You could rent one from Portland Productions, and they have them for sale too. 503-528-4799

It's east of 82nd between Halsey and Johnson creek

I use Noelani Rodriguez.

Like Fatale says, most commercial areas in town (NW, downtown, Lloyd Center/Broadway, Hawthorne etc) have at least a few. Residential areas tend not to anyway. I think there may be less littering here (there's still too much) because, long ago, we realized how shitty it looks and is. Oregon's been pretty good about the anti-littering message for about the last 40 years at least. I mean, jeez, how hard is it to hold onto your cups or cans or wrappers until you get to somewhere you can dump 'em?

Yes. The Mercury does accept submissions.

Regarding rules, I don't know that there are any rules.

You submit it. If they like it. They contact you. Those are the rules.

I live in North Portland and have heard and seen the same thing you have. It was extremely annoying to hear it at 1 and 2 AM, not to mention all evening.
From what I was told on Twitter, it was part of the PoPo's attempt on stepping up gang enforcement and presence. I don't know if that is true but it sounded about right to me. I tried googling more info about their Operation Cooldown but didn't see anything about a plane...so your guess is as good as mine.

I doesn't sound like a military aircraft if it's a single engine plane. I would call the Portland Airport Noise Management Office. Here's the message I found on their website.
"19 days ago
North runway closed temporarily. All operations currently using the crosswind runway. Expect changes in overflights and noise. 503-460-4100"

However, that doesn't account for the noise during July and August. I left a message inquiring about this. I called this number to do so.
800.938.6647
Here's their office website link:
http://www.portofportland.com/Noise_Mgmt_Home.aspx

As a whistleblower, I'm willing to bet that tons of other people have the same complaint but didn't know who to call or what to do. They probably didn't make a formal complaint to this office. So, if you just take a little time to talk to them and express your concerns, then you'll be helping all of the other people this is agitating. I wish more people would voice concerns about these types of issues. Society would evolve quicker and things would change faster and for the better. I'm so glad you've asked for help with this.
Let me know if you need more help. I just shut down a construction company nearby for a noise complaint. They were using their bandsaw 12 ft. away from my bedroom window at 10pm. I spent about 20 mins on the internet and found out that the Department of Development has a rule that says industrial type work cannot be heard after or before Mon- Fri. from 7am-6pm, and absolutely no noise on Sundays.
If someone violates this you call in a complaint. First, the company gets a warning in the form of a mail notice and a phone call for violating code 18. If you complain again because they aren't adhering to this after they've been warned then they get an $8,000 fine. I also called the foreman of the project and told him what I intended to do. They tried to deny it, but I had sent a policeman out to tell the construction crew to leave and that he was my witness. I offered to fax their police report. That was all it took. VICTORY!!
Sorry for this long response. I just wanted to give you an example.

The light lady! I'm unsure of the name of the shop, but there is a shop on Mississippi near failing st. The shop is open all year.

Post on craigslist under items wanted. People have so many Xmas lights.

I think it's Scott Campbell.