The great big "ask an airline pilot" thread!

xflyer

Maybe it's not the same with modern airliners but older aircraft even within the same sub type often had noticeable differences in handling and performance. Pilots would have their favourites and regard some as 'dogs'. I remember Electras and 727s, some were favoured some not.

Certainly it's still true of lighter aircraft particularly when they get a bit older and have been modified or bashed about. Flight schools often have a favoured trainer which although externally identical to all the others seemed to feel and fly better.

Weight and loading of course makes a difference. A type I fly can be flung around like a fighter when empty and land on a postage stamp. Fill it up with six or seven people and it feels like a mini airliner and effectively has to be flown as such.

A320

Any Preference to CFM56 or V2500 engines Priority Right or does it matter,i know a few little differences regarding indication etc but performance wise????

Delta Kilo

I'd be interested in the answer to that too A320.

I know from an operations point of view, the CFM56-5B on the A320 is preferred to the V2500. Most operators tend to choose this option on the A320 fleet. Its a more expensive engine but perceived to be more reliable and efficient than the IAE.

But from a pilots point of view, is there a notable difference between the two? Do the engines behave differently etc?

A320

From a maint point of view i prefer the CFM,some of the wiring in the v25 tends to be routed poorly and thus chafing

Priority Right

I prefer the CFM engines. They startup faster, and respond faster. Which when you're starting out in the flare that extra time it takes the power to reduce can help you out but normally it's better to have a faster reacting engines. (very small difference but noticeable).

When I moved from V25 and was in the first day in the sim with CFM. They started in such a short time I asked the instructor if that was a sim anomaly. He just stared at me and I'm sure was thinking I was mental. But when I explained that I was used to the V25s he understood. They do take ages to start. CFM you can wait until half way through the pushback before starting.

bladeruner

Plowman wrote: »

This post has been deleted.

a heavy 321 is a dog in the climb , not enough power (engine dependent of course but its no 757 now matter what way you cut it )
on the other hand its a tad more stable coming in for landing...every cloud and all that ...

pclancy

I for one have run out of questions for our folks up front. Anyone got any good ones?

IrishB.ie

Runway length dictates the takeoff weight of an aircraft.

We've seen aircraft 'lift' from a standing position during a storm, so my question
is, does headwind ever influence the allowed takeoff weight of an aircraft?
Can the weight be increased if the headwind is strong enough?

bladeruner

IrishB.ie wrote: »

Runway length dictates the takeoff weight of an aircraft.

We've seen aircraft 'lift' from a standing position during a storm, so my question
is, does headwind ever influence the allowed takeoff weight of an aircraft?
Can the weight be increased if the headwind is strong enough?

Yes generally increased head wind = increased RUNWAY RESTRICTED take off weight.
Conversely, taking off with a tailwind would reduce the RUNWAY restricted Max take off weight.

There are some reasons such as max brake energy speeds/weights why u may not get head wind increase but most of the time you do.

Obviously only a constant wind could be used for these calculations - gusts could not.

eatmyshorts

IrishB.ie wrote: »

Runway length dictates the takeoff weight of an aircraft.

Runway length is only one of the contributing factors.

Others are:
Temperature
Density altitude
Wind velocity
Air pressure
Runway surface condition (dry, wet, contaminated, etc)
Engine rating
Aircraft CofG position (some aircraft)
Obstacles within the take-off cone
Use of engine anti-ice
Some active Configuration Deviation List items
Some active Minimum Equipment List items

Any variation in any of these is enough to have an effect on the Regulated Take Off Mass allowable.

Our man in Havana

What is the most difficult airport that any of our pilots have used?

LLU

Saw a documentary the other day about that famous safe landing in the Hudson river in 2009 and apparently one of the key saving factors was that the captain switched on the APU very early on in the process, even though this step came much later on in the emergency procedures. This meant that his instrumentation and controls continued to work throughout and were not impacted by the loss of main engine power. They said that this enabled the planes systems to keep it in a safe envelope throughout.

To me it seems like a brilliant piece of thinking but I can't help wondering if he would have been hung out to dry for this if there hadn't been such a happy outcome (and assuming he still lived). So is there any scope for thinking on your feed in a situation like this? Is there an emergency procedure for *everything* which needs to be stuck to?

Thanks!

Priority Right

Hardest airport. Well some places in mid Africa and Moscow can be fun because the ATC is daft sometimes. Hard airports to fly into can turn out to be fun if you're safe and can be easier than big "easier" airports.

There is a checklist for every emergency. It was good thinking to start the apu but we do it a fair bit if ground staff disconnect the apu. Straight away you turn on the apu. But to do that in an emergency is harder to do. You can deviate from the checklist sometimes because some are checklists not a do list.

Keedowah

Is there a key to open the aircraft or cockpit and is it a key that is used to start the aircraft? If so how does this key(s) get handled in the airport going from one crew to the other?

bladeruner

Priority Right wrote: »

Hardest airport. Well some places in mid Africa and Moscow can be fun because the ATC is daft sometimes. Hard airports to fly into can turn out to be fun if you're safe and can be easier than big "easier" airports.

There is a checklist for "NEARLY" every emergency. It was good thinking to start the apu but we do it a fair bit if ground staff disconnect the apu. Straight away you turn on the apu. But to do that in an emergency is harder to do. You can deviate from the checklist sometimes because some are checklists not a do list.

FYP

bladeruner

Keedowah wrote: »

Is there a key to open the aircraft or cockpit and is it a key that is used to start the aircraft? If so how does this key(s) get handled in the airport going from one crew to the other?

No key for door and no key to start up.
Airports are secure places to park !

Priority Right

bladeruner wrote: »

FYP

Very true. I'd hate to see the QRH for every eventuality they could imagine!

lord lucan

Are pilots bad passengers? By that i mean do you find yourself monitoring various aspects of the flight and being critical/judgemental or do you sit back and chill out and not give it a second thought?

donvito99

Is diplomatic mail still carried by airlines across the Atlantic? And is there a gun in the cockpit.....:cool:?

bladeruner

donvito99 wrote: »

Is diplomatic mail still carried by airlines across the Atlantic?

Yes, ships are too slow and sea lions proved unreliable.

donvito99 wrote: »

And is there a gun in the cockpit.....:cool:?

I can't speak for every airline but I'm 99% sure no European airline has guns in the cockpit.
That was an American "initiative".
Guns have no place on an airliner.

Skuxx

donvito99 wrote: »

And is there a gun in the cockpit.....:cool:?

I've never seen a gun in a cockpit, but most do have an axe! Worked on a turkish plane before that had an axe in the cabin, on the aft lav wall behind the last row of seats!! Seemed a bit accessable!!

Our man in Havana

A gun in a pressurised vessel is a very bad idea.

Bearcat

donvito99 wrote: »

Is diplomatic mail still carried by airlines across the Atlantic? And is there a gun in the cockpit.....:cool:?

No and No

bladeruner

Bearcat wrote: »

donvito99 wrote: »

Is diplomatic mail still carried by airlines across the Atlantic? And is there a gun in the cockpit.....:cool:?

No and No

Quite often some poor junior at an embassy will be sent on a "mail run" to deliver diplomatic bags/mail.
That is my take on airlines still carrying diplomatic mail.

Bearcat

Europe yes, USA no..... Tbh as time marches on mail is more electronic orientated as against some suit dropping a bag into a cockpit. On many occasions no one was there at the other end to collect same which Kinda makes a mockery of the diplomatic tag.

xflyer

lord lucan wrote: »

Are pilots bad passengers? By that i mean do you find yourself monitoring various aspects of the flight and being critical/judgemental or do you sit back and chill out and not give it a second thought?

Don't know about others but my wife hates me when I turn to her looking concerned and say: 'I don't want to worry you but.....' It's amazing how often she gets caught.

As for guns, well only in America as they say. American airline pilots are authorised to carry guns but only after a training course and being deputised as law enforcement officers. As for the danger of a discharge in a aircraft, it's not that big a deal unless it hits something vital. Despite the the movie cliche. The aircraft won't disintegrate if someone puts a bullet through window at 34000 feet.

amen

So you are cruising along at 10,000m and auto pilot is set with altitude hold.

After a period of time due to the earths curvature you are going to be higher then 10,000m.
So does the Auto pilot
1: Constantly adjust trim to keep you at the desired altitude
2: wait until you are x % from the require height and then adjust

On a similar vein if you encounter severe turbulence and the plane changes altitude does the autopilot disengage and you manually fly back to the required altitude ?

tricky D

amen wrote: »

So you are cruising along at 10,000m and auto pilot is set with altitude hold.

After a period of time due to the earths curvature you are going to be higher then 10,000m.
So does the Auto pilot
1: Constantly adjust trim to keep you at the desired altitude
2: wait until you are x % from the require height and then adjust

You'd need to be travelling at a few kilometres per second to have to worry about that.

http://en.wikipedia.org/wiki/Escape_velocity

BostonB

amen wrote: »

So you are cruising along at 10,000m and auto pilot is set with altitude hold.

After a period of time due to the earths curvature you are going to be higher then 10,000m....

Why. The height is relative to the ground/sea. As such its not a straight line, as I think you are visualising it. It follows the curvature in general.

View Profile

On a similar vein if you encounter severe turbulence and the plane changes altitude does the autopilot disengage and you manually fly back to the required altitude ?

If the turbulence is severe enough the autopilot may disengage. The pilot will then take manual control until the turbulence has passed and he/she can re-engage the AP.
Sometimes in turbulence you may notice the AP struggling to keep the altitude or speed in which case you will intervene and take manual control.

However for moderate turbulence the AP is generally quite good at keeping speed/heading/altitude.