BO105 fatal accident back in 2006(?)
Dear Boy.....if one is very, very, very petite....perhaps one could approach a 90 degree banked turn but I am sure it would never be a level turn (measured within the airmass it is operating) but could do so if it were in a thermal or rising column of air...heck...it could even climb with the right amount of Umph!
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A ram air parachute requires airspeed to remain inflated, and its BAD, BAD news should it deflate. Any problems turning up wind down wind? Absolutely none, and nothing can turn quicker than one of those babies. They are certainly affected by changes in airspeed due to gusts and care has to be taken in such conditions because they will collapse
There won't be problems provided there is some airspeed as you say, and there usually is from below due to descending. Try an instant 180 "level" turn to downwind at 90 degree bank with a parachute and see what happens.... same effect as the gusts you mention: negative airspeed.
A ram air parachute requires airspeed to remain inflated, and its BAD, BAD news should it deflate. Any problems turning up wind down wind? Absolutely none, and nothing can turn quicker than one of those babies. They are certainly affected by changes in airspeed due to gusts and care has to be taken in such conditions because they will collapse
There won't be problems provided there is some airspeed as you say, and there usually is from below due to descending. Try an instant 180 "level" turn to downwind at 90 degree bank with a parachute and see what happens.... same effect as the gusts you mention: negative airspeed.
Ok I should've said "theoretical" turn. I wondered what the parachute example was trying to illustrate, since you said there are no problems turning up- or downwind and then say they are certainly affected by changes in airspeed! Of course they are, but providing they keep descending then they have some "flying" speed (in parachute terms), so horizontal wind direction mostly wouldn't matter.
The issue here is that if turning sharply from upwind to downwind puts you below the airspeed for required lift for your aircraft (performance/capability), you go down at a steeper angle than you would turning upwind whilst trying to regain that speed, since you are now chasing the air you require. Downwind turns require more altitude to recover should lift be lost during/exiting the turn than upwind.
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Dear Boy.....if one is very, very, very petite....perhaps one could approach a 90 degree banked turn but I am sure it would never be a level turn (measured within the airmass it is operating) but could do so if it were in a thermal or rising column of air...heck...it could even climb with the right amount of Umph!
Just to clear this up, I don't actually think that 'chutes are fully aerobatic or self-powered!
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Overdrive - you are way, way out of your depth and display no understanding of canopy flight. Nothing wrong with that of course, but you should refrain from posting on matters of which you have no knowledge.
I said "affected by changes in airspeed due to gusts". Do you understand what a gust is? Do you understand how a gust might affect airspeed?
Should you desire to learn a bit about flying ram airs send me a PM with your email addy and I'll send lesson notes given to students learning advanced canopy flight. Written by one of the worlds leading educators in the subject.
SAS - we had a fellow (jockey, all of 60 pounds by the look of him) jumping with us and regularly had that problem on a summer day and catching the thermals, and that was with the old round canopies.
you said there are no problems turning up- or downwind and then say they are certainly affected by changes in airspeed
Should you desire to learn a bit about flying ram airs send me a PM with your email addy and I'll send lesson notes given to students learning advanced canopy flight. Written by one of the worlds leading educators in the subject.
it could even climb with the right amount of Umph
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Overdrive - you are way, way out of your depth and display no understanding of canopy flight. Nothing wrong with that of course, but you should refrain from posting on matters of which you have no knowledge.
I said "affected by changes in airspeed due to gusts". Do you understand what a gust is? Do you understand how a gust might affect airspeed?
If you can pick holes in what I wrote in my last paragraph, go ahead, you may win 2-0! If not, let's call it 1-1....
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Downwind turns require more altitude to recover should lift be lost during/exiting the turn than upwind.
Again.....a helicopter or parachute or airplane does not know the wind. It only knows airspeed. Ignoring gusts, gradients and wind sheer, thermals, the altitude lost in recovery will be the same. It is only the distance tracked over the ground that will be different.
I must be sounding like a broken record at this point, but I cant believe some are serious.
Now to really stir the pot a little,......... Here is the scenario. Two gliders are flying at less then 1000'agl. One makes a downwind turn and the other makes a turn into the wind. Upon turning, the pilots stall both aircraft,... if a steep wind gradient exists, the recovery on the downwind would happen with less altitude lost then the aircraft that was flying into the direction of the prevailing wind.
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I wrote in post 24:
I dont get it. The downwind element
It is clear that a large proportion of the participants in the discussion have a misunderstanding of the situation, and that confusion is not limited to the inexperienced. Despite thorough and eloquent presentation of the facts by many, this myth is not going to be busted in the minds of its supporters. It's too deeply ingrained.
A thoroughly interesting thread all the same.
Quote:If turning from upwind to downwind is no problem and does not affect the aerodynamics and the helicopters performance, then we should all be ok with taking off downwind
You not a helicopter pilot I hope.
