The Great Ongoing Aviation Thread (general and other)

In other news, here’s a surprise:

A firefighting 737 crashes in the wilderness and the pilots walk away. I would not have given high odds on a successful forced landing anywhere off airport in a big jet. The article’s depiction of the terrain they ended up on is not real promising at first look.

Lucky them. With no doubt some real cool under fire at the end. Here’s hoping the cause of the forced landing / crash wasn’t something bone-headed they did earlier.

It is absolutely not 10 degrees off. It is exactly parallel. You can still see it on a map; they just painted over the markings and turned it into a taxiway.

Of course, in a 172, you can land 10 degrees off and barely notice…

Couple different issues here.

Often FAA names runways 1 number different even though they are absolutely parallel. At Atlanta the north two runways are 8/26 and the south three runways are 9/27. All 5 are absolutely parallel. LAX has the same with two runways 7/25 and two runways 6/24 . Same idea at Dallas, Miami, Ft. Lauderdale, O’Hare, etc.

The underlying motivation is they’re OK with up to three runways with the same number e.g. 17L, 17C, and 17R if they’re all close enough together left-right. But if they put in another batch of runways a mile or two away, in the interest of avoiding confusion it’s better to name them something else. Like with a different number.

A different scenario is the one you describe: a big jet airport that also serves lightplanes on a parallel runway. Sometimes they’ll give the lightplane runway a different number. The idea is to make the label more different hoping to reduce the potential for confusion. Jets lined up on a short GA runway or lightplanes doddling along on a jet final are both recipes for disaster.

Unrelated to the above is the need to periodically rename runways as the magnetic variation changes. In the absence of multiple sets of runways as in my first topic, a runway is named for its magnetic heading rounded to the nearest 10 degrees. Magnetic variation changes very slowly in most of the world. It might take decades to drift 10 degrees. But if by chance the magnetic heading was, say 85, and they named the runway 9, and then the variation reduced to 83, maybe now’s the time to rename it to 8. Or maybe we wait 10 years and then do it. Or not do it at all.

I’d say the best way to think of all this is the runway number is generally aligned with roughly what the magnetic heading is now or was some time in the last 20 years. It’s not more precise than that.

You’re right. It would have changed to 30 to match magnetic heading. Then it would be 30L, 30C, 30R.

That’s what I was expecting. 29 was the short runway, about half the length, and you don’t want to confuse it with the two main runways.

I don’t see how it’s unrelated, though. Or rather, I’m trying to figure out how all the reasoning ties together. They allow 10 degrees of variation in some cases; why not all cases?

Or, consider if the runway heading at SJC was 304 once, and now has drifted down to 286. Is there any need to rename? 29 (if it still existed) would still be “correct”, and 30LR would be an acceptable +1. Or would it? Maybe the FAA demands that one runway be primary and that others all follow it around, with the same offsets.

I guess the answer, as you say, is “it’s not more precise than that”, but that seems a little inconsistent with the article.

Not 100% certain which “the article” you’re referring to, but if it was @Magiver’s Wired cite, I’d suggest that is mostly well-meaning “lies to laymen”, outlining the vanilla base case as if that’s all there is to it. The devil, as always, is in the details.

I don’t have any special knowledge of the airfield engineering regulatory arcana, just an experienced end user’s experience.

I will suggest that once an airport’s runways are settled into a numbering pattern, if they change any of the numbers in response to variation drift, they change them all. Thereby keeping the relationships between the numbers the same. e.g. if Atlanta needed to be renumbered they’d change all 5 runways on the same day, and the north runway pair would still be designated as one number lower than the south runway group of three.

It was this one that smithsb linked to above:

Ok, that would make sense. That would be equivalent to my inkling that they designate one as the primary. If that shifts, they rename, and any +1s or -1s or whatever get shifted along with it.

I think it’s just a matter of assessing the risks. Having a runway that is off by more than 10º from the magnetic heading isn’t ideal and would normally be avoided, but if you’ve got a bunch of parallel runways then changing the names of one or more to better distinguish them might be the lesser of the two evils. And it’s not like this kind of renaming happens all of the time, it’s normally a rare occurrence. The airports I flew out of 30 years ago have the same runway names now as they did back then.

Yes indeed.

Coulson lost a C130 tanker in Australia a couple of years back and the results were not so good.

More photos and story here:

It’s hard to correlate the bottom photo with the others, but those guys came out of that wreckage.

Some classic understatement here from the ATSB (Australian NTSB equivalent) spokesperson:

“In this particular instance it does look as though it’s potentially clipped the ridge line and has pancaked down, so it’s certainly a horizontal landing as opposed to vertically into the ground, [it] makes a big difference.”

Airport Transport Safety Bureau’s Chief Commissioner Angus Mitchell said it was a horizontal landing, rather than a vertical landing.

