This year’s Gordon Bennett gas balloon race has finished & what a finish! Less than 2 miles separate the top three teams after greater than 1300 miles traveled & two of them end up out over the ocean before curling back onto the tip of Portugal.
Not a flight I’d want to be on:
I dunno, it doesn’t look that tough in the videos:
I would think that most of the fluttering type of objects are things that the plane can fly without. Can a widebody fly and land if a sing flap section departs the aircraft midflight?
As bad as the wing flap section could be to people on the ground, it sounds like a bigger problem for everyone on the plane. I doubt there’s a form to fill out when a wing falls off.
In general, yes. Has happened way more than once. Widebody flaps are 2 or even 3 sections per span and usually 2 spans. So 4-6 airfoils per side. Narrow-body are typically 2 foils times 2 spans per side.
Loss of any one induces rolling moment, but there’s a horrendous amount of control power available to counteract that. Add some airspeed on approach to counteract the missing lift and all is well.
Most likely your boss / commanding officer will be stuck filling it out posthumously on your behalf. If by some miracle you survive they’ll fill it out for you as a courtesy.
Either way, not your problem. FTW!! 
See also
This plane’s flaps refused to extend, so they had to land at a high speed (190 knots).
Technically a “mayday” situation, but never any real danger. The pilot insisted on using a runway that didn’t require a turn on final approach, to give them max distance to minimize the chance of severely overheating the brakes.
(Links to a 74Gear YouTube video analyzing the communications between a Cathay Pacific Cargo jet and a control tower.)
There are two broad categories of flap malfunctions.
One category, as your example points out, is what if they all don’t extend or they all only extend partially. The result then is a higher approach speed and need for a long runway. Which might not be readily available if you’re unlucky enough to have that happen at a place with only a short runway and no suitable alternates near enough versus your fuel supply. Perhaps with flaps stuck partially extended, which will really curtail your range.
The other category is where for whatever reason, you end up with a difference between the left and right sides of the airplane. Now you have two problems. Less than full deployment, so the same challenges as above, plus the extra challenge that the airplane will want to roll towards the less flap-ful side. Perhaps violently so. The term of art for that is “flap asymmetry”.
Lots of effort is spent on both preventing and also on promptly detecting a growing asymmetry early before it becomes challenging versus the roll authority available. But once parts start falling off the airplane it’s much harder to say exactly what will happen. I know at least some widebodies have lost big flap panels and returned successfully. I do not know of any accidents, at least not since the early jet days where loss of a flap led to loss of the aircraft. Not so say it’s never happened, just that it doesn’t ring a bell. And I’ve been following this stuff avidly since I was a kid.
I don’t know whether the certification standards require that a physically worst-case asymmetry be controllable. I.e. one side fully retracted, the other fully extended, but both sides otherwise intact. My gut feel is that would not be controllable for at least some jets under some conditions.
And even assuming that scenario was certified to be controllable, then you can always posit battle damage / parts falling off sufficient to exceed the neat assumptions of e.g. one side fully retracted, one side fully extended, but both fully intact.
Last of all, modern jets have both leading and trailing edge flaps, collectively “high lift devices”. Lotta possible combinations of stuff not working correctly once we consider all those components. In many cases the lion’s share of total lift increment / stall speed reduction comes from the leading edge devices, not the trailing edge devices. Despite the trailing edge devices being larger, having a larger range of motion, and being more obvious to the layman.
If anyone has questions about gas balloons, or hot-air for that matter, ask away.
Not remotely close to my area of expertise (but I’ve met some flight load and flight control specialists!) but …
The certification standards don’t generally require that any imaginable scenario be controllable, but rather than the occurrence of “worst case” scenarios be shown by a combination of design, maintenance (inspections), and procedures to be extremely improbable in the case of catastrophic scenarios, or improbable for hazardous scenarios, etc. Those terms are defined in regulatory guidance and there are reams of instructions on how to go about calculating and demonstrating this stuff.
Everything comes back to 14 CFR 25.1309 (for transport category aircraft) and the acceptable means of compliance to that standard. The analysis of failure modes, fault trees, common cause failures and all the other stuff that goes into this is an incredibly in-depth process that contributes heavily to the definition of the use, inspection, maintenance, etc of each part and system and should, in theory, prevent a modern aircraft from ever getting near the point of having a flap panel fall off at all. If one does fall off, the subsequent investigation and corrective action (airworthiness directives) should prevent it from ever happening again.
