Incident - Cavalon N518DT - Arizona

[rcflier]

In my opinion this is a good example of bad instruction.

Gyroplanes are not all the same.

Please familiarize yourself with the procedures and speeds in the pilots operating handbook for your particular gyroplane.

The Eurotub remark is my own (maybe faulty one) - as they seem to have copied each other.

I have flown only my own MTO.

And what is wrong with that procedure?

From my POH:

Align gyroplane with rudder and correct drift with lateral control input, even if this
results in a side slip indication
 Maintain approach speed until approximately 5m above runway
 Initiate round out to reduce sink rate and let ground approach
 Perform final flare close to ground as speed will decay rapidly
 Let gyroplane settle on main gear with nose wheel slightly above the ground
 Hold nose wheel closely above ground and let it sit down with pedals neutral at the
lowest possible ground speed
 Maintain aft control stick to reduce speed until walking speed. Wheel brake may be
used to assist, if needed

Is it any different on an ELA for instance?

 

[Sv.grainne]

Flew my Genesis today and did some takeoffs at WOT. Climb rate about 1200fpm. No noticeable torque roll or need for any control corrections.

I'm going to stick to my earlier procedure for pattern work around airport.

 

[PJB]

I see the value for obstacle avoidance, but not HV purposes. Climb rate would seem to be irrelevant to the profile required for HV purposes.

That is the current Cavalon HV diagram. You cleared 50ft and if you are flying accurately you are c.10mph away from being inside the Avoid area. You have an engine failure. I'm not sure how quickly you think you'd recognise the failure or how accurately you continue to fly whilst figuring your position out but I'd think it a reasonable bet that you might loose those 10mph? If climb rate = sooner to gain height then climb rate would definitely seem relevant?

 

[WaspAir]

Climb rate can't even be plotted on that graph, because the horizontal axis is airspeed, not time.

The suggested climb profile on that chart has you climbing at 100 kmh airspeed, but if you did that at 1500 fpm or at 0.15 fpm climb rate, you would follow the very same dotted blue line, with no difference in the "distance" from the avoid region on that chart. If you fly at 100 kmh and take five years to reach 300 feet, it's still the same blue curve.

Higher climb rate can be useful for quickly reaching safe height above terrain to make it to a particular landing spot without hitting anything, but it has nothing to do with HV. HV is all about adequate total energy for a flare to arrest your descent rate when you reach the ground without regard to your path in space and time that gets you to that spot.

This is, in my experience, the single most misunderstood graph in aviation, because the axes are not intuitive. For example, if you cruise at 300 feet and 100 kmh for a week, the plot on the HV graph would be a single dot, not a curve.

 

[PJB]

I feel difference training has value, I do not feel a lack of difference training that is well defined and mandated is the reason people are wrecking gyroplanes in the USA.

The NTSB said about N261MD
The employee of the gyroplane manufacturer who conducted the flight training with the accident pilot reported that during training, he had issues with excessive power applications and over-controlling the gyroplane. He reported that the pilot needed additional transition time and training in the gyroplane. The employee offered the pilot additional training, but the pilot declined. Page 2 of 8 WPR21LA070 Probable Cause and Findings The National Transportation Safety Board determines the probable cause(s) of this accident to be: The pilot’s failure to follow the procedures for takeoff in the Pilot Operating Handbook, which resulted in a loss of control and collision with the terrain. Contributing to the accident was the pilot’s failure to receive additional training in the gyroplane

In my opinion we take different things away from these NTSB reports.

As things relate specifically to Cavalon, there are as far as I can see circa 60 Cavalon's flying in the USA and yet 12 have been subject to NTSB reporting including 4 fatal accidents. Given the short time frame these things have been around [c. 2018 in the US and we lost a year with the virus!] that is some strike rate but in fairness to the aircraft it seems to me a there is some training gaps.

The Rosberg [N477AG] accident seems low time pilot accident, and if you read the witness statement he had struggled to land the previous day, that and a previous accident suggest he needed help tbh.

Chris Lords accident was inexperience with the make/model, some professional pressure and a casual attitude likely born out of his wider experience.

