Can bizjets do acrobatics ?
Discussion
As per title, they are a small airliner but nearer in size and shape to a military jet, some airliners can be thrown about, so are biz jets nearer in ability to a small airliner or a military jet, I am guessing they have a good power to weight ratio but not quite like a fighter and won't be designed for high g loadings but probably higher than a 737 ?
This one didn't fair well with whatever happened to it.
http://www.aircraftmechanic.org/showthread.php?164...
http://www.aircraftmechanic.org/showthread.php?164...
SlipStream77 said:
This one didn't fair well with whatever happened to it.
http://www.aircraftmechanic.org/showthread.php?164...
You know that feeling you get in your stomach when you have just fhttp://www.aircraftmechanic.org/showthread.php?164...
ked up and now you have to go and tell someone..hman said:
SlipStream77 said:
This one didn't fair well with whatever happened to it.
http://www.aircraftmechanic.org/showthread.php?164...
You know that feeling you get in your stomach when you have just fhttp://www.aircraftmechanic.org/showthread.php?164...
ked up and now you have to go and tell someone..
Ginetta G15 Girl said:
There was a Wg Cgr who got Court Martialled for barrel rolling a Dominie (HS-125) in 1971.
There was also a certain ex-Phantom pilot who regularly did 'sporty' wing overs in the Dominie in the mid 1990s.
Providing you kept the loading to 1g or less and the wing-over/roll constant and gentle, generally speaking would you be OK?There was also a certain ex-Phantom pilot who regularly did 'sporty' wing overs in the Dominie in the mid 1990s.
HoHoHo said:
Providing you kept the loading to 1g or less and the wing-over/roll constant and gentle, generally speaking would you be OK?
In a 125 yes. In fact you could go to 2G quite happily (1.5G with max aileron).Not everything will barrel roll however; during my time on the Jetstream we looked into using 'big' wing-overs as part of the display routine. Naturally this lead to the idea of assessing whether the a/c could be barrel rolled (despite it not being cleared for aeros). Multiple attempts were made in the simulator - all resulting in simulated death. The problem was that whatever pitch up you made before starting the manoeuvre, the nose would 'fall through' resulting in an excessive nose down angle with an excessive rate of descent that would require more G than the a/c could pull in order to recover the situation.
Ginetta G15 Girl said:
HoHoHo said:
Providing you kept the loading to 1g or less and the wing-over/roll constant and gentle, generally speaking would you be OK?
In a 125 yes. In fact you could go to 2G quite happily (1.5G with max aileron).Not everything will barrel roll however; during my time on the Jetstream we looked into using 'big' wing-overs as part of the display routine. Naturally this lead to the idea of assessing whether the a/c could be barrel rolled (despite it not being cleared for aeros). Multiple attempts were made in the simulator - all resulting in simulated death. The problem was that whatever pitch up you made before starting the manoeuvre, the nose would 'fall through' resulting in an excessive nose down angle with an excessive rate of descent that would require more G than the a/c could pull in order to recover the situation.
The fact the nose down angle was excessive, was that because you couldn't enter the manoeuvre with sufficient forward speed and then also keep the speed up throughout and so the aircraft basically stalled half way through, hence you found yourself in the poo?
Any ability to pull highish G in an aeroplane designed to carry stuff will be missing out on payload thanks to excessive structural weight. Of course some aeroplanes designed to carry heavy stuff in a straight line can end up having a reasonable margin when flown empty and can be chucked about with care. The Italians were looping and rolling a Spartan twin engined transport at airshows a couple of years back.
If the structure can cope with it, it then comes down to handling qualities.
If the structure can cope with it, it then comes down to handling qualities.
Ginetta G15 Girl said:
In a 125 yes. In fact you could go to 2G quite happily (1.5G with max aileron).
Not everything will barrel roll however; during my time on the Jetstream we looked into using 'big' wing-overs as part of the display routine. Naturally this lead to the idea of assessing whether the a/c could be barrel rolled (despite it not being cleared for aeros). Multiple attempts were made in the simulator - all resulting in simulated death. The problem was that whatever pitch up you made before starting the manoeuvre, the nose would 'fall through' resulting in an excessive nose down angle with an excessive rate of descent that would require more G than the a/c could pull in order to recover the situation.
Was that basically what went wrong with the A26 at Biggin?Not everything will barrel roll however; during my time on the Jetstream we looked into using 'big' wing-overs as part of the display routine. Naturally this lead to the idea of assessing whether the a/c could be barrel rolled (despite it not being cleared for aeros). Multiple attempts were made in the simulator - all resulting in simulated death. The problem was that whatever pitch up you made before starting the manoeuvre, the nose would 'fall through' resulting in an excessive nose down angle with an excessive rate of descent that would require more G than the a/c could pull in order to recover the situation.
On a happier note
http://www.youtube.com/watch?v=lw4z0hf1s3Q
HoHoHo said:
Interesting, thanks.