When a plane comes down vertically, you generally don’t call it a landing, but who am I to quibble…

Harrier pilots would like a word :wink:

It’s more a matter of which way you’re pointed as you near the ground than whether your approach to the ground is vertical or horizontal.

Doing it right :slight_smile: :




Doing it wrong :scream: :

Aside: there’s some cool old airplanes in the background of this latter photo.

Golly is it refreshing to read an article that’s more than a teaser and a photo. Journalism as it used to be.

Although there is one picture mid-article that shows the airplane being loaded with fire retardant that’s mis-captioned as the aircraft being refueled. Fuel goes into a fitting behind the leading edge of the right wing a few feet outboard of the engine. There’s not a receptacle on an ordinary 737 where that hose is plugged in.


Looking to the accident itself, the terrain is about as good as can be had: dead flat, no obstacles, and only small shrubby bushes, no established trees. They got sideways enough that the cockpit wasn’t being used as a plow, but not so sideways that the leading wing (right in this case) was in danger of spearing something and flipping them over. So the post-touchdown part was excellent.

I bet it’ll be a long time before we know much more about the pre-touchdown part.

Here’s more on the infamous MAX accidents. Quoting myself for context. The post just below this quoted one is also relevant.

What’s new today (or at least new to me today) is that ~4 weeks after the NTSB and BEA attacked the Ethiopian report as a whitewash, as referenced in my quoted post(s), on Jan 24 NTSB came back and did it again with even more specifics. See their press release NTSB Publishes Additional Comments on Ethiopia’s Final Report on 737 MAX 8 Accident.

Their 7 pages of actual comments directed to the Ethiopian authorities are here Response to EAIB final report.pdf (ntsb.gov) and are in addition to the 9-page complaint they issued back in Dec 2022.

The substance of this new complaint being that the Ethiopians essentially invented a false cause for how the AOA sensor malfunctioned in the first place, setting off the whole chain reaction leading to the mishap. Which invention transparently fails the engineering smell test. But which just happens to place all the blame for the first link in the failure chain fully on Boeing, rather than the Ethiopian government and its various subdivisions. And they refused to include NTSB’s findings even as a dissenting view; they simply got flushed.

NTSB is not happy.

Changing them all on the same day seems risky to me. Today, the runways are 8/26 and 9/27. Suppose they get changed to 7/25 and 8/26; they’re using the same number they did yesterday, but today it’s a different runway. If anybody didn’t get the NOTAM, they’re going to head for the wrong runway.

I would suggest that they change 8/26 to 7/25 and leave the others as is. Keep those numbers for 6 months until everyone is used to them, and then change 9/27 to 8/26.

A nitpicky post, to be sure, but planes have crashed over smaller details than that.

Remember the Notam system failure last month? There’s a high priority rush job to fix this:

The FAA acknowledges the shortcomings and plans improvements, but acting Administrator Billy Nolen notified House lawmakers Jan. 27 that fixes wouldn’t be fully completed until 2030. Congress first ordered the agency to begin upgrading the Notam system in 2012

That conclusion might be a bit of a hasty hatchet job.

The problem with NOTAM dissemination in Jan was an IT tech botching a server move done without adequate backup. The problem itself was corrected in about 90 minutes. The ripple effects from the disruption during the morning rush hour lasted much of the rest of that day.

The 2030 project is all about a root-and-branch re-thinking of how FAA can keep track of all the real time imperfections and short-term (days-to-weeks) anomalies in all the airports and facilities around the country. And how to package and prioritize that info in ways the user community can get real decision-making value from, not merely be handed a wall of mind-numbing fine print whose sole result is transferring legal liability from FAA onto those users.

Two very different problems of very different scope with very different timelines for solution.

Here’s something fun coming up:
These guys

are getting very close to flying this thing

The interesting thig to me is they’re going for pure hydrogen fuel cell output direct to the propellor motors. No batteries for backup or peak loads or anything. So no bulky heavy ballast-from-hell problem that battery or hybrid aircraft have.

It remains to be seen if this can work out, but IMO (and I’m NOT an expert on anything about electric aviation) it’s one of the smarter bets out there.

Cirrus Aircraft, maker of high-performance single-engine aircraft, has grounded its SR22 and SR22T models after “an issue” was discovered with its Continental Aerospace engines.

The grounding is for Cirrus-owned and operated aircraft only, but was revealed in an email to all of the types’ owners on 8 February…

“We anticipate Continental to issue a Service Bulletin in the near future, which will detail the specific range of affected aircraft, the root cause of the issue and corrective action,” the company says. “The Continental Service Bulletin will accompany a Cirrus Aircraft Service Advisory notification.”

Why not just designate your airport’s runways as A through Z (I assume there’s no airport with more than 26 runways)? Why peg them to magnetic heading and then have to keep renaming them?