Let me explain, the metar and tafors (the airport meteorological reports we use) during the flight in San Juan show that the flight was doable. No crazy winds during landing, and worsening during take of but well within the limits you may find in a local thunderstorm.
The predictions allowed them to see the window to fly in and out. If arriving the weather was too bad or you see the hurricane getting too close to the airport,they could have got away without landing.
For take off either you have the right conditions (under the legal limits) or you don't.
What they risked IMHO is having some kind of technical problem or delay once in San Juan and having to stay there to weather the hurricane. That could mean heavy damage to the airplane while on the airport, even a total loss.
That said for me the most amazing of it all, is not the short stay at the ground. While very fast is not uncommon to see them with an experieced team, the slower part is the disembarking and embarking of the passengers, and they surely were all motivated to hurry.
The most impressive is how they followed the quite thin alley between the hurricane arms till they were clear of the bad weather. In a situation like that you only see red and magenta in your radar and a narrow black or green zone where you can fly safely. That's surely was the most scary part for them beyond the adrenalin of a fast and potentially dangerous operation.
Looks like the typical movie scene of a spaceship passing between closing doors!!
Certainly brass balls.
Edit: some typos and a "don't" that I left behind and was changing the meaning of a sentence. Sorry written from the cellphone.
It if was totaled by the hurricane it would not have looked good on the company books.
Honestly there is NO reasonable explanation. But wait few days to find out there was some high ranking company member or CEO/C level exec or his/her family stuck over there and thats why they send a plane.
And no - if it wouldnt take off that minute, you are talking about wreck taken off the books.
 Whatever that means. And I have no personal opinion about the risk involved in what Delta did, because I'm not qualified to form one.
Edited to add: it is nice to be able to applaud an airline for a change. Yay, Delta.
Plus, of course, there is the humanitarian benefit.
The risk was to the aircraft: if it had been delayed on the ground at SJU for any reason, it might not have be able to depart before the storm hit and would likely have suffered severe damage.
> hundreds of millions of dollars in my rolling stock
would refer to the aircraft ... except that's a nearly 1-order-of-magnitude overestimate of it's value (a single $100M, not multiple).
What a heroic effort! Salute to the entire team!
Not sure if they are also part of recorded flights though.
The F-15 and F-22 have an extra bonus. They can climb straight up through the eye. The U-2 could probably manage a spiral climb within the eye.
The point where they meet is called "coffin corner". It is really not a nice place to be: If you are in coffin corner, if you try to descend, you risk speeding up and breaking the plane. If you try to slow down, you risk stalling - although it is possible to recover from a stall, you cannot recover without speeding up.
It is generally advisable stop climbing before you box yourself in like that.
The older bombers they flew were all manual controls (as opposed to fly by wire), which meant physical exhaustion from wrestling the plane into the storm was a major factor - so they'd bring extra fuel to be able to circle the eye of the storm for some amount of time to build up the strength to fly back out.
- On August 24 Typhoon Hato hit HongKong hard. All airlines canceled their service in and out of HKIA, except a lone KLM flight from Amsterdam. Similar to the delta flight into San Juan, this flight created a large media storm into the risk involved. http://liveandletsfly.boardingarea.com/2017/08/24/klm-747-ty...
While I am not a pilot, I know that such flights involve sophisticated planning (route, fuel, approach), weather prediction as well as diversionary plans if things do not work out. No airline would undertake such a high-risk move without the confidence that they are not putting lives at risk.
The extreme overestimate was ostensibly due to "double counting", which I find to be a wholly unsatisfactory explanation. With all the info that they collected about each person who was missing -- name, DOB, photos, ID numbers, where they worked in the building or who they were visiting -- how can they possibly double count 3000 people?
And you're saying that generally after a disaster it works exactly the opposite way: a low number initially which gets adjusted upwards. Interesting. Almost as if there was a desire to make 9/11 look even worse (as horrible as it was).
Edit: What I meant by "didn't choose to make the flight" was that the pilot didn't wake up and decide he was going to San Juan that day. He was assigned the flight, and presumably did have the authority to say it would be too dangerous. Maybe not though, I'm not an ATP.
I can't image what it must be like to fly into a storm system like that. Nerves of steel.
