Why does the B738 take so much runway?
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Expedite,
Because of this greatly reduced MTOW, and the fact that you cannot legally derate by more than 25%, this means that at many airfields, the 757 and 767 are taking off with considerably greater thrust than is required. I would assume that this is seldom the case for a 738?
Because of this greatly reduced MTOW, and the fact that you cannot legally derate by more than 25%, this means that at many airfields, the 757 and 767 are taking off with considerably greater thrust than is required. I would assume that this is seldom the case for a 738?
Props are for boats!
Join Date: Oct 2000
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Doors auto 
Well it may have felt like 1800ft Sir but, really?
I dont fly jets, but I am on a DHC-6-300 Twin Otter which you all may have heard. Its a STOL 19 seat Turbo Prop, still very popular in the PNG New Guinea and Africa and any other Countries that has short strips or short commutes.
Take off Distance on a 35 degree day, nil wind, nil slope, at MTOW which is 12,500 lbs, sea level, and Temp adjusted torque computer power Setting will give a take roll to 50 feet agl of the following:
1. FLAP SET 10 deg-------1750 ft
2. FLAP SET 20 deg-------1350 ft.
Now your telling me a 757 can nearly match this?
May remind all of you, when you watch these Jets take off, do you know what their respective loads are?
Because in the Otter for eg. when Im light we can get Airborne with 20 Flap in around 800-900 if needed.
Im at MBJ and I see the 738S take off here, AA and Delta and yes, they use alot of Runway in the busy period. Runway here is just over 8000ft.
Virgin Blue in Australia have 738 and 737-700. The later version they aquired with the smallest powerplant available as they were made for another Carrier that didnt go thru with the lease. These Jets pose obviously different calculations and performance than a standard -700. Its the same with - 800S it depends on the Engine thrust option ordered with the Aircraft.
Generally though the "Hair Dryer" CFM56 doesnt have the Thrust of a "Roller" OR BIG "PRATT". Hence the reason there on all the Plastic Buses and New Gen 737 which was incidently derived to compete with the Airbus hence the same Engine selection.
In the end You would have to get the books out guys to compare. Maybe someone out there can do the Math if they have the Manuals. 757, 737-800 Comparison or whatever.
Regards
Sheep
once experienced a shorter t/o run in a 757 than in a Cessna - about 1800ft.
I dont fly jets, but I am on a DHC-6-300 Twin Otter which you all may have heard. Its a STOL 19 seat Turbo Prop, still very popular in the PNG New Guinea and Africa and any other Countries that has short strips or short commutes.
Take off Distance on a 35 degree day, nil wind, nil slope, at MTOW which is 12,500 lbs, sea level, and Temp adjusted torque computer power Setting will give a take roll to 50 feet agl of the following:
1. FLAP SET 10 deg-------1750 ft
2. FLAP SET 20 deg-------1350 ft.
Now your telling me a 757 can nearly match this?
May remind all of you, when you watch these Jets take off, do you know what their respective loads are?
Because in the Otter for eg. when Im light we can get Airborne with 20 Flap in around 800-900 if needed.
Im at MBJ and I see the 738S take off here, AA and Delta and yes, they use alot of Runway in the busy period. Runway here is just over 8000ft.
Virgin Blue in Australia have 738 and 737-700. The later version they aquired with the smallest powerplant available as they were made for another Carrier that didnt go thru with the lease. These Jets pose obviously different calculations and performance than a standard -700. Its the same with - 800S it depends on the Engine thrust option ordered with the Aircraft.
Generally though the "Hair Dryer" CFM56 doesnt have the Thrust of a "Roller" OR BIG "PRATT". Hence the reason there on all the Plastic Buses and New Gen 737 which was incidently derived to compete with the Airbus hence the same Engine selection.
In the end You would have to get the books out guys to compare. Maybe someone out there can do the Math if they have the Manuals. 757, 737-800 Comparison or whatever.
Regards
Sheep
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Bally,
You are quite correct, but not sure on the 757 'most airfields' will be well below the max derated MTOW.
Dont know about the loads and fuel that MIA emp is referring to, but with a 233 pax today, LGW - AGP, 15 tonnes fuel, TOW was off the top of my head circa 94 tonnes. Well below 113400 (or as we call it 102,000). Yer the derate was to 53 degrees, the max derate being 57.
Homeward bound with just 180 pax, 13 tonnes, AGP rwy 14 (out to sea), yes it was a max derate, but only just.
I suppose the answer would be to get hold of some performance charts for miami ??
You are quite correct, but not sure on the 757 'most airfields' will be well below the max derated MTOW.
Dont know about the loads and fuel that MIA emp is referring to, but with a 233 pax today, LGW - AGP, 15 tonnes fuel, TOW was off the top of my head circa 94 tonnes. Well below 113400 (or as we call it 102,000). Yer the derate was to 53 degrees, the max derate being 57.
Homeward bound with just 180 pax, 13 tonnes, AGP rwy 14 (out to sea), yes it was a max derate, but only just.
I suppose the answer would be to get hold of some performance charts for miami ??
