Further on, from the Two Blade design?
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Further on, from the Two Blade design?
Good morning , the thread I started re the probs with two blade heads has, because of the brill answers which you people out there gave, raised another question of a safety nature, recently I have been asked to ferry two B206,s one I think is about 1978 and the other about 1985, having read Lu's message 's over and over, has made me wonder how would a pilot Pre-flight the Blades for, the majority of the blade is out of reach, so that it is impossible to run ones hand along the leading or trailing edge's, without ref to some serious technical books( which I dont have) what is the timed life of a set of B206 Blades, by using the Datcom time you could work out the use that has gone into the blade, or is that to simply and not entirly safe?
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To VFR
Don't get too focussed on just the blades and head, just think how many other mechanical disasters can lie in wait, a helicopter is sooooo complex, you could never check everything.Most important is to check all the paperwork if you are asked to ferry a machine you don't know!And ask plenty of questions.
I was once asked to ferry an enstrom, it only turned out after some investigation that the heli hadn't actually been flown out of the hover since a MAJOR rebuild!.
Beware
Regards
hoverbover
Don't get too focussed on just the blades and head, just think how many other mechanical disasters can lie in wait, a helicopter is sooooo complex, you could never check everything.Most important is to check all the paperwork if you are asked to ferry a machine you don't know!And ask plenty of questions.
I was once asked to ferry an enstrom, it only turned out after some investigation that the heli hadn't actually been flown out of the hover since a MAJOR rebuild!.
Beware
Regards
hoverbover
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Re blades...
It's not just a question of how many hours have been flown on 'em...
I once had a chat with a 206 pilot who claimed he could get more airspeed out of his max cont torque figure by beeping back on Nr; apparently 7 or 8 % Nr reduction was worth around 10kts, so geeting him home quicker.
I fix, not drive, so I don't know if it was true or B/S, but I do know those blades would have been taking one helluva (huvver?) lot more bending load...
I'm beginning to feel that maybe staying on the ground wasn't the second choice after all...not sure I could handle all the worry
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Ground tested, no fault found
It's not just a question of how many hours have been flown on 'em...
I once had a chat with a 206 pilot who claimed he could get more airspeed out of his max cont torque figure by beeping back on Nr; apparently 7 or 8 % Nr reduction was worth around 10kts, so geeting him home quicker.
I fix, not drive, so I don't know if it was true or B/S, but I do know those blades would have been taking one helluva (huvver?) lot more bending load...
I'm beginning to feel that maybe staying on the ground wasn't the second choice after all...not sure I could handle all the worry
------------------
Ground tested, no fault found
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Don't know about the 206, but in the UH-1H (205) we commonly beeped the N2 back to 6400 from the usual 6600, and therefore reduced Nr as well, (all within flt manual limits though) and it seemed to save a bit of gas.
Don't think it gave us any more airspeed though, as I remember.
The explanation that the old and bolds gave was that at that speed, the rotor was running in a more efficient aerodynamic state, and that the usual setting (6600) was for a smoother ride. (Also a bit more tail rotor RPM too, obviously you'd want to be at the higher setting in the hover).
Don't think it gave us any more airspeed though, as I remember.
The explanation that the old and bolds gave was that at that speed, the rotor was running in a more efficient aerodynamic state, and that the usual setting (6600) was for a smoother ride. (Also a bit more tail rotor RPM too, obviously you'd want to be at the higher setting in the hover).
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Exactly Mr Arm. Stay within the flight manual limits, they're there for a reason. That reason may be torsional or bending loads, pitch link or bearing loads. On soft in plane systems there may be yoke or flexure issues. The limiting factor may have nothing to do with the rotor at all, but some other drivetrain component. They all spin in harmony with Nr as well!!
Coriolis, your pilot friend who was beeping back 7-8% was not only misinformed as you suspected, but his aircraft was also miserably misrigged. The beep range on a 206B is 97-101%.
[This message has been edited by CTD (edited 12 April 2001).]
Coriolis, your pilot friend who was beeping back 7-8% was not only misinformed as you suspected, but his aircraft was also miserably misrigged. The beep range on a 206B is 97-101%.
[This message has been edited by CTD (edited 12 April 2001).]
