Business jets aim to deliver the ability to fly at high altitudes because of the following benefits:
Lower air resistance in the thin atmosphere at high altitude allows faster flight speeds.
Lower air resistance means the engine requires less power than at lower altitude, improving fuel economy.
At higher altitudes aircraft are less affected by bad weather and turbulence from jet streams, allowing a smoother journey.
As the atmosphere becomes thinner and air pressure drops at high altitude, cabin pressure must be maintained by sealing the plane's interior with an airtight wall and circulating air via an air conditioning system.
In this situation, cabin air tries to swell outward to reduce the pressure differential. The ability of the fuselage to withstand this pressure is what determines an aircraft's maximum operating altitude.
The HondaJet has achieved a class-leading maximum operating altitude of 13,000m (43,000ft) in an FAA-conforming test model, a product of the superior fuselage strength of the aircraft's integrally molded carbon composite body. (May 17, 2011)