Autogyros
Author
Discussion

Doofus

Original Poster:

34,279 posts

202 months

Wednesday 7th November 2012
quotequote all
I have one person telling me that they're inherently safer than most flying machines because the rotors aren't powered, and so continue to spin as long as there's forward motion.

Then there's somebody else, who says that you need a PPL to fly one, and the CAA won't licence them above FL95 (whatever the heck that is), because they're so dangerous.

So, PH, thou great knower of things; what's the truth?

JoeBolt

284 posts

191 months

Wednesday 7th November 2012
quotequote all
FL95. 9500 feet with 1013.2mb (29.92inHg) set on the altimeter sub scale.
Fairly high.

hman

7,497 posts

223 months

Wednesday 7th November 2012
quotequote all
I would have thought that gliders are in-fact the safest as they are totally un-powered and yet can climb, descend, turn etc with no problem (so long as theres updrafts and thermals to allow them to gain height)

Autogyros, in an engine fail situation, would need to descend to allow the rotors to keep turning from the air pushing the blades around (the shape of the blade is optimised for this effect) so you'd still be looking to emergency land the thing.

Powered heli's can auto-rotate in an engine fail situation but the height vs forward speed equation is a lot more acute as the blades are designed to be powered by the engine not by the air hitting them. So in an auto rotate the pilot goes to negative pitch and descends to get the blades spinning, then transfers to positive to slow the descent and land.


Odie

4,187 posts

211 months

Wednesday 7th November 2012
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I saw one landing last week at the little airport close to were I work, it was a windy day and it looks a bit scary.

Eric Mc

125,606 posts

294 months

Wednesday 7th November 2012
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They are "different" and have inherently different handling characteristics to both fixed wing aircraft and helicopters.

Geneve

4,018 posts

248 months

Wednesday 7th November 2012
quotequote all
hman said:
So in an auto rotate the pilot goes to negative pitch and descends to get the blades spinning, then transfers to positive to slow the descent and land.
That's not negative pitch.

The collective is lowered but there is still a small amount of positive pitch which is adjusted slightly to maintain the correct rotor rpm. In autorotation, instead of the induced airflow from above, the rate of descent creates the relative airflow from below and in front of the rotor. Hence the sycamore leaf comparison.

Doofus

Original Poster:

34,279 posts

202 months

Wednesday 7th November 2012
quotequote all
I may not have been entirely clear in that I know next to bugger all about flying. Are autogyros safer for low level vfr flights (and do we even have vfr rules in the UK?) of 80-100 miles than a small fixed wing or a helicopter?

On the understanding, of course, that the pilot is properly trained... smile

IforB

9,840 posts

258 months

Wednesday 7th November 2012
quotequote all
An autogyro is the safest form of air transport?

Errrr. No.

Quickest way of killing yourself if you get in one that wasn't designed by Ken Wallace?

Errrr. Yes.

Ginetta G15 Girl

3,220 posts

213 months

Wednesday 7th November 2012
quotequote all
IforB said:
An autogyro is the safest form of air transport?

Errrr. No.
Retreating Blade Stall.

Blade Sail on pitch forward.


Hmmmmmmmm.

anonymous-user

83 months

Wednesday 7th November 2012
quotequote all
What are you all on about?
Two words: Little. Nellie.

hman

7,497 posts

223 months

Wednesday 7th November 2012
quotequote all
Geneve said:
That's not negative pitch.

The collective is lowered but there is still a small amount of positive pitch which is adjusted slightly to maintain the correct rotor rpm. In autorotation, instead of the induced airflow from above, the rate of descent creates the relative airflow from below and in front of the rotor. Hence the sycamore leaf comparison.
" Autorotation is permitted mechanically because of both a freewheeling unit, which allows the main rotor to continue turning even if the engine is not running, as well as curved main rotor blades such that when the collective pitch is fully down the inner part of the blade has negative pitch relative to the horizontal plane and can be spun up by the relative wind. "

IanMorewood

4,309 posts

277 months

Wednesday 7th November 2012
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AutoGyros whilst fun I wouldn't say are safer than a fixed wing aircraft.

renmure

4,917 posts

253 months

Wednesday 7th November 2012
quotequote all
Think the actual stats show that Foot launched Microlights (FLM) are the safest form of aviation.

