He lived to tell ...

[ckurz7000]

Dear friends, here is a near accident account of a German gyro pilot who agreed that I post his story for discussion and learning in this forum (slightly edited and abreviated):

(begin translation)**************************
Hello to all gyro pilots still alive!

As experience grows -- in my case flying an MT03 -- it becomes increasingly harder to resist trying out new stuff. In particular there is one maneuver which I like to practice and perform. I fly into the wind, throttle back and push the nose slightly down to pick up speed. At the low point you pull back and push the throttle in and climb. At or near the crest you kick in full rudder, turn and transition to normal flight. I have tried this dozens of times but was never quite happy with the transition to normal flight, because speed drops fast and the gyro tends to lose altitude quickly until regaining sufficient forward speed.

Yesterday, far from any spectators, I was flying east into the wind at about 600 ft when I tried to perform the above described maneuver. Everything went according to plan until I kicked in full left rudder and the nose had turned 90°, now pointing north. Suddenly the gyro rolled inverted to the right and I thought, "This is the end!" I am used to flying inverted from my aerobatic training and maybe this experience was what saved my ass. The rotor kept on spinning and I applied left rudder and throttle. Meanwhile the nose was pointing south and steeply downward. A couple of feet above ground I was able to recover and fly a left turn toward the east. Back at the airfield, legs shaking, I discovered that the stabilizer was covered with a significant oil film, confirming that I indeed must have been inverted.
(...snip...)
(end translation)***************************

In a subsequent post the pilot writes that what happened must have approximated an "Immelmann" maneuver, which is a half roll to inverted followed by a half loop, thereby going back into the direction one came from.

Here is a picture of the height (top) and vertical speed (bottom) plots from his flight log:

46804

Translation: "Fahrtaufnehmen mit wenig Gas": picking up speed with a little throttle.

"Hochpunkt und Umschagpunkt": Crest and point point of roll to inverted.

"Abfangbogen": Recovery.

This is the somewhat abbreviated and slightly edited account of the pilot. To me this is extremely valuable information since he lived to tell of his mishap which leaves us a lot more to learn from than looking at a twisted wreckage.

In the light of the "pedal turn" discussion in a related thread I encourage everybody to discuss and learn from this.

Greetings, -- Chris.

[ckurz7000]

Since I started this thread, let me also be the first one to offer an explanation in order to get the discussion started.

As the pilot neared the crest and kicked in left rudder, the gyro veered sharply to the left and thereby presented its broadside to the airflow. The resulting drastic increase in drag combined with the partially unloaded rotor made the gyro roll to the right sufficiently for the rotor to undercut the airflow and start "breathing top air". At that point the roll accelerated and he went inverted and subsequently managed to recover from that attitude.

An aggravating factor is, in my opinion, the prop torque which exacerbated the tendency to roll to the right (the prop spins counter clockwise).

So you have three ingredients to the disaster:

(1) Sudden increase of fuselage drag due to violent yaw to the left.

(2) Partial unloading of the rotor at the crest of a push over maneuver.

(3) Prop torque.

Don't hold back with your comments, -- Chris.

[barnstorm2]

Can you give us any details on how this flight log was generated?

Also, please thank the pilot for sharing his experience with us.

.

[All_In]

I love this site!
Thanks!

[automan1223]

After reading this forum and ones before it for the last 10 years, I do believe that this is the very first guy to survive something like this.

There have been several guys that went broad side to the wind, and tipped over so to speak. None ever survived as far as I know.

My only experience (hanger talk) was when you have lost control and are pointing at the ground, if your rotor has stopped flying, push the throttle forward, accelerate the wind over the rotor and you will start flying again.

At an ROC event I saw pilot Mike Solano do this manuever several times. Slow the rotor in flight, nose over point at the ground, apply power, and fly out of it.

Not something I would want to do.

Jonathan

[All_In]

Yes but "the rotor kept on spinning"!

To a FW guy it sounds like a stall where one wing drops.

That can happen unless you unload the rotor? Correct?

So what caused the gyro to roll inverted to the right?

