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Ref.: 

Re : 

1117 CJ Schiphoi-Oost 

The Netherlands 

Fokker50Freighter STC Corp 

Attn.: Arnaud J. Smit, President 

13394 East Control Tower Road 

Englewood, Colorado 80112 

United States of America 

Cc: Randy Blosser 

8249 Dote: February 191

h 2013 

FAA request for further information with regards to the petition to increase the maximum operating 

altitude from FL200 to FL250 for the FokkerSOFrelghter aircraft equipped with Large Cargo Door 

Installations r STC ST01916LA . 

Dear Mr. Smit, 

With reference to FAA's letter dated 28 January, 2013 requesting for more supporting 

information with regards to the abovementioned petition, we can inform you as follows. 

1) Fuel and Emission reduction - FL250 

We have attached a fuel savings calculation comparing the fuel used on a normal and 

average flight profile for the Fokker 50 at FL 250 (which is the normal passenger 

version) and FL200 for the Fokker50Freighter. This calculation is performed by the 

senior airline analyst from the OEM (Fokker Aircraft Company), who has retired but 

is still actively consulted by the industry and the OEM for route studies and other 

airline studies related to the Fokker Aircraft Products. 

The calculation shows a 9.19% fuel saving or an approximately 52 kilogram of fuel 

per flight hour in case the flight is done on FL250. With an average utilization of 1200 

FH per year this amounts to at least 62,000 kg less fuel spend per year (per aircraft). 

This also translates to a (9 .19 %) reduction of emissions, which is at least 725 kg NOx 

and 312 kg CO per year per aircraft (deducted from attached study results from the 

Swedish Defense Research Agency FOI dated 17 December 2001). 

2) Fuel and Emission reduction - Operational Flexibility 

The possibility of flying at FL250 will also have a substantial impact on the 

operational flexibility and flight time. We have consulted the airlines again and their 

feedback was loud and clear. This aircraft has a designed potential to fly at FL250, but 

the Freighter operation is limited to FL200 only because the pilots are not allowed to 

fly with supplemental oxygen to a cabin altitude of 12,000 ft. 

This is for the airlines a serious operational limit which has a substantial impact on the 

amount of wasted fuel by rerouting for the lower FL due to A TC issues, natural 

barriers, weather avoidance and plain safety reasons which would not occur if the 

FL250 could be used. It even means that some routes cannot be served at all. 

1 

Rabobank: 

I BAN: Nl24 RABO 0126878048 

Co( Amsterdam: 34198811 

VATnr: Nl8129.07.978.B01 

mRinr: NLB1290797B 
AircraftConversions 

Plane Solutions 

One airline quoted that they are highly penalized at FL200 such as: 

Quote .... 

-unable to fly the airway on Mont Blanc, we waste at least 15 minutes from Bergamo 

Airport to Charles de Gaulle Airport 

- Bergamo to the UK, we must fly through Brussels with at least 20 minutes more 

because not allowed to fly above Paris 

- Routes above some countries can not be flown due to the restriction of minimum 

altitude ofFL250, which means that significant rerouting over other countries is 

required. 

- Several more cases can be listed . 

...... Unquote 

Considering the above specific cases a reduction of at minimum 350 kg fuel wastage 

on a 5 Flight Hour mission (10% reduction or 70 kg fuel per FH) and thus 10% Fuel 

emission can be saved. This does not yet include the benefits from other specific cases. 

Another airline quoted: 

Quote .... 

. . . that most important of all must be the environment savings and fuel savings. Higher 

altitude and modified aircrafts with 8:33 Khz channel spacing will open up other 

routes up in the sky that must be one of the primary reasons to get higher level. 

..... Unquote 

In discussions with potential customers, the FL restriction is a major discussion point 

as well. Moreover, one of the airlines is already flying their fleet of older type Fokker 

F27's at FL250 with supplemental oxygen for many years without any significant 

problems. 

3) Conclusively 

It can be said that a total reduction fuel and emissions of at least 52 kg per flight hour 

for higher altitude (Ref 1) and 70 kg per flight hour for operational flexibility (Ref 

2) can be achieved. This means that a reduction of 146,400 kg fuel wasted per year per 

aircraft and reduction of related emissions can be achieved if the request can be 

granted. 

With kind regards, 

2 
AircraftConversions 

Plane Solutions 

Influence flight level on fuel consumption 

Cruise condition 

Speed schedule 

Actual cruising altitude 

: ISA, no wind 

Proc. 5H3 alternate 

Climb 150 kts CAS 150 kts CAS 

Cruise 227 kts/M.507 99% best sfc 

Descent 227 kts CAS 180 kts CAS 

: Lowest of minimum rate of climb 200 ftlmin or 

minimum 20% of distance covered in cruise 

Max. aircraft rate of descent: 3000 ftlmin 

Max. cabin rate of descent : 300ft/min 

Manoeuvring allowances Time 

4 min 

2 min 

4 min 

2 min 

Fuel reserves applied 

Payload 

Result 

Route distance 550 nm 

Block time [min]: 

Block fuel [kg] : 

Payload [kg] : 

MRL-50-fff-140213-fl250-2b 

Engine start and taxi-out 

Take-off to start of climb@ 1000 ft: 

Approach and landing from 1 000 ft: 

Taxi-in 

Total 12 min 

No distance credit during manoeuvring 

: - Diversion to standard alternate at 87 nm plus 

- 45 minutes extended cruise 

: 60% of max. structural payload 

FL200 FL250 Diff. VS 

FL200 

134.2 138.4 

1306 1186 -9.19% 

4260 4260 

fueli 

23 kg 

35 kg 

28 kg 

12 kg 

98 kg 

r 
om080501 Fokker 50 Srs 100 AIR TRAFFIC 

Method Master using Hurdy-Gurdy 1.2 

Method Expiation Hurdy-Gurdy manages Flight Cases, where performance, fuel comsumption and emissions are 

based on modelling of results according to PIANO (above Lto altitude) and HARP (Lto) methods. 

