Um, because during approach much smaller navigation errors could endanger the plane than during cruise?

Paul

Which is why this has been anticipated in the design of critical avionics - redundant microprocessors self checking each other on a regular basis in case one of them experiences such a fault. I think the Boeing 777 autopilot has 9 microprocessors (3 triple redundant multi-architecture processors).

Unfortunately when the ILS/VOR system was designed in the (1940s?) they didn't think about cell phone interference...

Paul

I'm a commercial helicopter pilot and engineer with avionics experience. I've heard of interference second hand over the years: we had one local pilot who couldn't talk to Lawrence Tower because the tower frequency at that time was a harmonic of the microprocessor in the GPS system he had on board. A pilot I fly with occasionally told me he had made a nice mount for his iPhone and it totally interfered with the tachometers in the helicopter he was flying. I was talking recently with a 757 crew and they were complaining about a passenger using a cell phone - they knew because it was bleeding over into their comm system.

If you saw how close to things an airplane gets flying an instrument approach you'd be worried about interference with the navigation radios. There is very very little room for error. I worry less about GPS because I think interference is likely to just knock the aircraft GPS receiver totally out and is very unlikely to give wrong navigational solutions. However, ILS/VOR systems worry me because they are just AM analog signals and it seems much more likely that interference could cause a wrong indication causing a pilot to (fatally) hit an obstacle on approach.

As for people getting upset when people don't listen to the crew members, I side with them. Ever had someone start pulling overhead luggage out of the bins while the aircraft is still taxiing? I have. Imagine some schmuck pulling a heavy bag out just as the plane jostles him and some unlikely fellow passenger gets injured. Would you really just sit there and let him do that? I wouldn't; I'd yell at him to sit down. Why should his fellow passengers be put at risk because of his impatience?

I think the same thing goes for electronic devices. If you really really need to use that phone, lobby FAA/FCC to allow it, but don't just ignore the crew because you don't personally think the risk is that big. It's not your decision to make! And if you decide to put the rest of us at risk by ignoring crew instructions, you shouldn't be surprised when someone gets upset with you!

You are not correct that AIRCRAFT need to stay 500 feet above the bridge. Helicopters (which are a kind of aircraft) have no specific minimum altitude limits. The pilot needs to be sure that his flight isn't going to endanger people or property on the ground.

I have done photography jobs in NYC that required very low altitude flying. I doubt I would be able to see and avoid an RC aircraft of this size. We generally can identify when a field is being used for RC flying (the people and their equipment has a generally identifiable signature). It's very very difficult to see the RC aircraft themselves because of their size, so a FPV RC aircraft being flown from a remote location is probably a collision hazard.

I'm not sure whether an RC aircraft of this size would go through a canopy or not. If the helicopter were at speed and you had a head on with an RC plane flying at 80 mph, I think there is a fair chance the RC plane could go through the bubble (it's just a piece of plastic, after all). I'm CERTAIN it would take out my tail rotor, and that could certainly lead to a fatal accident.

I guess I have the same worries about this sort of thing as I do about UAVs - the person on the ground is taking no personal risk at all, but is putting the helicopter crew and their passengers at risk for their lives. It's not a big worry right now because these things are pretty rare, but what should we do if it becomes commonplace?

Ok, so this is pretty cool because in the section where they are interviewing Jack Burness about the GT-40 version, he mentions me!

  >>> Years later, a co-worker told Burness that the reason he got into programming was because he had played Moonlander as a teenager.

I had helped to video tape a symposium on stereochemistry at Wesleyan University, and the room that we put the video equipment away happened to have a GT-40 vector graphics system in it. Some students were playing Moonlander and I got to try a few times. It was so cool that I started sneaking into Wesleyan and stealing time on their PDP-10 computer system. I taught myself BASIC, then FORTRAN, and finally assembly language. Years later I worked at a startup and worked with Jack Burness programming a graphics coprocessor. "Help" included the time I accidentally wiped out the source to all the code he had been writing for months. Luckily he had it all inside Emacs and was able to write it back out to the disk! I almost tubed the company that day! Yikes!

My recollection is that Jack told me he wrote the entire Moonlander program over a weekend for our then-boss ex-DEC executive Lorin Gale. I was also told that Moonlander was used in a case against Nolan Bushnell, where he tried to patent the idea of video games (he invented "Pong"). The options were to wheel a (huge) PDP-1 into court to demonstrate Space War, or a little (portable) GT-40 running Moonlander. The GT-40 had the nice property that since it used core memory, you could load the program and start it up, unplug the computer from the wall, transport it elsewhere (like, to a courtroom) and plug it in and have it pick up from where it left off. I don't have first hand knowledge of this, but this is what I was told (possibly by Jack?).

Anyway, cool program and Jack is a really cool guy and great programmer!

Paul Cantrell

I've been losing confidence in NASA manned missions for years. NASA (manned) is an organization without a worthwhile achievable goal. They need more money than the budget allows to do revolutionary work like Mercury through Apollo was. So, they cast about to and fro trying to think of something they can do within their budget. That's seems backwards. If they could commit to a worthwhile project (like, colonize [not visit] Mars) they might be able to get their budget increased to what it would take to achieve that goal. It would take the political will for the country to sign up for long term funding of the project, and an innovative not-business-as-usual approach by NASA.

As it is, seeing $100,000,000,000 blown for what seems like little return, or more likely seeing them playing a brinkmanship game for funding (give us more money or we'll be forced to burn up the space station you just built for $100B), that just makes me want to shut them down. Gut the manned space part of the agency, and give the remaining money to robotic exploration programs that will have a scientific return for the money.

Apollo ended up being a dead end (although I don't think NASA thought it would be). The shuttle and the ISS have turned out to be dead ends. NASA either needs to find a legitimate, achievable goal for manned flight, or give it up. I don't mind supporting science with my tax dollar, but I resent supporting white elephant projects which only benefit Boeing & gang, and a bunch of career bureaucrats.