[fiveboy]

There is a really neat game I heard about involving a revolver and a single bullet.... Whats the point of doing something like this? Does it in any way enhance the sport? He doesnt even know how or why he survived so we are now supposed to explain it to him. How do you translate even a blind chicken sometimes finds corn into German?

But what do I really think?

Fiveboy

[mceagle]

"Dead man walking" - thank goodness he lived to tell the tale. This admission may well save some lives. He must be commended for sending in this report.

[WaspAir]

I think what is being described is more like a split-S than an Immelmann (an Immelmann starts with half-looping and ends with rolling, with a net climb; a split-S starts with rolling and ends with half-looping, with a net descent). In any event, it makes me wonder what the profile of the gyro looks like - how much side surface area is above/below the center of gravity? Yaw - roll coupling has been an issue on many gyro designs (and on some helicopters with floats, too). I've never had a up-close look at an MT03. Is there a lot of surface (viewed from the side) down low?

[Timchick]

Here's a photo of an MT-03.

[Vance]

I would not be comfortable performing that maneuver.

Thank you, Vance

[ckurz7000]

It's been shown that the most accident prone phase in a pilot's carreer is not the one right after he gets his ticket. Nor is it after a thousand hours of flight experience. The most dangerous period is when you have some limited experience as a mid-time pilot. That's when you tend to overestimate your skills and do stupid things in overconfidence.

This German pilot is one of generally sound judgement with a good understanding of the limitations of the gyro. He had exhaustive gyro training, since the German UL license for gyros requires (apart from a theoretical test) 30 hrs of flight time (at least 5 of which are solo and at least 10 of which are with an instructor before the first solo), 150 take-offs at different airfields, out field landing exercises, at least 2 xc flights of more than 100 km with at least one intermediary landing as well as an intro to unusual flight attitudes.

And I know his instructor very well; he's competent, experienced and knowledgable. What bit him was overconfidence performing a maneuver that one needs to approach with extreme caution and loads of experience or -- best -- not at all. This is the kind of experience that if you can learn from it, you will be a safe pilot from then on. I hope we can all learn from it.

-- Chris.

[Gyro_Kai]

Hello,

I was also involved in the discussion in the German group.

The manaeuvre intended seems to be something like a Hammerhead, ending like an Immelmann. A lot of the events is still unclear, even to him. To me it seems a miracle, that the plane stayed with negative G long enough to spill oil, but not decayed the RRPM beyond return.

I think, this is something that simply doesn't belong in a gyro. Even if you have a lot of hours, physics still apply.

Unloading the rotor and then doing fancy tricks is a fatal combination.

He lived to tell the tale, not to brag about it, but to warn.

Kai.

[mceagle]

This type of Gyro does have considerable frontal side area well in front of and lower than the C of M. The triple rudder has good command with forward speed but is inadequate at low of zero airspeed. This is not a fault if the Gyro is flown within its limitations.
An induced sidways slide (as an attempted turn at the top of a hammerhead) would tend to roll the aircraft rather than turn it and then the fuselarge would take over the cyclic control and roll the gyro further into what would normally be an irrecoverable situation. Once this situation has developed, I doubt whether the rudder would have enough authority to turn the aircraft back into the direction of travel, even with a burst of power.
We are very lucky to have this pilot able to relay this loss of control to us. It is very likely that his aerobatic training saved his life.

[troed@aon.at]

And I know his instructor very well; he's competent, experienced and knowledgable. What bit him was overconfidence performing a maneuver that one needs to approach with extreme caution and loads of experience or -- best -- not at all.

So now I wonder WHO this "gyro-instructor" could be that teaches SUCH maneuvres. As can be read in any gyro-instruction-book all over the world and- by the way - in every physics book on auto-rotation You NEVER EVER PUSH THE STICK FORWARD AFTER A STEEP CLIMB WITH FULL THROTTLE. The practical and physics result is a bunt-over and as such a (in this case fortunately not) deadly sin in gyro-flying.

The comparison alone with maneuvres that can be done ONLY with fixed-wing aircrafts shows the deep misunderstanding of the limitations of a gyroplane.

