V1 vs Vmcg
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Originally Posted by bubbers44
Most of the time a little common sense and long runways can get you out of most anything whether it is legal or not.
Moderator
bubbers44,
took off in a Citation 500 ... max power had to be delayed until he wasn't using full rudder to keep it straight
Most of us would probably opine that this was somewhere between stupid and very stupid ...
One guy forgot the flaps on a 737 but still had an uneventful takeoff except for a slight stick shaker at rotation
Similar incidents have resulting in a ball of fire and fatalities ... that's what scans and checklists are intended to prevent ..
stall recovery lesson in a Falcon 20 and the instructor failed an engine when I went max power
Most of us would have broken the instructor's arm at the time as well ... for exposing the operation to an unnecessarily silly risk ..
common sense and long runways can get you out of most anything whether it is legal or not
In addition to MFS' wise counsel .. what might one be able to say in defence of one's inappropriate actions at the subsequent Inquiry ?
took off in a Citation 500 ... max power had to be delayed until he wasn't using full rudder to keep it straight
Most of us would probably opine that this was somewhere between stupid and very stupid ...
One guy forgot the flaps on a 737 but still had an uneventful takeoff except for a slight stick shaker at rotation
Similar incidents have resulting in a ball of fire and fatalities ... that's what scans and checklists are intended to prevent ..
stall recovery lesson in a Falcon 20 and the instructor failed an engine when I went max power
Most of us would have broken the instructor's arm at the time as well ... for exposing the operation to an unnecessarily silly risk ..
common sense and long runways can get you out of most anything whether it is legal or not
In addition to MFS' wise counsel .. what might one be able to say in defence of one's inappropriate actions at the subsequent Inquiry ?
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So John
Taking your point of aft C of G's etc affecting noise wheel loads, does the position of the C og G affect the value of Vmcg? C of G towards centre being easier to control than say far forward C of G?
Yours pondering...
Taking your point of aft C of G's etc affecting noise wheel loads, does the position of the C og G affect the value of Vmcg? C of G towards centre being easier to control than say far forward C of G?
Yours pondering...
Moderator
jollyboy,
.. other way around ..
CG usually has a very powerful effect on directional control .. other things being equal, one would expect the lowest real world Vmcg at the forward limit and highest at the aft limit. What this means is that minV1, being based on aft CG, has a higher margin above the real Vmcg at the forward limit. Idealised, the forward CG failure is a doddle while the aft failure is full of huff and puff sweating, beating of breasts, turning of control yokes and pushing of rudder bars .. and, not infrequently, the odd expletive from the handling pilot.
In simulator exercises intended to expose students to something approximating worst case, I used to work back from
(a) typical weight mid CG, to
(b) min weight forward CG to get down to minV1 but with less critical handling, and then progressively
(c) move the CG back to the aft limit.
On one box, the operator had programmed in a wonderful (large) bird strike based on an inflight event and using the FDR history (if I recall correctly, in this case the event involved the bird going down the gullet and doing dreadful things to the BRT .. in any case, this failure event always got the attention of the folk up front .. especially when we hit the button accidently during cruise, but that's another tale altogether) ...
I figured that if the guys and gals could handle a box event with
(a) min weight
(b) max aft CG
(c) the bird strike half way through the rotation flare (I tried to make it swing just as the visual cutoff angle went above the horizon)
and then
(d) backtrack the opposite LLZ for the departure ...
then they could handle any failure .. any time ... anywhere.
It was wonderful to see the confidence grow in the front seats ... I can recall one initial command chap who came across as being a bit superior ... after this particular session he 'fessed up that he never had been comfortable with engine failures .. maybe even a little frightened by them .. but now ... no problems at all .. one of those days I went back to the pub with a spring in my step. Then again he had done a LOT of practice failures during that session ..
.. other way around ..
