"This is a great time to be developing a new airplane," Groom said.
The Altaire has 170 cubic feet of cabin space. There are also 20 cubic feet of pressurized aft baggage space and a 20-cubic-foot unpressurized baggage compartment in the nose, large enough to carry golf bags. With the 70-cubic-foot cockpit area, total pressurized volume is 260 cubic feet, more than a Mustang (230 cubic feet) and a little less than a Phenom 100 (282 cubic feet). The new, round fuselage shape and redesigned windows give the cabin a much airier feel to go along with its more generous volume. The drop-down floor is 12.5 inches wide, and because the redesigned Altaire has no spar carry-through (the fuselage sits atop the main spar, à la the Beechcraft Premier 1A), there should be less stumbling involved in getting around the cabin. With a view to serving passengers of larger size, Piper also widened the entry door to three feet but stuck with the basic functionality of the Meridian door, which has proven to be one of that airplane's strong suits.
As you board the Altaire, you'll find yourself literally facing one of the cabin's most innovative features. The space immediately opposite the door can fulfill a number of functions. It can be used for extra storage, a seventh seat, a refreshment center or the previously mentioned lavatory. The best part is that each of those options is available in modular form. So you can use the space for cargo on a morning flight, then reinstall the lav for a trip later in the day. And then drop in the refreshment stand another time. Piper estimates about two hours' work to swap modules. Groom believes that most buyers will opt for at least the lavatory when ordering an Altaire. For many passengers, the security of simply knowing that private space is available can make a refreshing difference on a long flight, even if it's never used.
The Altaire's seats were designed and will be constructed by Millennium Concepts in Wichita, Kansas. They are able to withstand 26 Gs forward motion and 32 Gs downward. Making that G-rating is important for Piper, since having seats with that level of passenger protection might waive the 61-knot FAA stall-speed limitation for a single-engine aircraft.
It is expected that the Altaire will have stall speeds "in the 70s," Groom said, which is faster than any single-engine airplane that we know of. This could prove one of the chief certification challenges that Piper will encounter in working with the FAA on approving a single-engine jet. The rules on slow-speed performance for singles were written with lighter aircraft in mind. Certifying a single-engine jet represents breaking a lot of new ground. Groom said Piper has been in constant contact with FAA certification authorities to ensure they are on the same page with logical certification requirements for the Altaire. Piper estimates a published landing distance of 2,075 feet over a 50-foot obstacle under standard conditions.
That segues neatly into a discussion on the new wing. Though the span and the airfoil remain the same as those on the old PiperJet, there is an increase in wing area of 30 square feet — all in the chord. Vince Warbington, director of engineering for the Altaire project, said this change had as much to do with adding fuel capacity as with the need for extra wing area to lift the new fuselage. Based on the added wing area and its increased lift, Piper engineers were also able to change the flaps to a simpler drop-hinged design in contrast with the more complex Fowler flaps on the existing PiperJet. The simpler design will help make the Altaire easier and less expensive to produce and less complex and costly to maintain, Warbington said. Another benefit of the increased chord is allowing more room to work for the engineers to simplify the landing gear installation, again leading to easier production and maintenance — and thus lower costs for PiperJet operators. Warbington also hinted that the larger wing would make a great platform for a stretched version of the Altaire.
It's interesting that, though the airplane we've been looking at for the past few years used the same fuselage cross-section as that of the PA-46 Mirage/Meridian, Warbington said Piper could have used only about half the existing PA-46 tooling to build the Altaire. So coming up with totally new tooling for the Altaire's all-new fuselage does not represent as much of a production-cost penalty as might be expected. Another benefit of reinventing the fuselage — all lighting has been designed from scratch with modern low-voltage LEDs. That means the resulting lower-gauge wiring is much lighter and temperatures much lower. So insulation requirements are much less of an engineering and production burden. Interior panels are also designed to be easy to remove, with two or three screws each.
Another one of the big advances with the Altaire is its two-zone climate control system. Even some much larger jets don't have this feature, and the unhappy choice has always been between having the passengers refrigerated in the cabin or the pilots slow-roasted in the cockpit. In the Altaire, each area will have its own climate control, keeping everyone on board comfortable.