This story has nothing to do with "trying what is possible", it simply is, as stated before in this thread, more dangerous than playing "Russian Roulette". It is like having 5 bullets in a 6-shooter. So I propose that no serious self-responsible gyro-pilot should never ever undertake a "that one needs to approach with extreme caution and loads of experience" unless in case of willing suicide.

As BFI for the European Branch of ASC I definitely reject teaching maneuvres like that.

Angelo

[troed@aon.at]

To make it clear to everyone here the description of a correct U-Turn after full throttle steep climb:

1. T/O as usual and climb with 50-80 mph (depending on type of gyro) forward speed, full throttle
2. After having reached safety height 500ft AGL pull stick and take back throttle until You hover in level attitude (fwd speed 0-10mph, motor rpm around 4000 in ROTAX-gyro, depending on MTOW)
3. Step into pedal (preferrably left in ROTAX-driven gyros) and make Your safe U-Turn 180°. If in 700 ft AGL could also be a 360° turn.
4. Release stick slowly to trim speed and add slowly throttle until level flight is accomplished.

Angelo

[Doug Riley]

Chris, your analysis in Post #2 seems correct to me. The Rotax 900s' prop shafts turn counter-clockwise viewed from the rear. Therefore, their torque-induced rolling moment is clockwise -- the direction that this MT rolled.

If a gyro lacks vanes in the propwash to counteract torque fully, then rotor thrust provides the counter-moment. In low or zero G, there is little/no rotor thrust, and therefore the prop torque is free to cause a roll.

Maneuvers like this will always be unreasonably dangerous in an autogyro. However, certain design strategies can lessen the risk of accidentally getting into such a situation.

First, the fuselage side area should be placed and shaped so that its center of pressure is at or above the aircraft's CG. This will eliminate the slip-roll coupling that (as you observe) likely added to the right-rolling tendency. Slip-roll coupling in tandem gyros with low centers of pressure has been a problem at least since the Air & Space 18A encountered it (causing some crashes). The MT03 unfortunately copies the low-riding tandem configuration of the Magni. In most instances in both these gyros, the lowrider issue is resolved by the large tail surfaces -- but not in this case.

Second, the tail surfaces -- vertical and horizontal -- should be placed in the propwash and their incidences adjusted to counteract torque roll. It's pretty well known by now that Cierva did this. Ron Herron learned about it from his readings, and used the technique on his Little Wing, too.

[All_In]

Ah Ha!
Doug to my recuse, now I understand!

Thanks

[Vance]

To make it clear to everyone here the description of a correct U-Turn after full throttle steep climb:

1. T/O as usual and climb with 50-80 mph (depending on type of gyro) forward speed, full throttle
2. After having reached safety height 500ft AGL pull stick and take back throttle until You hover in level attitude (fwd speed 0-10mph, motor rpm around 4000 in ROTAX-gyro, depending on MTOW)
3. Step into pedal (preferrably left in ROTAX-driven gyros) and make Your safe U-Turn 180°. If in 700 ft AGL could also be a 360° turn.
4. Release stick slowly to trim speed and add slowly throttle until level flight is accomplished.

Angelo

Hello Angelo,

Why would you want to hover in a level attitude to turn?

What is the allure of a flat turn?

Thank you, Vance

[troed@aon.at]

This is part of the advanced pilot training in Germany and Austria. Actually there should be no situation when this maneuvre is necessary but training this could be useful in Alpine regions where ULs T/O sometimes in very narrow valleys.

Actually it is simply a normal T/O and then added a flat U-Turn instead of a banked curve.

Angelo

[Udi]

Does anybody know if the pilot observed his rotor RPM during this maneuver?

I suspect the need to observe and maintain a minimum safe rotor RPM and positive G is something our European friends are failing to teach new gyro pilots. The root cause of this incident is the pilot failing to maintain RRPM and/or positive G. Secondary contributing factors are prop torque and airframe rolling moment, as described above. Unlike fixed wing airplanes, gyros lose roll (and pitch) control when the rotor thrust is reduced. At 0 G there is absolutely NO roll and pitch control. Is this little detail being taught in Europe?

This incident sounds very similar to a fatal accident that happened to an Italian aerobatic pilot, who was flying his friend's 914 Magni a few years ago. He didn't live to tell the story.

