V1 - Vr split on long runways
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If you are really interested in the reasons for V1/VR splits, maybe Boeing produce an equivalent to the Airbus "Getting to grips with
aircraft performance".
Some time back, I can remember using performance charts that displayed both V1min and V1max, but guidance from some quarter (I can't remember whether it was JAR or CAA) was to have SOP geared towards being 'GO Minded' and subsequent revisions to the paper performance only displayed V1min.
In the Airbus document "2.4.3.3. MTOW limited by three limitations" gives the reasons for having a range of V1. While there are some aspects of the required factors that are different for the Airbus fly-by-wire, the overall subject is just as relevant to other manufacturers/types.
Airbus Performance Optimization appendix read and enjoy!
aircraft performance".
Some time back, I can remember using performance charts that displayed both V1min and V1max, but guidance from some quarter (I can't remember whether it was JAR or CAA) was to have SOP geared towards being 'GO Minded' and subsequent revisions to the paper performance only displayed V1min.
In the Airbus document "2.4.3.3. MTOW limited by three limitations" gives the reasons for having a range of V1. While there are some aspects of the required factors that are different for the Airbus fly-by-wire, the overall subject is just as relevant to other manufacturers/types.
Airbus Performance Optimization appendix read and enjoy!
depending on the type of aircraft, the actual take off mass as well the flap setting for t.o you may be brake energy limited regarding the split between v1 and vr .
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hm... i would like to highlight a scenario that this software is in real something like a freeware app or a program for a pc game and the only answer is that is has a program error while several people here perform a brain storming.
in this case you will get no answer- in the case your question is for real i would suggest to contact your technical department instead an anonymous forum which should help you.
when you claim brake energy is not a limiting factor i personally have no idea what is going on.
best regards
in this case you will get no answer- in the case your question is for real i would suggest to contact your technical department instead an anonymous forum which should help you.
when you claim brake energy is not a limiting factor i personally have no idea what is going on.
best regards
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One of our normal runways at MIA was 13,000 ft long taking off to the west. Our airline required us at V1 to continue the takeoff. A friend of mine took off and had a thrust reverser deploy at V1 taking off to the east in a 727. He managed to get it back and land but aborting was the safest procedure. He followed company policy and returned for landing. All was sucessful but sometimes staying on the ground is the best answer. Remember the DC10 at Chicago crash? Sometimes company procedures will kill you.
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Hi bubbers44
How often do you have V1 above VR?
Report of DC-10-10 AA Accident near O'Hare
"During the takeoff rotation, the left engine and pylon assembly [see fig. 16.1] and about 3 feet of the leading edge of the left wing separated from the aircraft"
I remember it very well. All was going OK at their initial climb out speed. The crew increased the rate of climb and reduced the speed towards V2. The left wing then stalled.
ASN Aircraft accident McDonnell Douglas DC-10-30CF EC-DEG Mlaga Airport (AGP)
"The airplane continued to accelerate through VR. As the captain tried to rotate by applying up elevator, the vibration was of such magnitude that he feared that the plane might become uncontrollable after takeoff. He decided to abort the takeoff. At that point, with a maximum speed attained of 184 kts, there was 1295 m (4,250 feet) of runway left. The captain retarded the throttles and tried to select reverse thrust. The nr. 3 throttle slipped from his hands, causing a power asymmetry. The airplane veered slightly to the left. The Dc-10 overshot the runway at a speed of 110 kts, colliding with an ILS building, causing engine number 3 to separate. The airplane went through a fence and crossed a highway were it damaged three vehicles. It then collided with a farming construction, causing three quarters of the right wing to break off, as well as the right horizontal stabilizer. The aircraft stopped 450 m (1,475 feet) past the end of runway 14. A fire erupted in the rear of the fuselage."
All because of nose wheel shimmy!
Remember the DC10 at Chicago crash? Sometimes company procedures will kill you.