It was more to do with the pitch authority (or lack of) vs roll rate vs G available vs IAS in the Jetstream.Basically if you tried to barrel at a speed where you had a good roll rate, you couldn't pitch the nose high enough prior to entering the manoeuvre (owing to the G limitations), so you ended up extremely nose low on exit.
If you went in at a speed where you could generate a sufficient pitch rate, the roll rate was so low such that by the time you'd completed the roll you'd run out of pitch authority and you (again) ended up extremely nose low on exit.
Either way, the G you would have to pull to get out of the ensuing dive would severely overstress the airframe.
Dr Jekyll said:
Was that basically what went wrong with the A26 at Biggin?
More or less, yes. Low level Barrels have probably resulted in more accidents than any other manoeuvre. The problem is that a Barrel is not simply a rolling manoeuvre but a rolling and pitching one where the a/c describes a helical flightpath through the sky (like flying around the surface of a barrel, hence the name). Since you are both rolling and pitching constantly throughout the manoeuvre, if you don't get the nose high enough at the start you will inevitably end up nose low at the end. Get nose low close to the ground and... well you can see the problem.For display flying you will (or should) have 'gates' (altitudes and speeds) which you have to make before starting or continuing with a manouvre. If you fail to make your 'gates' then you throw the manoeuvre away. In a fast jet that can be relatively as simple as 'unloading' the a/c (push to zero G) and rolling wings level. The problem comes with larger and/or older a/c where you can't develop the roll rate so you are commited to the manouvre at a far earlier stage.
J4CKO said:
So the answer is no really, more akin to a commercial airliner than a fighter in terms of what the airframe will put up with ?
The issue is probably less of what the aircraft can do, more what it's certified to do. I would hazard a guess that most biz jets could handle gentle aeros without falling to bits, but why the manufacturer would be wasting their time and money getting that sort of aircraft certified for something it's never going to do.
Inkyfingers said:
J4CKO said:
So the answer is no really, more akin to a commercial airliner than a fighter in terms of what the airframe will put up with ?
The issue is probably less of what the aircraft can do, more what it's certified to do. I would hazard a guess that most biz jets could handle gentle aeros without falling to bits, but why the manufacturer would be wasting their time and money getting that sort of aircraft certified for something it's never going to do.
Flying in a straight line for hours on end or hearing the Captain saying 'OK everyone, brace yourselves for the ride of a lifetime'?
Would make flying much more fun (as I'm sitting here at Gatwick waiting for my flight!)
Sounds like a sound argument to get them certified for + or - 6g
Ginetta G15 Girl said:
HoHoHo said:
Interesting, thanks.
It was more to do with the pitch authority (or lack of) vs roll rate vs G available vs IAS in the Jetstream.Basically if you tried to barrel at a speed where you had a good roll rate, you couldn't pitch the nose high enough prior to entering the manoeuvre (owing to the G limitations), so you ended up extremely nose low on exit.
If you went in at a speed where you could generate a sufficient pitch rate, the roll rate was so low such that by the time you'd completed the roll you'd run out of pitch authority and you (again) ended up extremely nose low on exit.
Either way, the G you would have to pull to get out of the ensuing dive would severely overstress the airframe.
Dr Jekyll said:
Was that basically what went wrong with the A26 at Biggin?
More or less, yes. Low level Barrels have probably resulted in more accidents than any other manoeuvre. The problem is that a Barrel is not simply a rolling manoeuvre but a rolling and pitching one where the a/c describes a helical flightpath through the sky (like flying around the surface of a barrel, hence the name). Since you are both rolling and pitching constantly throughout the manoeuvre, if you don't get the nose high enough at the start you will inevitably end up nose low at the end. Get nose low close to the ground and... well you can see the problem.For display flying you will (or should) have 'gates' (altitudes and speeds) which you have to make before starting or continuing with a manouvre. If you fail to make your 'gates' then you throw the manoeuvre away. In a fast jet that can be relatively as simple as 'unloading' the a/c (push to zero G) and rolling wings level. The problem comes with larger and/or older a/c where you can't develop the roll rate so you are commited to the manouvre at a far earlier stage.
Ooh, went all Eric there V8LM said:
Interesting fact from the last time I was at XH 558's base. I believe the FAA have a definition of aerobatics as more than 90 degrees wing roll. Fortunately the CAA do not have such a definition.
With the creation of the EASA Aerobatic Rating, however, it is largely a moot point - but thankfully not entirely so.I'm never comfortable seeing large, multi-engined types being hooliganised in close proximity to the ground for display purposes - it's like watching your grandmother dive off the stage and crowd-surf at a Prodigy gig - she might be enjoying it, but it isn't dignified, is probably sooner rather than later going to lead to serious injury, and even if it doesn't can lead to some serious underwear attrition - and frankly, for her to contemplate doing so is a sound indication she really isn't firing on all cerebral cylinders.
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