What are the pros and cons of a twin-engine turboprop over a single-engine turboprop? Mike Chase compares the Beechcraft King Air 350i against the Pilatus PC-12 NG to discover where their respective strengths and weaknesses lie...
Beechcraft King Air 350i
In this month’s Aircraft Comparative Analysis, Mike Chase provides information on two popular business turboprops – one a single-engine model, and the other a twin-engine model - for the purpose of valuing the pros and cons of each.
How does the twin-engine Beechcraft King Air 350i turboprop compare to the single-engine Pilatus PC-12 NG turboprop in the market today? Over the following paragraphs, we’ll consider productivity parameters (Payload, Range, Speed and Cabin Size) and cover current market values.
Is a single-engine or twin-engine turboprop the better choice for your mission needs? We’ll explore the merits of each over the following paragraphs…
King Air 350i
The King Air family has been in continuous production since 1974, the longest production run of any civilian turboprop aircraft in its class. The first King Air 350 deliveries occurred in 1990 as the ‘Super’ King Air 350, and the King Air 350 was built until 2009.
The King Air 350 is essentially a model 300 with a 34-inch fuselage stretch; two additional cabin windows on each side; 41ins wing span increase; drag-reducing winglets (for extra range); and 1,000lbs additional MGTOW.
The model 350i is a derivation of the original model 350 featuring a "FlexCabin" configuration that can be swapped easily for a variety of missions such as passenger transport, cargo, air ambulance or other special missions. The King Air 350i also boasts a quieter cabin with sound levels reduced to an average of 78dBA.
Pilatus PC-12 NG
The Pilatus PC-12/45 is a high-powered single-engine turboprop with a four-blade propeller. The first flight of the first of two prototypes took place in 1991. Swiss and US certification was received in 1994.
The PC-12/45 was manufactured from 1995 to 2008; the PC-12/47 was manufactured between 2006 and 2008; and the PC-12 NG (Next Generation) is the updated version, starting at serial number 1,001 in 2008. The cockpit is equipped with Honeywell Apex Avionics.
The PC-12 NG is equipped with both a passenger door and a cargo door, and is available in several configurations, including six-passenger executive, nine-passenger standard, or commuter, cargo and combi. It is also certified for single-pilot operation.
The total number of PC-12 NG aircraft manufactured (as of this writing) is 798, with 754 remaining in operation globally (per JETNET). 688 are wholly owned, 33 are in shared ownership and 39 in fractional ownership. Two have been retired.
As of April 2018, the PC-12 NG market is comprised of 72% flying with the same owner since new versus 28% purchased on the used aircraft market. Just 3.9% of the fleet is currently ‘For Sale’ and the average time on the market is 180 days.
By comparison, 398 King Air 350i aircraft have been built, with 363 in operation globally. 360 are wholly-owned with three in fractional ownership. Six have been retired.
As of April 2018, the King Air 350i market is comprised of 84% flying with the same owner since new versus 16% purchased on the used market. The fleet percentage currently ‘For Sale’ is just 2.8%. Average time on the market before a sale is completed is 255 days.
North America is home to the majority of the PC-12NG and King Air 350i fleet (accounting for 66% of each), whereas next, the PC-12 NG has 17% of its fleet based in Europe while the King Air 350i has 16% in Asia.
Status of ADS-B Out Equipage
Of the 760 PC-12 NGs worldwide, 208 (27%) are ADS-B equipped, leaving 73% of the fleet yet to comply. Meanwhile, 134 (37%) of the 363 King Air 350i fleet is ADS-B equipped. That leaves 63% yet to comply.
Payload & Range
As we have mentioned in past articles, a potential operator should focus on payload capability as a key factor. Table A shows the King Air 350i ‘Available payload with Maximum Fuel’ (2,500lbs) is greater than that offered by the Pilatus PC-12 NG (2,257lbs), per Conklin & de Decker.
TABLE A - King Air 350i vs Pilatus PC-12 NG Payload & Range Comparisons
Cabin Cross-Section Views
Chart A shows a cabin cross-section comparison with the King Air 350i offering less width (4.5ft) than the PC-12 NG (5.0ft). The height of the King Air 350i (4.8ft.) is also slightly less than the PC-12 NG at 4.83ft. However, the King Air 350i cabin length is longer (19.2ft) compared to the PC-12 NG (16.92ft).
CABIN A - King Air 350i vs Pilatus PC-12 NG Cabin Cross-Section Comparison
Overall, according to Conklin & de Decker, the King Air 350i has a smaller cabin volume (344cu.ft) compared to the PC-12 NG (356cu.ft), or a difference of 3.5%. Also worth noting is that the PC-12 NG has 40cu.ft of internal baggage space, while the King Air 350i has 56cu.ft of internal and 16cu.ft external baggage space.
As depicted by Chart B using Broomfield, Colorado as the origin point, the PC-12 NG (1,635nm) shows slightly more range coverage than the King Air 350i (1,550nm). Each turboprop’s range covers all of the US (excluding Alaska), Mexico and much of Canada.
CHART B - King Air 350i vs Pilatus PC-12 NG Range Comparison
Note: For turboprops, ‘four passengers with available fuel’ represents the maximum IFR range of the aircraft at Long-Range Cruise with four passenger seats occupied. NBAA IFR fuel reserve calculation for a 100nm alternate is assumed. The lines depicted do not include winds aloft or any other weather-related obstacles.
The Pilatus PC-12 NG aircraft has a single Pratt & Whitney Canada PT6A-67P offering 1,200shp. The King Air 350i aircraft utilizes two PT6A-60A engines, rated at 1,050shp.