You not a helicopter pilot I hope.
I was compairing the effect of downwind when doing wing-over or steep turn where velocity is lost to below translational lift to takeoff.
I hope agree with me that you are better off ending into wind from wing-over or steep turn,just as you are when taking off....
see Dennis Kenyon post #22
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I can not believe some of you guys are serious.
Making a very tight 180 turn at a steep bank like the helicopter that started this thread will require a huge amount of extra lift to maintain altitude, due to g loading (as Brian Abraham also said). For a time at the apex of the turn (at 90 degree bank or more), there is no vertical lift component relative to the ground, since the rotor is on its side... the aircraft wants to descend. Bear in mind also loss of forward velocity (read; airspeed), converted into centripetal force in making a turn like this.
If the aircraft is to complete the turn and maintain or regain level flight, in the absence of enough spare available power for lift, it needs more airspeed. Will it gain this more quickly with a 30kt wind up its ar*se or 30kts into its face? When exiting a steep 180 turn downwind like this it has less airspeed than the identical manouevre made into wind. It takes more time to accelerate to the required airspeed, whilst still subject to the same value of gravity. Hence it will lose more height. The altitude lost is not the same: the amount of air travelled through to regain lift is the constant.
Maybe someone else can explain it better than I have.... anyone got any crayons?
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Now to really stir the pot a little,......... Here is the scenario. Two gliders are flying at less then 1000'agl. One makes a downwind turn and the other makes a turn into the wind. Upon turning, the pilots stall both aircraft,... if a steep wind gradient exists, the recovery on the downwind would happen with less altitude lost then the aircraft that was flying into the direction of the prevailing wind.
Maintaining constant airspeed well within performance limits in a relatively gradual turn with lift to spare is one thing, and I agree with you... wind direction makes no difference
I was of the assumption that aircraft in level flight balanced weight/drag against Lift/thrust.
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B105 accident
Hi again,
I see that an earlier post has suggested that nothing 'constructive' by way of instruction is coming out of this discussion. True.
So may I add this to my notes. If the video of the BK 105's final manoeuvre is studied, it reveals that from the level position, Hoffman first 'rolled' right and then applied aft cyclic to climb. My display experience tells me - THAT IS THE WRONG SEQUENCE.
For a pull up manoeuvre from anything less than 100 feet, aft cyclic must be used first, then followed by cyclic roll, albeit at the higher speeds of a run-in, uncorrected disc flap back is usually sufficient to obtain the required steep 'nose-up' attitude.
What is an absolute 'no-no' is to set up a high angle of bank with insufficient collective to provide the thrust vector required to maintain height, especially at low level. I've actually watched two helicopters do this and strike the ground.
And regarding the upwind/downwind and inertia ... the situation is exactly as I outlined in the original post.
An odd thought that may help the dis-believers, (and there shouldn't be any if they hold a flying licence!) ... I was just this morning watching a recording of a Japanese Richter 7 earthquake taken from an office mounted CCTV.
The earth was shaking and reciprocating some 30 cms back & forth quite rapidly. Guess what. The PC monitor and the larger photo copiers weren't moving as the ground they sat on flapped around. I think its called inertia ... and its relative to space!
More fuel for the bon fire perhaps?
Good and safe flying to all,
Dennis K.
I see that an earlier post has suggested that nothing 'constructive' by way of instruction is coming out of this discussion. True.
So may I add this to my notes. If the video of the BK 105's final manoeuvre is studied, it reveals that from the level position, Hoffman first 'rolled' right and then applied aft cyclic to climb. My display experience tells me - THAT IS THE WRONG SEQUENCE.
For a pull up manoeuvre from anything less than 100 feet, aft cyclic must be used first, then followed by cyclic roll, albeit at the higher speeds of a run-in, uncorrected disc flap back is usually sufficient to obtain the required steep 'nose-up' attitude.
What is an absolute 'no-no' is to set up a high angle of bank with insufficient collective to provide the thrust vector required to maintain height, especially at low level. I've actually watched two helicopters do this and strike the ground.
And regarding the upwind/downwind and inertia ... the situation is exactly as I outlined in the original post.
An odd thought that may help the dis-believers, (and there shouldn't be any if they hold a flying licence!) ... I was just this morning watching a recording of a Japanese Richter 7 earthquake taken from an office mounted CCTV.
The earth was shaking and reciprocating some 30 cms back & forth quite rapidly. Guess what. The PC monitor and the larger photo copiers weren't moving as the ground they sat on flapped around. I think its called inertia ... and its relative to space!
More fuel for the bon fire perhaps?
Good and safe flying to all,
Dennis K.
I give up
This thread has had a usefull discussion for the scientific minded, but for us ex crop sprayers it has proved nothing new... you f**ck up, you die..... As I said before, that turn was BOLD!!!!!!!!!!!!!!