Thunderstorms, however, are much more difficult to fly through, because the air is moving vertically in an unpredictable fashion.
The word has been since overloaded to be the study of the past. Which is fine, except that leaves no reason for the word pre-history
Edit - also the call is made continuously. They can back out any time.
Why create an account to make your initial comment? It doesn't seem very substantial or on-topic. The two reasons I can think of aren't very charitable, which is why I'm asking, assuming that it's neither of those.
To answer your question if you know the sex, you say the sex.
If not you use sexless pronouns like "their" and "they" even if they are not 'proper' by old strict standards, basically they are, because language evolves.
They may or may not have volunteered for the flight, but they do get the final decision to go in or turn back once the airline OKs it.
1) Hurricanes are actually harmless to planes. The only part of the flight that includes any danger is landing, due to wind and low visibility. But flying at cruising altitude or even through the storm is fairly harmless, as most winds are horizontal and nothing out of the ordinary for a plane. Keep in mind that the NOAA regularly flies commercial jets (such as a Gulfstream V) into hurricanes. Also keep in mind that never in the history of aviation has a plane been brought down by a cyclone. Thunderstorms, on the other hand, are much more dangerous. The main difference is that in a cyclone, air moves horizontally, while in a thunderstorm it moves vertically in bursts, which is much more difficult to navigate.
2) From what I've heard, this was not a commercial flight but a flight mainly aimed at evacuating non-rev airline employees. The main issue with doing this flight for regular passengers would be fear and discomfort due to turbulence. Airline employees on the other hand are used to flying, know that turbulence is harmless, and would rather just get home.
This was a flight to evacuate crew who are stationed in PR. Non-rev refers to crew who are commuting or on holiday. On a typical flight a plane may turn over in a few hours but the crew may remain for 24 hours and leave the following flight. This crew was down route and needed to head back to their operating base.
Your having lived through hurricanes on the ground is entirely irrelevant to a discussion about the safety of overflying the hurricane.
At the flight altitudes of a commercial jet none of the effects you mention happen. You need to plan your path carefully for the descent, landing, and takeoff. But at cruising altitude, hurricane winds are not a major safety concern.
Yes, so harmless that no one does it. NOAA has to use an extremely reinforced, highly maintained fleet of P3 Orions. You've mentioned repeatedly in your parent posts that hurricanes are harmless to planes when commercial pilots in this forum say they wouldn't do it without excellent weather planning.
> You need to plan your path carefully for the descent, landing, and takeoff. But at cruising altitude, hurricane winds are not a major safety concern.
Planes have all sorts of cruising envelopes. Gulfstreams are in the 40k feet. Commercial jets cruise at 25-35K foot band. And commercial turboprops (commuter shuttles) are in the 10-20k foot band. While the first 2 won't feel the gale force winds they can experience the updrafts as turbulence. Commercial jets fly in the lower stratum of the stratosphere. There is still weather phenomena at the height, just much less than the troposphere.
Finally, the captain will avoid a hurricane even if it doesn't really affect them. They may need to decend to a lower attitude for an engine flameout, for example. And why deal with the added complication of emergency landing during a hurricane.
But people here are making wild claims that overflying hurricanes is inherently dangerous and puts lives at risk. That's factually incorrect and is what I came here to correct. You (and others) are making examples about the NOAA's Orions (which are reinforced to fly through, not over hurricanes, flying into the wildest parts on purpose), and or other turboprops which fly 10-20k ft. That's not what we're talking about here… we're talking about commercial jet aircraft which fly at 30-40k ft. Business jets fly even higher, sometimes up to 52,000ft. Just this week, I flew private in a Citation X at 49,000ft.
E.g. the plane in this story flew through the eyewall of a hurricane at 1,500 feet. A commercial jet flies at a cruising altitude of up to 45,000 feet.
I've been on flights from Asia to the US with a 150+ mph tailwind in the jet stream making the ground speed 700mph+. However, from the perspective of the air frame, it's still just traveling at a normal speed relative to the air it's in.
The earth rotates at 1000 MPH and you don't see people wondering if cars can handle that.
You give it more context
It seems like you're looking for a particular point of view here.