Udi

[Vance]

Thank you Angelo,

Does it take less space than a banked u turn?

How much altitude does it typically consume?

I am trying to understand the advantage of flat turns over banked turns.

When I fly slower than about 18 miles per hour I lose altitude even with full power unless I am in an updraft.

I have practiced s turns at 20 miles per hour and they seemed to take a lot of distance to get turned around.

I am trying to imagine a situation where a flat turn would be the best option.

Why do a flat turn at the top to the climb?

Thank you, Vance

[Vance]

Unlike fixed wing airplanes, gyros lose roll (and pitch) control when the rotor thrust is reduced.
Udi
Hello Udi,

Does a fixed wing have roll and pitch control at 0 forward airspeed?

Thank you, Vance

[Udi]

Hi Vance,

Aerobatic planes do have some control at 0 airspeed thanks to prop wash over the control surfaces. Gyros have full control at 0 airspeed, as long as positive G is maintained, but have no control at 0 G. Airplanes have full control as long as there is sufficient airflow over the control surfaces, regardless of G.

Also, for experienced FW aerobatic pilots, the consequences of stuffing-up a simple maneuver are rarely fatal -- as long as they have sufficient altitude to recover. This is not the case for gyros.

I suppose FW aerobatic pilots must be especially aware of these differences, if they are going to perform unusual maneuvers safely.

Udi

[Vance]

Thank you Udi,

My limited experience in fixed wing aircraft taught me that below an airplane’s stall speed there is not much control and altitude is used to regain airflow over the wings in order to not have an inelegant landing. The NTSB is full of reports of airplanes becoming inverted when they stall. There seems to be lots of ways to initiate the inverted landing. The common thread seems to be low airspeed combined with low altitude.

I can relate to the desire to explore the flight envelope.

I felt uncomfortable doing S turns in a gyroplane at 20 miles per hour airspeed. The engine was struggling to maintain level flight and the rudder controls felt vague. Wind gusts seemed to have more effect at 20 miles per hour airspeed than at 50 miles per hour airspeed.

When I practice engine out 180 degree turn landings into the wind from 50 miles per hour it is not hard to keep the radius of the turn less than 75 feet. I was at 3,000 feet agl when I was practicing my slow flight S turns so I didn’t have a good distance reference. I suspect that it was not much tighter. They were not really flat turns, there was a shallow bank and they were initiated with the stick. If I would try a tighter turn with more bank I could not maintain my altitude even with full power.

At what rotor RPM does low rotor speed become a non recoverable event?

Thank you, Vance

[troed@aon.at]

Hi Vance !

Here are my answers and all descriptions refer to European gyros with a max. MTOW of 900lbs and Rotax 914 Turbo (Magni M16, Magni M22, ELA 07S, MT03, XENON 912 RST which I have a rating for):

Does it take less space than a banked u turn?

Yes, if You do it in headwinds and a full pedal step left turn slip will be around max. 15-20 ft. Right pedal a little bit more.

How much altitude does it typically consume?

Depending on the MTOW and motor rpm between 100 to 150 ft. until level flight can be reaccomplished.

I am trying to understand the advantage of flat turns over banked turns.

Actually there is NO advantage. My prior explanation with T/O in narrow valleys is somehow vague and just to find ONE reason thinkable at all. Nevertheless it is a safe maneuvre put together of two (T/O and 180-360° turn) flight situations.

When I fly slower than about 18 miles per hour I lose altitude even with full power unless I am in an updraft.

With the above mentioned European gyros (of course depending on the prop-pitch, weather-conds and MTOW) You can hover without loss of altitude in headwinds of 10 mph (0 IAS = 10 mph TAS). In winter (cold, dry air) it´s easier than on a hot summer day.

I have practiced s turns at 20 miles per hour and they seemed to take a lot of distance to get turned around.

Depends on the gyro You fly, the weather conds and motor rpm. And: the heavier the rotor the more space You need (light rotors have less inertia)

I am trying to imagine a situation where a flat turn would be the best option.

ME TOO !!! ;) but feel free to construct the wildest abstruse ideas of a traffic situation at a UL-airport when it once could be the best option. As with everything in this world: what You can think of and imagine: IT WILL HAPPEN !

