The Great Ongoing Aviation Thread (general and other)

Miscellaneous and Personal Stuff I Must Share
3503

It’s not a passenger announcement per se. My current employer doesn’t do this, but my previous one had something along the lines of “Cabin crew must now be seated for take-off”. Where I am now, this is done by the lead flight attendant and all we do as pilots is wait for cabin ready to be indicated on our systems display. On the descent through 20,000’ we make a PA announcing “Flight attendants prepare the cabin for landing” and then a double chime through 10,000’. This is necessary because the cabin crew wouldn’t otherwise know where we are in the arrival phase of flight. Again the final check is the cabin ready message on the systems display.

As for the welcome and arrival PAs, they’re listed in the manuals so we normally make them. We sometimes get feedback about them, mostly good but sometimes negative (rambling, unintelligible, too fast, etc). My take-away is that people largely either appreciate them or don’t care with very few who actively dislike them.

3504

Does a fuel cell have a supply line? I’ve tried to find a good explanation as to how these would be set up on an electric plane.

3505

Despite the clickbait title, this is quite a good video covering a flight to Queenstown, New Zealand, plus a shorter segment covering a landing into my home base, Wellington.

Sam Chui was given access to the flightdeck for both flights and there are a some interesting nuggets for the enthusiast such as use of iPads for landing performance calculations plus approach chart and en route map display. The training captain on the Queenstown flight discusses the use of RNP (AR) approaches that use GPS to take the aircraft through valleys surrounded by mountains down to just 400’ above the ground.

What wasn’t mentioned is the visual circuit procedure that can be used to manoeuvre for another landing in suitable conditions.

3506

A fuel cell is a chemical reactor that converts hydrogen to electricity without using fire. Hydrogen goes in one end via a pipe, ambient air comes in via a second pipe, chemical magic happens inside, and electricity comes out of the wires at the other end. Meantime, some exhaust gases and water come out the side. And the whole thing gets hot. Feed a little bit of hydrogen in → get a little electricity out. Feed a lot of hydrogen in → get a lot of electricity out. So it’s easy to throttle and with negligible lag time.

You can think of it as a hydrogen-powered portable electrical generator but with no moving parts. Or as a battery that is “recharged” by filling its associated tank with hydrogen, not by pumping electrons into it via wires.

3507

Returning to the Yeti ATR-42 crash from 6 days and 80 posts ago(!)

There are now articles & vids online indicating the ATR was flying the approach no-flap. I’ve never been an ATR pilot, but that seems abnormal. I had noted that as a possibility after @Johnny_L.A’s post.

We sometimes use reduced flaps for heavy / high / hot arrivals to improve go-around capability. But field elevation there at Pokhara is around 2500 feet, and the terrain immediately around the airport is not very challenging. I don’t see a STOL airplane like an ATR-42 needing reduced for that reason.

At least in a jet, no-flap landings are always the result of flap jams or failures.

Flying an approach using speeds computed for flaps deployed normally but with the flaps mistakenly not deployed could certainly set up a stall. But not without various warnings of impending stall. Unless everyone was really confused and / or warnings failed.


As with the JFK taxi FUBAR, it’s a good bet when all is investigated and reported we’ll find that several things went wrong and had any one of those several things gone right, this would have been an apparently nominal flight, not a 100% fatal crash.

3508

Thanks, all, as to pilot announcements and hydrogen fuel cells.

3509

And doesn’t make a lot of sense. It includes this:

But for the first time, under new procedures introduced Jan. 2, she also had to make an announcement informing passengers and flight attendants of the impending takeoff, said the source, a pilot who has knowledge of the incident and who asked not to be named.

The procedures require the 777 first officer to inform passengers and flight attendants that takeoff is imminent. That announcement was previously made by the captain. It requires the first officer to interrupt continuing tasks, be precise on timing and change intercom settings.

At the time of the taxi screw-up, the 777 was more than 4000’ from the departure end of the runway - seems far too early to be announcing that takeoff is imminent.

3510

A couple articles which talk about the Forbes article:

3511

Thanks for the refs. Wow. The union sure comes off as whiny tin-eared brats in this one. Which does not enhance their credibility when legit safety issues need to be raised.

