The great big "ask an airline pilot" thread!

LeftBase

keith16 wrote: »

What does the term 'rotation' mean when taking off? I often watch "air crash investigations" and they always say "rotate" just as they pitch the nose up for take off.

Also, what is the role of the flight engineer? Does this role even exist anymore?

Rotate means that the aircraft has reach take off speed and that the nose can be pitched up to climb away. You will hear them say "V1" before rotate. V1 is the speed at which you are committed to take off as you will not have enough runway to slow down if you abort. V2 is the take off safety speed reached after rotation and the minimum safe speed to climb out.

Flight engineers do exist on some flights, but most commercial flights do now have them now.

smurfjed

The inter-relationship between takeoff speeds is quite fun:)
"Rotate" is a crew call-out that indicates that the aircraft should be pitched up at a normal rate 2-4 degrees per second in order to achieve two criteria:
1: 1.05% of VMU with one engine in-operate, or 1.10% of VMU with all engines operating (VMU is the minimum unstick speed, i.e the minimum speed at which the aircraft will actually lift off)
2: Achieve V2 (1.2 Vstall / 1.13 V1G-Stall) by 35 feet.
The flight tests to establish these speeds are also conducted at a rapid rotation rate (4-6 degrees per second) is to ensure that the aircraft will still meet the regulatory criteria if the crew conduct a rapid rather than normal rotation. The published Rotation speed means that we will meet both of these criteria.
So you can see that there is an inter-relationship between these speeds, as well as V1 and VEF, so we cannot look at any of them in isolation.

smurfjed

keith16

LeftBase wrote: »

Rotate means that the aircraft has reach take off speed and that the nose can be pitched up to climb away. You will hear them say "V1" before rotate. V1 is the speed at which you are committed to take off as you will not have enough runway to slow down if you abort. V2 is the take off safety speed reached after rotation and the minimum safe speed to climb out.

Flight engineers do exist on some flights, but most commercial flights do now have them now.

smurfjed wrote: »

The inter-relationship between takeoff speeds is quite fun:)
"Rotate" is a crew call-out that indicates that the aircraft should be pitched up at a normal rate 2-4 degrees per second in order to achieve two criteria:
1: 1.05% of VMU with one engine in-operate, or 1.10% of VMU with all engines operating (VMU is the minimum unstick speed, i.e the minimum speed at which the aircraft will actually lift off)
2: Achieve V2 (1.2 Vstall / 1.13 V1G-Stall) by 35 feet.
The flight tests to establish these speeds are also conducted at a rapid rotation rate (4-6 degrees per second) is to ensure that the aircraft will still meet the regulatory criteria if the crew conduct a rapid rather than normal rotation. The published Rotation speed means that we will meet both of these criteria.
So you can see that there is an inter-relationship between these speeds, as well as V1 and VEF, so we cannot look at any of them in isolation.

smurfjed

Interesting stuff. Next time I shout "ROTATE" at whoever happens to be sitting beside me on a flight just as we begin to take off, I will now have a coherent answer when they look at me in utter bewilderment and ask "what the fcuk?"

RangeR

keith16 wrote: »

Interesting stuff. Next time I shout "ROTATE" at whoever happens to be sitting beside me on a flight just as we begin to take off, I will now have a coherent answer when they look at me in utter bewilderment and ask "what the fcuk?"

Or just shout it out in any crowded room.

"V1"...."ROTATE"...."FOOK, WE AREN'T REACHING V2. ABANDON ROOM"

smurfjed

V1 is the speed at which you are committed to take off as you will not have enough runway to slow down if you abort

with the introduction of computerised takeoff analysis, the concept of V1 has gotten a little bit more complex than that, the complexity isn't helped by the increasing number of amendments to the regulations pertaining to how accelerate stop/go is calculated, especially in the FAR's, or the ability to reduce the takeoff thrust.

We can operate with multiple V1's, it all depends on the airline philosophy, these are V1min, V1bal, V1max, V1opt, V1 fixed ratio.
V1(min) is the minimum speed at which an engine can fail and you and you can still accelerate to Vr and V2 at the TODA.
V1(max) is the maximum speed at which an engine can fail and you can stop before the ASDA used.
V1(Bal) is a speed at which an engine can fail and you can stop before the ASDA or go and achieve V2 at the TODA.
V1(opt) optimises the speeds based on the actual runway.
V1 fixed ratio, allows you to select a fixed V1/VR ratio.

In my world, we can alter the speed to suit our own preferences, for example, Luton is a relatively short runway but with no obstacles, we can therefore reduce the V1 in order to reduce our stopping distance and increase the excess runway. Or in Geneva where the runway is longer but surrounded by obstacles, we can increase the V1 in order to get us to V2 faster.

We don't do overspeed or improved climb.

smurfjed

greenybaby

jessiesmom wrote: »

please can i ask you 2 questions, i have a 10 yr we went with onur air to turkey last year and she was speaking a little turkish with the air crew and the captain but was too shy to ask to see inside the cockpit but i dont think your allowed to do that anymore??

Sorry if this has been replied to already, major long thread haha, but anyway i have been in the cockpit on 3 occasions since 9/11, most recent was in august coming back from lanzarote, have to say they have changed over the past 10 years!! all lcd screens in a nice purplely colour :Dvhere's me with the captain

LeftBase

greenybaby wrote: »

Sorry if this has been replied to already, major long thread haha, but anyway i have been in the cockpit on 3 occasions since 9/11, most recent was in august coming back from lanzarote, have to say they have changed over the past 10 years!! all lcd screens in a nice purplely colour :Dvhere's me with the captain

My company allows(or at least does not forbid) visit's to the cockpit when the aircraft is on stand.

A320

greenybaby wrote: »

Sorry if this has been replied to already, major long thread haha, but anyway i have been in the cockpit on 3 occasions since 9/11, most recent was in august coming back from lanzarote, have to say they have changed over the past 10 years!! all lcd screens in a nice purplely colour :Dvhere's me with the captain

Greenbaby you look familiar,are you a rep for an airline by any chance or along that line of work??

greenybaby

A320 wrote: »

Greenbaby you look familiar,are you a rep for an airline by any chance or along that line of work??

I wish! Nope i'm just a normal aerosexual lol

A320

ha lol,no you just look like someone so!!!!

eatmyshorts

greenybaby wrote: »

Sorry if this has been replied to already, major long thread haha, but anyway i have been in the cockpit on 3 occasions since 9/11, most recent was in august coming back from lanzarote, have to say they have changed over the past 10 years!! all lcd screens in a nice purplely colour :Dvhere's me with the captain

Having a look into the cockpit after the flight is no problem. It's always good to show people around, especially nervous flyers.

Bessarion

greenybaby wrote: »

I wish! Nope i'm just a normal aerosexual lol

Are we seen as 'normal' now?

Locker10a

Speaking to visits to the flight deck, on my most recent flight, on a well know airline I witnessed something i thought was not allowed anymore! During boarding, i was seated at the overwing exit (manned by crew member during boarding, actually why is this?)The Captain gave a welcome announcement and told us his name etc, on hearing this the gentleman seated across the aisle from me spoke to the crew member and asked could he visit the flight deck! She went to the galley, made a call to the Senior cabin crew, then went into the cockpit, returned and asked the mans name and then sent him on his way to the flight deck! Now in the hustle and bustle of boarding i never saw him come out of the flight deck! He did not return to his seat across from me, the flight was full and this airline has assigned seating so i came to the conclusion he stayed in the cockpit for the flight!
Is this allowed??

Bessarion

The captain has discretion over entrants to the cockpit. He is within his rights to allow off-duty flight crew, or 'individuals personally known to him/her' into the cockpit. It may well be that the gentleman you saw was a friend/colleague of the aircraft commander. Or at the captains request he may have been reseated in another seat closer to the front of the cabin.

greenybaby

Bessarion wrote: »

Are we seen as 'normal' now?

A point very well made :cool: All my friends and most of my family think I'm a looper cos of my fascination with planes

bluecode

greenybaby wrote: »

A point very well made :cool: All my friends and most of my family think I'm a looper cos of my fascination with planes

You are but all of us here are guilty of that. We all share the asylum!

But you to be really insane you have to try and make it a career. Now that's certifiable!

amen

So there is a really strong headwind 50 knots and you account for this in calculating V1 and V2.

Just as you pass V1 and before you reach V2 the headwind disappears (0 knot headwind).

What happens?

If you had just started the climb out and the headwind disappeared what happens?

or do you ignore the headwind when calculating V1 and V2 ?

View Profile

amen wrote: »

So there is a really strong headwind 50 knots and you account for this in calculating V1 and V2.

Just as you pass V1 and before you reach V2 the headwind disappears (0 knot headwind).

What happens?

If you had just started the climb out and the headwind disappeared what happens?

or do you ignore the headwind when calculating V1 and V2 ?

I generally would not take a headwind into account when calculating take off speeds.

If you encounter a windshear on climbout, depending on the severity, you would either perform a "windshear escape manoeuver" or just pitch down slightly to gain some more speed.

IngazZagni

amen wrote: »

So there is a really strong headwind 50 knots and you account for this in calculating V1 and V2.

Just as you pass V1 and before you reach V2 the headwind disappears (0 knot headwind).

What happens?

If you had just started the climb out and the headwind disappeared what happens?

or do you ignore the headwind when calculating V1 and V2 ?

You generally ignore the strength of the wind for take off speeds. Strong headwinds can effect your rotation and cause a tail strike so you do have to be careful.
During approach it's a different story. Then you do add on speed on top of the calculated approach speeds. Sometimes up to 30 knots above normal approach speed. The reason for this is because you are on a low speed/low thrust setting and jet engines can take quite a while to generate power when you jam the throttles forward. On take off you are almost full thrust so you should be able to counter a sudden drop in headwind relatively easy.

smurfjed

If you ever look at an aircraft flight manual you can see the wind adjustment lines that are used for takeoff calculations, starting from the reference ZERO, the lines for headwinds and tailwinds are at different angles, thats because the certified calculation allows for only using 50% of the reported headwind and 150% of the reported tailwind for the calculation. This is to account for the headwind decreasing or the tailwind increasing.
In aircraft where V-speeds are calculated manually, we have the option of using the headwind value to increase takeoff weight, but its mandatory to use the tailwind value, but these are limited to 10 or 15 knots depending on the aircraft.
In aircraft where the FMS calculates the V-speeds, you must enter the winds, so the calculation will always include a wind correction.
How does wind affect takeoff weights? if you want to clear a specific obstacle that is X miles away in zero wind conditions, with a headwind the air distance to this obstacle becomes further so you have more time to clear it, so rather than clear it by a higher amount, we just add more weight The reverse happens for a tailwind.

smurfjed

amen

if you want to clear a specific obstacle that is X miles away in zero wind conditions, with a headwind the air distance to this obstacle becomes further so you have more time to clear it, so rather than clear it by a higher amount, we just add more weigh

Yikes but then are you not gambling that the headwind remains and if it disappears you will have insufficient height to clear the object ?

Does this calculation account for single engine failure on climb out ?

RangeR

Go on, which one of you 'civvies' helped land the 747 in Dublin yesterday?

Tenger

RangeR wrote: »

Go on, which one of you 'civvies' helped land the 747 in Dublin yesterday?

Someone did mention that Suits wasn't online.................

seachto7

Could anyone point me to a thread (I did a search) on how someone could train to be a helicopter pilot? I'm in my 30s, but was always into planes and the likes. I know the first thing would be to "have a load of money for flight training".....

Bearcat

seachto7 wrote: »

Could anyone point me to a thread (I did a search) on how someone could train to be a helicopter pilot? I'm in my 30s, but was always into planes and the likes. I know the first thing would be to "have a load of money for flight training".....

I'm not being a smart ass here but google is your best friend.

smurfjed

Amen, thats the reason that headwinds are calculated at 50% of their report value and tailwinds 150%. Takeoff calculations taken from the AFM are based on an engine failing just before V1 and climbing with an engine out. Although this isn't the only limitation pertaining to calculating the takeoff weight.

For those that don't use headwind corrections, what wind do you enter in the FMS?

smurfjed

amen

I get it now thanks.

faceman

2 Questions about the A330-300 and turbulence. I'm flying transatlantic in a few days and upto all my long haul travel has been either on a 777 or the rare use of an A380

As I'm flying over the Atlantic in December I'd imagine it could be bumpier than a summer trip so I was wondering about the A330 and turbulence. I've heard that the 330 isn't the most comfortable flight in turbulence compared to the 777. Then again turbulence isn't comfortable full stop!

So question 1 is the turbulence matter an urban myth?

Question 2, from a pilot's perspective is the B777 or A330 the more preferable choice and why? (Purely from a pilot's perspective)

smurfjed

We started operating the B777-200 in 1997 and the A330-300 last year, the general consensus is that the A330 isn't as smooth in turbulence.

I have friends who have flown both, both are excellent aircraft, but at least for us, the B777 is the preferred fleet due to the size of the fleet, the route structure and the earning potential (more flying = higher productivity payments).

smurfjed

Bearcat

Turbulence is no fable but reality...google inter tropical convergence zones. Winter months can see strong jet streams and associated turb on the polar side of these jets.

Managing routes through these areas is critical.

A330 I don't have issues with in Turb.

If your in moderate Turb be it in a 330/777 your still going to get chucked about.