Serious question for a QFI
"What is the angle of bank at the highest point of a barrel-roll"
The wings are level...................
The most important killer is:
Where is the nose????????
E L W, LM is correct; the wings are level. but inverted and the nose is above the horizon ,by the same amount it was at the bottom(lowest part) at the start of the `barrel`. If it`s not above you may end up lower and faster as you recover..
D-R; if you can maintain a constant speed around a loop,then the momentum will stay the same throughout,( if you fly an F-15/6/8,Typhoon etc). Most aircraft can`t so there is a loss of speed going up,due to gravity and Drag,mainly lift induced by pulling `G`,and then gained on the way down. If you try to maintain the `G` you will stall; ie if the stall speed is 80 kts in level flight,in a 4 G loop it is 160 kts(sq.root of load factor); practically, starting at 250 kts in a J-P,over the top ,the speed may be between 90-130 kts,but the `G` will be down to possibly less than 1,if you are trying to `shape` a vertical circle,and you will have gained about 3000 ft,depending on how hard you pull..
Now , in level flight ,starting and maintaining the same speed,the radius of turn of 1500ft,gives a bank angle of about 75-77 degrees for about 4G.
Is that good enough for a B2 ?
D-R; if you can maintain a constant speed around a loop,then the momentum will stay the same throughout,( if you fly an F-15/6/8,Typhoon etc). Most aircraft can`t so there is a loss of speed going up,due to gravity and Drag,mainly lift induced by pulling `G`,and then gained on the way down. If you try to maintain the `G` you will stall; ie if the stall speed is 80 kts in level flight,in a 4 G loop it is 160 kts(sq.root of load factor); practically, starting at 250 kts in a J-P,over the top ,the speed may be between 90-130 kts,but the `G` will be down to possibly less than 1,if you are trying to `shape` a vertical circle,and you will have gained about 3000 ft,depending on how hard you pull..
Now , in level flight ,starting and maintaining the same speed,the radius of turn of 1500ft,gives a bank angle of about 75-77 degrees for about 4G.
Is that good enough for a B2 ?
Teeters,
I thought that if I pulled the stick back, I came to the hover, it's the uppy/downy lever on the left that makes the cows get bigger or smaller or have I been doing it wrong all these years?
I thought that if I pulled the stick back, I came to the hover, it's the uppy/downy lever on the left that makes the cows get bigger or smaller or have I been doing it wrong all these years?
Now , in level flight ,starting and maintaining the same speed,the radius of turn of 1500ft,gives a bank angle of about 75-77 degrees for about 4G.
Is that good enough for a B2 ?
Is that good enough for a B2 ?
Next - explain (without hand waving) why the 'victory roll' was such a dangerous manoeuvre. Nothing to do with the tired old excuse of "You might have unknown combat damage", incidentally.
(Chopper pukes needn't bother to answer - not something they would understand!)
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I dare say that the Playpen is more fun, but all we need now is for Seldom to wear his Membership Police hat in here and it will have descended to the immature levels of much that surrounds it. It would be nice if the rubbish could be aimed at Jetblast and at least some mature conversation maintained without interfearance.
Beagle: One suspects fuel starvation as the Spit tends to cough a black cloud worthy of a Wessex when it is done to this day.
Beagle: One suspects fuel starvation as the Spit tends to cough a black cloud worthy of a Wessex when it is done to this day.
Nope - the manoeuvre shouldn't result in -ve G!
Mrs Shilling later fixed the problem of the rich cut with her famous orifice!
Mrs Shilling later fixed the problem of the rich cut with her famous orifice!
Well DR most on this thread are very mature with loads of experience! A little light hearted interference (I think thats how you spell it!) should be encouraged!
Maybe you should try Google if you want a serious reply to the question!
Maybe you should try Google if you want a serious reply to the question!
Gentleman Aviator
(Chopper pukes needn't bother to answer - not something they would understand!)
...... but to be outed as a "chopper puke" (a naval expression surely?)
I am not worthy to share a forum with sky gods like yourself
But I am an A2 QHI
* Note correct use of subjunctive mood.
There is another variation on the theme of which lever does what. With a substantial amount of thrust vectoring available, as in the VAAC Harrier, it is possible to introduce computer control that enables odd, but logical, responses. For instance, the right hand lever can control vertical movement, while the left controls fore-and-aft acceleration; both would have a central position for zero demand. Thus, to take off, pull the right hand back. If sufficient power-to-weight margin is available, thrust will be vectored to vertically down, and the engine will go to full power. When the required altitude is reached, put the right hand lever to the central position. To accelerate to wingborne flight, move the left hand lever forwards. When the required speed is reached, move the left lever to the centre. To slow down, pull it back to get the necessary combination of engine power, thrust vector and airbrake.
