Engineer defends concept circular runway idea • Hacker News Board

Re: Engineer defends concept circular runway idea

#41

Post by htwillie » Sat, Apr 22, 2017, 3:59 AM UTC

alejohausner wrote: post #28

rpmcmurphy wrote: post #19

Earlier quoted context omitted.

If only airplanes all landed and took off at the same speed. Actual take off and landing speeds will vary depending on the aircraft's characteristics, fuel/passenger load, wind conditions, and density altitude (which varies depending on temperature and humidity). So the idea that you could build a runway with a bank angle that produces 0 lateral force for all aircraft is just not possible. Sorry.

Why couldn't the runway adapt to these conditions? Why not arrange gigantic superfast hydraulic jacks all along the track, to vary the runway's tilt, according to the needs of the current aircraft? Oh and very flexible and strong runway materials to handle the change in circumference. As long as there were no power failures, this would be a piece of cake. Frankly, the circular design isn't ambitious enough, as initia…

Yeah - make a huge rotating disc of a runway that rotates at a constant speed, so the pilot can stick the landing at whatever radius has an angular velocity equal to groundspeed.

Then slow down the disk enough to allow taxiing toward the center exit drain.

Re: Engineer defends concept circular runway idea

#42

Post by htwillie » Sat, Apr 22, 2017, 4:13 AM UTC

tropo wrote: post #37

rpmcmurphy wrote: post #36

Earlier quoted context omitted.

That was a trick suggestion. Also while dealing with flying the airplane, also be sure to keep track of whether the landing pattern is clockwise, or counter-clockwise, or was it clockwise, and which heading you are currently on and how that relates to your rejected landing turn in case you need it, which you probably will. I don't see what could possibly go wrong. All I'll say is if I was the head of the programming…

I don't see why a human has to do this. Even if they do, I don't see why it can't be done with an awareness system like the F-35 helmet. That would let you see the outline of the runway through arbitrary fog. There is no special "rejected landing turn". You rise up just a bit, keep following the runway, and retry when you wish.

> I don't see why a human has to do this.

Because a human driving the plane has a vested interest in surviving the landing.

A person who writes buggy landing software, or an operator "piloting" it from the ground can get another job if they fail.

Re: Engineer defends concept circular runway idea

#43

Post by htwillie » Sat, Apr 22, 2017, 4:29 AM UTC

For any given approach, with a circular runway there's exactly one point tangent to the runway to land. Landing short or long isn't an option.

Things are conventional because they tend to work well. And part of working well is being resilient to errors and non-optimal situations.

Re: Engineer defends concept circular runway idea

#44

Post by burfog » Sat, Apr 22, 2017, 5:32 AM UTC

htwillie wrote: post #42

tropo wrote: post #37

Earlier quoted context omitted.

I don't see why a human has to do this. Even if they do, I don't see why it can't be done with an awareness system like the F-35 helmet. That would let you see the outline of the runway through arbitrary fog. There is no special "rejected landing turn". You rise up just a bit, keep following the runway, and retry when you wish.

> I don't see why a human has to do this. Because a human driving the plane has a vested interest in surviving the landing. A person who writes buggy landing software, or an operator "piloting" it from the ground can get another job if they fail.

The Romans would put civil engineers underneath newly-built bridges, then march the army over. Very few low-quality bridges were built, and nobody built more than one low-quality bridge.

This sort of thing works for planes too.