Twin Turboprop At 37K ft.


#1

A little suprised to see this Piaggo P 180 flying this high!
what makes it perform at this altitude when most turboprops normally fly much lower?
flightaware.com/live/flight/N155SL


#2

Sorry about the wrong forum, tried to move unsucessfully!
But, This is quite an airplane.

Specifications

PERFORMANCE
Maximum Cruise Speed
398 KTAS (737 km/hr) at 28,000 ft (8538 m)
Take-off Distance
S.L. - ISA 2850 ft (869 m)
Landing Distance
S.L. - ISA 2860 ft (872 m)
Rate of Climb
S.L. - ISA 2950 ft/min (899m/min)

CEILING
41,000 ft/12,500 m
Maximum IFR Range
1,507 nm/2,791 km

ENGINES
Two Pratt & Whitney Canada PT6A-66B, 1630 Thermodynamic HP each, flat rated at 850 SHP

EXTERNAL DIMENSIONS
Wing Span
46.03 ft/14.03 m
Length
47.28 ft/14.41 m
Height
13.06 ft/3.98 m

CABIN DIMENSIONS
Height
5.74 ft/1.75 m
Width
6.07 ft/1.85 m
Length
14.93 ft/4.55 m

WEIGHTS
Maximum Take-Off Weight
12,050 lbs/5,466 Kg
Standard Equipped Empty Weight
7,800 lbs/3,538 Kg
Useful Load (Incl. Crew)
4,300 lbs/1,950 Kg
Maximum Payload
2,000 lbs/907 Kg

SEATING CAPACITY
Maximum Seating Capacity
9 + 2 crew
Typical Executive Payload
6 + 1 crew


#3

Part of it is that the cabin pressure differential is so great. The maximum is 9psi, meaning it can hold sea level pressure up to 24,000 ft. The PC12 has a max pressure differential of only 5.75, meaning sea level pressure up to 14,000 feet, corresponding to our ceiling of 30,000ft the cabin pressure is at 10k.
The P180 has extremely low drag. The “three lifting surface” (3LS) design means that there is no counterproductive downward force vector like a conventional aircraft design (the tail usually pushes down) The 3LS system also means that the main wing can be reduced in size by 34%. Also, a single, uninterrupted aerodynamic curve sweeps from the nose to the tail, changing diameter all the way. The fuselage of the aircraft actually becomes a lifting body, yielding 20% of the total lift! The pusher configuration means the main wing can take advantage of the undisturbed, smooth air in front of the wing.

How do I know so much about the P180? hmmmmmm…


#4

Thanks for the reply. Spoken like a true CFI, and someone who is about to Hmmmmmm!


#5

The P180 isn’t the only turboprop capable of such high altitude flight. The Cheyene 400LS was certified to FL410 (a scary thought) and the KingAir 200 and 350 are certified to FL350. Most turboprops simply aren’t used for missions where a climb to that altitude would make sense. For longer trips where a really good tailwind is available though, they certainly have the performance to take advantage of it. Although, as James mentioned, the P180 has the advantage of a very strong pressurization system.