How quickly can a commercial plane land?

[wavinwayne]

In a recent incident, a Jetblue plane made an emergency landing in Kansas after a "smoke in the cargo hold" warning, which thankfully was a false alarm. But it made me wonder: If you are a commercial pilot flying something like an Airbus A320 at 35000', and you get a "LAND RIGHT NOW" warning, how fast can you descend and safely land your plane? AI says a descent rate of 4-6k ft/min. in an emergency.

I know we've got several pilots here, so what say you all?

 

[SeaJay]

Doesn't it depend upon the availability and distance of an airfield long enough to safely allow an Airbus A320 to land would be my first question.

 

[Astro14]

The AI has oversimplified the problem.

There is a vertical component, and in that you have to lose the altitude. But you cannot sustain 4 to 6000 feet per minute until you achieve ground impact. At some point, during the approach, you must slow the aircraft down, fly the arrival and achieve a normal descent rate of 6 to 800 feet per minute until landing.

The horizontal component is the more difficult. Which airport do you go to? How far away is that airport?

You have to answer some questions before making that decision - How well do you know that airport? What is the runway length? what is the field elevation? what is the current weather? what are the Approach facilities and procedures? What aircraft rescue and firefighting equipment do they have?

If you’re flying a narrow body aircraft over the central United States, there is probably a suitable (that meets all of the above criteria) airport within 15 minutes.

If you are two hours west of LA on your way to Hawaii, there is a suitable airport three hours ahead of you, or two hours behind you. There is nothing closer than that.

You a few are flying a large aircraft, like a 747, there may not be a suitable airport even in the middle of the United States within an hour. The 747’s landing weight precludes most of the airports in the United States. The concrete would crumble under the aircraft as it turned onto the taxiways of an airport that wasn’t suitable. If it even fit on the taxiways at all.

If you are flying across the north Atlantic on a cold winter night, there may be airports of sufficient runway length, but with enough terrain and or bad weather that flying in there is a bigger risk than the fire onboard.

This isn’t a simple answer - it can’t be.

 

[Hall]

You a few are flying a large aircraft, like a 747, there may not be a suitable airport even in the middle of the United States within an hour. The 747’s landing weight precludes most of the airports in the United States. The concrete would crumble under the aircraft as it turned onto the taxiways of an airport that wasn’t suitable. If it even fit on the taxiways at all.

Does the level of urgency or emergency override that though ? If the runway is (more than) sufficient, isn't it better to get it on the ground safely ?

 

[IndyIan]

The AI has oversimplified the problem.

There is a vertical component, and in that you have to lose the altitude. But you cannot sustain 4 to 6000 feet per minute until you achieve ground impact. At some point, during the approach, you must slow the aircraft down, fly the arrival and achieve a normal descent rate of 6 to 800 feet per minute until landing.

The horizontal component is the more difficult. Which airport do you go to? How far away is that airport?

You have to answer some questions before making that decision - How well do you know that airport? What is the runway length? what is the field elevation? what is the current weather? what are the Approach facilities and procedures? What aircraft rescue and firefighting equipment do they have?

If you’re flying a narrow body aircraft over the central United States, there is probably a suitable (that meets all of the above criteria) airport within 15 minutes.

If you are two hours west of LA on your way to Hawaii, there is a suitable airport three hours ahead of you, or two hours behind you. There is nothing closer than that.

You a few are flying a large aircraft, like a 747, there may not be a suitable airport even in the middle of the United States within an hour. The 747’s landing weight precludes most of the airports in the United States. The concrete would crumble under the aircraft as it turned onto the taxiways of an airport that wasn’t suitable. If it even fit on the taxiways at all.

If you are flying across the north Atlantic on a cold winter night, there may be airports of sufficient runway length, but with enough terrain and or bad weather that flying in there is a bigger risk than the fire onboard.

This isn’t a simple answer - it can’t be.

So say you are piloting a large passenger 747 type aircraft over the midwest, and the cargo hold has been on fire for a while, I assume they would rather you try to land at the closest more remote airport even though you'll probably damage it? I would hope they just let you get the plane on the ground ASAP and worry about the details later?

 

[4WD]

The AI has oversimplified the problem.

There is a vertical component, and in that you have to lose the altitude. But you cannot sustain 4 to 6000 feet per minute until you achieve ground impact. At some point, during the approach, you must slow the aircraft down, fly the arrival and achieve a normal descent rate of 6 to 800 feet per minute until landing.

The horizontal component is the more difficult. Which airport do you go to? How far away is that airport?

