The Amazing History of BB-1

The Amazing History of BB-1

The Amazing History of BB-1

I was fortunate to be employed by the Beech Aircraft Corporation’s Training Center during most of the development and certification process for the most popular King Air of all time, the model 200. I was the first ground and flight instructor for this model and had the privilege of learning directly from the engineers and test pilots. I want to tell you about this model’s development and, specifically, about BB-1, the very first member of this family of airplanes. Of course, I do not know every detail of the development process and, if I did, it would take an entire book to thoroughly present the entire story. So, this article only covers some of my personal experiences with the great model 200 and, specifically, the story of BB-1.

The King Air made its appearance in 1964 as the model 65-90, better known as the “Straight 90.” The A90 came in 1966 to replace the 65-90, and in 1968 the A90 was superseded by the B90. The success that the King Air obtained encouraged Beech to develop a larger version. Picking the tail, landing gear and wings from their “parts bin” – systems that had been previously designed, certified, and manufactured for the Model 99 Airliner – they combined it with a King Air fuselage lengthened by 4 feet and the model 100 was born. Customer deliveries of that larger King Air commenced in 1969 and an enhanced version, the A100, replaced it in 1972.

Although the 100-series enjoyed moderate sales success – customers really liked the roomier interior due to the extra length added – it did not have eye-opening performance. Much like the B90, powered by the 550 SHP PT6A-20 engine, the 100 and A100, powered by the 680 SHP PT6A-28, were not known for their stellar climb nor blistering speed. Rarely could the full-rated horsepower be utilized except at sea level on cooler days. The 99/100 wings – about 5 feet shorter than the B90 wings, but the same span as on the 65-90 and A90 wing with a drooped center section leading edge – were optimized for low altitude operation on the unpressurized model 99 and performance suffered when used much above 20,000 feet. It became obvious that the 100’s cabin size was popular and if it could be combined with much improved performance, Beech would have a real winner on their hands. Thus, was the impetus for designing the model 200.

At first, this new King Air had the internal Beech designation of “Model 101.” After all, it was exactly the same size as the 100 just with more performance. Even now, most factory parts unique to the 200 begin with the “101-” part number prefix. It was not until just before the model had its official public debut that Mrs. Olive Ann Beech herself suggested the name be changed to “Super King Air 200.” Some of the Beech employees – and I was one! – turned their noses up at this idea, thinking the name was too long and pretentious. But when I first flew it … wow, it really was “super!” (As a side note, when the Beech Model 18 got its 4-inch higher cabin in the mid ’50s with the change to the E18S model from the D18S, it was known as the “Super 18.” So, the “Super” moniker was not without precedence in the Beechcraft lineup.)

Here is a list of the major changes made to the 100 that turned it into the 200:

  • More power: The 680 SHP PT6A-28s were replaced with the new and longer PT6A-41 of 850 SHP. To mount this engine to the airframe, a new engine mount was developed that held the engine in four instead of three places to accommodate the greater weight and torque. A new cowling needed to be made to house the longer engine and the new design included elimination of the electric heating element on the cowling lip – replacing it with an exhaust-gas heated, stainless steel lip – as well as a different and more efficient ice protection system.
  • Larger propeller: To efficiently absorb the 850 SHP, a three-blade propeller with longer blades needed to be fitted. Although it is getting somewhat rare now to see a model 200 with three-blade propellers, this was the only factory-offered propeller for all of the 200s and the first 10 years or so of B200 production. Four-blade props did not become factory standard on the B200 until 1993.
  • Longer wingtips: For decades and decades, Beech has provided a shorter and a longer wingtip, the piece that attaches outboard of the wing spar’s end. The shorter one is on all Bonanza models except the B36TC. The longer one is the tip on Barons. The 99/100-style wing uses the shorter tip but for the 200 Beech reverted to the longer tip of the B90.
  • Wider wing center section: The larger propeller would not fit where the model 100 propellers sat without (A) hitting the fuselage, and (B) providing almost nil ground clearance. Instead of making a very minor increase in center section width – enough so the propeller would not hit the nose – the designers decided to widen it by 50 inches (25 per side) to not only accommodate the propeller but also to make the cabin quieter by moving the propeller tips farther away. The new engine mount, mentioned previously, raised the propeller
    4 inches higher to make for satisfactory ground clearance. With both the wider center section and the longer tip, the 200 has a ten-foot longer wingspan than the 100-series.
  • The T-Tail: I have written an entire article about the reasons behind the choice of the T-Tail. To recap, the overriding reason is to maximize rudder effectiveness. With more powerful engines sitting 25 inches further out on each side, Beech knew that keeping VMCA down to a reasonable number would be a challenge. Theoretical calculations, wind tunnel tests, and then flight tests in BB-1 all proved that VMCA could be kept at 91 KCAS (identical to that of the 65-90!) thanks to the T-Tail. By moving the horizontal stabilizer to the top of the vertical stabilizer (A) it prevented the bottom half of the rudder from being “blanked” of wind by the horizontal stabilizer in the high angle-of-attack situation associated with VMCA, and (B) it provided an “end plate effect” that maximized the rudder’s effectiveness by not allowing air to escape past the rudder’s top.
  • Increased pressurization: By installing double-pane cabin windows, beefing up the door attaching hardware, and going through extensive cyclic pressure testing, Beech managed to increase the maximum differential pressure (∆P) from 4.6 psid to 6.0 psid. The 4.6 value was used in everything from the A90 through the A100. With 6.0 psid, the cabin would be about 4,000 feet lower for a given airplane altitude. This made it feasible for the 200 to routinely cruise in the 25,000- to 30,000-foot range, much higher than the previous King Air models.
  • Improved electrical, fuel and environmental systems.
  • Although not obvious to pilots, much attention was given by the designers of the 200 to improve maintenance accessibility. Replacing a blown 325-amp current limiter takes a lot less time in a 200 than in a B90!
  • Again, not obvious unless pointed out by someone, more metal bonding and less riveting is used in the manufacturing of some parts, specifically the rudder and the inboard flap sections.
  • A new, stronger, main spar: Known as the “super spar” at Beech, the bathtub fitting in which the lower forward wing bolt resides is now an integral part of the lower spar cap, no longer a separate, riveted-on piece. (This was changed again in 1985 when the fitting was totally redesigned to have the bolt under shear-loading instead of tension-loading.)

Throughout 1972, rumors were rampant around the Beech workforce concerning the progress on this fancy new model. We all were anxiously anticipating the day when BB-1 would makes its maiden flight. That day finally came Oct. 27, 1972. Most of the workforce was permitted to leave their stations and gather near the south end of Runway 18-36, where BB-1 was being prepared for its maiden flight. As the time grew near, Chairwoman of the Board, Mrs. Beech and President Frank Hedrick arrived on-site in Mrs. Beech’s “Beech blue” Cadillac to take their positions of honor. Jim Webber, the head of Beech’s Experimental Flight Test department, was in the left seat and Bud Francis, who was slated to become the head of the 200 flight test project, was in the right seat.

BB-1, N38B, was painted all white with black numbers. If you looked closely, you would have observed two noticeable differences between BB-1 on this day and the later 200s to come. First, the junction of the horizontal and vertical stabilizers at the top of the T-Tail was smooth, with no “bullet” projecting forward. Second, the ailerons were identical to the ones on the A100 and B90, ending where the wingtip began. (Some turbulence originating at the T-Tail junction was eliminated by the “bullet” that was installed during the flight-test program. The longer wings and more powerful engines made the original ailerons a bit lacking in effectiveness and this problem was eliminated when the 200’s ailerons were redesigned to extend all the way to the end of the wing. The trailing edge of the wingtip extension was cut away and a third aileron hinge point was added.)

The engines were started, pre-takeoff checks completed, and then she taxied down the runway to the north end, made a U-turn and took off southbound, climbing out over the assembled crowd before turning east and climbing out of sight. What a thrill to witness the first time a 200 entered the bright blue sky!

About an hour later BB-1 returned to Beech Field. The crowd had moved to the north end of the runway to get a better view of the landing. Jim came in low over the wires and then used maximum reverse to show off the short stopping distance of this newest King Air. It was most impressive! BB-1 did a 180 and taxied back to its parking spot near the crowd. As the engines spooled down and Mrs. Beech and Mr. Hedrick stood by the door to welcome the crew, a worrisome murmur began to be heard in the crowd. What the …? Was the prototype going to burn up right before our eyes? White smoke had started to pour out of both sides’ exhaust stacks! About the time the cabin door started down, the smoke stopped and we all breathed a welcome sigh of relief.

You see, the 200 was the first King Air model in which residual fuel in the nozzle manifolds would no longer be permitted to dump onto the ramp at shutdown. Allowing it to drip into the hot combustion chamber liner was the cause of the white smoke … fuel “steam” you might say. Some work remained for the engineers to perfect that initial Environmental Protection Agency (EPA) Kit!