The above manoeuvres keep the aircraft in a constant attitude, so you would probably use a speed filter to get to a regime where the right hand controls attitude, enabling you to point weapons if necessary, and to make conventional turns using Gz at high speed.
Chopper pukes might argue that they have a logical control system, with a go-up/go-down lever that goes up or down, but they never need to concern themselves about transition to high speed flight.
The above manoeuvres keep the aircraft in a constant attitude, so you would probably use a speed filter to get to a regime where the right hand controls attitude, enabling you to point weapons if necessary, and to make conventional turns using Gz at high speed.
Chopper pukes might argue that they have a logical control system, with a go-up/go-down lever that goes up or down, but they never need to concern themselves about transition to high speed flight.
Grammar school oik? Well, at least it wasn't a 'comprehensive' school....
Direct entrant? Not many other options these days.
Diesel car? Old chap, historically diesel was simply not an officer's fuel. But if it's powered by a high performance turbocharged engine, you can always say that the car is turbine powered and simply uses the reciprocating element as a gas generator.... Audi A5 3.0 Tdi quattro, for example. But people will still know....
Helicopters? Someone has to do it, I guess.
A2? Definitely enhances the status and more than compensates for all the above. So mote it be...00
But gas? Gas?? Sorry, but you fell at the final hurdle!
Subjunctive?
- that brings back memories of 'Ut and the subjunctive' and other terrors of prep school Latin lessons... I never did understand why Gerundives were considered 'attractive' either. If you didn't have to study such horrors at your school, you were very lucky.
Anyway, back to the dangers of the 'victory roll'....
Usually observed to be a high speed beat-up, balls-out on the deck, followed by a climbing aileron roll. As the aircraft runs in at high speed, it will very likely be trimmed for such speed. Pulling up, it will begin to decelerate. Full aileron and rudder to balance will cause a lot of drag, so it'll decelerate even more. It has now slowed down and the untrimmed state will tend to pitch the aircraft nose down as the roll progresses; the pilot may well pull against this, reducing the apex height accordingly. As the roll reaches the final wings level state, the aircraft will probably be descending and significantly out of trim. In addition, the attitude needed for level flight at the new speed will require a higher pitch angle than did the initial beat up. So the pilot may well need full aft control column to stop the descent and to oppose the out of trim state...
...and recovery to level flight may well take longer than anticipated, or may not be achieved until terra firma prevents any further descent.
How many of us have seen Bloggs cock-up a barrel roll and bury the nose on exit....
?
Direct entrant? Not many other options these days.
Diesel car? Old chap, historically diesel was simply not an officer's fuel. But if it's powered by a high performance turbocharged engine, you can always say that the car is turbine powered and simply uses the reciprocating element as a gas generator.... Audi A5 3.0 Tdi quattro, for example. But people will still know....
Helicopters? Someone has to do it, I guess.
A2? Definitely enhances the status and more than compensates for all the above. So mote it be...00
But gas? Gas?? Sorry, but you fell at the final hurdle!
Subjunctive?
- that brings back memories of 'Ut and the subjunctive' and other terrors of prep school Latin lessons... I never did understand why Gerundives were considered 'attractive' either. If you didn't have to study such horrors at your school, you were very lucky.Anyway, back to the dangers of the 'victory roll'....
Usually observed to be a high speed beat-up, balls-out on the deck, followed by a climbing aileron roll. As the aircraft runs in at high speed, it will very likely be trimmed for such speed. Pulling up, it will begin to decelerate. Full aileron and rudder to balance will cause a lot of drag, so it'll decelerate even more. It has now slowed down and the untrimmed state will tend to pitch the aircraft nose down as the roll progresses; the pilot may well pull against this, reducing the apex height accordingly. As the roll reaches the final wings level state, the aircraft will probably be descending and significantly out of trim. In addition, the attitude needed for level flight at the new speed will require a higher pitch angle than did the initial beat up. So the pilot may well need full aft control column to stop the descent and to oppose the out of trim state...
...and recovery to level flight may well take longer than anticipated, or may not be achieved until terra firma prevents any further descent.How many of us have seen Bloggs cock-up a barrel roll and bury the nose on exit....
?
Gentleman Aviator
BEagle, Sir, you are too kind (it is of course a TDi!)..... and I shall be replacing the BBQ next year so who knows what may not happen ....
...... but what about the fly landing on the ceiling? Is it from the top of a loop, or halfway around a (slow? hesitation?) roll?
...... but what about the fly landing on the ceiling? Is it from the top of a loop, or halfway around a (slow? hesitation?) roll?
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DR
Rubbish?! As an ex-A1 sky-god, and ex-display pilot, I can assure you that this is all serious stuff your'e reading here
It would be nice if the rubbish could be aimed at Jetblast
Rubbish?! As an ex-A1 sky-god, and ex-display pilot, I can assure you that this is all serious stuff your'e reading here