You have to answer some questions before making that decision - How well do you know that airport? What is the runway length? what is the field elevation? what is the current weather? what are the Approach facilities and procedures? What aircraft rescue and firefighting equipment do they have?

If you’re flying a narrow body aircraft over the central United States, there is probably a suitable (that meets all of the above criteria) airport within 15 minutes.

If you are two hours west of LA on your way to Hawaii, there is a suitable airport three hours ahead of you, or two hours behind you. There is nothing closer than that.

You a few are flying a large aircraft, like a 747, there may not be a suitable airport even in the middle of the United States within an hour. The 747’s landing weight precludes most of the airports in the United States. The concrete would crumble under the aircraft as it turned onto the taxiways of an airport that wasn’t suitable. If it even fit on the taxiways at all.

If you are flying across the north Atlantic on a cold winter night, there may be airports of sufficient runway length, but with enough terrain and or bad weather that flying in there is a bigger risk than the fire onboard.

This isn’t a simple answer - it can’t be.

Was at YYT for 9/11 and still amazed how many large jets packed in so fast at that little airport …

 

[Kira]

Going on 60 years ago.
I know, not an A320 or 747.

 

[Astro14]

Does the level of urgency or emergency override that though ? If the runway is (more than) sufficient, isn't it better to get it on the ground safely ?

Override what?

One consideration?

No. It can’t. That would be foolish, to determine the suitability of the airport based on one factor - runway length.

The greatest level of safety is determined by the pilot in command who has to weigh dozens of factors.

Anyone of those factors may, or may not, result in a greater level of safety.

So, for example, the runway is more than sufficient, but the instrument approach is below minimums due to weather.

Flying below minimums can result in a crash, or at best, not landing. So, sure, the runway is long enough, but that doesn’t mean you can safely get the airplane there.

The nearby mountains do not care about your urgency - if you fail to follow the correct procedures, and you hit one, well, everyone is dead.

So, no, urgency cannot ever allow you to ignore important considerations that may not be obvious to the non-pilot.

 

[Astro14]

So say you are piloting a large passenger 747 type aircraft over the midwest, and the cargo hold has been on fire for a while, I assume they would rather you try to land at the closest more remote airport even though you'll probably damage it? I would hope they just let you get the plane on the ground ASAP and worry about the details later?

The fire suppression system on the 747 is designed to contain a fire for several hours. Designed, they anticipated this. You have to be able to fly to the nearest SUITABLE airport, not just the nearest airport.

I don’t think you guys understand what is at stake - if you crash the airplane, and everyone dies, you have failed.

Exceeding the limits, whether that be for approach procedure, runway stopping distance, landing weight, flight through mountainous terrain, whatever, results in a crash. That is a fail. Every time.

It isn’t a question of “damaged the airplane” - if the landing gear breaks through the runway on touchdown, because you picked the wrong airport, one that couldn’t handle the weight, and the airplane rolls up in a ball of fire, then that wasn’t a good choice of airport.

Rip the landing gear off an airplane because you missed the runway in bad weather, and ran off the end, or hit the middle of the field, and all that fire gets to all the fuel that just got released from the damaged tanks - even if the passengers survived the impact, they won’t survive the conflagration that follows.

Another fail.

Airport suitability, determined through multiple factors, is not simple. It cannot be. Wind, weather, terrain, approach facilities, approach procedures, lighting, runway length, and yes strength, all have to be considered because ANY ONE OF THEM could cause a crash.

 

[thunderfog]

So say you are piloting a large passenger 747 type aircraft over the midwest, and the cargo hold has been on fire for a while, I assume they would rather you try to land at the closest more remote airport even though you'll probably damage it? I would hope they just let you get the plane on the ground ASAP and worry about the details later?

I would think the bigger issue is that a more "remote" airport likely wouldn't have enough runway *length* for a 747 to land...

 

[Astro14]

I would think the bigger issue is that a more "remote" airport likely wouldn't have enough runway *length* for a 747 to land...

Again, though, it is much more than length. It is appropriate approach facilities. It is lighting. It is weather. It is width. it is weight-bearing capacity.

All of that, and a few more, considerations, before you can say it is suitable.

There are lots of remote airports with runway length and weight bearing capacity, because if it was built for a B-52 during the Cold War, it can probably handle a 747.

But if they don’t have approach facilities appropriate to the situation, then, you’re not getting in there. Not safely.

 

[The_Eric]

Astro - lets assume worst case - fire is licking up at your backside... Are you going to flump that big bird down where you can and get the heck out (and passengers if applicable, of course) or still shoot for something suitable. Or is what I ask simply so far from the realm of possible things that it's not worth engaging? Of course I understand that it's a wholly different beast from a little bug smasher where just about anywhere long enough to be a runway and devoid of things that will rip the baby pop can about is feasible.