Anyhow... to fly a Gyrocopter you need a NPPL(G)
Tons of info here (http://gyrocopterexperience.com/training/58)

As stated, the rotors aren't powered in flight, although they do take a small bit of power from the engine to get them rotating on the ground prior to take-off.

Engine (thrust) failure in flight would lead to a controlled decent and landing. Mind you, although I have flown a gyro I fly flexwing microlights and a similar engine failure in flight would lead to a similar controlled glide decent so no real difference.

Gyrocopters suffer from a fairly poor rate of climb so tend to fly fairly low (1000-3000ft) anyhow. Think you might have a birthday sometime between take-off and 9500 feet. They are obviously no less safe at 9500 feet than they are at 950 feet. Both are a long way up if something goes wrong with the rotors!

Edited by renmure on Wednesday 7th November 21:59

Ginetta G15 Girl

3,220 posts

213 months

Wednesday 7th November 2012
quotequote all
renmure said:
They are obviously no less safe at 9500 feet than they are at 950 feet. Both are a long way up if something goes wrong with the rotors!
So there is no IAS / TAS relationship then?


Edited by Ginetta G15 Girl on Wednesday 7th November 22:26

Doofus

Original Poster:

34,279 posts

202 months

Wednesday 7th November 2012
quotequote all
renmure said:
Think the actual stats show that Foot launched Microlights (FLM) are the safest form of aviation.

Anyhow... to fly a Gyrocopter you need a NPPL(G)
Tons of info here (http://gyrocopterexperience.com/training/58)

As stated, the rotors aren't powered in flight, although they do take a small bit of power from the engine to get them rotating on the ground prior to take-off.

Engine (thrust) failure in flight would lead to a controlled decent and landing. Mind you, although I have flown a gyro I fly flexwing microlights and a similar engine failure in flight would lead to a similar controlled glide decent so no real difference.

Gyrocopters suffer from a fairly poor rate of climb so tend to fly fairly low (1000-3000ft) anyhow. Think you might have a birthday sometime between take-off and 9500 feet. They are obviously no less safe at 9500 feet than they are at 950 feet. Both are a long way up if something goes wrong with the rotors!

Edited by renmure on Wednesday 7th November 21:59
Thank you smile

Right. I'm off to buy one then biggrin

renmure

4,917 posts

253 months

Wednesday 7th November 2012
quotequote all
Doofus said:
Thank you smile

Right. I'm off to buy one then biggrin
HTH smile

http://www.afors.com/index.php?page=browse&sec...

IforB

9,840 posts

258 months

Wednesday 7th November 2012
quotequote all
Doofus said:
I may not have been entirely clear in that I know next to bugger all about flying. Are autogyros safer for low level vfr flights (and do we even have vfr rules in the UK?) of 80-100 miles than a small fixed wing or a helicopter?

On the understanding, of course, that the pilot is properly trained... smile
Don't worry, it's plainly obvious!

Autogyros have a shocking safety record compared to virtually every other form of aviation other than the base jumping.


Doofus

Original Poster:

34,279 posts

202 months

Wednesday 7th November 2012
quotequote all
IforB said:
Don't worry, it's plainly obvious!

Autogyros have a shocking safety record compared to virtually every other form of aviation other than the base jumping.
Ok, now that's a claim I've heard before, as I may have mentioned... But is that due to pilots, or an inherent 'weakness' in the concept?

IforB

9,840 posts

258 months

Thursday 8th November 2012
quotequote all
Doofus said:
Ok, now that's a claim I've heard before, as I may have mentioned... But is that due to pilots, or an inherent 'weakness' in the concept?
Design of the aircraft is one major flaw. Google the RAF2000 autogyro for proof of that. Death trap is the only way to describe them.

Don't think about aviation in a conceptual way like this. Big ideas are not what kills you, it's a load of small ones that gang up and cause trouble that's the real issue.

Fundamentally Gyros should be safe, but they have suffered from poor training, oversight, design and a lack of knowledge and a small population which means that the lessons are often learned the hard way.

I fly fixed and rotary wing and wouldn't go near an autogyro unless a certain gentleman known for his exploits in a certain Little Nellie was flying.