Financial Analysis

of the King Air C90A with the

Blackhawk XPR135a Engine upgrade

Introduction
Blackhawk Modifications, Inc. has an engine modification program to upgrade the PT6A-21
engine of the King Air C90 family to a PT6A-135A engine. The PT6A-135A engine upgrade
offers several advantages:

• More power at altitude

• Faster cruise speed at altitude
• Potential for reduced operating costs
• Potential for enhanced resale value

This report examines each in turn.

Note: The costs and assumptions used are typical estimates based on known costs and mar-
ket conditions. These calculations do not represent any financial guarantee of return.

Enhanced performance
The King Air C90GT with the PT6A-135A engines has the same performance at a given weight
as the Blackhawk XP135A. All XP135A performance estimates were based on the C90GT flight
manual performance data. For the standard C90, the C90A flight manual performance data
was used.

Up to about 14,000 feet at ISA, the PT6A-21 delivers its full take-off torque. At recommended
cruise1 this is 1,315 ft/lbs per engine. Above this altitude, the engine loses torque and at
26,000 feet produces only 862 ft/lbs torque. This yields 235 KTAS for a mid-weight King Air
C90A.

At normal cruise, the PT6A-135A produces 1,520 ft/lbs torque up to 18,000 feet2. At 26,000
feet, it still produces 1,170 ft/lbs torque—36% more power than the PT6A-21.

This additional power results in faster climbs to higher altitudes.

Time to Climb in Minutes

The XP
Take off at 9,000 lbs, ISA, No-wind C90A XP135A Advantage
To FL160 9 7
An average of
To FL220 14 12 20% quicker
climb time
To FL260 19 15

1
Model C90A performance, page 5-32
2
Model C90GT performance, page 5-46

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rev. 8/09
 Financial Analysis
of the King Air C90A with the
Blackhawk XPR135a Engine upgrade

The XP135A cruise

Cruise Performance
speeds are from 10%
to 14% greater than 8.500 lbs, Max Cruise 1900 RPM, ISA
the standard C90A. FL160 C90A XP135A The XP Advantage

Torque (ft/lbs/Engine) 1,246 1,520

Fuel Flow (lbs/hr) 592 642 25 knots faster

Speed (KTAS) 247 272

FL220
Torque (ft/lbs/Engine) 1,014 1,355
Fuel Flow (lbs/hr) 490 576 29 knots faster
Speed (KTAS) 242 271
FL260
Torque (ft/lbs/Engine) 862 1,170
Fuel Flow (lbs/hr) 422 504 32 knots faster
Speed (KTAS) 235 267

If long range and efficiency is required, you still have the option of climbing to higher altitudes
and reducing power to maximum range cruise. Even though the PT6A-135A is more powerful
than the PT6A-21, if needed, it can also be more efficient.

Efficient performance
8,500 lbs, Max Range 1900 RPM, ISA
FL260 C90A XP135A The XP Advantage
Fuel Flow (lbs/hr) 304 302
Less fuel, more speed
Speed (KTAS) 195 202

For “real world” considerations, we calculated a pair of typical trips. One was a trip with four
passengers, 300 NM. We used NBAA IFR fuel reserves for a 100 NM alternate. Because the
Blackhawk XP135A has a significant power advantage over the C90A, it arrives sooner, and
yet, burns less fuel.

King Air C90A Blackhawk XP135A

Trip Distance 300 NM 300 NM
Altitude FL 160 FL 220
Time (take-off to touch down) 1 hr 18.5 mins. 1 hrs 13.7 mins.
Average Speed 229 kts 244 kts
Average Fuel Used 784 lbs 758 lbs

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rev. 8/09
 Financial Analysis
of the King Air C90A with the
Blackhawk XPR135a Engine upgrade

For a long range trip, we assumed three passengers and 700 NM. We used NBAA IFR fuel
reserves for a 100 NM alternate. Again, since the Blackhawk XP135A has a significant power
advantage over the C90A, it arrives sooner and burns less fuel.

King Air C90A Blackhawk XP135A

Trip Distance 700 NM 700 NM
Altitude FL 220 FL 260
Time (take-off to touch down) 3 hrs 2.6 mins. 2 hrs 47.3 mins.
Average Speed 230 kts 251 kts
Average Fuel Used 1,520 lbs 1,453 lbs

For the long range trip, the Blackhawk XP135A arrives over a quarter-hour sooner while burn-
ing 10 gallons less fuel.