The one piece of factual narrative info newly revealed is that the 777 switched frequencies from ground to tower shortly after the 737 had been cleared for takeoff; IOW sometime shortly before or after they’d entered the wrong runway. The exact timing of radio traffic versus airplane position is still nebulous IMO. Which represents two threats:

  1. The FO is looking down to the left to reset the radio panel on the center pedestal near the captain’s right knee which might interfere with looking up and to the right out her side window towards the 737 and seeing it before they were committed onto the runway.

  2. It suggests, based on the (possibly incomplete) radio excerpts we’ve heard, that the ground controller had decided the 777 was no longer their responsibility, but the tower controller didn’t yet realize it was his responsibility. Conversely, it also suggests that the 777 changed freqs on their own. Which may or may not be normal practice right there, but raises the possibility it left them on a different freq and listening to a different controller than those same two controllers expected. Who’s on first? I thought you were watching the baby. Me? I thought you were watching the baby. Oops.

As I mentioned in earlier posts, this is another timing coincidence where had the freq change happened 15 seconds sooner or maybe even 15 second later events may well have unfolded very differently.

Separately …
Something sounds off about the comment about new to the airplane after 100 hours of training flights. Sounds like a mistranslation from jargon to lay terminology.

At least at my carrier, and we all answer to the same FAA, typically an experienced pilot changing to a new airplane “flies” the simulator for something around 40-50 hours.

Then flies what’s called “operating experience” in the real jet with real passengers along with a training / CQ pilot acting as captain. OE is typically 25 hours, which in a long-haul airplane represents 2 round trips to Europe = 4 flights. When I did OE as a 737 captain, it was 8 flights: east coast to midwest to west coast & back = 4 flights over 2 days, then do that pattern again a couple days later with different airports. Then east coast to midwest and back = 2 flights a couple days later. Came to about 29 hours all told.

The next day you’re an ordinary crewmember, just like somebody who’s been on that jet for years. With the small exception that there are some nuance limitations in especially challenging circumstances for the next 50 or 75 hours (roughly 3-6 weeks’ work) of the newbie’s growing experience. Darn good bet none of those nuance situations applied to a vanilla flight like NY - London on a nice night.


All interesting. None of it explanatory. Yet.

3512

Wouldn’t you normally switch from ground to tower when holding short of your intended runway?

3513

Depends. As a general rule you would not want to get all the way to #1 holding short position while still on Ground Control. Something is already going wrong if you’re there.

Whether you solve that by switching to tower on your own or querying the ground controller for a handoff depends on how big the airport is. Small fields switching on your own is common. As a rule of thumb, once you’ve passed the last place where another airplane could appear at an intersection, it’s time to swap over.

At large airports you stick with ground until told to switch, or until you decide to ask GC for the handoff because you think you’ve been forgotten.

The bigger picture is that the sooner you’re listening to tower, the sooner you’ll begin to develop situational awareness of who’s taking off, who’s where on approach, what the wind is, etc. Since jets don’t do runups, our ideal is to arrive at the end of the runway as quickly as possible, and also to be cleared into position or for takeoff immediately. We’re not trying to hurry, in fact we’re actively trying not to hurry, but also trying to avoid any unnecessary delay by being fully ready to go internally, and also by already listening / talking to the right people before we get to the approach end of the runway.


Many large airports have multiple tower frequencies continuously in use. DFW has 4 tower freqs, although usually only 2 are used for takeoffs; sometimes 3 are used for takeoffs. They also have 3 GC freqs. ATL and ORD are similarly complex.

At MIA there are two tower freqs and if you haven’t been handed off to tower by about a half mile before the approach end of the runway it’s time to ask; There are 4 streams of airplanes on 4 taxiways leading to the crotch of 2 runways forming a V. GC puts each stream in order, but it’s tower that deals the next jet off one of the 4 streams onto one of the two runways. And sometimes swaps folks between streams on various cross taxiways. Tower can’t do their sorting and swapping unless they’re talking to everybody down at that end of the airport.

