How can pilots manage to land in poor weather conditions

Quest 2

Термины в модуле (25)

So in order to prevent such things, airports and air companies should follow simple aviation security rules. For example, the airport authorities arrange security checks for passengers, crew and baggage using introscopes, metal detectors and sniffer dogs.

For inflight medical emergencies there is a first aid kit.(Для оказания неотложной медицинской помощи в полете имеется аптечка.)

Many major airports have parallel runways and can perform simultaneous(одновременнуые) landings or takeoffs. That increases traffic capacity greatly(пропускная способность).

Other airports have intersecting runways. Such airports are more flexible(гибкие) in terms of crosswind operations but much more difficult in terms of taxiing. They have more so-called hot spots.

It might seem at first that more engines mean higher reliability and thus(таким образом) lower safety risks. Historically, four-engine commercial airplanes were the first to get approved for transoceanic flights. But the truth is, more engines mean more hardware(аппаратного обеспечения на борту) onboard the aircraft that theoretically can fail. Higher complexity brings higher probability of fire, structural damage or other malfunctions.(Чем выше сложность, тем выше вероятность возгорания, повреждения конструкции или других неисправностей.)

For example, in case of any fire on board, the pilot must declare an emergency and say MAY DAY. It advises the ATC that the aircraft needs absolute priority and there is an immediate threat to the safety of the airplane and the passengers.

The PAN-PAN means that something happened onboard but the crew controls the situation and there is no immediate threat.

How does technology help pilots with takeoff and landing in poor visibility?

Responsibility is the cornerstone of our operations, and safety is our guiding principle in everything we do. Our Sum of Good Things series highlights details of Finavia’s responsibility work. This story is about instrument landing systems.

Finnish airports serve passengers and airlines even in weather conditions that would elsewhere lead to closing the airport. In fact, runway conditions are practically the same throughout the year, despite snowy and icy weather in the winter.

But what if it’s fog and not snowfall that is making the conditions demanding? How can pilots land in non-existent visibility?

An instrument landing system helps pilots

According to Heikki Isomaa, who is responsible for air navigation services at Finavia, Helsinki Airport’s technical equipment is considered the best in Finland and is internationally competitive. The airport stays in operation even if visibility is extremely poor.

“With the help of our instrument landing system, or ILS, aircraft can land safely in poor visibility,” Isomaa says.

Most Finavia airports use an ILS. The system includes a glidepath antenna and localiser beam. The system sends out a radio signal according to which the devices in an approaching aircraft tell the pilot how to navigate to follow the glidepath leading to the runway.

Air traffic is regulated during thick fog

During a spell of poor visibility, airports adopt low visibility procedures, or LVP in short.

“Low visibility procedures mean that the airport stops all traffic that may skew the ILS localiser beam or accidentally end up in a safety-critical zone. Operations in the traffic area are minimised, and at Helsinki Airport, air navigation services guide both aircraft and land traffic, primarily based on radar information,” Isomaa explains.

Vehicle traffic is restricted, and ground staff leave the traffic area. Any maintenance work that is not essential is discontinued until visibility improves. To minimise aircraft’s reflection effect on the ILS’s localiser beam, air traffic is guided to holding points farther from the runway than usual.

Additionally, at other Finavia airports, air navigation services only handle one aircraft at a time, which means that only one plane can move at a time. Such restrictions to the flow of traffic typically cause changes in air traffic schedules.

Preparation for landing starts before takeoff

How does poor visibility impact the pilot’s job? According to captain Tapio Siivola, who flies with Cityjet, preparations for landing in restricted visibility begin before the plane takes off.

“If visibility in the destination is known to be poor, the aircraft is fuelled up before departure with a lot more fuel than usual. Since the airport cannot receive as many aircraft in poor visibility as it can in normal conditions, an approaching plane may have to circulate in the air for a long time before it is granted permission to land,” Siivola explains.

Landing in thick fog requires experience

Approaches are divided into three categories based on visibility conditions. In good conditions (category 1), the pilot can see the runway lights at 60 metres’ altitude at the latest. In category 2 approaches, the lights can be seen from the altitude of 30 metres, and in category 3 approaches, from 15 metres, which means only a few seconds before touchdown.

However, according to Tapio Siivola, such poor visibility conditions occur rarely. He has flown around 3,500 passenger flights, which have only included 16 category 3 approaches.

“It’s always the captain who handles category 3 landings. A captain has thousands of hours of experience in flying. Moreover, we regularly train approaching in fog in a simulator,” Siivola says.

According to Siivola, in thick fog, takeoff is more critical than landing.

“There’s a risk of engine trouble during takeoff. It’s challenging to pilot the plane when you can’t see the other end of the runway and one of the engines is skewing the aircraft,” describes Siivola.

