I began as an instructor at the Beechcraft Training Center on Jan. 3, 1972. If anyone had told me then that I would still be teaching King Air pilots in 2022, I would have thought they were crazy, but so it is. To steal a line from “Saturday Night Live:” “King Airs been very, very good to me!”
The Beechcraft factory’s training center had formed in late 1964, soon after the first King Airs began being delivered to customers. It started with only two employees: Bob Nielson, the pilot instructor and manager, and Dave Howe, the maintenance instructor. It was located in a small building at the west end of the Delivery Center’s hangar. Most of the actual flight training in the customer’s new King Air was provided by the production test pilots, the guys who flight-tested the airplanes as they came off the production line.
With the demand and rapid delivery pace of the first successful small turboprop, the training center quickly expanded, moved into upstairs rooms in the Delivery Center, and hired more instructors: Scott Hutchinson for maintenance; Don Cary, Bruce Addington and Bud Small for pilot ground and flight training.
About 1969, it was obvious that the Training Center had outgrown its meager facility. A failed restaurant/nightclub – Ken’s Club East – just to the east and adjacent to the Beech complex, was purchased and became the location of the Beechcraft Training Center for many years to come. It was to this locale, with Don Cary now the center’s excellent manager, that I reported. Back then, the entire staff consisted of six employees: Don Cary, our manager and pilot instructor for the entire line of Beech airplanes; Jo Ann Louie, our amazingly competent secretary/assistant; Alan Roberts, pilot instructor with emphasis on the 100-series; Bud Small, our Duke instructor in both flying and maintenance, bilingual in English and Spanish; Scott Hutchinson, King Air maintenance instructor; and me, who was taking over from Don Peterson, the model 90-series instructor, who had been promoted to the head of Beech’s own Air Transportation Division.
Wow! What an exciting environment I was thrust into! Back in those days, the pilot instructors taught in the classroom and in the airplane. I had served over four years in the Navy, starting right after college. For all my life, I was nearsighted and had astigmatism. Although prescription glasses brought me up to clear vision, I knew that military and airline flying was not in the cards for my future. (Lasik eye surgery in the early 1990s made for miraculous improvement!)
But the Navy assigned me to a very unusual billet: an instructor in the Nuclear Power School, teaching the enlisted and officer staff who would be operating the nuclear powerplants on the submarines and aircraft carriers that were so-powered. My degree in Mechanical Engineering was why they felt I was suited for this billet, and it was a satisfying four years that I taught at “Nuke School” at Mare Island Naval Shipyard in Vallejo, California.
Having most weekends and many evenings free and not being married yet, I used that time to get most of my advanced flying licenses. I had soloed and obtained my PPL back in 1962 as a high school junior. Airplanes and flying had been my passion for as long as I could remember. Once equipped with my CFI rating, I instructed part-time at Sonoma Skypark – a one-runway, 2,500-foot, paved strip a few miles west of the Napa VOR. By the time my four-year enlistment was completed, I had about 1,500 total hours in my logbook.
With such relatively low time and with no Beechcraft experience whatsoever, why the heck did I get hired by the Beechcraft Training Center?! My low flight experience was offset by my extensive ground school teaching experience at Nuke School, or at least Don Cary thought so. I guess he was right since I’ve been at it ever since.
I had never flown a King Air until getting checked out by Don Cary and Alan Roberts in the first few months of my Beech employment. Wow was I a novice, barely one step ahead of my first students! But it seemed to be a good “fit,” and I rapidly advanced in the Training Center to become the senior pilot instructor after a couple of years and then the Center’s manager when Don Cary got promoted to be the head of Beech’s Parts and Service operation.
The growth in aviation in the 1970s was astounding. Beech kept ramping up the production schedule and eventually, we were making over 30 King Airs a month. This boom continued until the early ‘80s and then the shoe dropped. I think the GAMA (General Aviation Manufacturer’s Association) total delivery numbers went from 17,000 airplanes to 1,700 airplanes in the course of a couple of years. It has never recovered to the halcyon days of the middle and late ’70s.
But enough of this. In the remainder of this article, I’d like to tell you about the 90-series with which I was initially associated. It is astounding to know of the many and rapid improvements that Beech quickly implemented on the good ol’ BE-90. For filing flight plans, it is a Be9L (Be9T for the F90 series).
Ever heard of the Model 87 Beechcraft? Probably not. But it was the first PT6-powered, twin-engine Beechcraft. It was a Queen Air – Lycoming powered, unpressurized, executive transport – now fitted with the first version of the PT6 … the PT6A-6 powerplant. This engine was capable of 550 shaft horsepower (SHP), but Beech decided that 500 SHP would be enough. After all, the Queen Air model 80 had a mere 380 SHP. By marking the torque redline at 1,190 ft-lbs. instead of the 1,315 that the gearbox could handle, the power reduction was achieved. Holding 500 SHP at hotter and higher elevation airports was more likely to be achieved than pulling the full 550 SHP. But don’t be led to think this was a major flat rating of the -6. Oh no! Because of temperature limits, full torque could rarely be achieved except on colder days at lower elevations.
And speaking of temperature limits, the -6, unlike any subsequent PT6, measured exhaust gas temperature at engine station 4, the compressor turbine inlet. This is the location of the highest, most critical, exhaust gas temperature since it measures the temperature of the exhaust before any energy has been extracted to drive the Compressor Turbine (CT) or the Power Turbine (PT). Monitoring this highest, most critical temperature location in the engine made sense, so TIT – Turbine Inlet Temperature – was what the pilot could see in the cockpit of -6-powered airplanes. Unfortunately, it was quickly found that the TIT probes didn’t last long. They got too hot and failed quickly. Temperatures in the 900°C range were common.