Thanks for pointing this out though
What are the odds something could go wrong compared to the relative good of squeezing in one last flight's revenue for a while? Is flying in a hurricane actually not that bad and the airport turnaround/takeoff the most dangerous part?
"Let's see... 50% chance of incremental $200*150=$30K (idk the price nor the capacity, so just entertain me) in revenue. Let's bump that with the expected loss/lawsuits if this fails = ... Who cares? It's in the millions. Just don't do it."
I think this is one of those cases where the airline took it upon themselves to really try to help as many people get out as they could.
It's also not just an airline decision - you've got a pilot in control who can make the no-go call at any point, and their training should prevent them from undertaking unnecessary risks.
Just look at all this free PR.
But I choose to believe it was about giving people one last chance to get out.
Yes, timing calm air effectively requires calculation. I'm at a loss when deciphering how that relates to what I'm saying.
(In no way am I playing down what they did though. I'm only commenting on your analysis.)
So the realized risk is fuel and cost of a grounded plane.
> Once the plane landed in San Juan, the alternative—leaving the plane on the tarmac or in a hangar—would probably have destroyed the airplane ... If the plane had gotten stuck, Delta probably could have gotten the humans out safely. But it almost certainly would have lost a plane.
Obviously it would be quite bad to fly into a hurricane's rain bands (the weather outside of the "corridor" that the DL431 flight moved through).
The real feat here is the real-time and reliable coordination between all interested parties -- as mentioned in the article, the meteorologists, dispatchers, pilots, cabin crew, and ground crew. Everybody involved had a distinct sense that the window of opportunity was narrow and it should be quite clear that they acted with a high degree of professionalism and skill.
As for the life-threatening danger: it's risky, that's for sure, and I would by no means calls this a small feat, but there is no intense wind shear like those found in tornadoes, thunder storms, microbursts, or other such things.
But what does get interesting is flying through the
hurricane's rainbands and the eyewall.
But hurricanes are immense, and immensely powerful. The size and energy drive all manner of dangerous phenomena. For example, growing up in Florida we were worried less about the hurricane, per se, than the many tornados they often spawned.
NOAA has been flying aircraft into hurricanes since the 1950s. It is not inordinately dangerous, but it is not just another flight, either.
I wonder, is this a good (and incredibly positive) example of what quality real-time/near-real-time data can do for decision-making?
You need meaningful data to make meaningful decisions. Otherwise you are mistaking luck for expertise.
But yes, this flight would have been absolutely impossible to conduct safely without satellite and weather radar data, as well as good forecast models of the storm's movement.
Many of the houses and buildings there are sturdier than you'd think. My parents house is at the end of a row of six or so that share walls. So they buffer each other's flanks during a hurricane. Their windows don't have glass. Instead it's screens covered by storm shutters with iron bars over those. Also, the houses are constructed of thick reinforced concrete rather than the picturesque wood, siding, and shingles that you might be thinking of. It's actually rather bunker like. Hurricanes can hit several times per year and those houses are built to take the punishment.
(Got word from my parents last night that the power was out and their street is filled with windblown debris that they and their neighbors will be cleaning up today, but otherwise they came through fine.)
However, its the destruction and risk that it could be WEEKS before help comes if infrastructure is completely destroyed... and an island with limited resources means that the people still on the island will (compared to mainland) very quickly start to realize that they need to eat and acquire things to survive... and survival mode is the worst part of any natural disaster. The damage done by Katrina to New Orleans was horrible, but honestly, the damage done afterwards by the people that lived there (that was done to survive, im not criticizing, morality changes real quick in survival mode) wsa pretty horrible, too. Imagine a small-ish island with not a lot of natural resources and no quick way to get truckloads of supplies en mass...
Not saying thats what's going to happen - but thats the kind of outcome people forget when they volunteer to ride out a natural disaster. The actual event is just the prelude to a pretty bad period of time for the area it hit... and the pain you will feel after the hurricane is likely to be much higher than the hurricane itself.
There are probably at least some NTSB human factors specialists cringing at this.
Anyone with knowledge of this?
