Neither of those would appear to meet the curfew definition for "regularly scheduled commercial operations" and "advertised or otherwise made available to members of the public" for the commercial curfew to apply (Sec. 2-1-30.4.(c) of the ordinance and definition "a federally certificated air carrier at John Wayne Airport under a current Certificated Passenger Airline Lease or Operating Agreement"). The ordinance drops virtually all other users under "general aviation" which has a much looser restriction: You simply cannot exceed specified noise levels [+/-87dB] as measured at specified noise monitoring stations between 10pm and 7am (outside of those hours the level cannot exceed +/-102dB at 3 of the noise monitoring stations]. There are also exceptions for aircraft engaging in government, medical, law enforcement, and similar missions.

While the registered noise level at any given NMS will vary based on a number of environmental factors based on data in FAA advisory circular 36-1H which defines aircraft noise using EPNdB or "effective perceived noise level in decibels" it appears that RGY872's Beechjet 400 with a flaps 10 takeoff has a EPNdB of 88.6, assuming some natural attenuation over distance and use of noise abatement techniques, not to mention different measurement definitions, I can see that squeaking in under the most restrictive (NMS 3S-7S) 86.7 dB at the NMS location.

I'm having a hard time finding data for the B350 but since all of the data I'm seeing for other Beech turboprops show A-weighted dB measurements in the high-70s it seems even more likely that one was under the nighttime noise limits.

Thank you both for the answers regarding SNA curfew! A remaining curiosity is that both flights were scheduled to depart after the curfew lifts, but took off long before. It also seems weird that it's a free-for-all at an airport such as SNA during hours when no one is operating the control tower?

With unscheduled flights unless there are slot or routing restrictions it can turn into a "if everyone is ready to go lets go" (years ago an indirect client owned a G-something and my understanding is the APU had more hours on it than either engine because of the "I might want to go do some shopping in .... oh, never mind", conversely there were also "let's bop over to XX real quick" (the privileges of not only owning your own aircraft but having a full-time flight crew on salary). Similarly look at UA's repositioning/ferry flights -- they're often filed to depart at X but rarely if ever (from my observation) actually depart within an hour of either side.

There are also hundreds of uncontrolled airports (either no tower or less-than-24/7-tower) around the US. When the ATCT is closed there are specific procedures for aircraft to announce their position and intentions on a common frequency (CTAF or "common traffic advisory frequency" -- at SNA this is 126.8) and Unicom (122.95) used to communicate more generally, such as with the FBO staff.

For SNA particularly also:
https://www.airnav.com/airport/SNA
Translation:
When Air Traffic Control Tower closed, pilots can activate Medium Intensity Approach Lighting System for runway 20R and Precision Approach Path Indicator (lights) for runways 2L and 20R using the Common Traffic Advisory frequency (usually by "clicking" the mic some number of times).

Runway 2R/20L (the short one) is closed when the control tower is closed.

For IFR Clearance Delivery when Air Traffic Control Tower is closed, contact SoCal Approach at 800-448-3724. When Air Traffic Control Tower Closed, no local training or touch and go operations.

Awesome info! Thanks again!

UA1731 diversion
 

Question for Larry about a recent diversion of UA1731 from Kona to Denver on Dec 26. It so happened this flight departed from the same gate prior to my flight so it really stood out on flightradar24.

I was curious why the diversion happened so I pulled the liveatc logs from here, but the gist is this: the crew was told by dispatch to divert to HNL because something that rhymes with "engine eyes" wasn't working. The crew was quite specific this isn't an emergency and otherwise nothing is wrong. My best interpretation is something like united dispatch was unable to remotely monitor engine performance and at least on Hawaii flights this is a no-go? Another angle of this question is whether remote monitoring is even reliably possible over the pacific?

I see UA1731 taxied to a gate at HNL and arrived four hours later at the planned destination. Four hour sounds like a reasonable time to turnaround an unscheduled 777 stop, so I imagine the solution was simple enough.