The solution to these rapidly failing TIT probes was to relocate the probes from the inlet of the compressor turbine to its outlet. From station 4 – Compressor Turbine Inlet – to station 5 – the Interstage Turbine location, downstream of the CT and upstream of the PT. Since nearly two-thirds of the combustion product’s energy is used to drive the CT, the exhaust gas loses a lot of temperature as energy is being extracted. That’s why ITT – T5 or Interstage Turbine Temperature – tends to run in the 700°C range, and the temperature probes have a relatively good life. But it is also why ITT should not be used as the primary power-setting instrument since it is not monitoring the most critical locale in the engine. Torque and propeller speed (Np) is the correct way to set cruise power, based on graphs and tables that are based on pressure altitude and OAT.
Back to the Model 87: This was a Queen Air powered by PT6s. The first flight occurred in May 1963. It would go on to become the U-21 “Ute” line of airplanes that the U.S. Army would buy and operate for many years in many different roles. Soon thereafter, the first flight of the King Air, the model 65-90, took place in May 1964. It is amazing that the airplane received its type certificate in just a few months and customer deliveries began before the end of the year. The number “65” was the official name for all Queen Air models – the 65, 70, 80, A80 and B80 – all were added to the original FAA type certificate. The “improvements” that rapidly came with the pressurized King Airs were, for a long time, simply add-ons to the 65 type certificate. That explains why the Model 90 and the Model A90 King Airs are officially designated as 65-90 and 65-A90. When the B90 model and subsequent King Airs appeared, the 65 prefix was deleted.
Take a Queen Air, pressurize the fuselage a little, put on PT6A-6s, throw in the extra gauges and switches wherever they will fit on the panel and voila! – we have a King Air 90! At the time, the 90 was a very hot item. Looking back, however, it was quite primitive. The maximum differential pressure was a lowly 3.1 psid. At 20,000 feet, the cabin would already be above 10,000 feet. Realistically, the airplanes cruise speed rarely exceeded 200 knots. The “Straight” 90 saw seven being delivered into customers’ hands in 1964, the same year it received FAA certification. Sixty-nine airplanes were delivered in 1965 and another 36 in 1966 for a total of 113 airplanes, LJ-1 through LJ-113. If you add the yearly delivery figures presented here, they total 112, not 113. What’s wrong? LJ-76 became the prototype for the A90 and is considered a 65-A90 instead of a 65-90.
The A90 is a huge improvement over the straight 90! Although the dimensions are the same, and they both have a 9,300-pound maximum gross weight limit, that’s about all they share. The PT6A-20 engine was installed, with ITT replacing TIT. The pressure vessel was strengthened and tested to be certified with a 4.6 psid maximum differential. Now the airplane could climb to 25,000 feet before the cabin reached 10,000 feet. However, perhaps the best feature was a cockpit redesign to make it much more ergonomically satisfying. For the first time, an annunciator panel perched on top of the glare shield consolidated all of the warning, caution and advisory lights into an easily scanned location. (The panel is in, not on, the glareshield in later models.) Before, the lights had been haphazardly placed all over the instrument panel. Also, there was now a “master warning” light that would flash red whenever a warning annunciator appeared, to grab the crew’s attention. With usually minor changes – including switching from a horizontal placement of engine instruments to a vertical stack – this panel continues to be on all King Airs to the present day.
In addition, and perhaps the most popular improvement of all, was propeller reverse! The 90s had non-reversing props, so no Beta nor Reverse ranges on the power levers and no condition levers! (The power levers included the fuel cutoff feature when a mechanical gate was opened to allow them to be pulled aft of idle.) The A90 introduced reversing props as an option, but I believe only one A90 was ever built without that wonderful improvement.
The following year, 1966, saw the 65-90 production end and the 65-A90 take its place. This popular model continued through 1967, through LJ-317.
The B90 began customer deliveries in 1968 and continued through 1970, LJ-318 through LJ-501; no longer was the “65” prefix used. Although the systems on the A90 and B90 are virtually identical, the B90 offered huge improvements in two areas. First, the gross weight went up by 350 pounds, to 9,650 MTOW. The engines, although still PT6A-20s, were now allowed to utilize their full 550 SHP. To allow the higher gross weight, the wingspan was increased by about 5 feet by longer wing tip extensions, outboard of the main spar, and aileron ends. Also (and so very satisfying to pilots!) the handling quality improved immensely. Due to balanced ailerons and elevators, the airplane felt like it had power steering. What a delightful handling machine, one of the best of all the King Air models!
In 1969, the King Air model 100 appeared, with the cabin stretched by 4 feet, 680 SHP PT6A-28 engines, dual main landing gear, an improved fuel system, a higher gross weight, and with identical left and right “Bleed Air Flow Control Packages” – Flow Packs, for short – replacing the single roots-type supercharger on the left engine only. This was a huge improvement and continues to the present day.
In brief, Beech took some of these improved systems from the 100 and installed many of them on the B90 to create the C90, beginning with LJ-502, appearing in 1971. Gross weight, fuselage and controls, engines, fuel system, performance all remained the same as the B90. But the bleed air pressurization source – putting out a lot of compressed and therefore hot air – allowed the somewhat troublesome Jet-A-burning combustion heater to be removed, replaced by a simple and reliable electric heater. From 1971 until 2020, the King Air C90 line continued, with lots and lots of small and large improvements made along the way. A C90GTx looks almost identical to LJ-501, yet the systems and performance are tremendously improved.
But that’s fodder for a future article. I consider myself very blessed, indeed, to have entered the King Air world as early as I did, 50 years ago.