PDA

View Full Version : "v1..vr...v2..."


flydreamer
29th Sep 2003, 18:53
Hi, Pilots

I heard that pilot will read out some statement while taking off. something like " V1, VR, V2..."
I guess it should relate to airspeed. But I don't know the indication of such specific speed. and then I have following question:
1. what is the meaning of each airspeed?
2. Why pilot need to read it out while taking off?
3. What is the entire statement which pilot will read out during take off and approach?
Could anyone enlighten me?
I would appreciate for your kind reply.

SeldomFixit
29th Sep 2003, 20:10
Some times, something along the lines of " Have you got the clearance Clarence " or " Get me a vector Victor " or " I picked a bad day to give up smoking "

moggie
29th Sep 2003, 21:02
1: V1= last chance to stop, Minimum speed to go
VR = Speed for initiating rotation
V2 = basically minimum safe climb speed

2: as a back up to you looking at the airspeed indicator.

3: depends very much upon the airline. Generally you can add "positive climb" at which point the gear is raised. Most airlines will also have a call at "80knots" or "100knots" as a chance to check that both airspeed indicators are working correctly. Approach calls to numerous to go into, really.

flydreamer
29th Sep 2003, 23:22
SeldomFixit and Moggie

Thanks for your so nice reply.
And Moggie, I hope you can still see this message. I would like to know, what is the meaning of initiating rotation? Thanks.

I think PPRNE is an open forum. I has read at here, there are really so many nice pilots and people who have passion to aviaition.

For someone, flying maybe just like a job, but for others, it is their dream!

So please respect each other, man.

mrben
30th Sep 2003, 00:10
Hi, flydreamer.

Did you receive my PM?

Keith.Williams.
2nd Oct 2003, 03:17
Flydreamer,

V1 is the take-off decision speed. It is the minimum speed from which it is possible to complete a safe take-off in the event of a single engine failure. It is also the maximum speed at which sufficient field length remains available to bring the aircraft safely to a halt if the take-off is aborted. If the pilot has not already started to abort the take-off when the aircraft reaches V1 he/she must continue the take-off.

VR is the rotation speed. It is the speed at which the pilot must pull back on the control column to bring the nose of the aircraft up into the take-off attitude. The term "initiate rotation" means starting this nose-up manoeuvre.

VLOF is the lift-off speed. It is slightly higher than VR and is the speed at which the aircraft first becomes airborne.

V2 is the take-off safety speed. It is the minimum speed that must be achieved by the time the aircraft reaches screen height following a single engine failure detected at V1. If none of the engines have failed the aircraft must reach a slightly higher speed of V3 by screen height.

The term "screen height" refers to an imaginary screen of a specified height at the end of the take-off distance. The height of this imaginary screen will be either 50 ft for small aircraft or 35 ft for larger aircraft and multi-engine jets.

Please do not hesitate to ask more questions if feel the need. Those members who do not wish to read them can simply scroll down.

Brenoch
2nd Oct 2003, 08:34
And that 35ft screen height being on a takeoff from a dry runway..

ftrplt
2nd Oct 2003, 12:56
and no mention of balanced or unbalanced field length for V1??

Brenoch
2nd Oct 2003, 19:04
This could go on forever...

Keith.Williams.
3rd Oct 2003, 03:05
Brenoch and ftrplt,

Yes of course there are many, many more aspects of the take-off procedure that could have been included in my previous post. But the question was a very simple one and clearly required an equally simple answer. When teaching this subject I prefer to start with the simple stuff and build up to the more complex matters gradually. As they say in all the best Safari park restaurants "If you want to eat an elephant it is best to do it a slice at a time" When you were taught this stuff I suspect that you were relieved that a similar approach was taken.

If of course either of you would like to contribute a fully comprehensive, yet suitably digestible description of the take-off procedure, I would be more than happy to see it.

Lump Jockey
3rd Oct 2003, 04:13
And there you have it!! Keith, you rule baby!!:ok:

ftrplt
3rd Oct 2003, 18:11
Keith, was firmly tongue in cheek; should have put a smiley!

reverserunlocked
4th Oct 2003, 15:43
I'd just like to say good luck, we're all counting you....;)

RYNCLEE
5th Oct 2003, 01:08
Keith.
How about "pull the stick back, the cockpit gets airborne and the rest of the aircraft follows ( hopefully)";)

Keith.Williams.
5th Oct 2003, 02:18
Hmmmmm?

Don't you need to start the engines first?

Oh ::mad: Now I'm starting to be too picky.

Sorry

Ignition Override
5th Oct 2003, 06:45
When the non-flying pilot calls out "100", after this speed we only plan to abort for an engine failure or some major problem which could seriously affect the aircraft's ability to fly. :(

ftrplt
5th Oct 2003, 12:08
Do all glass cockpits have any EICAS warnings for airspeed discrepancies?

mutt
5th Oct 2003, 12:42
Combining this V1 is the take-off decision speed. with If the pilot has not already started to abort the take-off when the aircraft reaches V1 he/she must continue the take-off.

Wouldnt that mean that V1 is not a decision speed, but an action speed?

Mutt.

HotDog
5th Oct 2003, 13:39
Mutt, don't try and re-write the perfomance manuals mate.
V1= Decision speed in the event of an engine failure on take-off; at which the take-off may be abandoned or continued. Do you have a problem with this? Cheers, HD.

mutt
6th Oct 2003, 12:55
Hot Dog.....

Not me, but Mr Boeings men and the FAA might......

Definitation of V1 from FAR 25-107(a)(2).

V1 Takeoff decision speed, it cannot be less than VEF plus the speed gained with the critical engine inoperative during the time interval between the instant the critical engine has failed and the instant the pilot has recognized and REACTED to the engine failure by application of the first retarding means...

Now if we were talking about the OLD days, i might actually agree with you, but not now.

Mutt. :):)

LEM
8th Oct 2003, 06:43
They've realised that "decision speed" is too simplistic.

It takes some time to recognise the failure, decide and act.

Today, as mutt has pointed out, V1 is best defined as the speed at which the Captain reacts, not the speed at which the failure occured.

Brenoch
8th Oct 2003, 09:26
I'm sorry Keith..

No offence ment, much like ftrplt I should have added a smiley..