Thank you. Always enjoy following this thread.

Curious about @LarryJ's take but it sounds like engine anti-ice wasn't working on one of the engines; when this happens an aircraft cannot be flown through known or expected icing conditions. While there is the possibility for remote monitoring there's also the possibility that it was MELed (or became inoperative in flight) and the crew determined that they would be flying through icing conditions, then coordinated with dispatch to determine resolution.

Back in January of 2018 I had something similar happen as a passenger -- I was flying ORD-JAX (UA3620, E175 N87319 operated by Republic). Somewhere south of Macon, Georgia the pilot announced that our anti-icing was inoperative and because there were icing conditions forecast on all sides of Jacksonville we were diverting to Atlanta to "figure it out" -- I remember being amused that in January we had no icing anywhere between Chicago and Atlanta but it was when we got to Florida that the problems started :)

In our case we diverted to ATL, deplaned while Dispatch, Maintenance Control, etc. figured out what to do with us. Eventually it was decided that we were going to take an E170 (N648RW) that was scheduled to arrive "shortly" to continue our flight while our E175 would be sent to Houston, operating the flight the E170 had been scheduled to use. All crew and catering items were swapped between the aircraft, and because there were fewer seats--not to mention the uncertainty--the GAs were playing "Lets make a deal" in the gate area -- Want to fly Delta to Jacksonville? Well get you set up! Fancy a scenic drive? We'll pay for your rental car! Want spend a day or two in beautiful Atlanta instead of dreary Jacksonville? We got a hotel for you!" -- I stuck with the aircraft and made it to Jacksonville about 5 hours after we left Chicago.

That is consistent with an inflight fault in the engine anti-ice system. They likely chose HNL, over returning to Kona, due to the availability of resources in HNL for the repair. I've never flown the 777 so am not familiar with its specific requirements.

With inoperative anti-ice systems you can not fly into known or forecast icing conditions. That generally means no visible moisture at the altitudes at which you are flying as temperatures conducive to icing are almost always encountered during climb and descent. Temperatures at cruise altitudes are usually too cold for ice to form (below -40°C) as the moisture is already frozen. Engine anti-ice is used in descent whenever visible moisture is present and the temperature is 10°C, or less.

Yes, now that you both say this, this seems what is being said on atc. They stopped climbing at 24000 and spent a good while there, probably deciding what to do. That makes sense now.

Furthermore, I didn't realize they did switch N769UA for N215UA. Does that mean United did have a replacement crew ready in addition to a replacement aircraft? Kona to Denver is just about 6 hours. The diversion took another 1.5 hours or so, plus of course the 4 hours on the ground. On the ground, I see the diverted and replacement aircraft being parked side-by-side. At least Honolulu timing was fortunate to have these available. The organizational effort to put this all together never fails to amaze me.

They likely just took the airplane and crew from another flight.

For the EWR pilots - How much "fun" is the Stadium Visual 29 approach? Every time I'm on a flight when it gets used I always get excited about the hard right turn to final.

Depends what you define as “fun.”

The approach itself is really cool and fun to do. Problem is, the only time you usually get to do it is when winds are gusting 40+ which really isn’t fun to land a plane in.

Not just EWR pilots. Anyone who flies domestic trips can end up in EWR.

My record for the final approach speed (minimum speed prior to the flare) in the 737 was on that approach in EWR. 165 KIAS, which is 190 mph. It was fun, but it was also a lot of work.

I love when they switch over to that approach. One of the waypoints - HILOK - is a beautiful park and a great spot to just sit and watch all the beautiful aircraft on approach.

Good point! I only have ~150hrs under my belt, so 15kts gets my blood running... I can't imagine the pressure you guys are under when it's gusting 40. Kudos to you all!!

When you're flying as much as we do, the high winds just become an annoyance. Makes you work harder.

I like to say that I prefer strong gusty crosswinds for my landings. I find they lower expectations!