LEARJET Testing Airframe
History of the Learjet TA05 testing airframe
The Learjet TA05 testing airframe and wings were kindly donated by Spirit Aerosystems (formerly Shorts / Bombardier). It was one of the first Learjets build by Shorts and the last to leave.
In 1986 Bombardier moved into the Aerospace business by buying the Canadian aerospace company Canadair. This was quickly followed in 1989 when they bought the Belfast based aerospace company Shorts.
In 1990, they bought the Wichit-based Learjet company followed in 1992 with the Toronto-based de Havilland company.
This formed the basis for the emerging Bombardier aerospace division, although the aircraft that they manufactured continued to be marketed under their initial company brand, e.g. Canada Air — Challengers and Regional Jets, Shorts SD330 and 360 series. de Havilland — Dash 8 series. Learjet — models 31, 35 and 60.
In 1989, Learjet started initial design concept studies for their next model which later became known as the Learjet 45. This was to be the first clean sheet Learjet design since the companies first, the model 23 back in 1963, as all other models had evolved from this original design.
This was to be the first Bombardier aerospace collaborative project involving all of the newly acquired companies / sites.
In the summer of 1991 a joint Bombardier multi-site and multi-functional team was set up initially located in Wichita. This was to develop a new entry level business jet combining the efficiency and price of a light jet with the interior space and range of a medium jet.
This aircraft was to be developed using the emerging CAD technology and adopting a design build team philosophy and approach with the team also looking at the manufacturing strategies including work share options, interface requirements, also testing and certification requirements and options.
This was going to be the new Learjet 45 so final assembly and Flight testing would be in Wichita, the Fuselage design and manufacture would be in Belfast; also the Belfast engineering test facility would take responsibility for some of the ground test units, including the Fatigue test unit which was later designed as TA05.
The Wings, initially Canadair design, but later to be de Havilland manufacture. In September 1992 Bombardier announced at the NBAA annual conference in Dallas that it was developing the Learjet model 45.
In October 1994 the first fuselage was delivered from Belfast. It was transported on a Shorts built Belfast transport aircraft. In October 1995 the Learjet 45 made its first flight from the Learjet facility in Wichita.
The Learjet 45 then received FAA certification in 1997. As the Model 45 was the first all-new design since the original Learjet this significantly altered the Learjet line.
Through its four primary variants — the original Model 45, the Model 45XR, Model 40 and Model 40XR — it was the Learjet Division's principal product from the 1990s until the introduction of the Model 75 variant in 2012 which continued in production until 2021.
During this time all the fuselages continued to be manufactured in Belfast.
TA05 History is based on a review of aeronautical fatigue investigations in the United Kingdom during the period May 2005 to April 2007 it reported that the Learjet 45 Wing and Fuselage fatigue, plus damage tolerance test (test article designation TA05) has completed all Fatigue Testing: 59,200 flights (3 design lifetimes), 2 of durability testing and one lifetime of damage tolerance testing with artificial damage introduced.
The loading applied represents gust, manoeuvre, and pressurisation loads to an altitude of 51,000ft.
Eight residual strength tests (as noted below) have been successfully completed.
1) Condition 1a & 1b — Engine beam up load without/with thrust
2) Condition 2a & 2b — Engine beam down load without/with thrust
3) Condition 6 — 1G wing up bending/fuselage down bending with 1.15 x 9.9psi (11.39psi), going to 105% (11.96psi) limit cabin pressure.
4) Condition 3 — Fuselage up bending — aft shear without/with 9.9psi cabin pressure
5) Condition 4 — Fuselage down bending — aft moment without/with 9.9psi cabin pressure
6) Condition 7 — Wing down bending/fuselage up bending — wing shear moment torque — fwd fuselage moment without/with 9.9psi cabin pressure
7) Condition 5 — Fuselage up bending — aft fuselage moment fwd fuselage shear without/with 9.9psi cabin pressure
8) Condition 8 — Wing up bending/fuselage down bending — wing shear moment torque — forward fuselage shear moment aft fuselage shear without/ with 9.9psi cabin pressure.
Upon completion of testing and after long and hard life TA05 remained at the Bombardier Belfast site (Shorts) until production completion in 2021 and it has now arrived at its new home with the UAS looking a little the worse for wear.