Etc. Times another 150 airports we serve just on my airplane from my base. Having familiarity with the local “house rules” is a valuable asset, one built up mostly by experience, plus some local “cheat sheet” type info distributed by the company.

At some airports there are signs along the parallel taxiway leading towards the runway saying “Change to tower 123.45 here”. Which may be a long ways short of the runway end, or right up close.

At some large airports it’s not always fixed which freq goes with which runway. So the only way to know which freq to switch to today when the winds are this way and they’re using Runways X and Y is for GC to tell you.

Relevant to this recent conversation about the JFK screw-up, JFK has two tower freqs used in different configurations depending on which way they’re aiming the airport. Sometimes GC does the handoff, or tells you something like “contact Tower 123.4 passing taxiway BW” which may at that time be a mile away and 20 minutes in your future. For at least one runway end they don’t do the handoff at all, they have “contact tower” signs set out about where you’d be #3 or 4 for departure given typical airliner sized jets.


Bottom line: the whole process is clear as mud and totally standardized and consistent. See? :slight_smile:

To be a little more fair, there is a consistent strategy to what’s going on. The tactics are all over the map based on local needs, but dealing with that is the difference between doing something for a living and doing something for a hobby. My brother builds houses. I go to Home Depot to buy stuff to make a mess out of fixing my house. He’s a pro and deals with complexities I’ve never heard of every day. Me, I just make a mess & draw blood. My blood.

3514

Your summary on ground handoff to tower sounds like an after-the-fact future solution in the making.

3515

Yeah. It’s quite an accretion of ad hoc-isms as the industry developed from the logical clarity & simplicity of the 1950s to today.

Here’s an interesting item. This is the NTSB regulation on reporting various “oops” to them. eCFR :: 49 CFR Part 830 – Notification and Reporting of Aircraft Accidents or Incidents and Overdue Aircraft, and Preservation of Aircraft Wreckage, Mail, Cargo, and Records. The relevant tidbit is the opening paragraph of 830.5 and 830.5(a)(12)(2).

At least where I work, “immediately” means notify HQ as soon as flight workload and communications permit, but definitely before deplaning at the other end. Then HQ will notify NTSB. My personal view is the crew → HQ notification should have happened before takeoff. Did it? If HQ knew this occurred, did they approve them pressing on to London? Seems a bit unlikely to me. If HQ didn’t know, was that another crew mistake, or a deliberate decision? If deliberate, was it wise, or stupid / clueless, or a forlorn hope it’ll be never noticed and ignored?

All worrisome thoughts.

3516

I’m not sure if this accident was discussed:

Surely there’s no reason to pay attention to your mechanic when he says not to fly the plane–especially when you’ve had experience flying–for example having your license more than 5 weeks?

3517

Great, now I have to send my Stupid Meter back for repair. the needle bent itself into the shape of a clock spring.

3518

OTOH, the engine ran most of the way to the destination. The owner / pilot just needed a slightly closer, cheaper hamburger as a goal and he’d have been fine. :slight_smile:

Wacky is as wacky does. “I forgot” may have been the next-to-last thing to go through the pilot’s mind. The last thing, you ask? A tree.

3519

Sadly the mechanic is probably going to get sued for not tagging the plane out of service.

3520

He will get sued by somebody for something. Everybody always gets sued by somebody for something.

3521

A maintenance story: At our flying club, we had one of our Cessna 172s go in to our hangar for a new engine. We installed a factory reman engine in it, and the AME went home.

Our club operator wanted the plane on the line the next day, so he decided to take the plane out for the post-install check and runup - in the freaking dark, without an outside observer to check for leaks and without consulting the AME. So he runs it up and the thing blows oil all over the pad - which he can’t see - then siezes up. It cost us $22,000. I think the drain plug wasn’t tightened up or something and blew out when the revs went up.

He violated several club procedures doing that, but he was our senior guy with 22,000 flight hours and a high rank in the CAF at retirement, so everyone just let it go.

3522

Years ago I joined a club that had a member taxi out and hit something with the prop and stopped long enough to look at it while it was still running. He then proceeded to fly it. Upon landing and shut-down it was discovered that the prop was bent.