Based on the 300 NM trip, we calculated the annual hours for 63,023 NM utilization—equates
to the average utilization3 of 275 hours/year for a PT6A-21 powered model C90.

King Air C90A Blackhawk XP135A

Flight Time for 63,023 NM/Yr 275.0 hrs 258.1 hours
Fuel for 63,023 NM/Yr 24,570 gallons 23,751 gallons

For an average year’s travel, the Blackhawk XP135A saves both time and fuel versus the
standard King Air C90A.

Reduced Operating Costs

The PT6A-135A, in addition to being more powerful than the PT6A-21 engine, also costs less
to maintain.
Engine Set-aside
PT6A-21 Cost Interval
Mid-life $32,100 1800 hrs
Overhaul $244,000 3600 hrs
Total for two engines $552,200 $153.39 per hour set-aside

PT6A-135A Cost Interval

Mid-life $30,000 1800 hrs
1st Overhaul $200,000 3600 hrs
Total for two engines $460,000 $127.78 per hour set-aside

At a PT6A-21 overhaul, the engine conversion to the Blackhawk XP135A would avoid a poten-
tial overhaul expense of $488,000 for a pair of engines.

3
Vref Aircraft Value Reference (resale price guide) average annual hours for a C90

7601 Karl May Drive | Waco, TX 76708 Report based on research prepared by
Phone: 254.755.6711 | www.blackhawk.aero Conklin & de Decker Aviation Information | Page 3
rev. 8/09
 Financial Analysis
of the King Air C90A with the
Blackhawk XPR135a Engine upgrade

Using the Conklin & de Decker Life Cycle Cost data, we calculated the average hourly costs
for a King Air C90A and a Blackhawk XP135A. The costs calculated were for 10 years and are
averages for the following items:
• Fuel. Fuel burn was calculated for a 300-nautical-mile trip using the manufactur-
er’s aircraft performance manuals. It was assumed that four passengers plus bags
(200 lb each) were on board; fuel reserves were based upon an NBAA IFR 100 NM
alternate. Standard conditions (ISA), no-wind were used.
• Maintenance Labor. This is the labor required to accomplish scheduled and un-
scheduled maintenance on this aircraft.
• Parts. This is the cost of parts required to accomplish all unscheduled and minor
scheduled maintenance on this aircraft.
• Inspections. This covers set-asides for the estimated cost of major airframe inspections.
• Engine Restoral. As calculated above. Assumes the engines make it to overhaul with-
out incurring a premature removal and that the expenses are typical for that engine.
• Parts Guaranteed Mx Plan. N.A.
• Airframe Guaranteed Mx Plan. N.A.
• Avionics Guaranteed Mx Plan. N.A.
• Component Overhaul (All). This covers set-asides for the estimated cost of major
At $4.75 per gallon average component overhauls. This includes the propellers.
fuel cost, the typical annual
operating cost of a Black- • Life Limited Components (All). This covers set-asides for the estimated cost of major
hawk XP135A is 14% less life limited components.
than for a C90A.

King Air C90A The average Non-fuel Variable Costs were calculated and then the
fuel savings were calculated separately. The non-fuel variable costs
NM Flown/Year 63,023 are detailed in Appendix A and are:
Hours 275.0
Variable cost/hr - no fuel $539.91 King Air C90A Blackhawk
XP135A
Fuel cost/hr ($4.75/gal) $432.25 Non Fuel Cost/Flight Hour $539.91 $443.53
Average Variable Cost/Hr $972.16
TOTAL Variable Cost/Year $267,344.00
When to do the conversion?
At Overhaul:
Blackhawk XP135A The typical cost of the Blackhawk conversion is $674,000 installed
NM Flown/Year 63,023 ($639,000 for the engines plus $35,000 for installation parts & labor).
Hours 258.1
Conversion at Overhaul
Speed Advantage at Cruise 24.0 (2) PT6A-21 overhaul avoided ($488,000)
Variable cost/hr - no fuel $443.53 (2) PT6A-135A conversions $674,000
Net Cost = Initial Investment $186,000
Fuel cost/hr ($4.75/gal) $446.50
Average Variable Cost/Hr $890.03 When accounting for the PT6A-21 overhaul costs avoided, the
TOTAL Variable Cost/Year $229,718.00 Blackhawk conversion has a net cost of only $186,000.