PIANO is a trademark of Lissys Ltd, UK. 

Copyright 2001 FOI, Sweden. 

Creator FOI Aviation and Environment 

Date 2001-12-17 

Aircraft ID Fokker 50 Srs 100 

Hurdy_Gurdy Key Fokker 50 Srs 100, Cabin Factor 65% 

Emission_ key PW125B 

No of Engines 2 

Engine Category Turboprop 

Cabin Factor 65% 

C02 Fuel Factor 3,16 

Flight_Distance [nm] 125 250 500 750 1000 1500 

Flight Distance [km] 232 463 926 1389 1852 2778 

Flight Altitude [ft] 25000 25000 25000 25000 25000 25000 

Flight Altitude [m] 7620 7620 7620 7620 7620 7620 

Takeoff Mass [kg] 16280 16534 17043 17553 18063 19085 

Landing Mass [kg] 15950 15950 15950 15950 15950 15950 

Sum Total Time [min] 53,26 83,45 143,83 204,23 264,66 385,59 

Sum Lto Time [min] 16,35 16,38 16,44 16,5 16,56 16,68 

Time Taxi Out [min] 5 5 5 5 5 5 

Time Take Off [min] 0,31 0,31 0,32 0,33 0,33 0,35 

Time Climb Out [min] 1,2 1,22 1,28 1,33 1,38 1,48 

Time Climb Cruise Descent 3000 ft [min] 36,91 67,07 127,39 187,73 248,1 368,91 

Time Approach Landing [min] 4,85 4,85 4,85 4,85 4,85 4,85 

Time Taxi In [min] 5 5 5 5 5 5 

Sum Total Fuel [kg] 427,8 681,6 1189,5 1697,9 2206,8 3226,3 

Sum Lto Fuel [kg] 124,1 124,6 125,7 126,7 127,7 129,7 

Fuel Taxi Out [kg] 28,8 28,9 29 29,1 29,2 29,4 

Fuel Take Off [kg] 5,6 5,7 5,8 6 6,1 6,4 

Fuel Climb Out [kg] 18,1 18,5 19,3 20,1 20,9 22,4 

Fuel Climb Cruise Descent 3000 ft [kg] 303,6 557 1063,9 1571,2 2079,1 3096,5 

Fuel Approach Landing [kg] 42,7 42,7 42,7 42,7 42,7 42,7 

Fuel Taxi In [kg] 28,8 28,8 28,8 28,8 28,8 28,8 

Sum Total NOx [kg] 5,378 8,214 13,893 19,58 25,277 36,705 

Sum Lto NOx [kg] 1,244 1,252 1,268 1,284 1,3 1,332 

NOx Taxi Out [kg] 0,208 0,208 0,209 0,21 0,21 0,212 

NOx Take Off [kg] 0,103 0,104 0,107 0,109 0,112 0,117 

NOx Climb Out [kg] 0,296 0,302 0,315 0,327 0,34 0,365 

NOx Climb Cruise Descent 3000 ft [kg] 4,134 6,962 12,625 18,296 23,977 35,373 

NOx Approach Landing [kg] 0,43 0,43 0,43 0,43 0,43 0,43 

NOx Taxi In [kg] 0,207 0,207 0,207 0,207 0,207 0,207 

Sum Total HC [g) 0 0 0 0 0 0 

Sum Lto HC [g] 0 0 0 0 0 0 

HC Taxi Out (g] 0 0 0 0 0 0 

HC Take Off (g] 0 0 0 0 0 0 

HC Climb Out [g] 0 0 0 0 0 0 

HC Climb Cruise Descent 3000 ft (g] 0 0 0 0 0 0 

HC Approach Landing [g] 0 0 0 0 0 0 

HC Taxi In (g] 0 0 0 0 0 0 

Sum Total CO [g] 2580,9 3717,1 5990,1 8264 10539 15092,6 

Sum Lto CO [g] 724,1 725,4 728,1 730,8 733,5 738,9 

CO Taxi Out [g] 259,5 260 261 261,9 262,8 264,7 

CO Take Off [9] 11,3 11,4 11,7 12 12,2 12,8 

CO Climb Out [g] 34,5 35,2 36,7 38,1 39,6 42,6 

CO Climb Cruise Descent 3000 ft [g] 1856,8 2991,7 5262 7533,3 9805,5 14353,7 

CO Approach Landing [g] 159,8 159,8 159,8 159,8 159,8 159,8 

CO Taxi In [g] 258,9 258,9 258,9 258,9 258,9 258,9 

Emission Inventory Guidebook Page 1 of 1 8851