 

[wpod]

Flying a big plane is so much more of a skill than we could imagine it is.

 

[Just a civilian pilot]

35,000 feet to touchdown, 12 minutes, max if the situation warranted getting the aircraft on the runway that fast.

Lots of cargo smoke warnings turn out to be false alarms but you don’t know for sure and need to land ASAP ( but not in 12 minutes ….that was just how fast I could do it , safely, if I had to ).

That of coarse depends where we are when it happens.

Get down to 10,000 ASAP if can in case you have to depressurize if smoke is a concern or ongoing issue.

Don’t slow below 10,000 ( normally slow to 250 per regulations ) and keep the speed up until 7 miles before intercept the “ glide slope” and drop the gear at 250 to slow as fast as possible on final.

Once level at 340 knots ( max indicated ) , Airbus says it takes 1 mile to lose 10 knots of indicated airspeed but double if speed brakes out.

To slow from 340 to 250 ( gear speed, even more deceleration once down ) would take about 5 miles. Once the gear is down, and the speed brakes are deployed, the rate of deceleration would be very high in level flight.

You could maintain 340 knots until about a 15 NM final if at 3000 if you had to and be fully stabilized for landing prior to touchdown.

If did it in the sim when I had a cargo fire warning about 4 years ago. Calgary to Toronto, cargo fire warning climbing out of 20,000.

Many pilots forget, you get more speed brakes with the AP off, take it off, hand fly it down ( Airbus A320 ).

Edit: cargo smoke warning ( LAND ASAP in red ) on the Airbus means land at the CLOSEST airport where a safe landing can be made.

Not what’s most suitable, what’s closest.

Obviously certain other factors have to be taken into consideration before you just head for the closest airport ( runway needs to long enough, is the weather good enough to get in , etc ).

Cargo smoke is Red LAND ASAP


LAND ASAP DEFINITION according to Airbus:


If red LAND ASAP is part of the procedure, land as soon as possible at the nearest airport at
which a safe landing can be made.
Note: Red LAND ASAP information is applicable to a time-critical situation.
If amber LAND ASAP is part of the procedure, consider landing at the nearest suitable airport.
Note: "Suitable" means an airport that is deemed suitable in the judgement of the captain.

 

[Just a civilian pilot]

Doesn't it depend upon the availability and distance of an airfield long enough to safely allow an Airbus A320 to land would be my first question.

A319/A320 needs at least 6000 feet. A321 needs 7000.

 

[Just a civilian pilot]

Like I was saying , lots turn out to be a false warning but we have to assume it’s real

https://www.usnews.com/news/best-st...s-after-false-alarm-about-smoke-in-cargo-area

 

[wpod]

A319/A320 needs at least 6000 feet. A321 needs 7000.

I am a simple person that is over a mile.

 

[Just a civilian pilot]

I am a simple person that is over a mile.

That’s too complicated for me.

I either have enough runway or I don’t

 

[Just a civilian pilot]

They were 40 miles from that airport in Kansas at 36,000 feet and managed to get the aircraft on the runway in 20 minutes.

They did a great job.

Incident: Jetblue A321 near Salina on Sep 21st 2024, cargo smoke indication​

By Simon Hradecky, created Sunday, Sep 22nd 2024 07:42Z, last updated Sunday, Sep 22nd 2024 07:42Z​ A Jetblue Airbus A321-200, registration N944JT performing flight B6-1189 from New York JFK,NY to San Diego,CA (USA) with 130 people on board, was enroute at FL360 about 40nm northeast of Salina,KS (USA) when the crew received a cargo smoke indication and decided to divert to Salina for a safe landing on runway 17 about 20 minutes later. Passengers reported the captain announced a cargo smoke indication, some fellow passengers also indicated they had heard a bang. Subsequently some mist came through the air conditioning vents. A replacement A321-200 registration N945JT positioned to Salina, resumed the flight and is currently estimated to reach San Diego with a delay of about 8 hours. The occurrence aircraft is still on the ground in Salina about 8 hours after landing.​

 

[jhellwig]

Astro - lets assume worst case - fire is licking up at your backside... Are you going to flump that big bird down where you can and get the heck out (and passengers if applicable, of course) or still shoot for something suitable. Or is what I ask simply so far from the realm of possible things that it's not worth engaging? Of course I understand that it's a wholly different beast from a little bug smasher where just about anywhere long enough to be a runway and devoid of things that will rip the baby pop can about is feasible.

A 160mph flaming barrel roll isn't what I would call a better option...