This thread has had a usefull discussion for the scientific minded, but for us ex crop sprayers it has proved nothing new... you f**ck up, you die..... As I said before, that turn was BOLD!!!!!!!!!!!!!!
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In my last attempt to convey something..... I will just restate the example that another posted earlier.
Think of riding on a buss. Does it take more energy to sprint to the front, stop, turn 180 and sprint back the other direction down the aisle if the buss is traveling at 100mph vs standing still in a parking lot?....
Or fly a rc helicopter in the bus. Does it fly and turn differently if the buss is moving down the road at a constant velocity (same as traveling in the wind), vs flying the rc helo while the buss is parked?..
Wind does NOT exist while flying. It can only be observed in reference to the ground. (again this is assuming no gradient, gusts, or sheer) Just as we are not effected by the fact that the earth is rotating at over 1000mph, and it is traveling in orbit around the sun at 18.5 miles per second (or 66,600mph), and the universe expanding at between 55 and 85km/s/Mpc depending on who you believe!!
Boy if we had to account for these, in addition to upwind and downwind when we turn.....flying would be even more difficult.
Think of riding on a buss. Does it take more energy to sprint to the front, stop, turn 180 and sprint back the other direction down the aisle if the buss is traveling at 100mph vs standing still in a parking lot?....
Or fly a rc helicopter in the bus. Does it fly and turn differently if the buss is moving down the road at a constant velocity (same as traveling in the wind), vs flying the rc helo while the buss is parked?..
Wind does NOT exist while flying. It can only be observed in reference to the ground. (again this is assuming no gradient, gusts, or sheer) Just as we are not effected by the fact that the earth is rotating at over 1000mph, and it is traveling in orbit around the sun at 18.5 miles per second (or 66,600mph), and the universe expanding at between 55 and 85km/s/Mpc depending on who you believe!!
Boy if we had to account for these, in addition to upwind and downwind when we turn.....flying would be even more difficult.
Griffo, I think it's just that some people are taking the idea that wind doesn't have any effect on an aircraft in a steady-state turn and then strictly (and wrongly) trying to apply that principle to the Bolkow in question and the very obvious crash that ensued. They're just confused.
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Quote:
Maintaining constant airspeed well within performance limits in a relatively gradual turn with lift to spare is one thing, and I agree with you... wind direction makes no difference
Can you show us the math formula for that situation please?
I was of the assumption that aircraft in level flight balanced weight/drag against Lift/thrust.
Maintaining constant airspeed well within performance limits in a relatively gradual turn with lift to spare is one thing, and I agree with you... wind direction makes no difference
Can you show us the math formula for that situation please?
I was of the assumption that aircraft in level flight balanced weight/drag against Lift/thrust.
This is dragging on alright. I will say again for the final time, that during a turn like that in question, airspeed is LOST. So upwind/downwind DOES matter.
From DennisK post No. 22:-
I know that on one of the occasions I experienced the problem was when I failed to achieve the correct 'gate' speed for a 270 degree 'wing-over' following a 'toward the crowdline' level approach into a stiff breeze.
In the second half of the 270 degree heading change - the resultant tailwind significantly slowed the recapture of translation lift. The unexpected loss of immediate cyclic response and loss of height gave me more than a second of concern.
I now don't do 'into wind' display wing overs without an extra margin of 'gate' height and speed for the manoeuvre entry.
In the second half of the 270 degree heading change - the resultant tailwind significantly slowed the recapture of translation lift. The unexpected loss of immediate cyclic response and loss of height gave me more than a second of concern.
I now don't do 'into wind' display wing overs without an extra margin of 'gate' height and speed for the manoeuvre entry.
If anyone can prove to me that a turn like that in question can be made with no loss of airspeed, i.e., constant airspeed throughout the turn, I'll retract everything I've said.
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BO105
Sounds like you no what your talking about so can you give some advice on the BO105
What are the Hot and High capabilitys.
Where in the world is good to get a type rating.
Any other info much appreciated by anyone
PS Have not read the Manuel yet.
What are the Hot and High capabilitys.
Where in the world is good to get a type rating.
Any other info much appreciated by anyone
PS Have not read the Manuel yet.
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I have not been able to view the video, but the problem with the BO-105 is due to the collective-to-cyclic coupling inherent in a rigid rotor system with such a high degree of effective offset. This was demonstrated to me while flying the BO-105 at WTD-61 in Manching, DE. We entered a high powered, high angle of bank turn to the right and attempted to roll left out of it. Full left cyclic, aircraft continued to roll right. The recovery consisted of a split-S with a symmetrical pull-out. All of this was planned and we ended up recovering at 1000' AGL from an entry altitude of 1500' AGL. The PIC stated to me that the German Army had lost several BO-105s due to high AOB maneuvering while NOE. Very maneuverable aircraft and quite confidence inspiring in any attitude, but in my short exposure, there are definitely some handling characteristics that demand respect.
