. The engines utilize Dual Channel FADEC and are rated for 3,435 pounds normal takeoff thrust each. They also employ Williams' Exact passive thrust vectoring technology. This utilizes the Coanda effect to provide a three-degree vectored thrust during high-power operations. (The Coanda Effect is a phenomenon in which a jet flow of air attaches itself to a nearby surface and remains attached even when the surface curves away from the initial jet direction. NASA has used Coanda effect to improve performance on a number of exotic designs.) More than five percent additional thrust will be available through a new Automatic Thrust Reserve feature, boosting max power to 3,600 pounds.

The engines also feature Williams' Quiet Power Mode, a self-starter that will provide limited ground power and eliminate the need for an APU. TBO has been set at 5,000 hours with an on-wing inspection of the hot section at 2,500 hours.

The Pilatus jet is partially the result of a Pilatus market survey that asked PC-12 customers what features they'd like to see in a new model. To no one's surprise, the answers were almost universally higher, faster and bigger into the same unimproved short strips that the PC-12 uses so handily and with the same palletized cargo capability.

That's a slightly more difficult task for a pure jet. Pilatus engineers began design studies five years ago, configuring a jet that could carry roughly the same load as the company's premier turboprop, fly roughly 150 knots faster at flight levels as high as FL450 and land in a short distance. In this case, balanced field length is less than 3,000 feet. Pilatus calculates that the PC-24's short and unimproved runway capability will open up something like 21,000 additional airports worldwide that aren't currently available to other jets.

The PC-24 will be certified for operation that will allow for as many as 11 passengers. The Pilatus cabin is huge, 504 cubic feet, nearly twice the size of the competition's aft compartment. The cabin will be similar to that in the PC-12, but four feet longer. This will allow a variety of quick-change configurations, including all cargo or EMS missions.

More typical business layouts will accommodate two pilots and six to eight passengers with copious room for baggage. Cabin dimensions are 61 inches tall by 67 inches across, and as with the PC-12NG, the PC-24's pressurized, heated aft baggage compartment will still accept a shipping pallet loaded by fork lift (with extreme care).

Pressurization differential is 8.8 psi, which will allow inflating the PC-24 to offer a sea-level cabin at 23,000 feet and an 8,000-foot cabin at the airplane's maximum operating altitude of 45,000 feet.

Performance will be well into the medium-jet class. Climb at the PC-24's max takeoff weight of 17,650 pounds will be over 4,000 fpm, and an unrestricted ascent from near sea level to FL450 should require only about 30 minutes.

Max cruise is slated for 425 knots, slightly slower than the Phenom 300 and Cessna Citation CJ4, but on a typical 1,200 nm trip, the difference in time en route should be no more than 10 minutes. All three models will probably be operated at 400-420 knots, anyway.

The reality is that a drawing-board aircraft will nearly always beat a real machine in performance, so we probably won't know for another year if Pilatus' projections are accurate (first flight is planned for early 2015), but CAD/CAM design and computer projections are typically fairly close to reality.

The PC-24 will carry nearly 6000 pounds of fuel for long-range, light-payload missions, but it may be able to utilize out-and-back missions because of its ability to operate from abbreviated or unimproved strips where fuel isn't available. The PC-24's dual wheel main landing gear swings inward into uncovered wells and is designed specifically for rough runways.

Assuming Pilatus meets its performance projections, it will have a pronounced advantage in short-field performance over the competition, both in takeoff and landing. The PC-24 should record takeoff distances well below 3000 feet and landing requirements closer to 2,500 feet.

Pilatus estimates the PC-24 will sell for $8.9 million in 2017 dollars, whereas that's roughly what the Embraer Phenom 300 and Cessna Citation CJ4 cost today. For that reason, again assuming the economy doesn't tank, it's probably a safe bet the PC-24 will be the least expensive medium jet in the sky when the first one is delivered. To date, Pilatus has deposits on nearly 100 PC-24 jets.

If the PC-24 can even approach the level of market penetration experienced by the PC-12NG (so far, the company has delivered 1,200 of its best selling corporate turboprops), the Swiss manufacturer could indeed be building what Pilatus chairman Oscar Schwenk dubbed an SVJ, for Super Versatile Jet.