Learjets and Swiss fighters

 - January 31, 2007, 9:48 AM

In the January issue of AIN (page 39), we recounted the origins of the Learjet, complete with references to the well worn tale of the Swiss fighter connection. We then heard from Bill Lear’s eldest son, who suggested that “since you can’t get it straight from the horse’s mouth, here it is from the horse’s offspring, who followed closely in the horse’s hoofsteps!”

My father first moved to Geneva in 1955. I followed in 1956 and resided there until 1975. Therefore, my father did not “jump at the opportunity to fly to Switzerland to look at the P-16 fighter project that the Swiss government had recently scrubbed.” He was already living there and hadn’t gotten serious about designing the Learjet until a few years later–about 1959, as I recall. The airplane envisioned was called the SAAC-23 (Swiss American Aircraft Corporation-23rd design). Only later was it called the Learjet when he moved the project from Switzerland to Wichita in 1962.

In March 1960, while the SAAC-23 was in the initial stages of design, I was invited by Flug- und Fahrzeug-werke AG (FFA), the privately owned Swiss aircraft company that had designed and built five prototypes of the P-16, to fly the aircraft. I was a former USAF fighter pilot with extensive experience flying ground-attack jets, and FFA wanted an evaluation of the P-16 from an independent source. I had the very good fortune of flying that magnificent aircraft on five different occasions from Altenrhein’s 3,600-foot runway and tested it to limits that even FFA said the aircraft was incapable of achieving.*

It was after these flights that my father questioned me about the various flight characteristics of the P-16. As it was originally anticipated that the SAAC-23 would be built in Switzerland it became obvious that FFA in Altenrhein might be an ideal place to accomplish this–especially in view of the Swiss government’s recent decision to cancel the P-16 project. My father made contact with Dr. Claudio Caroni, owner of FFA, and they reached an agreement to begin work on the SAAC-23 prototype.

My father was never one to take a nibble at a problem or project. He liked big bites–great big bites. He decided, therefore, to build the prototype on “hard” tooling rather than waste time and money on a hand-built proof-of-concept airplane on “soft” tooling. He didn’t need any “proof-of-concept” because he was confident that his design would be just perfect. And so it was!

The story that he bought the P-16 tooling, wind tunnel data, drawings and all is pure fantasy. It never happened. The “type” of wing construction used on the P-16 was interesting because of its multispar design–eight spars, good for +13g and -9g load limits.

The Learjet and P-16
There are several noteworthy differences between the Learjet and the Swiss fighter.
1.    The P-16 wing airfoil was 63 A109A. The Learjet airfoil was 64 A109. Similar, but not the same. Some of the P-16 wind tunnel data were used due to the similarity of the wing airfoil. Other wind tunnel tests were done in the Wichita University tunnel.
2.    The P-16 had Krueger leading-edge flaps for added lift. The Learjet doesn’t.
3.    The P-16 wing aspect ratio was about 4.15, while the soon-to-be Learjet’s aspect ratio was 5.4. The P-16 wing sweep was zero, while the Learjet’s was 13 degrees.
4.    The P-16 used double-slotted Fowler flaps that extended under the fuselage. The P-16 also had ailerons that could be drooped 18 degrees.
The Learjet uses single-slotted flaps, confined to the wing area only, and has no leading-edge high-lift devices or drooped ailerons.
5.    The P-16 had a cruciform tail and the Learjet a T tail. There is no resemblance there either.

Just where is the similarity? We bailed out of Switzerland, even though labor was half the price, because it took four times as long to get anything done. We didn’t have the money or the time to waste and Wichita was very good to us.

This tale of the Swiss P-16/Learjet relationship has persisted for many years. I hope that this bit of history will serve to enlighten and clarify.

It’s interesting to note that the entire Learjet program from inception to certification cost $12 million in the early 1960s. Certification broke all records, taking a mere 10 months. Some 20 years later we, together with private domestic and foreign investors, had spent $240 million on the Lear Fan program before its demise just months before certification in 1985, seven years after my father’s death in 1978.

*Test flight performance: Mach 0.965 right on the deck (1,190 km/hr or 740 mph IAS) followed by an 8.5g zoom-climb at that Q in a fully instrumented (recorders) airplane. Supersonic flight (Mach 1.03) in a straight-wing aircraft on five different occasions. The P-16 was the best ground-attack fighter I had ever flown and, at that time, could be bought for $500,000 per copy!