ATR-72 500 & A-320 200 OPERATING & DISPOSAL COSTS

For what concerns the operating cost, the Roskam model is still the best one for calculating it because it is the only one that takes into account the importance of the depreciation periods and depreciation coefficients. Once again, in order to calculate , the software Matlab was used. As it has been made for the manufacturing and acquisition costs, the parameters that had already been set in the RDTE cost inputs are not reported one more time. The inputs are shown in table 4.5:

TOTAL AEP M-USD 21.65 102.7

ATR-72 500 A-320 200

MAN & ACQ OUTPUT

N

_m

N

_m

= 875

C

_OPS

OPERATING

INPUT ATR-72 500 A-320 200

Range [nm] 230 874.43

Burned fuel weight [Lbs] 1220 4636

Engine MMH/FH 0.8 1

Airframe MMH/FH 0.8 1

OPERATING INPUT

BFW B_d

MMH_air MMH_eng

Fuel cost [USD/GALLON] 2 2

Fuel density [lb/gallon] 6.4 6.4

N. of first officers 1 1

N. of captains 1 1

N. of flight assistants 2 4

Engine depreciation [Y] 15 20

Airframe depreciation [Y] 15 20

Avionic depreciation [Y] 10 10

Airframe spare parts depreciation [Y] 15 20

Engine spare parts depreciation [Y] 15 20

Airframe spare parts factor 0.4 0.4

Engine spare parts factor 0.5 0.5

Airframe depreciation factor 0.9 0.9

Engine depreciation factor 0.9 0.9

Avionic depreciation factor 0.95 0.95

Airframe spare parts depreciation factor 0.9 0.9 Engine spare parts depreciation factor 0.9 0.9

Crew factor 0.26 0.26

Captain annual salary [USD] 80000 80000

First officer annual salary [USD] 70000 70000 Flight assistant annual salary [USD] 28000 28000

Annual crew flight hours [h] 900 900

Travel expense factor [USD/blhr] 7 7

Airplane maintenance labor rate [USD/h] 16 16

Engine maintenance labor rate [USD/h] 16 16

ATR-72 500 A-320 200 OPERATING

INPUT

ENGs_f N_fass

AH AVIONICd_f

AVION_d

R_leng F_c

K_j AIRFs_f N_captain

SAL_fass ENGd_f AIRF_d

R_lap ENGs_df

ENGs_d N_officer

SAL_officer AIRFd_f

ENG_d

TEF AIRFs_df

AIRFs_d F_density

SAL_captain

Table 4.5ROSKAM operating cost program inputs

As we can easily see from table 4.5, there are far more input data required to compute the operating cost. This happens because both the direct operating costs and the indirect ones take into account many factors, from crew members salaries to the depreciation of every single aircraft system. For instance:

•

, the crew factor, accounts for such items as: vacation pay, cost of training, crew premium, crew insurance and payroll tax. It strongly varies from operator to operator and it is often suggested to use 0.26 as a value of reference

•

is associated with each tipe of crew member. It deals with costs related to hotel stay and travel expenses in general. Since flight crews normally stay in the same hotel, it is not necessary to vary this coefficient from one member to another

•

is an empirical coefficient which has been derived from figure 4.3

•

^and are factors intended to cover expenses such as: building, lighting, heating, as well as administrative costs related to the airplane maintenance.

They were derived from figure 4.4

•

represents the crew interchange factor ( ). More precisely, it takes into account that every aircraft does not have a single crew operating all year long but they interchange

Attained period between engine overhaul [h] 3000 3000 Attained period between engine overhaul

factor

1.4 1.4

Overhead distribution factor for labor cost 1.3 1.3 Overhead distribution factor for material

cost

0.6 0.6

Navigation fee per flight [USD/flight] 10 10

Crew interchange factor 2.8 2.8

Taxes coefficient 5 5

Disposal factor 0.012 0.012

ATR-72 500 A-320 200 OPERATING

INPUT

K_hem

f_disp H_em

f_tax f_change

C_apnf f_ambmat f_amblab

K

_j

TEF

K

_Hem

f

_amblab

f

_ambmat

f

_change

1.5 < f

_change

< 3.5

•

is a coefficient that takes into account the increase of taxes (landing fees, registry taxes and navigation fees) occurred between 1971 and 2017

different kind of airplane management

Figure 4.4 and for different kind of airplane management [48]

Figure 4.3 graphic for turbine and reciprocating engines [47]

A precise and detailed estimation on the block hour value has been made as well. The world “block-hour” represents the average journey made by the aircraft itself. Once the block hour gross amount is known, the sub-items were calculated and put in the Matlab software. After having estimated them, the aircraft block speed was computed assuming the aircraft speed per flight phase. The results are shown in the following table:

f

_tax

f_amblab f_ambmat

H_em− K_Hem

V

_bs

Table 4.6 ROSKAM block hours division

As said before, the Roskam model is the best cost model for the operating cos phase as well for it takes into account the depreciation. The cost estimation relationships (CERs) are given in US dollars per nautical mile, as we have considered the aircraft block hours; derived in table 4.6. The results are summarized in the following table:

OPERATING

INPUT ATR-72 500 A-320 200

Ground maneuver [h] 0.15 0.15

Climb [h] 0.25 0.2

Descent [h] 0.2 0.15

Maneuver ATC [h] 0.08 0.08

Cruise 0.54 1.5

Block-time [h] 1.14 2

Block speed [Kts] 201.75 437.21

t_cr t_atc t_de t_cl t_man

V_bs t_bl

OPERATING OUTPUT ATR-72 500 A-320 200

Crew cost USD/nm 4.29 2.48

Fuel & Oil cost USD/nm 1.74 1.74

Insurance cost USD/nm 1.36 1.69

DOC of flying USD/nm 7.39 5.91

Airframe/Sys (labor) USD/nm 0.065 0.037

Airframe/Sys (material) USD/nm 2.76 5.9

Engines (labor) USD/nm 0.17 0.098

Engines (material) USD/nm 0.41 0.56

Applied maintenance burden

USD/nm 2.1 3.94

OPERATING OUTPUT

Table 4.7ROSKAM operating cost program outputs

In order to compute the operating costs per year, per aircraft fleet, we must use formulas 1.34 and 1.35:

+ = 13.5 [B-USD] for ATR-72 500 (4.1)

+ = 42.5 [B-USD] for A-320 200 (4.2)

This is the cost an aircraft company has to undergo every year in order to fly its fleet of ATR-72 500 and A-320 200. The term (the block distance) is nothing more than the

DOC of maintenance USD/nm 5.52 10.55

Airframe depreciation USD/nm 2.14 3.2

Engines depreciation USD/nm 0.12 0.1066

Avionic depreciation USD/nm 0.22 0.23

Airframe spare parts depreciation

USD/nm 0.93 1.33

Engine spare parts depreciation

USD/nm 0.092 0.08

DOC of depreciation USD/nm 3.51 4.97

Landing fees USD/nm 2.18 1.94

Navigation fees USD/nm 0.21 0.057

Registry taxes USD/nm 0.23 0.29

DOC of fees/taxes USD/nm 2.62 2.28

TOTAL DOC USD/nm 19.43 24.18

TOTAL IOC USD/nm 9.72 12.09

Total Operating Cost USD/nm 29.15 36.27

ATR-72 500 A-320 200 OPERATING OUTPUT

C

_OPS

= (DOC)(R

_bl

)

_i

N

_i

(IOC)

_i

(R

_bl

)

_i

N

_i

C

_OPS

= (DOC)(R

_bl

)

_i

N

_i

(IOC)

_i

(R

_bl

)

_i

N

_i

R

_bl

product between and and it was computed in the Matlab software. The indirect operating costs have been calculated simply as the half of the DOC and it is an estimate which is close to market estimates as well. The result shown in 4.1 and 4.2, are the operating costs of the entire fleet per year; if we want to obtain the operating cost of the single aircraft per year, we only need to divide that result by , thus having:

million USD for the ATR-72 500 and million USD for the A-320 200. If we want to know the total operating costs (meaning the operating cost incurred during the whole time the aircrafts are flying during their operative lives) we

only need to multiply the terms and by , which

is normally the operative time taken as reference for these types of airplanes. In formula:

203.3 [B-USD](4.3) 850 [B-US] (4.4)

The 4.3 is related to the ATR-72 500 while the 4.4 is related to the A-320 200. Now we have all the variables that allow us to calculate the life cycle cost (LCC): the total cost required to research, develop, test, produce and fly our ATR-72 500 and A-320 200 fleets. Using formula 1.1.

225.96 [B-USD] for ATR-72 500 (4.5)

958.29 [B-USD] for A-320 200 (4.6)

Where the disposal cost for both aircrafts has been calculated using the following two formulas:

2.71 [B-USD] for the ATR-72 500 fleet (4.7)

= 11.5 [B-USD] for the A-320 200 fleet (4.8)

V

_bs

t

_bl

N

_i

C

_OPS

= 15.49 C

_OPS

= 48.57

(DOC)(R

_bl

)

_i

N

_i

(IOC)(R

_bl

)

_i

N

_i

AIRF

_d

Total(C_OPS) = (DOC)(R_bl)_i(N_i)AIRF_d+ (IOC)(R_bl)_i(N_i)(AIRF_d) = Total(C_OPS) = (DOC)(R_bl)_i(N_i)AIRF_d+ (IOC)(R_bl)_i(N_i)(AIRF_d) =

LCC = C_RDTE + AEP + Total(C_OPS) + C_disp= LCC = C_RDTE + AEP + Total(C_OPS) + C_disp=

C

_disp

= f

_disp

(LCC) =

C

_disp

= f

_disp

(LCC)

Where is a factor associated with all the difficulties encountered in get rid of the materials and components the aircrafts are made of and it takes into account if some parts of the aircraft can be recycled and reused after the end of their operative lives. It strongly depends on many factors such as: the materials used, the form of the airplanes, the size of the aircrafts, etc…

There are precise and complex methods which would allow us to compute this voice cost; however they consider too many factors (such as: the labour cost, the material cost, the energy cost, the facilities cost, the tooling & equipment cost, the eventual residual value of the aircraft, the cost of recycle and re-certifications and various other miscellaneous costs like the overhead cost) for which it is difficult to find data easily, unlike the data found, concerning RDTE, Manufacturing & Acquisition and Operating phases. Furthermore, a deep discussion of such methods would go far beyond the aims of this document. For this reason, we have used a single factor which is often found in literature, that takes into account all the previous variables quoted (normally, the disposal cost is around 1% of the LCC or, all the same, around 10% of the AEP).

Nel documento Effetto delle nuove tecnologie sul costo del velivolo = EFFECTS OF NEW TECHNOLOGIES ON THE AIRPLANE FINAL COST (pagine 113-120)