Why do a flat turn at the top to the climb?

1. To show off as a big guy to the watchers below
2. To show off as a big guy to the lady beside/behind You
3. To show off to both
4.-98: see points 1.-3.
99: it´s fun
100: You fly in a valley with heavy downdrafts and You still believe You can make it over the mountain wall in front of You although Vertimeter tells You: 0 fps up at full throttle and the valley end comes closer and closer and it gets narrower and narrower.... then You will do a flat turn (although there is no climb any more) :rolleyes:

Angelo

[Vance]

Hi Vance !

With the above mentioned European gyros (of course depending on the prop-pitch, weather-conds and MTOW) You can hover without loss of altitude in headwinds of 10 mph (0 IAS = 10 mph TAS). In winter (cold, dry air) it´s easier than on a hot summer day.

Angelo

Thank you very much Angelo,

I feel confused on a higher level now.

I do not understand what you are saying about head winds. I think it a semantics challenge. It is my understanding that airspeed is airspeed and wind is in relation to the ground. Am I missing something here?

I did not intend to sound critical. I was trying to imagine the value of a flat turn and I did not have sufficient imagination. Someone thought it was useful or it would not be part of your teaching syllabus.

I am off to fly!

Thank you, Vance

[All_In]

Doug, Angelo, Udi!
You rock! I learn so much at this site.
Thank you

[ckurz7000]

I feel confused on a higher level now.

I do not understand what you are saying about head winds. I think it a semantics challenge. It is my understanding that airspeed is airspeed and wind is in relation to the ground. Am I missing something here?

Hi Vance, you're absolutely right and didn't miss anything. Angelo wrote:

"You can hover without loss of altitude in headwinds of 10 mph (0 IAS = 10 mph TAS)."

This is actually not correct. When you hover in a headwind your IAS (indicated air speed) will be equal to the wind speed and your GS (ground speed) will be zero. Your TAS (true air speed) is for all intents and purposes equal to your IAS. Lest we get into a discussion of all the various airspeeds (IAS, CAS, TAS, etc), I stop here and only remark that IAS=TAS holds strictly true only for a perfect instrument on a standard day at sea level.

Hovering at a headwind of 10 mph (15 km/h) I find impossible with my MT03. I can hover upward of 25 km/h but I'm not sure of even that when at MTOW. It's actually kind of hard to get a good reading of your airspeed at such low speeds because of the pronounced nose-high attitude. The pitot tube (on an MT03 it's actually just a piece of brass tubing sticking out of the nose) is not accurate and displays erroneously low values when not aligned with the oncoming airflow.

-- Chris.

[Doug Riley]

Vance, mate, one reason t'do a flat U-turn is when yer chasin yer moos, ay?

Seriously, I'm sure the Aussie musterers find this maneuver useful in their work. For others, it's an aerobatic meneuver performed for thrills.

Gyros can be built that will retain roll and pitch control at zero airspeed. One way is continue using direct cyclic, but employ outboard flap hinges. In that case, the moments applied to the frame by the rotor are created partly by centrifugal effect, rather than just by vectoring the rotor's thrust. Unlike rotor thrust, centrifugal effect remains in place as long as the rotor has RPM, even at at zero or negative rotor AOA.

Another way to retain control by design is to use aerodynamic control surfaces -- necessitating wings and full-span ailerons, as well as elevators. In that setup, the rotor head could be fixed, as it was in the winged Cierva/Pitcairn machines. It would be tough to arrange this on a pusher gyro, though. While the winged Cierva-Pitcairn gyros were notorious for having no roll control at zero airspeed, they apparently didn't have full-span ailerons to catch propwash.

[Vance]

Thank you Chris,

I wasn’t trying to make Angelo wrong.

I ran what Angelo said past my limited experience and it was confusing.

Your explanation is aligned with my understanding.

I stumble over the word hover. I feel that you are saying is you can fly straight and level at 25 kilometers per hour indicated airspeed in you MT103.

