@Koyovis I'm still not buying it, a cat launch will mean heavier beefier landing gear, even if low acceleration, because that's an unusual direction of force on the LG; and a tailored engine won't save much, the smaller fan GE90 ranges from 360-433 kN, the higher settings are just different software, so if we were to envision a 'smaller' GE90 targeted at the 360 figure, it will cost more to maintain, as it will be running at its max setting then

@Koyovis on the wider topic of going green, let planes fly oceanic routes, and let's focus on trains for the continental travel

@ymb1 The landing gear is dimensioned to absorb impact at 10 m/s vertical speed, with all the forces associated with a huge bang like that. The direction of force on the gear is the same as that of reverse thrust - nothing to beef up. Yes the design costs of an engine series are huge and limiting thrust by software is cheap, but for large numbers like the A320 and B737 it might be worthwhile for the manufacturers. I see only problems of economy and investment, not technical problems really.

@TannerSwett you say "merely", but the truth is both the ailerons and rudder work together when you want to turn

@Koyovis 10 m/s is close to 2,000 FPM, according to Boeing their jets are designed for 600 FPM touchdowns, and 350 when overweight. Legend has it the 747 is 1000 FPM, close to carrier-borne acft, if yoy watch a carrier landing where there is a RIO, he/she would be calling 700, 600, 700, 700, etc, that's the V/S they maintain down to deck

but perhaps the 600 is the plane, so the LG may take 2000, but then it will survive intact, on its own :D

like this:

@ymb1 yeah, 2000FPM would be basically a "limit load" figure, while 600FPM would be simply a no-flare landing

@mins this ^^^ is what I mean when I say that deleting your comments indiscriminately creates more problems than it solves. Now the post is gone, so in this particular case no major harm done, but in all other cases there are replies than now do not have their original comment, so context is completely lost.

Losing context creates more distraction than having one extra comment there. If you really feel they are not needed, please flag them!

:42421449: Will try to not forget next time!

However look at the chronology... the last comment was posted after I deleted my last comment (unless I'm wrong)

yes, was posted after, but given the length they could have started writing it before. anyway, my point stands :P

@ymb1 Answering your old message. The point I wasn't sure is about resetting the direction of the INS axes with the ILS locator signal. To me the INS position can be reset using the GPS fix (I wrote 'aligned', but this is not a full alignment).

This indeed reset the offset accumulated prior to this operation, no pb with that. However the next INS position will be calculated using this reset position (accurate) and a 3D increment (accurate, from accelerometers). This increment is based on the current INS system of reference (3 axes, that have drifted with time, and were not realigned like the position) which is not accurate.

So the result is not accurate either. After adding increments in the wrong direction up to 100 ft, maybe the error will be 10 ft... (if the axis had drifted by 90° :-( the error would be of 100 ft in two axes). So unless the INS angular system can be reset from the GPS or the ILS locator, the position reset is not sufficient. So the question is whether you can reset the INS both in location and in orientation? (and was the APALS capable of that?)

@Federico : You point stands indeed.

I just wanted to note, if this were the olympics, I'd be winning in the gold medal count I do believe. It's my one claim to fame in all of stack overflow I believe.

@JayCarr whoa nice haul!

@mins I'm not convinced yet, the INS can be upside down, what is doing the calculation is the FMS--as for APALS, if he rumors are true, the project was shut down by the government, export embargo on all SAR technology, which was lifted in 2000's I think

@JayCarr almost forgot--welcome back! :P