To say that a 737 would have "no problem" would be overly optimistic. A 737, like all commercial airliners, is pretty tough, but there are plenty of things in a hurricane that could bring one down. There's hail, up-and-downdrafts that far exceed the capability of the aircraft to overcome them, and turbulence severe enough to flip the plane inverted. The least likely event is turbulence severe enough to structurally damage the plane, though even that is possible, and hail could definitely damage the plane, especially the engines, to the point where it would no longer be airworthy. You might make it, but you'd be rolling some pretty serious dice.
Landing in a hurricane would be impossible. You can handle being kicked around in the air because there's nothing to hit. But near the ground you need reasonably stable air in order to make a controlled landing. Anything more than around 50 knots is pretty much a show-stopper for any civilian aircraft, and even much slower winds than that can present significant challenges if they're gusty or not aligned with the runway.
That's true, but they can (and usually do) contain embedded thunderstorms.
> and has very limited vertical movement in its airflows.
Except for the embedded thunderstorms.
> The hurricane hunter P3s do it.
That's true, but they can do it because their destination is the eye of the storm. That allows you to do all your navigation relative to the storm.
Commercial airliners are trying to reach a destination on the ground, i.e. a target that is moving relative to the hurricane. Trying to navigate with this additional constraint is a whole different ballgame.
Landing and taking off in one, however, would be really bad once the winds pick up.
It's vertical winds that are dangerous to fly through, which is what thunderstorms create.
That depends on what you mean by "non-hurricane air." An embedded thunderstorm by definition has to be embedded in some other weather system. That other weather system doesn't have to be a hurricane, but so what? That doesn't change the fact that one of the many dangers of flying into a hurricane is the embedded thunderstorms it contains.
"Hurricanes and tropical storms can also produce tornadoes. These tornadoes most often occur in thunderstorms embedded in rain bands well away from the center of the hurricane; however, they can also occur near the eyewall."
> The hurricane by itself presents very little danger to a plane in the air
That's a vacuous statement. Yes, if you remove all the dangerous parts of a hurricane, whatever remains is, by definition, not dangerous. And yes, it's true that strong winds by themselves are not dangerous. Commercial airliners regularly fly through the jet stream which is comparable to a hurricane in terms of wind speed. But that doesn't change the fact that hurricanes contain embedded thunderstorms, which can be very dangerous.
It's not rocket science.
I won't claim one way or the other, but let's presume that this person is a professional pilot. Does that not make their opinion/analysis more valuable, rather than explaining it away?
Bona fides: FAA Licenced Aircraft Dispatcher; 11 years industry experience. (Left the industry in 2000)
Staff title: Chief Dispatcher
I'll not attempt to address the many meteorological or airframe engineering aspects of this mission other than to note that Delta staffs its own meteorology department (or did last I was privy to their operations). The capabilities that lend to the carrier are net positive, as should be obvious.
On to some specific questions raised ...
>>>[qume] The captain makes the same call on every flight. The plane and passengers are her responsibility regardless of the situation.
Edit - also the call is made continuously. They can back out any time.
Only half true: the pilot-in-command (PIC) along with the aircraft dispatcher share responsibility for the "initiation, operation and termination of the flight." (Yes, I think the regs use 'termination'; that always made me wince.)
So, it's a quorum of two: if either one chooses to terminate (or 'not initiate') a given flight, it cannot be operated. That doesn't mean that a dispatcher who disagrees won't spend some effort presenting evidence for his position (e.g., ten-minute phone calls), but at the end of the day of those two don't agree, the flight cannot operate.
They may or may not have volunteered for the flight, but they do get the final decision to go in or turn back once the airline OKs it.
This statement begs the question: who is "the airline?" The relevant US regulations (CFR 14 Part 121) refer throughout to this entity as the 'certificate holder' -- because an air carrier holds an operator's license -- a business license, of sorts -- granted by 'the administrator,' the regulatory term for the FAA. I'd gamble that since the FAA descended from the CAA that the policy authors thought it wise to anonymise the parties wherever possible in the event of future language changes. Smart move.
So for any given flight, "the airline" would be the dispatcher, who by proxy, exercises the right of 'the certificate holder' to "operate a particular flight over a specific route under specific conditions" (going from memory, mind you).