I don’t like the way my aircraft feels below about 30 kilometers per hour indicated airspeed. The nose is high and the rudder feels mushy. It feels like the engine is working too hard and when I practice an engine out from this attitude it takes a while and some considerable altitude to recover airspeed for the landing flair. This tends to reduce my landing area options.

Thank you, Vance

[Vance]

I love your creativity Doug.

It is an interesting challenge to design something to show off.

Would the thrills still be there if the aircraft was designed to manage that part of the flight envelope?

I have not reached the level of flying skill where I am looking for thrills.

I find something strangely alluring when I watch people fly autogiros.

I am not alone in this as more than one person at the airport has said that they always come out to watch when they hear me fly.

I have succumbed to the desire to show off.

Thank you, Vance

[ckurz7000]

I stumble over the word hover. I feel that you are saying is you can fly straight and level at 25 kilometers per hour indicated airspeed in you MT103.


Yes, that's what I was trying to say. Although I'm not sure how accurate the 25 km/h really are. It's certainly not any slower than that.


I don’t like the way my aircraft feels below about 30 kilometers per hour indicated airspeed. The nose is high and the rudder feels mushy. It feels like the engine is working too hard and when I practice an engine out from this attitude it takes a while and some considerable altitude to recover airspeed for the landing flair. This tends to reduce my landing area options.


Yes, you're right. Particularly for a FW pilot the slow and mushy nose-high feeling of being way behind the power curve sets off alarm bells left and right. It's a perfectly safe place to be in a gyro, however, if you have enough altitude to let the nose drop and pick up speed.

-- Chris.

[Udi]

...Gyros can be built that will retain roll and pitch control at zero airspeed. One way is continue using direct cyclic, but employ outboard flap hinges...
I think you meant to say - retain roll and pitch control at zero G - Doug. No?

Udi

[Udi]

Vance - sure there are ways to lose control in FW planes too. The 2 points I was trying to make are - 1. Positive G is not required for airplane controls to work (it is in teetering rotor gyros), and, 2. Given sufficient altitude, loss of control in airplanes (stall, spin) is not an automatic death sentence. People are dying in airplanes every day for various reasons but the purpose of my post was to highlight the differences between airplanes and gyros that might cause experienced FW pilots to lose control of a gyro.

BTW - I don't think anyone has commended yet the MT03 design for saving this pilot's life. There was some luck (and maybe some skill) involved in this save for sure but I think the fact that this gyro righted itself up without the rotor first chopping parts to pieces deserves some positive kudos. Bravo MT03!

Udi

[Gyro_Kai]

Hello,

we don't all have the same instructor, but I do think, due to the close cooperation between them that our education was very similar.

The "climb and then flat turn", on the other hand, I never learnt. My program is: "climb and then a banked turn", like Vance is hinting at. This can be very tight, it doesn't loose height and you come out with a faster RRPM plus airspeed.

I did, however, learn the "careful slow down to 0 airspeed then pedal turn". It has no practical value and is only for frightening FW pilots. After some fright in the other thread, I now think is safe, again. (I'm afraid to challenge again, though)

Does anybody know if the pilot observed his rotor RPM during this maneuver?
No, he had other things on his mind :)


I suspect the need to observe and maintain a minimum safe rotor RPM and positive G is something our European friends are failing to teach new gyro pilots.

eh, no again. That was a very important and continously repeated part of theory and practice. There were about 8 questions in the multiple choice alone around this subject. I know "the survivor's" instructor and he is definitely not endorsing unsafe behaviour, in fact he is very picky.


The root cause of this incident is the pilot failing to maintain RRPM and/or positive G. Secondary contributing factors are prop torque and airframe rolling moment, as described above. Unlike fixed wing airplanes, gyros lose roll (and pitch) control when the rotor thrust is reduced. At 0 G there is absolutely NO roll and pitch control. Is this little detail being taught in Europe?

Yes again. But you do have very good control at 0 airspeed, the rudder reaches well into the propwash. 0 G is however the absolute no-no, no discussion!


This incident sounds very similar to a fatal accident that happened to an Italian aerobatic pilot, who was flying his friend's 914 Magni a few years ago. He didn't live to tell the story.

Udi

Thanks for the insights presented here, Udi.
I said before, one couldn't pay for all the tuition one gets in this forum.