A month later BB-2, the second prototype, had its first flight. This airplane sported a complete paint job and interior, very different from the stark non-upholstered interior of BB-1. BB-2 was the first to carry the N200KA registration number; you likely have seen its picture. It was used for systems integration and icing tests. BB-2 was actually the first 200 that I ever flew, getting instruction from test pilot Mike Preston on a cross-country flight to and from Colorado. Later, I flew BB-1 with Bud Francis. I have written about some of the things I learned from Bud in that airplane … such as the power of the T-Tail and the tendency to “self-rotate” at the initiation of a highspeed abort.

When the 200’s Federal Aviation Administration (FAA) certification program was completed – the Type Certificate was issued in November 1973, just 13 months after first flight – BB-1 was tied down on the grass by a Beech hangar and flown very rarely. BB-2 kept being fairly active as the first factory demonstrator.

In 1975 BB-1 was brought back into the Experimental Flight Test hangar; the two turboprop engines were removed and two JT-15D turbofans were installed in their place! Was this the first “Beech jet?” No, not really, since Beech had marketed and sold the MS.760 – a twin-engine, four-place, French-made jet, back in the late 50s and early 60s. But BB-1 was now the prototype PD 290, Preliminary Design 290, the name given to this experimental project.

Bud again was the chief program test pilot and he told some hair-raising stories about trying to get that prop-less wonder stopped on the 5,000 feet of Beech’s Runway 18-36! Little tires with no antiskid and a lot of residual jet thrust made for a challenge.

Although we may never know the complete, correct story, speculation is that the main reason why there was a PD 290 project was to get Wall Street speculating about a Beechcraft jet. The hope was that this would drive the stock price higher, as it did, before Olive Ann sold the company to Raytheon.

When fitted with the JT-15s, BB-1 was flown in two configurations. One had the jet’s exhaust constrained within a duct that terminated at the trailing edge of the wing; the other was a “blown wing,” as shown in the picture above, wherein the exhaust flowed freely from the engine’s exhaust duct over the top of the wing. I have heard – as the aeronautic guidelines would suggest – that the latter configuration created more lift but also more drag.

BB-1 fitted with JT-15s, flown with a “blown wing” where the exhaust flowed freely from the engine’s exhaust duct over the top of the wing.”

After BB-1 flew the PD 290 tests, it was again relegated to the forlorn grass tie-down area.

Gerald Mobley was the chief pilot for Guardian Air Transport of Billings, Montana, an air ambulance operation that was using King Air 100s and 200s in the 1980s. Gerald believed that they were losing some business because of the public’s perception that being transported in a “light airplane” was uncomfortable and unsafe. He had the thought that if Guardian could show a mock-up of their actual BE-200 air ambulance interior to the end users – showing how roomy it was, the stretcher installation, exhibiting plenty of room for the flight nurses and even a seat for a relative of the patient – that Guardian would likely gain plenty of new customers. In his quest to find a 200 fuselage to make into the mock-up, he contacted Beech. He ended up purchasing BB-1 from Beech, having the wings and tail removed, cutting away the left side of the fuselage, mounting the assembly on a flatbed truck, and taking the rig to all of the county fairs they could find in Montana. He said that the program was quite successful in alleviating the public’s worry.

Still later, when BB-1 had finished its roll as a movable air ambulance mock-up, Stevens Aviation bought the remains and used the cockpit portion as its Garmin G1000 simulator. Within the past year or so, it has been upgraded to the G1000NXi configuration. I, personally, have spent quite a few hours teaching both myself and some colleague pilots about the workings of this marvelous system while sitting in the “front office” of BB-1. She still sits at the Stevens’ facility in Nashville, Tennessee, when she’s not on the road at some aviation trade show.

The BB-1 cabin at Stevens Aviation in Nashville, Tennessee, recently upgraded with the Garmin G1000XNi.

Go give her a loving pat sometime when you are in the area. She is the grandmother that started it all … started the BE-200 down the path of being the most popular executive turboprop ever manufactured.

King Air expert Tom Clements has been flying and instructing in King Airs for over 46 years, and is the author of “The King Air Book.” He is a Gold Seal CFI and has over 23,000 total hours with more than 15,000 in King Airs. For information on ordering his book, contact Tom direct at twcaz@msn.com. Tom is actively mentoring the instructors at King Air Academy in Phoenix.

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