419LB accident reads:

. Two days before the accident was the pilot’s first solo flight.
The pilot’s flight instructor reported that the pilot had about 20 total hours of flight training over the course of about a year. He would fly a few hours at a time with large gaps in-between. The pilot traveled a long distance to obtain the instruction and about 3 months prior to the accident, he elected to move the gyroplane closer to his home despite the instructor informing him he was not ready for solo flight. It is unknown if the pilot obtained additional flight instruction as advised. Given the pilot’s overall lack of experience, along with his decision to take off with a tailwind, it is likely he did not possess the necessary skill or experience to safely conduct solo flight.

401GR so far tells me we have another low time pilot and when I look at the video stills and the end result one initial thought is that the pilot is trying to correct yaw with stick.... perhaps that isn't a "differences" training but it is a training issue.

 

[Vance]

The Eurotub remark is my own (maybe faulty one) - as they seem to have copied each other.

I have flown only my own MTO.

And what is wrong with that procedure?

From my POH:

Align gyroplane with rudder and correct drift with lateral control input, even if this
results in a side slip indication
 Maintain approach speed until approximately 5m above runway
 Initiate round out to reduce sink rate and let ground approach
 Perform final flare close to ground as speed will decay rapidly
 Let gyroplane settle on main gear with nose wheel slightly above the ground
 Hold nose wheel closely above ground and let it sit down with pedals neutral at the
lowest possible ground speed
 Maintain aft control stick to reduce speed until walking speed. Wheel brake may be
used to assist, if needed

Is it any different on an ELA for instance?

What is the approach speed for your MTO?

How do you know that with your aftermarket rotor blades?

Did you do any flight testing?

What you have there are the basics for an MTO in a standard configuration.

I feel it is important to read the pilot's operating handbook for your gyroplane year make and model.

Gyroplanes are not all the same.

If landing a gyroplane was that simple there would be no need for flight instructors and pilots would not be rolling them up.

There would be no value in transition training.

I have found even two gyroplanes of the same make and model may have substantial differences in the way they fly and should be approached with caution.

 

[PJB]

Climb rate can't even be plotted on that graph, because the horizontal axis is airspeed, not time.

The suggested climb profile on that chart has you climbing at 100 kmh airspeed, but if you did that at 1500 fpm or at 0.15 fpm climb rate, you would follow the very same dotted blue line, with no difference in the "distance" from the avoid region on that chart. If you fly at 100 kmh and take five years to reach 300 feet, it's still the same blue curve.

Higher climb rate can be useful for quiclky reaching safe height above terrain to make it to a particular landing spot without hitting anything, but it has nothing to do with HV. HV is all about adequate total energy for a flare to arrest your descent rate when you reach the ground without regard to your path in space and time that gets you to that spot.

This is, in my experience, the single most misunderstood graph in aviation, because the axes are not intuitive. For example, if you cruise at 300 feet and 100 kmh for a week, the plot on the HV graph would be a single dot, not a curve.

We are either misunderstanding each other or something else is going on.

If I relate to the HV diagram if we maintain 100km/h in our climb out then we are golden. No issues. My point is that in the event of a real engine failure - i.e. there is no instructor saying "Practice engine failure, 3...2...1...go" With a nose attitude consistent but now no thrust airspeed must decay. If I am at 50ft and my airspeed decay's 10mph I am now in the avoid area. That margin increases with height.

Therefore my reference to rate of climb is that I will be at a greater height sooner. Therefore I gain greater margin with greater height to the point where I can be perhaps more casual at +400ft.

 

[bell206]

HV curve was meant to show that in the event of an engine failure and your aircraft was operating inside this area a safe emergency landing may not be possible. It did not say that you must never cross into this area during emergency landing.

 

[Vance]

In my opinion we take different things away from these NTSB reports.

As things relate specifically to Cavalon, there are as far as I can see circa 60 Cavalon's flying in the USA and yet 12 have been subject to NTSB reporting including 4 fatal accidents. Given the short time frame these things have been around [c. 2018 in the US and we lost a year with the virus!] that is some strike rate but in fairness to the aircraft it seems to me a there is some training gaps.

The Rosberg [N477AG] accident seems low time pilot accident, and if you read the witness statement he had struggled to land the previous day, that and a previous accident suggest he needed help tbh.

Chris Lords accident was inexperience with the make/model, some professional pressure and a casual attitude likely born out of his wider experience.