Kai.

[Vance]

Yes, you're right. Particularly for a FW pilot the slow and mushy nose-high feeling of being way behind the power curve sets off alarm bells left and right. It's a perfectly safe place to be in a gyro, however, if you have enough altitude to let the nose drop and pick up speed.

-- Chris.

Thank you Chris,

How much altitude is that?

Thank you, Vance

[Udi]

Does anybody know if the pilot observed his rotor RPM during this maneuver?
No, he had other things on his mind
No doubt he had other things on his minds after he became inverted, but -- up to that point -- RRPM should have been on the top of his mind. At least if he was purposefully unloading the rotor at the top of the climb.

What is a safe RRPM? That depends on the rotor/aircraft and the maneuver that you are about to perform. You can get away with a lower RRPM if you stay S/L with no engine torque or prop pitching moments. Nobody will, or should, give you a "safe" low RRPM because as soon as you trust that number, you will find a maneuver in which that number is too low. Aerobatics should be left for those who've got a good understanding of gyros and their own aircraft specifics.

Udi

[ckurz7000]

Thank you Chris,

How much altitude is that?

Thank you, Vance

I did some experimenting by descending vertically to a particular altitude and then pushed the nose forward, picked up speed, flared and landed. I found that as long as I'm about 150 feet up or higher before I point the nose down, I can pick up sufficient speed to make a safe landing. I guess you can push that limit some more, but that wouldn't be safe anymore.

-- Chris.

[troed@aon.at]

Hi Vance !

Sorry, I goofed it........ Was answering You between two surgeries ........

Of course the correct reading should be: 0 mph GS (Ground Speed) and 10 mph TAS.

Logged this values in a MT03 in Jan. 2006 at -8° Centigrade, Humid. 10%, Motor-rpm 5.700 (Rotax 914), 600 ft ASL/150ft AGL, TAS (10 mph) was taken by external pitot with the MGL Avionics "STRATOMASTER" since original MT03 AIS is not reliable .

Rotor-rpm was 310, Hovering for 82 secs.

Please leave some error margins to GS/TAS + 5mph due to lack of precision of instruments............

To give You another extreme on the other side of gyro-flight-envelope but still safe: Andreas Siebenhofer, head of the flight school down in Hungary and so called "extreme-pilot" - in fact safety is his highest priority also when he works as test pilot for new gyro models - still goes up with gyros in 50-60 mph headwinds. Dunno if he does flat turns in these conds, have to ask him.

Conclusion:

Flat turns, if set up correctly as described (stick pulled), are WITHIN safe flight envelope of gyros, no matter when they are performed. If they are useful is a totally different question. :yo:

Have fun in the air and fly safe

Angelo

[birdy]

It's been shown that the most accident prone phase in a pilot's carreer is not the one right after he gets his ticket. Nor is it after a thousand hours of flight experience. The most dangerous period is when you have some limited experience as a mid-time pilot. That's when you tend to overestimate your skills and do stupid things in overconfidence.
That bout sums it up.

1. T/O as usual and climb with 50-80 mph (depending on type of gyro) forward speed, full throttle
2. After having reached safety height 500ft AGL pull stick and take back throttle until You hover in level attitude (fwd speed 0-10mph, motor rpm around 4000 in ROTAX-gyro, depending on MTOW)
3. Step into pedal (preferrably left in ROTAX-driven gyros) and make Your safe U-Turn 180°. If in 700 ft AGL could also be a 360° turn.
4. Release stick slowly to trim speed and add slowly throttle until level flight is accomplished.
Anyone do'n this should be sure bout the their life insurance.

Yes, if You do it in headwinds and a full pedal step left turn slip will be around max. 15-20 ft. Right pedal a little bit more.
Wind direction will make no difference.

Depending on the MTOW and motor rpm between 100 to 150 ft. until level flight can be reaccomplished.
If dun properly, you wont loose any alt.