These costs ignore the value added to a PT6A-135A powered

Annual Operating Cost Savings $37,626.00 King Air XP135A.

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rev. 8/09
 Financial Analysis
of the King Air C90A with the
Blackhawk XPR135a Engine upgrade

Potential for Added Resale Value

The Blackhawk XP135A has established a record of increased value after the conversion.
A popular aircraft value reference, Vref, in their appraisal points for the King Air C90 adds
$674,000 to the aircraft value for Blackhawk conversion4. That price happens to be the full
cost of the conversion with installation with no discount.

It is doubtful to assume that an operator will perform the conversion just to sell their King Air
immediately afterwards. However, if a sale after conversion were required, there is a very high
likelihood of enhanced value.

What about over a period of time? Return on Investment has a number of ways to be calcu-
lated. In this analysis we used the following considerations:

• Five years operation at 258 hours per year with operating cost savings.
• A reduction in the enhanced value of the Blackhawk XP135A engines based upon
the Vref value adjustment method for engine time of a PT6A-135A of $55.55 per
engine hour. (First overhaul estimate of $200,000 divided by 3600 hours).

For our analysis, we also conservatively assumed that the Blackhawk XP135A conversion
would only add 90% of the cost of conversion to the value of the aircraft. We also looked
at the annual operating cost savings of operating the Blackhawk XP135A as compared to a
standard C90A. If performing the conversion at the time the PT6A-21 engines are due for
overhaul, the five year Return on Investment looks like this:

Return on Total Operating

Investment Blackhawk XP135A Cost Savings Annual Return
Enhanced value
At Conversion $606,600
After Year 1 $577,922 $37,626 $615.548
After Year 2 $549,244 $75,252 $624,496
After Year 3 $520,566 $112,878 $633,444
After Year 4 $491,888 $150,504 $642,392
After Year 5 $463,210 $188,130 $651,340

Initial Investment ($186,000)

Added Residual Value $463,210
Operating Costs Saved $188,130
Excess return over initial investment if converted at mid-life $465,340

After five years operation, there is still a net excess return over the initial investment of the
Blackhawk XP135A conversion.

Conclusion
Our analysis shows that for a King Air C90A operator whose engines require overhaul, an en-
gine upgrade to the PT6A-135A offers increased performance, increased efficiency, and net
cost savings due to the value added offsetting the expense of the conversion.

4
Vref for Windows, 2008 – Volume 4.

7601 Karl May Drive | Waco, TX 76708 Report based on research prepared by
Phone: 254.755.6711 | www.blackhawk.aero Conklin & de Decker Aviation Information | Page 5
rev. 8/09
 Financial Analysis
of the King Air C90A with the
Blackhawk XPR135a Engine upgrade

Appendix A king air C90A vs. Blackhawk Xp135A

Used King Air

Direct Cost (average) Used King Air C90A Blackhawk XP135A
Fuel - -
Fuel Additives/Lubicants - -
Maintenance Labor $172.87 $142.93
Parts $174.17 $133.06

Inspections $8.19 $8.20

Engine Restoral $153.39 $127.78
Engine Guaranteed Mx Plan - -
Parts Guaranteed Mx Plan - -
Airframe Guaranteed Mx Plan - -
Avionics Guaranteed Mx Plan - -

Component Overhaul (all) $18.71 $17.32

Life Limited Components (all) $12.58 $14.24

Other Services - -
Flight HourCost - -
Fixed Cost - -
Landing/Parking Fees - -
Crew Expenses - -
Small Supplies - -
Total Direct Cost per Hour/10 yr. avg. $539.91 $443.53

Calculated with Conklin & de Decker Aircraft Cost Evaluator (Win)

Type of Operation: Corporate; Program Length: 10 years

7601 Karl May Drive | Waco, TX 76708 Report based on research prepared by
Phone: 254.755.6711 | www.blackhawk.aero Conklin & de Decker Aviation Information | Page 6
rev. 8/09