Taxiing is the real challenge

It may not occur to a layperson that from a pilot’s point of view, the most difficult part of flying in poor visibility is in fact taxiing between the runway and the terminal.

“Finding your way from the runway to the terminal is difficult, especially if you’re sitting in the cockpit of a large, widebody aircraft and have to peer at the signs from above,” Siivola says.

According to him, taxiing can be made easier with lights that guide the plane to the terminal. Another option is a “Follow Me” vehicle that leads the plane. Many Finnish airports make use of such cars.

“Experienced airport ground staff can guide aircraft from the runway to the terminal safely even if visibility is very poor,” Heikki Isomaa states.

Flying in Bad Weather: Is it safe or possible?

Pilots frequently worry about flying in bad weather. This topic is covered in various parts of the PPL syllabus, and so it should be, for bad weather flying can be dangerous.

So if you are a private pilot, can you fly safely in bad weather? And if so, how bad does it have to be to be considered too bad, and when should you stay on the ground? What weather conditions should you very definitely steer clear of?

Moving on to larger aircraft, many of us know that they do not have the same restrictions as small planes. Indeed, modern large aircraft can fly in most weather conditions. But there is some weather which can be dangerous for any type of aircraft.

We will take a look at all these issues in turn….

Can a Private Pilot Fly in Bad Weather?

The answer to this is ‘depends’. It depends on both your qualifications and experience, and also the type of plane you are flying.

If you are fairly new to flying, and are in a simple single engined plane with minimal instrumentation, you would be well advised to stay on the ground if the weather is bad. There will be plenty of time for learning about bad weather flying at a later date. If you really want to fly, ask an instructor, and maybe take him or her with you.

However, if you have an instrument qualification and are in current instrument practise, and flying an aircraft with suitable instrumentation, you can fly in much worse conditions. Even so, this does not mean you can completely ignore inclement weather.

So let us take a look at different weather conditions and whether you should fly in them.

Flying in Low Cloud

Low cloud is rarely a problem. But if the cloud is so low that you cannot keep clear of it, and you only have a PPL, you should definitely stay on the ground.

But if you have an Instrument Rating and are in current practice, you can probably fly safely in most low cloud conditions. Cloud in and of itself is not dangerous. It is the poor visibility which arises as a result of it which can cause problems.

Flying in Heavy Rain

Rain is not actually dangerous to aircraft, and you can often fly through rain with no issues at all. The main problem is that heavy rain often leads to poor visibility. Again, whether or not you can fly in heavy rain depends on your qualifications and what sort of instrumentation your aircraft has.

Instrument qualified pilots should have no problem flying in rain. But pilots with a basic PPL might, depending on the intensity of the rain.

Every pilot should beware of freezing rain, which is very dangerous as it can cause a quick build-up of ice on the wings. In conditions like this, stay on the ground.

Flying in Strong Winds

Small aircraft may get tossed around in strong winds, but unless the winds cause severe turbulence, winds by themselves are unlikely to do much harm. It can, however, be quite frightening to fly in strong winds. And if you or your passengers tend to suffer from airsickness, it is really not a good idea.

Strong winds can also make landing difficult, particularly if the wind is right across the runway. If this is the case, you will need to calculate if the crosswind component is too strong for your particular aircraft….and for your experience too. If necessary, you can fly to another airport with a runway pointing into wind, where it will not be a problem for you to land.

Flying in Snow and Ice

Small aircraft need to be quite careful of snow and ice. If ice builds on the wings of a small plane, this can be very dangerous, and small aircraft generally do not have de-icing equipment. If you find ice is building on the wings, fly lower, and land if necessary.

Snow is not that much of a problem, although you do not want to try landing on it unless you are used to doing that kind of thing.

So if snow and/or icing conditions are forecast, be careful.

Flying in Thunderstorms

Thunderstorms can be very dangerous for small aircraft. They often involve severe turbulence, which can cause structural damage. So you really should steer clear of them.

Luckily, storms are usually limited to a fairly small area, and it is possible to fly around them. You would be advised to avoid them by 1 – 20 nautical miles, which means in practice that you keep well away from the turbulence they cause. If you cannot do this – as in my personal example given below – then it’s time to land.

Can Commercial Airliners Fly in Bad Weather Conditions?

All of the above applies mainly to light aircraft being flown by private pilots. Contrary to what many passengers believe, commercial airliners can fly in almost all weather conditions, and are rarely affected too badly by bad weather.

Strong winds might be a little frightening for passengers, and make serving meals difficult for the flight crew. It is also possible for the crosswind component to be too high for a safe landing, although this is unusual in a modern airliner.

Heavy rain could theoretically affect visibility, but these planes generally fly on instruments anyway, so this will not be an issue in itself. Low cloud is not a problem unless the cloud extends all the way down to the ground, ie fog. Many modern airliners can land in fog using automatic landing equipment, even in zero visibility. However, it may then be impossible for them to taxi!

Snow and ice should not be an issue, as airliners have de-icing equipment. But they still need to beware of freezing rain, which can cause ice build-up too fast for even the de-icing equipment to cope.

Airliners can usually fly around or even through thunderstorms, and contrary to what many people believe, there is little or no danger of being struck by lightning. Airliners do occasionally get hit by lightning, but there is no danger to passengers even if this happens.

This explains why it is rare for commercial flights to be canceled due to bad weather. But of course, it does happen occasionally.

Are Some Weather Conditions Too Bad for Any Aircraft to Fly?

Yes, just occasionally the weather is too bad for any aircraft to fly safely. Modern weather forecasts can usually predict this, and this means that aircraft stay on the ground when this is likely to occur.

But just occasionally the weather is far worse than forecast, and everyone gets caught out, including commercial airliners. As a fairly new PPL, I was once caught out by severe and widespread thunderstorms, too extensive for any aircraft to fly around them. It was very frightening and a real lesson to me at the time. Here is an account of what happened….

A Personal Example of Really Severe Weather

It was about nine months after I got my PPL. I had teamed up with Ed (not his real name) a little earlier, and we often flew together. We had around 100 flying hours apiece, we got on well, and we arranged a flight together most weekends, checking out all the local airfields; then those a little further afield. This time we decided to go to XXX. Neither of us had ever been there, but it didn’t look too difficult, and it would be a good day out.

Leaving our Base

We checked the weather carefully before we went. At our base there wasn’t a cloud in the sky, and all looked good for later on too. So I flew us there, and it was an uneventful flight in lovely weather. We landed safely and walked into town for lunch.

About mid-afternoon, with the weather still looking good, we decided it was time to head back to base. But as we were about to walk out to our aircraft, one of the firemen at the airport mentioned having just heard about thunderstorms “somewhere close by”. However, we shrugged and laughed it off. There still wasn’t a cloud to be seen; storms weren’t likely to affect us. Besides, we could always divert to YYY, which was more or less on our route home, if we really needed to, and Ed lived near there, if we really got stuck. So we climbed aboard – with Ed now acting as Pilot in Command – and prepared to depart.

Signs of the Thunderstorm

The first signs of trouble came very soon after we departed. We heard another aircraft calling on the radio, saying that he was returning “due to thunderstorms”. But he was further East, so we still weren’t too worried. However, soon afterwards, someone near YYY said he was returning to XXX too. It didn’t sound good and I think we both began to realize it.

Just moments later, I noticed that the haze was getting thicker, though the weather was still perfectly flyable. At last I started to wonder if I should say anything to Ed. But he seemed quite happy, and I thought maybe I was worrying unnecessarily, so I kept quiet. After all, he was Pilot in Command, so it was his decision.

The Situation Gets Worse

Soon things began to get worse, much worse. All my instincts were now screaming at me to turn back, that we wouldn’t even make YYY, never mind our home airfield. Ed wasn’t completely stupid either and was clearly thinking similarly, for when a few seconds later XXX Approach tried to pass us on to another frequency, he asked if we could stay with them “for a minute or two, as we may well be turning back”.

Barely a minute later, we felt the beginnings of definite turbulence. In front of us now was a huge black wall of cloud. No-one but a complete fool would have attempted to fly into that, and Ed said, or rather croaked hoarsely, “What do you want to do?”

It was quite obviously the right decision…even if we made it a little late. We reached XXX just before the two other returning aircraft which we’d heard on the radio, which had had further to fly. XXX Tower was by now warning of “severe wind shear on final, with a pilot reporting a loss of 10 knots of airspeed”.

Ed executed a perfect landing on the numbers, and the storm hit five minutes after we were safely on the ground, a dramatic affair with high winds and bright pink forked lightning. By now there were several other people who’d returned or diverted, and we swapped stories: “We were 9000 feet up in the airways and dropping at 2000 feet a minute…” You know the kind of thing. Some of the emergency landings were made by airliners, and they weren’t just playing safe! It really wasn’t a good idea for anyone to fly in these conditions.

But as the storm showed no signs of abating, and reports told of a wall of thunderstorms stretching from East to West, things quietened down, at least on the ground. We all began to realize that we were probably stranded overnight, and people began to call family or work, and generally try to reorganize their lives. And we began to look for somewhere to stay, since we clearly weren’t going to make it back until the morning.

We Fly Home Safely

The following morning the weather was good, and Ed flew us back, encountering nothing worse than some patchy early morning mist. We considered ourselves lucky to have survived the experience unscathed, if a little late!

Conclusion

Bad weather should be treated with respect but not fear. There may be conditions in which you can fly safely despite some other people staying on the ground, but the opposite can occur too.

Remember, flying accidents occur every year due to the weather. And as pilots often say, “It’s better to be down here wishing you were up there, than up there wishing you were down here”.

Is the ILS only used for landing when weather conditions are poor? [duplicate]

Either I’m missing something, or this article clearly suggests, that pilots are using ILS for landing only in bad weather conditions. Which could lead to an assumption, that in perfectly clear weather they’re landing always or nearly always in visual.

What am I missing?

5 Answers 5

The relevant question is not whether or not the ILS system is used at all, but when the pilot switches from ILS to visual.

At the beginning of an ILS approach, the ILS signals function as a navigation aid, helping to make sure that the aircraft is lined up correctly with the runway from a longer distance out than the runway itself would be visible clearly enough to the naked eye even in good weather.

It is possible (if all the involved equipment is maintained and certified to high enough standards) to have a decision height of 0 feet so the ILS/autopilot flies the aircraft all the way to touchdown, but doing this requires all other aircraft moving around on the airport surface to observe extended safety distances to the runway to minimize the risk of radio signals bouncing off their fuselages and sending a blind-landing aircraft astray. This can have bad effects for capacity, so in normal operation landings are done with a nonzero decision height.

In fact, most airports don’t spend the additional maintenance cost needed to certify their ILS systems for zero decision height («category III» ILS operation), or do it only for some of their runways. In case of bad weather at busy times, some flights will just have to divert to other airports.

How airlines and pilots prepare to fly in extreme weather

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When your flight is scheduled to hit the air during snowstorms, hurricanes, or even torrential downpour, you might wonder if your airline and the plane’s pilots are prepared.

Fortunately, on most commercial flights, lots of people are responsible for tracking and planning for weather conditions, whether it means mapping out alternative routes or making the decision to delay a flight.

Here’s how airlines and pilots prepare for extreme weather.

Everyone from the FAA to the pilots themselves monitors the weather before your flight

From a pilot’s perspective, flying ahead of a storm requires knowledge of weather before and after departure, what kind of turbulence to expect, and how and when to deviate from storms. Pilots are trained to instinctively handle inclement weather — with or without visibility — but by no means are they flying alone.

The FAA Flight Service Station (FSS) uses the N ational Weather Service (NWS) data to help inform pilots and airports about everything from dew point to adverse conditions and visibility.

Pilots and the FAA are also monitoring the weather during your flight, too

Weather can change in a moment, so even the best-laid plans can go awry.

The FAA and airlines know this, however, so they’re prepared. Since 1993, the FAA has required commercial aircraft to fly with a device called the » Airborne Wind Shear Detection and Alert System» that uses radar information to warn pilots about potentially dangerous conditions, such as what one expert called «microburst» weather to the Washington Post, or «downburst winds.»

Not only do planes have this equipment, but all major airports are watching their own Doppler radar. Plus, p ilots are trained to look out for weather conditions during your flight and have «escape options» to find better weather in the nearby area if necessary, according to the FAA.

There is a lot of pre-flight planning that goes beyond weather

Ground crews are extremely important for a safe flight, too.

The scariest conditions to fly in are snow and slush because they both affect take-off and landing and can impact the way a plane flies.

In his book, » Cockpit Confidential,» airline pilot and blogger Patrick Smith explained that even a quarter-inch-thick layer of ice on a plane can disrupt «the flow of air over and around a wing’s carefully sculpted contours, destroying lift.»

Because of that, airplanes are very carefully cleaned ahead of a flight since even the tiniest amount of ice can impact the effectiveness of a wing, Seth Laskin, a former aircraft deicer at Philadelphia International Airport, told Travel + Leisure.

At most major airlines, pilots have thousands of hours of flying experience and training for flying in various weather conditions

For pilots, major airlines hold the keys to some of the most sought after jobs in the aviation industry. Chances are, if you’re flying on a well-known airline, you’re under the command of a pilot and co-pilot with thousands of hours of experience in the air. Some airline pilots are also former military pilots and all undergo rigorous training while working for the airline.

And the training typically doesn’t stop when the pilots graduate their training. On Delta, for instance, its pilots are required to train again every nine months.

If conditions are bad, your flight will probably be delayed or canceled — and that’s in your best interest

All of this information adds up to a simple truth: chances are, days before you ever saw the first snowflake fall, aviation experts were already mapping alternative routes for your upcoming flight.

«Everything boils down to safety,» Eric Auxier, a Phoenix-based commercial airline pilot and blogger, told The Points Guy in 2018. «Planning for winter weather starts well ahead of time. If things are less than ideal, we’ll likely postpone or cancel flights. If the parameters look reasonable, we give it our best shot.»