This authorization is formally granted by way of a legal document prepared by 'the certificate holder' (read: dispatcher) known as the 'dispatch release,' which includes a minimum set of specific information (flight plan, equipment type and number, flight crew, fuel min/max/burn, alternate airports, and so forth) but typically have an abundance of supplementary information to better brief the flight crew of the expected conditions and details of alternatives that are likely to be available if the proposed plan cannot be followed.
Bonus fact: If you ever were waiting after boarding and the crew came over the PA to say they are "waiting on paperwork," most of the time it is a bag/weight count, but some times it's the dispatch release. If you know your flight is going across, or into, some crappy weather, the chances of the latter are greater than average.
Does anybody who works in the industry have any idea of what the risk management is like for these types of events?
The airline operations hundreds of flights a day; all have some risk, and all decisions must be made in real-time. In cases of long-running events such as a hurricane, there is likely to be some general tone taken by the carrier at the highest operational levels (chief pilots, chief dispatchers, VP of Operations, etc.). For my carrier, these strategic positions would be discussed in the morning meeting, which was a recurring conference call between all those parties and department supervisors -- kind of like a stand-up, except we were all sitting around a conference table.
Aside from that, as the day wears on the specific handling of a given route, weather event, etc., is handled in real-time by the assigned dispatcher and support team (meteorologists, mechanics, etc.)
Of note: some larger carriers maintain a 'Trouble Desk' staffed by dispatchers who are assigned a lighter workload than the regular line folks. This is a great system (one that my carrier didn't have) because, let me tell you, just one fubar flight can monopolize all your capability and time for quite a while. If/when one of those flights pops off the queue it can wreck your throughput for the remainder of the shift. For my money, the trouble desk is an excellent mitigation tactic capable of keeping the workload in the dispatch office sharded appropriately.
Does anyone know more about this type of pre-hurricane flight? Is that a common thing airlines do, to try to squeeze one last flight in? Are there rushes before other types of bad weather?
I only had a handful of duty experiences with hurricane landings that were in our region of operation, but I do have a wealth of experience with other severe weather systems here in the US -- aka, tornado season.
There were many occasions when a strong cold front would be bearing down on cities we served, with solid lines of thunderstorms sweeping through the region. The kinds of weather that serve up severe or extreme turbulence, large hail, and tornadic activity. And there aren't any "holes" to "slip through," either.
Frequently, it would come down to trying to get one more flight in and out of a city. (The pressures of 'completion factor' at an airline are a whole discussion in itself.) In these cases, I'd be measuring the relative velocity of the line versus the distance to the airfield, estimating the time of impact, so to speak, and cross-referencing that against my computed time en route and considering the turn-time at the station, etc., etc.
Assuming you judge that it can be operated safely, and you can provide a suitable alternate plan (and "turn back to base" is certainly a common choice) you have to get on the phone (or radio) and brief the PIC on some or all of the details (all of the details are in the dispatch, but people like to hear a human voice when facing stressful situations; think 911 operators), and if they concur (or accede, in some cases) then, from (1), by the necessary joint agreement, the flight is initiated.
And as you might expect, sometimes the flight got in and out, and sometimes it diverted or came back to base. In either case, occasionally the crew might call or radio back in with reports on the conditions (or vociferous complaints about the ride quality -- hey, it happens).
So then my unqualified answer to this question from joemi is "Yes."
Finally I'd like to call out the commenters who made mention of the ground (and other station) crew and their exposure to risk in these "irregular operations"; I'd say they exhibited a measure of aplomb no less than the flight crew, and those employees are too often overlooked as essential parts of the carrier's operations; both day-to-day and in extreme cases such as a hurricane landfall.
I guess a mix of heroes and craziness.
Congratulation to everyone involved and thankfully everything went alright.
An evac flight could even go full on quick load. No checked bags, one carry-on max, forget assigned seats and just fill the plane from back to front as fast as possible to get out of dodge.
No people loaded down with multiple huge carryons, no checked luggage, no searching for your assigned seat, no zone loading bullshit, just everybody walks on the plane and sits down in the first available seats they find leaving no empty seats. Everybody lined up at the door ready to go the minute the plane is empty. You could probably have the whole plane loaded before it finished refueling.
This is still the case.
The picture seems to use the "Jet" Matlab colormap, which is pretty bad by many accounts: