# A321 Two unsuccessful strong crosswind landing attempts. What was actually going on?

As a passenger on A321 I have recently experienced the following:

The plane took off in strong winds (25-30 knots) and then proceeded to the destination, which it reached in 45 minutes. At first attempt the plane touched the ground with its rear landing gear and then it immediately went full throttle and took off again. After making a circle, the situation repeated after which we flew back to the original port.

The pilot said: "I made the decision to go back because the wind is over 100 km/h, which is above this aircraft limits".

100 km/h is over 53 knots which is way above the limitations of A321.

Crosswind - Takeoff 29 kts
Crosswind - Landing 33 kts
Crosswind with Gusts 38 kts
Tailwind - Takeoff and Landing 10kts

My questions are:

1. Should the pilot have even attempted to land? Wasn't it too risky?
2. Should he have even taken off knowing about the weather conditions at the destination airport? How is this kind of decision normally made?
3. Since takeoff limits are lower than landing, was it safe take back off upon unsuccessful landing attempt? In other words if the winds are bad enough for landing do you want to take off rather than force the plane down and see what happens?
• IMO if the wind is head wind it should be fine though. Second question condition at destination may change quickly. Commented Jan 13, 2016 at 18:26
• The limits posted are for the crosswind component. For example if you're landing on runway 36 and the wind 53 kts. out of 270° then the crosswind component is the full 53 kts. But if the wind is out of 330° the crosswind component is only 26 kts, and if the wind is out of 360° then it is 0 kts. Commented Jan 13, 2016 at 18:41
• Specifically, the crosswind component is wind speed * sin(angle between wind and heading). Also, gusts can cause brief, but very significant changes in wind velocity. Additionally, the sustained wind speeds can also change quickly. It's unlikely that the pilot knew there would be 53 knot winds at the destination before he took off. He probably knew there would be high winds, but there could have been significant differences between the forecasts he had and what actually happened. Commented Jan 13, 2016 at 19:00
• Note that the values listed in the flight manual are not normally limits, but only maximum values demonstrated demonstrated during certification. Commented Jan 13, 2016 at 19:04
• I'm not sure who qualifies as an expert on xwind landings, but based on 30 years of flying with the last 10 on 747s and having had to deal with xwinds on a regular basis, I see nothing wrong with the pilot's decisions, whether to go in the first place or to return. You never know what the actual conditions are until you get there. Also, a go-around is not the same as a takeoff, even if the wheels are on the ground for a bit. My guess would be that when he had the main gear on, his judgement was that he might be unable to maintain directional control once he lost flying speed, so he lifted off. Commented Jan 13, 2016 at 19:18

Based on the provide date, I looked up weather history and the METAR (weather report for pilots) was:

CYUL 110700Z 24033G49KT 15SM -SHSN OVC033 M02/M08 A2937 RMK SC8 SLP948

Which translates, in English, to:

CYUL weather report at 11th day of the month, 0700 UTC time: Winds at 240 degrees at 33 knots gusting to 49 knots, visibility 15 statue miles, little snow, overcast clouds at 3300 feet, temperature -2C, dew point -8C, altimeter 29.37 inches of mercury; Remarks: scattered clouds at 800 feet, sea level pressure 948 milibars

49 knots would be equivalent to 90 km/h, but it is possible that the wind report by the ATC tower was higher at the time of landing.

## How much crosswind was there?

Assuming the pilots attempt to land at 24L / 24R, there would be little or no crosswind. However the high wind speed + high variation of wind speed would be a problem: the fluctuation is 16 knots. For a small airliner like a A321, 16 knots of airspeed gain / loss is a lot. The pilot did not feel comfortable putting it down, so he chose to divert. The decision was a wise one: he tried enough (2 attempts) and concluded he'd better get back while there is still fuel left.

(Side story: I once heard a GA pilot who go-around 9 times on the same runway because of high wind. On his 10th approach he crashed)

## Was it wise to takeoff?

Yes. Scrolling back the clock a few hours to the time when the pilots would prepare their flight, the weather forecast was:

(...) FM110400 24030G40KT P6SM BKN025 OVC050 (...)

Which translates to: from 0400 UTC time onwards, wind would be 240 degrees at 30 knots gusting to 40. Well, not good, but this was 9 knots below the reported gust when they actually arrived. Moreover, an alternate airport which was within reach and with better winds was chosen. This flight was short, and it is not surprising that on such short flights the alternate is return to the departure airport.

## Was it wise to abort the landing and apply full power?

Absolutely! Forcing the plane onto the runway is the exact opposite of what a pilot should do. I will tell you, most (I don't have a number, but a fair guess would be >80%) of the landing accidents occur because the pilots failed to recognize that the aircraft was not fully prepared for landing (gusting winds, too high on approach, flaps not configured etc.). If those pilots chose to apply full power, go around and give it another shot, many lives would have been saved. Many people perceive aborting a landing as "dangerous"; in fact, it's the best thing to do in those situations.

Should the pilot have even attempted to land? Wasn't it too risky?

Ultimately this is the decision of the pilot in command. While airlines have operating procedures (and the pilot can be reprimanded for not following them) the pilot can for any number of reasons attempt a landing, we can spend a lot discussing decision making but my guess is that the pilot felt the conditions were safe to make an attempt at a landing. The problem he encountered (most likely) is that high winds are often accompanied by things like turbulence or wind shear which can make landing dangerous in its own right. Upon his attempt to land he encountered this and decided a go-around and then eventual diversion was the safe choice.

Should he have even taken off knowing about the weather conditions at the destination airport? How this kind of decision is normally made?

Yes you do know the conditions when you depart however those are the conditions at the time of departure. Weather can change fast (even in 45 minutes). You could have departed with wind well within limitations and had it unexpectedly kick up. The most tragic and common example of this is VFR rated pilots who depart and encounter IMC in route which often unfortunately leads to accidents.

Since takeoff limits are lower than landing, was it safe take back off upon unsuccessful landing attempt? In other words if the winds are bad enough for landing do you want to take off rather than force the plane down and see what happens?

The limits you have listed are direct cross wind limits, in other words the wind is moving across the runway (90 degrees to the direction of the runway). There is generally no published headwind limit for landing (wind blowing down the runway). There is however a practical limit in the sense that if the wind speed is higher than the maximum speed of the aircraft you will not be able to approach the runway (and will move backwards relative to the ground). This is not really an issue for large planes but for something like a Cessna 150 which can only do about 100Kts it would not be an impossible case although I don't advocate for flying if the ground speed of the wind is over 100kts.

He also did not ever really "land" (even though the mains touched down) he executed a "go around". As long as sufficient runway and airspeed exists when the mains touched down, applying full throttle is more than safe.

In aviation you should never really do something so you can "see what happens" you should always strive to know what will happen as a result of your actions.

If you can provide the airport (so we can know the runway directions) and the wind reports for that day we will better be able to explain what happened.

• Thank you for your response. The Airport is YUL It was on Jan 11th at 0230 that landing was attempted. Wind at 0200: 53kmh, dir: 250 degr. Wind at 0300: 38kmh, dir: 250 degr. Commented Jan 13, 2016 at 20:17
• @AlexeiFimine, so given that YUL has runway 24L and 24R, the crosswind component was minimal. That makes it reasonable to attempt the approach. By the way, was the wind 53km/h, or 53kts (= 98 km/h, which would match what you said in the question; METARs normally give wind speed in knots). Commented Jan 13, 2016 at 21:02
• @JanHudec it's in kmh In the question I quoted the pilot. What I provided in the comment comes from the Environment Canada historical data. It's in Km/h. Commented Jan 13, 2016 at 21:10
• Sounds like the pilot either exaggerated or got confused, then: 53 kph is <29 knots, within the A320's crosswind landing limits even if it was a crosswind rather than a headwind! It's possible it was gusting, however, and the pilot wasn't happy with the situation. Commented Jan 14, 2016 at 14:44
• @JonStory With gust, it may be harder to touch down at the desired place, thus leaving not enough runway to stop safely. Anyway, not landing when not sure to make it safely is a wise decision. Commented Jan 14, 2016 at 15:26

Crosswind "limits" are demonstrated only. So not limiting. For example, Airbus max crosswind for landing on a dry runway is 38 kts including gust(320). It's not a hard limit, perhaps as wind varies and would be impossible to precisely calculate at the time of touchdown. Does this mean it's a good idea to attempt landing with a crosswind component of 45 or more kts? There are better solutions but it's a judgement call. Steady state wind vs gust. Many manufacturers have the crosswind limit steady state. Airbus includes gusts. Yesterday wind was 280/34 gusting 44 so landing on runway 24 had a 30 kt crosswind. Then short final tower reports 290/34 gusting 54. It's now a 37 kt crosswind. If the runway is covered in snow, the limit is 25 kts including gust. How can a pilot know that short final. Cant get the charts out. I have a number in my mind that's the max ahead of time. But as the wind direction shifts it becomes difficult. All that to say, they aren't hard limits. It's fluid and dynamic. Good judgement is always required and a go around is never a bad decision, although the crowd in the back may think it's a failure or indicative of skill.