Moderators: richierich, ua900, PanAm_DC10, hOMSaR
phugoid1982 wrote:Would you ever do this to burn a little more fuel if you're over MLW rather than dump fuel?
AirKevin wrote:phugoid1982 wrote:Would you ever do this to burn a little more fuel if you're over MLW rather than dump fuel?
Don't forget that not all planes have fuel dumping capability. None of JetBlue's planes can dump fuel.
phugoid1982 wrote:
Yeah. I didn't think the E-190 had fuel dumping capability but didn't know about the 320s. I guess for narrow bodies the difference between MLW and MGTOW is a lot smaller so that negates the need for that capability unlike the heavies.
VMCA787 wrote:phugoid1982 wrote:
Yeah. I didn't think the E-190 had fuel dumping capability but didn't know about the 320s. I guess for narrow bodies the difference between MLW and MGTOW is a lot smaller so that negates the need for that capability unlike the heavies.
Of course, you realize transport category aircraft are certified to land at its MTOW in an Emergency? The simple fact is, if you are over your MLW you don't land. Even it's just a little, you need to land below MLW.
phugoid1982 wrote:
I meant that any aircraft having an MTOW near MLW would have an easier time burning enough fuel circling or whatever to get down to MLW. Unlike, say a wide body that experienced a mechanical problem at time at takeoff fully fuelled where getting back was time critical and you couldn't afford to spend the time burning fuel to get down to MLW
VMCA787 wrote:phugoid1982 wrote:
I meant that any aircraft having an MTOW near MLW would have an easier time burning enough fuel circling or whatever to get down to MLW. Unlike, say a wide body that experienced a mechanical problem at time at takeoff fully fuelled where getting back was time critical and you couldn't afford to spend the time burning fuel to get down to MLW
You are missing my point. A narrow-body or wide-body who has an emergency after takeoff at MTOW, has the ability to come right back and land without dumping. If the PIC declares an emergency, then he can violate the AFM by using his emergency authority and fill the paperwork in after he/she lands. They aren't going to spend time, neither category of aircraft burning off fuel to get below MLW!
GalaxyFlyer wrote:I posted it 10 FPS for MLW, 6 for MTOW.
On jettisoning, see FAA AC 25-7D, page 25-1, but here’s the brief overview. The requirement for dumping is can the plane after a MTOGW take-off, allowing for 15 minutes of fuel burn meet the approach and landing climb requirements.
Section 25.1001(a) prescribes the conditions governing the need for installation of fuel jettisoning systems; if an airplane can meet the climb requirements of §§ 25.119 and 25.121(d), at the weight existing after a 15-minute flight consisting of a maximum weight takeoff and immediate return landing, a fuel jettisoning system is not required. Credit is given for the actual or computed weight of fuel consumed in the 15-minute flight using the airplane configurations, power or thrust settings, and speeds appropriate to each flight segment.
phugoid1982 wrote:VMCA787 wrote:phugoid1982 wrote:
I meant that any aircraft having an MTOW near MLW would have an easier time burning enough fuel circling or whatever to get down to MLW. Unlike, say a wide body that experienced a mechanical problem at time at takeoff fully fuelled where getting back was time critical and you couldn't afford to spend the time burning fuel to get down to MLW
You are missing my point. A narrow-body or wide-body who has an emergency after takeoff at MTOW, has the ability to come right back and land without dumping. If the PIC declares an emergency, then he can violate the AFM by using his emergency authority and fill the paperwork in after he/she lands. They aren't going to spend time, neither category of aircraft burning off fuel to get below MLW!
I meant that a widebodied a/c needs a fuel dumping mechanism to jettison fuel weight quicker than an a/c whose MGTOW is closer to its MLW and can achieve it by circling. Either way I get the gist of what you're saying. Aside, what dictates MLW? Touchdown velocity and thus tire rotation speed?