419LB accident reads:



401GR so far tells me we have another low time pilot and when I look at the video stills and the end result one initial thought is that the pilot is trying to correct yaw with stick.... perhaps that isn't a "differences" training but it is a training issue.

This is a thread about a Cavalon mishap caused by a failure of the nose gear (N318DT) Phil.

In my opinion this was not a training or transition issue and the accident pilot has had many successful flights over a number of years.

I consider him an experienced gyroplane pilot with good training.

As I have written many times before I feel difference training has value and I encourage it.

Also as I have written many times before I do not want to see more regulations.

I am grateful for the variety of gyroplanes that are available in the USA and the freedom we have to modify them.

I have grateful for the freedom I have in training gyroplane pilots.

Many people before you have recognized that low time gyroplane pilots are overrepresented in the accident statistics Phil; what is your point?

 

[WaspAir]

We are either misunderstanding each other or something else is going on.

If I relate to the HV diagram if we maintain 100km/h in our climb out then we are golden. No issues. My point is that in the event of a real engine failure - i.e. there is no instructor saying "Practice engine failure, 3...2...1...go" With a nose attitude consistent but now no thrust airspeed must decay. If I am at 50ft and my airspeed decay's 10mph I am now in the avoid area. That margin increases with height.

Therefore my reference to rate of climb is that I will be at a greater height sooner. Therefore I gain greater margin with greater height to the point where I can be perhaps more casual at +400ft.

Obviously, the manufacturer considers the entire blue line safe, even accounting for the typical response to an engine failure, because that's the assumption upon which the whole graph is based, regardless of climb rate (which is nowhere represented on the graph).

What you are worrying about here is simply not an issue for HV purposes.

Climb at a high rate for terrain and obstacle clearance and glide range. Don't bother for HV purposes because it doesn't matter.

 

[BEN S]

I love the free form discussions that this medium creates.
But....
I have noticed over the last 4 or 5 accident threads that the very experienced pilots/instructors contue to migrate towards low time pilots flying high horsepower enclosed 2 place machines.
Most of the accidents are on takeoff not landing so not sure the HV curve chart is super relavant.
What I don't see (other then Mike Gs warning system) is anybody trying to put forth an agreed upon standardized methodolgy to prevent future accidents.
Between PhillB, Waspair, Vance and Jim M and a few I forget right now, I don't see a specific recommendation moving forward.
If its training? CHANGE THE INSTRUCTION!
if its design issues? CHANGE THE DESIGN SPECS!
mike and I both are big proponents of fully castori g nose wheels and differential brakes...
And here is a perfect example in the Irish accident, a hard kinked nosewheel MAY have contributed.....
When Ford had a bunch of Pintos blow up, THEY CHANGED THE DESIGN TO A KNOWN SAFER DESIGN.
You can talk all you want about learning the machine, but you cannot argue there is a serious design setback to fully castoring with diff brakes. But you sure can argue theres a serious drawback to hardlinked.....
Soo......no more recommendations for any machine ever that doesn't have free castoring nose wheels and petition manufacturers and insurance companies to agree.....
As for the training or interpretation of for language speakers writing POH's I will let someone else take the reigns on that as I am not a gyro instructor.
However....in EOD if there is an improper practice that is getting guys killed, a saftey stand down is initiated and EVERYONE is alerted to the new methodology.
Not just posted on a forum and buried in pages of arguments.

If I had to pick one persons methodlogy that to me represents the safest way forward it would be probably be Jim Mayfields only because Jim V doesnt participate here. But I suspect they would agree.

Again if we had circular aerodromes and not runways that would help immensely!

 

[MikeBoyette]

Flew my Genesis today and did some takeoffs at WOT. Climb rate about 1200fpm. No noticeable torque roll or need for any control corrections.

I'm going to stick to my earlier procedure for pattern work around airport.

Well here we go with a comment that will fire the peanut gallery up. Nickolas has built your machine correctly with a full span HS to counteract torque and P factor. This shows the difference between a designer whom builds the machine for ease and safety of his customers and one that builds one for looks. The one built for looks has to come up with new ways to fly it to overcome the deficiencies that pretty causes over practicality. In my opinion designs

 

[MikeBoyette]

I love the free form discussions that this medium creates.
But....
I have noticed over the last 4 or 5 accident threads that the very experienced pilots/instructors contue to migrate towards low time pilots flying high horsepower enclosed 2 place machines.
Most of the accidents are on takeoff not landing so not sure the HV curve chart is super relavant.
What I don't see (other then Mike Gs warning system) is anybody trying to put forth an agreed upon standardized methodolgy to prevent future accidents.
Between PhillB, Waspair, Vance and Jim M and a few I forget right now, I don't see a specific recommendation moving forward.
If its training? CHANGE THE INSTRUCTION!
if its design issues? CHANGE THE DESIGN SPECS!
mike and I both are big proponents of fully castori g nose wheels and differential brakes...
And here is a perfect example in the Irish accident, a hard kinked nosewheel MAY have contributed.....
When Ford had a bunch of Pintos blow up, THEY CHANGED THE DESIGN TO A KNOWN SAFER DESIGN.
You can talk all you want about learning the machine, but you cannot argue there is a serious design setback to fully castoring with diff brakes. But you sure can argue theres a serious drawback to hardlinked.....
Soo......no more recommendations for any machine ever that doesn't have free castoring nose wheels and petition manufacturers and insurance companies to agree.....
As for the training or interpretation of for language speakers writing POH's I will let someone else take the reigns on that as I am not a gyro instructor.
However....in EOD if there is an improper practice that is getting guys killed, a saftey stand down is initiated and EVERYONE is alerted to the new methodology.
Not just posted on a forum and buried in pages of arguments.

If I had to pick one persons methodlogy that to me represents the safest way forward it would be probably be Jim Mayfields only because Jim V doesnt participate here. But I suspect they would agree.

Again if we had circular aerodromes and not runways that would help immensely!

The very last thing I am going to say about this is this. I know I said this before. The problem with hard coupled nose wheels and rudders that are barely big enough is not a new problem.

Blaming the pilot and yelling it’s a lack of training is nothing new either. I remember it coming up in the 80’s over and over. A certain red highly marketed and sold gyro that was popular but quickly was to found to have several design flaws. These design flaws were pointed out to the manufacturer and like many before and after him he said nothing was wrong and blamed the customer with the caveat of lack of training. They too had a hard coupled nose wheel which was exasperated by the wheel being in front of the pivot instead of behind. I know of quite a few that flipped because they made a simple mistake that cost them their whole machine. The fix was easy enough to do. Chuck Beaty made a mechanism that had springs on the linkage between the nose wheel and rudder pedals. This allowed for the nose wheel to be soft coupled. This was just enough give so that the nose wheel had a chance to straighten even if rudder was cocked. The fix was offered to the manufacturer for free and declined because there was nothing wrong with his design. Same line I hear on this forum from multiple folks. You shouldn’t set the nose down until you are completely stopped. If you don’t you deserve to wreck your machine. This is what I hear every time that is said. Instead of having a machine that is capable of wrecking itself for a simple mistake compromise and make the machine more forgiving of brain farts. It doesn’t take a major design change. Just some minor work on that linkage. Some inexpensive hardware and the willingness for a manufacture to admit there might be a better way that they didn’t think of. It comes down to ego in my opinion. Many designers and Manufacturers think their way is the best and refuse to consider any other way period. So the cost of this stubbornness is a customers machine being destroyed for a minor change and giant ego.

Done I will sit back and read as the accidents keep piling up and folks keep making excuses for flawed designs along with flawed teaching methods. Maybe eventually people will stop buying these unforgiving machines and go back to a gyro that is like a gyro not a 150/172 with blades.

 

[rcflier]

What is the approach speed for your MTO?

How do you know that with your aftermarket rotor blades?

Did you do any flight testing?

What you have there are the basics for an MTO in a standard configuration.

I feel it is important to read the pilot's operating handbook for your gyroplane year make and model.

Gyroplanes are not all the same.

If landing a gyroplane was that simple there would be no need for flight instructors and pilots would not be rolling them up.

There would be no value in transition training.

I have found even two gyroplanes of the same make and model may have substantial differences in the way they fly and should be approached with caution.

Vance, I use the approach speed from my POH, as the rotor isn't much different. And because my instructor said so.

My Carbon rotor is of same blade profile and diameter (8.4 meter) as the original.
It has a chord a few mm wider and is 8 kg heavier. Why I chose it over the Type2 is for (and in) another thread.

My instructor with his experience and general good "gyro feel" acted as test pilot.

He reported it flies the same as the Type2, but has more energy in the flare because of the higher inertia.

Implying I haven't read my POH would be beneath you - as I have even quoted the POH in my post. So I suppose it's just a general statement.

And at first you write, the POH is not for my MTO, as I have changed the rotor. Afterwards you state, I should read the POH
of my gyro's year, make and model. Maybe a general statement also?

It seems to me, that pilots "roll them up" because they deviate from good practice. And of course instruction is a must.

Writing and saying it is very far from doing it. You need the muscle memory and experience - you can't learn it just by theory.

So I take it, you mean I wrote it too shortly.

The MTO is very, very close to being a copy of the ELA - we all know that. In a German interview Otmar Birkner said so.

Of course they may not feel the same way, but the approach speed should not vary much with same rotor size and weight.

We had a new pilot in Denmark, who rolled his Calidus when landing in crosswind - he hadn't trained it enough - overconfidence.

Transition training is a good thing for safety, especially for low time pilots. And it is required in Denmark.

But we better get back to the Cavalon front fork....

I still think highly of you, Vance.

Cheers
Erik

 

[PJB]

On the HV point the blue line in the diagram becomes the speed that is Vy. Of course you can achieve that same speed at per throttle but you will be lower for longer and therefore the consequence of any speed decay at a lower height is greater where now we are not concerned about the take off but the forced landing.

To Bens point on the solution is in part linked to the point Jim makes around design. Gyroplanes globally have over regulation where it isn’t needed and seemingly no over sight where it is.

As example in the UK if I want to fly a perhaps better designed Aviomania I can’t, despite it flying well and safely around the world so now I’m stuck with AutoGyro and Magni. That might be OK but I suspect UK technical regulation is an echo chamber of AutoGyro.

Then in the US you can all read the same NTSB words I can around very recent accidents of Chris Lord, the AR1 in Utah and 419LB, whilst 477AG was subject to more than 1 NTSB report inside a few years.

Perhaps there is nothing to see and perhaps authority is all over things and no doubt the NTSB and FAA have more information than I do about these accidents but it seems odd to this reader that of just those 4 fatal accidents, 3 in Cavalon alone - and for context the UK has had 2 fatals total since 2017 and one of those was medical related - you have a worrying combination of very low time, a total resistance to even accept training that was offered and/or some obvious struggle with the skill set required.

 

[MikeBoyette]

To you point about NTSB reports. Unless things have changed recently they have absolutely no clue about gyros. My Dad’s best friend when I was young got killed from doing a PPO in a continental powered Bensen. The official NTSB final report that he lost his tail rotor. This was in the early 70’s. In the 90’s my Dad, Tom Milton, Gary Goldsbury, and other knowledgeable gyro people were part of a group tasked with investigations of gyro accidents nationwide. This helped the NTSB report and release more accurate accident causes. I’m not sure they have anyone who has experience with gyros at all.

 

[Vance]

Vance, I use the approach speed from my POH, as the rotor isn't much different. And because my instructor said so.

My Carbon rotor is of same blade profile and diameter (8.4 meter) as the original.
It has a chord a few mm wider and is 8 kg heavier. Why I chose it over the Type2 is for (and in) another thread.

My instructor with his experience and general good "gyro feel" acted as test pilot.

He reported it flies the same as the Type2, but has more energy in the flare because of the higher inertia.

Implying I haven't read my POH would be beneath you - as I have even quoted the POH in my post. So I suppose it's just a general statement.

And at first you write, the POH is not for my MTO, as I have changed the rotor. Afterwards you state, I should read the POH
of my gyro's year, make and model. Maybe a general statement also?

It seems to me, that pilots "roll them up" because they deviate from good practice. And of course instruction is a must.

Writing and saying it is very far from doing it. You need the muscle memory and experience - you can't learn it just by theory.

So I take it, you mean I wrote it too shortly.

The MTO is very, very close to being a copy of the ELA - we all know that. In a German interview Otmar Birkner said so.

Of course they may not feel the same way, but the approach speed should not vary much with same rotor size and weight.

We had a new pilot in Denmark, who rolled his Calidus when landing in crosswind - he hadn't trained it enough - overconfidence.

Transition training is a good thing for safety, especially for low time pilots. And it is required in Denmark.

But we better get back to the Cavalon front fork....

I still think highly of you, Vance.

Cheers
Erik

Your are reading things into my post that I never intended Erik.

I feel you have worked hard to become a gyroplane pilot and I have no way of knowing how well you read the POH.

It reads to me that your flight instructor is working with you to make you a better pilot.

I have great respect for you Erik as a pilot and as a human being.

I like your style.

In my opinion when you recommended that people use the numbers in your POH for all “eurotubs” that is bad advice.

My intent is to point out to everyone reading this thread that studying the POH for their particular gyroplane is important because gyroplanes do not all fly the same.

It appears to me to be the mind set of many on this forum that going to social media is a substitute for studying the POH for their particular make and model gyroplane.

For example the pre-rotation and takeoff procedure for a Magni is not even close to the pre-rotation and takeoff procedure for your aircraft.

I prefer the Magni method but it would not work with an Auto Gyro product.

I have flown a wide variety of gyroplanes and yet each time I instruct in a clients aircraft I spend a lot of time with the POH for that aircraft learning about what is important for that aircraft.

Part of the ground portion of a flight review with me is questions about the POH because I feel it is important.

If someone has different rotor blades on their aircraft I spend time finding Vh and Vy because it may have changed and I spend time finding out at what rotor rpm the blades become stable.

In the USA part of flying an Experimental Amateur Built Aircraft is phase one testing where the numbers in the POH are confirmed.

Many people think of this as a fly off and do very little actual testing.

I had a new phase one for The Predator when I changed the engine and rotor blades.

I wrote the POH for The Predator because I have changed things that affect how she flies compared to when Mark Givans did his phase one testing on The Predator.

I have since learned a lot about how she flies and have changed the POH that I wrote.

The emergency procedures, limitations and minimum equipment required are very important parts of the POH that many gloss over.

For example many pilots don’t realize how marginal the charging system on a Rotax 912 or 914 is and there have been accidents where part of the accident chain is the charging system limitations.

Some people have not learned that a 914 is battery dependent because they did not carefully read the POH for their aircraft or glossed over the differences between a 912 compared to a 914.

In my opinion it is a careless flight instructor who does not require a learner to study the POH and test on the learners knowledge of the POH before beginning the training.

Even if there is only one detail that is different in the POH there may be a safety issue attached.

So my point was and is; advising someone to use the information out of a different POH or from the Rotary Wing Forum is bad advice and poor flight instruction.

 

[rcflier]

In my opinion when you recommended that people use the numbers in your POH for all “eurotubs” that is bad advice.

For example the pre-rotation and takeoff procedure for a Magni is not even close to the pre-rotation and takeoff procedure for your aircraft.

I prefer the Magni method but it would not work with an Auto Gyro product.

So my point was and is; advising someone to use the information out of a different POH or from the Rotary Wing Forum is bad advice and poor flight instruction.

Thank you, Vance.

My comment was on landing a gyro as such, but I get your point on "internet pilots"...

I would also have liked a prerotator drive like the Magni and others.

Fewer parts to break and it's a neat solution to balance the thrust of propeller and rotor from 130 RRPM...

My heavier rotor is placing a higher load on the MTO prerotator drive.

And I just recently discovered there is a limiter valve on the actuator cylinder.

So I'll see, if I can lighten the burden on my prerotator drive next time I'm with my gyro.

 

[Abid]

Flew my Genesis today and did some takeoffs at WOT. Climb rate about 1200fpm. No noticeable torque roll or need for any control corrections.

I'm going to stick to my earlier procedure for pattern work around airport.

With 912ULS with an effective tail you should not really notice much of a correction. 914 is where you start to notice it a bit.

 

[MikeBoyette]

With 912ULS with an effective tail you should not really notice much of a correction. 914 is where you start to notice it a bit.

With a full span tail either in vertical or horizontal plain mounted close to the prop even with a 914 there is very little felt as well.