Total Variable Cost
The ‘Total Variable Cost’ illustrated in Chart C (per Conklin & de Decker), is defined as the Cost of Fuel Expense, Maintenance Labor Expense, Scheduled Parts Expense and Miscellaneous Trip Expense. The Total Variable Cost for the twin-engine King Air 350i computes at $1,277 per hour, which is considerably more than the single-engine PC-12 NG ($774 per hour).
CHART C: King Air 350i vs Pilatus PC-12 NG Variable Cost Comparison
Aircraft Comparison Table
Table B contains the 2017 model new prices from Vref for each aircraft. The average speeds and ranges are from Conklin & de Decker, while the number of aircraft in-operation and percentage ‘For Sale’ and average sold are as reported by JETNET.
TABLE B: King Air 350i vs Pilatus PC-12 NG Comparison Table
The King Air 350i fleet has 2.8% of its fleet ‘For Sale’ and the PC-12 NG has 3.9% ‘For Sale’ (as of the end of April 2018). Currently, the average number of used transactions (sold) per month shows five for the King Air 350i, and an impressive 13 for the PC-12 NG.
Maximum Scheduled Maintenance Equity
Chart D and Chart E display the King Air 350i and Pilatus PC-12 NG, respectively, and depicts/projects the Maximum Maintenance Equity available, based on the average aircraft’s age.
The Maximum Maintenance Equity figure was achieved the day the aircraft came off the production line (since it had not accumulated any utilization toward any maintenance events).
The percent of the Maximum Maintenance Equity that an average aircraft will have available based on its age, assumes:
CHART D: Beech King Air 350i Scheduled Maintenance Equity
CHART E: Pilatus PC-12 NG Scheduled Maintenance Equity
Aircraft that are owned and operated by businesses are often depreciable for income tax purposes under the Modified Accelerated Cost Recovery System (MACRS). Under MACRS, taxpayers are allowed to accelerate the depreciation of assets by taking a greater percentage of the deductions during the first few years of the applicable recovery period (see Table C).
TABLE C: Part 91 & Part 135 MACRS Schedule
In certain cases, aircraft may not qualify under the MACRS system and must be depreciated under the less favorable Alternative Depreciation System (ADS) where depreciation is based on a straight-line method, meaning that equal deductions are taken during each year of the applicable recovery period. In most cases, recovery periods under ADS are longer than recovery periods available under MACRS.
There are a variety of factors that taxpayers must consider in determining if an aircraft may be depreciated, and if so, the correct depreciation method and recovery period that should be utilized. For example, aircraft used in charter service (i.e. Part 135) are normally depreciated under MACRS over a seven-year recovery period or under ADS using a twelve-year recovery period.
Aircraft used for qualified business purposes, such as Part 91 business use flights, are generally depreciated under MACRS over a period of five years or by using ADS with a six-year recovery period. There are certain uses of the aircraft, such as non-business flights, that may have an impact on the allowable depreciation deduction available in a given year.
The US enacted the 2017 Tax Cuts & Jobs Act into law on December 22, 2017. Under the new Act, taxpayers may be able to deduct up to 100% of the cost of a new or pre-owned aircraft purchased after September 27, 2017 and placed in service before January 1, 2023.
This 100% expensing provision is a huge bonus for aircraft owners and operators. After December 31, 2022 the Act decreases the percentage available each year by 20% to depreciate qualified business turboprops until December 31, 2026.
Table D and Table E depict examples of using the MACRS schedule for a 2017 model King Air 350i and Pilatus PC-12 NG, respectively, in private (Part 91) and charter (Part 135) operations over five- and seven-year periods, assuming a 2017 list price of $6.5m for a King Air 350i and $4.7m for a Pilatus PC-12 NG (per Vref).
TABLE D: King Air 350i Sample MACRS Depreciation Schedule
TABLE E: Pilatus PC-12NG Sample MACRS Depreciation Schedule
Asking Prices & Quantity
The current used market for the King Air 350i aircraft shows a total of 11 aircraft ‘For Sale’ with five displaying asking prices ranging from $4.0-4.9m. We also reviewed the PC-12 NG (31 for sale) with 11 asking prices ranging between $2.9m and $4.7m.
While each serial number is unique, the Airframe (AFTT) hours and age/condition will cause great variations in price. The final negotiated price remains to be decided between the seller and buyer.
The points in Chart F are centered on the same aircraft. Pricing used in the vertical axis is as published in the Vref Pricing Guide. The productivity index requires further discussion in that the factors used can be somewhat arbitrary. Productivity can be defined (and it is here) as the multiple of three factors:
Others may choose different parameters, but serious business aircraft buyers are usually impressed with Price, Range, Speed and Cabin Size. After consideration of the Price, Range, Speed and Cabin Size, we can conclude that the King Air 350i and PC-12 NG display a high level of productivity.
CHART F: King Air 350i vs Pilatus PC-12 NG
The King Air 350i is offered at a much higher price $6.5m ($1.8m more than the PC-12 NG), with nearly the same range and cabin volume. The King Air 350i does have a higher ‘Available payload with Maximum Fuel’ number, and a greater long-range cruise speed (234kts versus 209kts).
However, the PC-12 NG has considerably lower variable cost per hour with one engine and one pilot compared to the twin-engine King Air 350i with two pilots.
Operators should weigh up their mission requirements precisely when picking which option is the best for them.
Within the preceding paragraphs we have touched upon several of the attributes that business aircraft operators value. There are other qualities such as airport performance, terminal area performance, and time to climb that might factor in a buying decision.
The King Air 350i and PC-12 NG continue to be popular today. Those operators in the market should find the preceding comparison useful in establishing not only which model is the most appropriate for their individual mission needs, but whether one engine or two will suffice.