Seriously, I'm sure the Aussie musterers find this maneuver useful in their work.
Doug, Vance, theres a few situations where a flat turn is safer, mainly coz if you banked, your rotor will strike the ground.
But theres anatha situation [ one i cant mention ona public forum] where a flat turn is very much safer than bankn. ;)

Flat turns, if set up correctly as described (stick pulled), are WITHIN safe flight envelope of gyros, no matter when they are performed.
Angelo, wenever you commanding a fast yaw input to the machine, the stick should be forward, not ' pulled'.

[Doug Riley]

Udi, what I REALLY wanted to say (before a phone call required me to "post and run") was "retain pitch and roll control at zero rotor thrust." For the FW plane, the critical situation is zero airspeed, but for the gyro with centered flap hinges, it's zero thrust.

Zero rotor thrust often happens at the top of a zoom when, in fact, airspeed IS zero -- but it can happen with lots of airspeed, too. It occurs when the rotor disk AOA is brought to (approximately) zero, either intentionally or accidentally.

Zero rotor thrust produces a sensation of "zero G" although, of course, gravity hasn't really gone away; rotor thrust has.

If the gyro's design is such that rotor thrust normally is needed to keep the aircraft in trim, naturally it'll go OUT of trim during zero rotor thrust. That's what PPO, torque-over and drag-over are all about.

[fiveboy]

If the gyro's design is such that rotor thrust normally is needed to keep the aircraft in trim, naturally it'll go OUT of trim during zero rotor thrust. That's what PPO, torque-over and drag-over are all about.

So this "maneuver" that is being tacitly encouraged to newbies as being safe if you know how and which no one has acknowledged as being ever really necessary or part of normal operating procedures is in fact within the brackets for the above events..... excellent now lets all run out and see if we can do it.... and then start another thread on the latest gyro pilot to go down and wring our collective hands and send his/her family our heartfelt sorrow.

There has to be a word for this but my mind is numbed and clouded by the irony of this thread.

Anyone have the stats or a method of approaching how to juggle radios that are plugged in while standing in a bathtub full of water? I hear it can be done if you know how to juggle.

Fiveboy

[birdy]

So this "maneuver" that is being tacitly encouraged to newbies as being safe if you know how and ...........................
Im kinda wundern if this thread should be deleated too.
At least the posts that say "how to" and include words like "safe" and "within the machine's abilities."

I woulda thought that the opening post woulda stated loud and clear that it aint a walk in the park. Afterall, the pilot did state he had plenty of advanced train'n, with a very good and experianced instructer, and still he stuffed it up.
The thread should be a warning to those with more balls than brains, not a manual for 'how to'.

[reelmule]

Ditto Birdy's last statement!

[scott heger]

Doing a flat u-turn is just another control maneuver in a experienced gyro pilots bag of tricks, and can be accomplished without loss of altitude, as Birdy stated. Vance asked if it can be done in a shorter distance than a banked turn....sure. Can it be done quicker in seconds than a highly banked turn....doubtful. That means, ya better have some altitude and should not be tried at low level(like trying to get out of a box canyon that you had no business going into in the first place). Sinking at the end of the turn is common for the unexperienced if airspeed bleeds. Single place open frame (stable)gyros will "u-turn"much easier than large machines with lots of fairings/windshields/pods etc that hinder quick turning movements.

Scott Heger,Laguna Niguel,Ca N86SH

[troed@aon.at]

Here is a very good video of a Magni M16 performing the maneuvre:

http://www.youtube.com/watch?v=b1Z0WqZSvaQ

Angelo

[ferranrosello]

Udi, is a mistake to think in rotor rpm as a low g indicator. The low g situation will happen before the rpm decays. And the rpm only will decay in transient manoeuvres involving low g.

If you want a good low g indicator you will need a very good g-meter. If you don't have it, PLEASE don't trust in rotor tachometer... It is a much better indicator the stick position: forward stick positions flying at normal cruise airspeed are dangerous. And this is what should be taught in all gyro schools.


Regards, Ferran.

[birdy]

I musta missed this comical thread. :(

Firstly, the best and only G meter you can use/trust in a gyro is stick pressure.
Wots more, every gyro is already fitted with one, and you dont have to watch it.

With respect Angelo, the flyn in the vid you linked has nuthn but gentle spins with a shallow bank.
Certainly not the low G, no AS at the top with hard yaw this thread is refern to.