So, as you say, the extreme asymmetric flap condition might not be controllable. That’s why you have position sensors, tandem movement (each side moves together or stops and reports a discrepancy), and cockpit alerts etc to warn you long before you ever get to that point.
How well are balloonists able to control where they land? Is there a protocol if you have to land on private land?
We can only control our vertical, either by adding heat (dropping ballast in a gas balloon, typically sand but will be water over populated areas) or pulling the vent line.
We go downwind. Sometimes there is steerage at different altitudes other days there isn’t. Albuquerque is famous for it’s ‘box’. Low winds go one direction but pop up & you’re clear of the Sandia mountain & higher winds are going the opposite direction. Like running on a track, we can do a couple of miles but start & finish on the same field. I know of one pilot whose personal best is 12’; not sure of total distance but his take off & landing spots were w/in 12’ of each other.
To answer your question - Land & ask permission. Seriously. We try to be respectful & not create ‘red zones’ for future flights because if you get too many that ruins a flying area. In general, we may land at a crop farm but not on planted fields as we don’t want to cause a farmer economic harm by damaging any plants; we’ll stay away if we see livestock. That big wide open golf course; we don’t want to mess up their carefully maintained greens.
Parks, schools (not in session), cul-de-sacs or residential streets, even someone’s yard are all great places to land. Most people want us to land on their property. Of course, the traditional bottle of champagne (or sparkling cider) payoff doesn’t hurt.
France - 1783 - The Montgolfier brothers were papermakers, when they burned their scraps they noticed the smoke rose, they thought it was due to the smoke, not hot air. Hmmm, they thought, let’s see if we can make a balloon & be the first man to fly so they built a balloon & a launch pit, with a big, smoky fire & ascended into the sky from Paris towards the French countryside.
Now back then there were only two things that flew, birds &…dragons!!!. The farmers saw this thing that didn’t look like a bird & it was belching smoke so clearly it was a dragon. When it landed, they attacked it with their pitchforks & destroyed it. While the Montgolfier brothers were doing okay financially, they weren’t ultra-rich & couldn’t afford to build a new balloon for every flight so they thought & thought. For their next flight, they took a bottle of champagne from a local vinter & gave it to the landowner. This showed they were 1) from the Earth 2) locals (how else would they have acquired a local bottle?) & 3) friendly; they came bearing gifts.
Thus the tradition of champagne after a flight was born…& still carried on til this day.
Ben Franklin, asked by a dismissive French nobleman what good the Montgolfiers’ balloon flights were, is said to have replied, “What good is a newborn child?”
could our resident experts weigh in on this newspiece?
(if I learned something from this thread, its “everything is way more complex, expensive and time consuming than you think it is” …)
The diversion was in line with company procedures as the furry stowaway posed a safety risk, airline spokesperson Oystein Schmidt told the AFP news agency.
Passengers on the flight were later flown to Malaga on a different aircraft.
Airlines usually have strict restrictions involving rodents on board planes in order to prevent electrical wiring being chewed through.
I’m disappointed to find no pictures of the mousie.
What’s worse than a live mouse in your food? A dead mouse.
or
What’s worse than a live mouse in your food? A half eaten one.
I show myself out.
They need to advertise that they serve the freshest food.
The DC-10 accident in 1979 at O’Hare came close to this, but not quite.
Many assume it was the engine falling off a wing during takeoff that caused it. As of course you know well, that in itself shouldn’t lead to an accident.
Unfortunately, hydraulic fluid lines were ruptured, so the flaps (or was it the slats?) on one wing were stuck in a certain position.
But even that need not be fatal, as you noted. No, it was the loss of the indicator — the sensor — for the slats position that was the main cause of the crash, if I understand correctly. The pilots couldn’t be sure of the reasons for their banking, and so couldn’t take proper corrective action.
(I just looked it up. It was the slats. And the main mistake was the speed. The pilot set the correct speed for taking off with an engine missing, which was slower than the correct speed for climbing with a slat retracted — so the plane stalled).
From Wikipedia: Specifically, the loss of that particular engine disabled the slats position indicator, as well as the stall shaker:
“The DC-10 incorporates two warning devices that might have alerted the pilots to the impending stall: the slat disagreement warning light, which should have illuminated after the uncommanded retraction of the slats, and the stick shaker on the captain’s control column, which activates close to the stall speed. Both of these warning devices were powered by an electric generator driven by the number-one engine, and both became inoperable after the loss of that engine.”