CG usually has a very powerful effect on directional control .. other things being equal, one would expect the lowest real world Vmcg at the forward limit and highest at the aft limit. What this means is that minV1, being based on aft CG, has a higher margin above the real Vmcg at the forward limit. Idealised, the forward CG failure is a doddle while the aft failure is full of huff and puff sweating, beating of breasts, turning of control yokes and pushing of rudder bars .. and, not infrequently, the odd expletive from the handling pilot.
In simulator exercises intended to expose students to something approximating worst case, I used to work back from
(a) typical weight mid CG, to
(b) min weight forward CG to get down to minV1 but with less critical handling, and then progressively
(c) move the CG back to the aft limit.
On one box, the operator had programmed in a wonderful (large) bird strike based on an inflight event and using the FDR history (if I recall correctly, in this case the event involved the bird going down the gullet and doing dreadful things to the BRT .. in any case, this failure event always got the attention of the folk up front .. especially when we hit the button accidently during cruise, but that's another tale altogether) ...
I figured that if the guys and gals could handle a box event with
(a) min weight
(b) max aft CG
(c) the bird strike half way through the rotation flare (I tried to make it swing just as the visual cutoff angle went above the horizon)
and then
(d) backtrack the opposite LLZ for the departure ...
then they could handle any failure .. any time ... anywhere.
It was wonderful to see the confidence grow in the front seats ... I can recall one initial command chap who came across as being a bit superior ... after this particular session he 'fessed up that he never had been comfortable with engine failures .. maybe even a little frightened by them .. but now ... no problems at all .. one of those days I went back to the pub with a spring in my step. Then again he had done a LOT of practice failures during that session ..
Moderator
Lots of stuff on the web these days .. still a problem in sorting the good guts from the drivel if you don't have some basics .. you might like to start with the links in the URL sticky. Note that these are not peer reviewed so there is no guarantee that the rigour is consistent but it is still a reasonable place to start ...
You might also like to become a routine reader of Genghis' mob's discussions over at Flight Test ...
Just running searches (for things which interest you) in
(a) Tech Log
(b) Safety, CRM & QA
(c) Questions
(d) Flight Test
will give you heaps to read ... the problem is sifting the good from the waffle .. but it is not to hard to isolate the folk who have appropriate backgrounds to permit a presumption of reasonable competence.
You might also like to become a routine reader of Genghis' mob's discussions over at Flight Test ...
Just running searches (for things which interest you) in
(a) Tech Log
(b) Safety, CRM & QA
(c) Questions
(d) Flight Test
will give you heaps to read ... the problem is sifting the good from the waffle .. but it is not to hard to isolate the folk who have appropriate backgrounds to permit a presumption of reasonable competence.
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JT
I have looked. In particular I was looking for aircraft airfield perfomance (TOF calculations) as a refresher (wife binned all my notes and reading material). Unfortunately many of the links are no longer valid.
Rgds
EM
I have looked. In particular I was looking for aircraft airfield perfomance (TOF calculations) as a refresher (wife binned all my notes and reading material). Unfortunately many of the links are no longer valid.
Rgds
EM
Moderator
Please, if you find expired links, let me know about them and either I will find the new one or, at least, get rid of the false link .. I don't have any time to keep a check on the links myself so I rely on feedback from users.
Suggest you have a read through the relevant bits of the regs, eg FARs, to get some basics. Then just start a thread on the bit you want to pursue and we will go with a to and fro discussion until you are happy that you have the level of information you need .. in the process others learn as well sitting on the sidelines ... please, don't be hesitant to ask questions .. there is a cadre of folk here who are frustrated teachers and instructors .... and there are a lot of folk who are very well heeled in the knowledge and experience stakes ... use us .. that's where we get our kicks.
Suggest you have a read through the relevant bits of the regs, eg FARs, to get some basics. Then just start a thread on the bit you want to pursue and we will go with a to and fro discussion until you are happy that you have the level of information you need .. in the process others learn as well sitting on the sidelines ... please, don't be hesitant to ask questions .. there is a cadre of folk here who are frustrated teachers and instructors .... and there are a lot of folk who are very well heeled in the knowledge and experience stakes ... use us .. that's where we get our kicks.