Report of DC-10-10 AA Accident near O'Hare
"During the takeoff rotation, the left engine and pylon assembly [see fig. 16.1] and about 3 feet of the leading edge of the left wing separated from the aircraft"
I remember it very well. All was going OK at their initial climb out speed. The crew increased the rate of climb and reduced the speed towards V2. The left wing then stalled.
ASN Aircraft accident McDonnell Douglas DC-10-30CF EC-DEG Mlaga Airport (AGP)
"The airplane continued to accelerate through VR. As the captain tried to rotate by applying up elevator, the vibration was of such magnitude that he feared that the plane might become uncontrollable after takeoff. He decided to abort the takeoff. At that point, with a maximum speed attained of 184 kts, there was 1295 m (4,250 feet) of runway left. The captain retarded the throttles and tried to select reverse thrust. The nr. 3 throttle slipped from his hands, causing a power asymmetry. The airplane veered slightly to the left. The Dc-10 overshot the runway at a speed of 110 kts, colliding with an ILS building, causing engine number 3 to separate. The airplane went through a fence and crossed a highway were it damaged three vehicles. It then collided with a farming construction, causing three quarters of the right wing to break off, as well as the right horizontal stabilizer. The aircraft stopped 450 m (1,475 feet) past the end of runway 14. A fire erupted in the rear of the fuselage."
All because of nose wheel shimmy!
Last edited by rudderrudderrat; 7th Jan 2012 at 10:01. Reason: still can't spell
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If you are really interested in the reasons for V1/VR splits, maybe Boeing produce an equivalent to the Airbus "Getting to grips with
aircraft performance".
aircraft performance".
http://"www.flightwork.com/library.h...sh&docID=722"]
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Is that a 3- or 4- credit course? 
Thanks for the link.
Thanks for the link.
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Like mutt said; why not just ask your chief pilot?
This is most likely due to a company policy to have the computer give you a V1 optimised for, say, slippery runways? They want their pilots to be "go minded".
There must be a reason why you don't get the whole V1 range presented; they do not want you to choose your own V1 based on runway length vs. runway condition. Maybe they don't trust their pilots to make a sound judgement?
My company wanted V1GO to be used for every take-off, because we operate on many short and sometimes slippery runways. They were afraid that some schmuck would some day select V1STOP and be "stop minded" instead of "go minded" when taking off on a short, slippery runway. This caused many pilots (idiots) to start increasing their V1 to a ramdom "suitable" value on 3.000m+ runways when the computer came up with a V1 of e.g. 93 kt and a Vr of 130. FOs started filing reports, and consequently, the company changed their policy: We now get a more optimised (higher) V1 when taking off from long (2.500m+) runways. However, we are still not given a V1 range, like some other companies I know of. As a captain, I'd like to be able to choose from a V1 range (baed on actual conditions and my own experience) rather than have some desk jockey decide what's the "on average best" V1 for me for any given take-off...
This is most likely due to a company policy to have the computer give you a V1 optimised for, say, slippery runways? They want their pilots to be "go minded".
There must be a reason why you don't get the whole V1 range presented; they do not want you to choose your own V1 based on runway length vs. runway condition. Maybe they don't trust their pilots to make a sound judgement?
My company wanted V1GO to be used for every take-off, because we operate on many short and sometimes slippery runways. They were afraid that some schmuck would some day select V1STOP and be "stop minded" instead of "go minded" when taking off on a short, slippery runway. This caused many pilots (idiots) to start increasing their V1 to a ramdom "suitable" value on 3.000m+ runways when the computer came up with a V1 of e.g. 93 kt and a Vr of 130. FOs started filing reports, and consequently, the company changed their policy: We now get a more optimised (higher) V1 when taking off from long (2.500m+) runways. However, we are still not given a V1 range, like some other companies I know of. As a captain, I'd like to be able to choose from a V1 range (baed on actual conditions and my own experience) rather than have some desk jockey decide what's the "on average best" V1 for me for any given take-off...
