... Two stops ...

2A- As the project is winding down, you receive invitations to three consecutive breakfast meetings to discuss follow-on efforts. The first is on Wednesday at the field office in Billings; the second is with a consultant in Chicago on Thursday; and the third is at the Boston home office on Friday. Naturally, you’re delighted to see that you can keep your two-stop routine in place for the entire cross-country trip. On the first day, each flight involves a different airline and a different aircraft type, and you’ll even have time for a beer or two and dinner with a college buddy in the airport where you change airlines. Further perusing the first airline’s timetable, you realize you can depart PDX on an earlier flight (on yet a different type) to one of the intermediate stops and have lunch at that airport (presuming, of course, that you’ll actually find a restaurant or bar in what’s sure to be a fairly small building) before picking up the original flight. Please identify both airlines, all three equipment types, and all stops in sequence.
HINT: The flights on the first airline operated with twin-engine aircraft; the flight on the second airline operated with a four-engine aircraft

2B, 2C- Both the second and third days are straightforward: a direct two-stop flight, each on a distinct airline and jet. As usual, please the airline, the aircraft, and the stops in order for each flight.
HINT: One has four engines, the other does not

3A- A month later, as you’re enjoying your second Bloody Mary and struggling with the Sunday crossword, a frantic-sounding project manager from the Newark office calls. The courier service just delivered the wrong drawing package for her client’s Monday morning visit. Can you somehow get the right files to Newark in time? Well, your Monday tickets are in your attache case, and your calendar has been blocked for months -- an early flight for a breakfast meeting with a Dartmouth professor to talk about a potential consulting arrangement, with further talks and tours of the research labs in the afternoon. Then you're supposed to proceed on the same airline to an airport near Long Island University, site of a 730pm welcome reception for a two-and-a-half-day symposium. Please identify the airline, both equipment types, the airport serving the Dartmouth campus, your arrival airport in the New York metropolitan area, and of course the intermediate stop on the southbound flight.
HINT: Both are twin-engine aircraft

3B- Your first thought is to switch your morning flight to a NYC departure, so you could simply check into the conference hotel tonight. Bummer, no two-stop trip today; it's a 1045am arrival, meaning it'll be a down-and-back by train and/or the Eastern shuttle. Or not! Here’s a nonstop to EWR, and a late evening one-stop on another carrier and aircraft type, back to BOS. The airlines, the aircraft, and the stop on the return flight, please.
HINTS: Both airlines in question operated these two aircraft types (and had several others in common); the two carriers competed on all three segments, although service to/from the intermediate stop may have used other NYC airports

3C- A few minutes later the phone rings again. Wait, what? She needs the Denison University folio, but has the Rutgers University one? Dang it, where’s a map? Where’s the OAG? Okay, here’s a workable single-carrier itinerary – but it's 13 brutal hours. The project manager agrees to meet you at a major airport, about an hour’s drive from Newark, where you’ll be disembarking from a direct First Class dinner flight (making, of course, two stops). Your return trip leaves just over four hours later -- plenty of time to review the files and have what will certainly be a much-needed drink -- and gets you back to Logan before sunrise; it involves two different jets, with the first flight making an intermediate stop before the connecting point. Please identify the airline, all aircraft types, the meetup airport, and all stops in order.
HINT: All three are four-engine aircraft

4- Following the symposium closing session, you’re headed to Mexico City. You certainly could have picked the simple same-plane two-stop itinerary, but you found a much more interesting option that involves two airlines, two aircraft types, and an unusual connecting point. It also arrives at the far-less-inconvenient hour of 955pm rather than shortly before midnight. You know the drill: we’re looking for the departure airport, the airlines, the equipment, and both enroute airports. Bonus points, of course, for the info for the direct flight.
HINT: All three aircraft are from different manufacturers