Survived Engine Out this morning.

[Magnifan]

I was about 300m behind and to the right of Len when I saw the nose go down and the gyro commence a 180 degree turn. After a moment or two I was sure that he had an engine out, when Learjet, who was left abeam me came on the radio and took control of the situation very professionally indeed. He follwed a drill that we have agreed to when flying as a group and followed len down whilst instructing the other five gyros in the gaggle to turn back to the nearest field, whilst keeping well clear of Len's gyro. I could clearly see Len descending towards the road and strangely I never once felt the slightest doubt that he would land safely.

Well done Len!

[Gyronaut]

Was the road the only option or first option that became more prominent ? Were you at any stage worried about cars coming from behind that you might loose sight of when consentrating on the landing spot ?

No, actually, the first option was a small half empty dam to the right of the main road, (the only one for miles and its clearly visible on the video I think) and that was my first 'Find the Field' choice. The second was what looked like an open field next to the road but I know that poles in vineyards will kill you and would not be visible from where I was.

As I approached the flat area behind the dam I looked behind me on the road and saw no immediate traffic. Of course I could see well ahead around the bend and saw only one car (way ahead) which I knew wouldn't be a problem on the wider section of road since it gets to 3 lanes there. (My rotor is 2 lanes wide [10m] if I land on the centre line). I kept the dam open as an option until the last moment. I could be faulted perhaps for not 'flying the plan' and opting for the road rather than the dam but I full well knew that we would be safe in the dry dam in any event - getting the machine out would be a bitch though. Strangely, I never thought of us crashing and burning... it was honestly a choice between plonking it in the dry dam to the right and the hassles afterwards or putting it on the road safely with less hassle to contend with.

Once I opted for the road, in retrospect it might sound blase~ but, during the event, I was more worried about getting hit by a truck from behind after landing than putting it down safely on the road.

Dave [Learjet], Jonathan [Magnifan] - I say again, hearing you guys on the radio KNOWING what was happening to us and KNOWING that I had you covering me was unbelievably comforting. If we did hit unseen wires perhaps and crashed and burned, I KNOW you guys would have been there to pull us from the wreckage. I don't know how to express the amazing feeling of camaraderie I felt at that moment (and always when we fly together). All I can say is Thank You!

I suppose that is why we choose to be each other's wingmen. I salute you guys. I respect you. True Airmen.

[Gyronaut]

There is a well-known aviation analogy that once enough holes in the Swiss Cheese line up an accident/incident will happen.

I am going to describe the sequence of events, as best I can, leading up to this incident now that the diagnosis is known.

On doing a thorough check over the machine and performing a quick test flight a few days before the Carnarvon weekend, I noticed the "TCU SENSOR" light on my gyro come on and go off intermittently during flight. It is a yellow caution light. On discussion with my AP we agreed that the worst this could signify was a malfunction of the Turbo Control Unit and that I may experience no more than 5 400 rpm if I was to engage the turbo. Since I very seldom use the turbo anyway, it was something that could be seen to afterwards and I filed the potential absence of turbo power in the back of my mind. It did seem a bit strange that I still had turbo power though (which I of course checked at the first opportunity when the light came on again).

On start-up at Morningstar on the day of the incident, the TCU Sensor light stayed firmly on and remained on. After about an hour's flight to Worcester and adding some fuel, the engine started perfectly and the yellow TCU Sensor light again remained on.

Upon close inspection of the machine after the incident, the AP found that the connector plug to the Voltage Regulator/Rectifier had some corrosion and was intermittently not connecting properly thus preventing the battery from charging. He also discovered that the yellow TCU Sensor light, labelled as such on the dashboard, was in fact NOT wired as the TCU sensor light but was actually the CHARGE light. In a magni it has a battery image on it and is a red light. In MT's I have flown it is a red light marked "Low Voltage".

The holes in the swiss cheese had been waiting, patiently, since the machine left the factory, 5 years ago, to line-up.

In reality therefore, I had flown in excess of 2 hours on the battery only without knowing it.

I feel responsible for not paying close attention to the volt meter and have no excuses for not doing so since this would have given me more than adequate warning - I have no idea why I didn't notice the voltage steadily dropping. Pilot error I must confess.

So, in essence, my summary of the incident is: A) Wiring/labelling fault, combined with a B) 'dry joint' connection fault, combined with C) pilot error that resulted in the engine-out. Three strikes - You're Out!

The lesson I have learned is NEVER to fly with ANY light on, or any abnormal indication, no matter how harmless it may seem. It is an indication of something wrong that may have much more serious consequences than one imagines.

As for the discussion about mechanical pumps and duration of adequate power from the battery in this event, I am comfortable that the battery is more than adequate to take one to a safe landing if the warnings are heeded. Check your charge lights, volt-meters and even if charge fails during flight, you should have plenty of time and charge left to make a safe landing.

I say thank you from the bottom of my heart to all of you who complimented me, for those that looked out for me and I will take criticism on the chin since I deserve it. Thankfully the only thing that has suffered from this event is my ego which is also a good thing. The upside is that perhaps someone, somewhere has learned something from my experience and weakness which may result in a life saved somewhere along the line.

Happily my machine is fixed, improved and better than it has ever been after this thorough inspection and correction.

My thanks to Patrick Owen, the proud new owner of Flynote's beautiful M22, for assisting me with recovering and towing my machine back from De Doorns and giving up his whole day to help me. I owe you mate.

Finally, my sincere thanks to Louis van Wyk, Aerosport, the AP mentioned. A man with such vast experience and high technical and safety standards, it humbles me.

Fly safe comrades

Len

[FO Gyro]

Thanks Len for sharing that with us.

It's amazing how often there is more to an incident or accident than a single cause. Your story is a classic case of the holes lining up that results in an incident, the cause thereof not necessarily being the pilot's. I hate the term "pilot error". It's always easy to blame the pilot, especially if he's dead, as all accountability goes to the grave with him. Although the press love to talk about "pilot error", modern accident investigation prefers to discuss the factors leading up to the incident or accident. It tries to find out why the crew or pilot made certain decisions at that time, and what led him/her to that decision. Mindset is often the danger, for example, Len knew the amber TCU light was on, and the possibility that that light be connected to a low reading on the voltmeter was not contemplated, because they were seemingly unrelated, or so it seemed. At the end of the day, unless a pilot is being negligent, he/she normally makes what he/she regards as the best decision at that point in time, with the information having been presented to them.

At least for those reading this, there will be some good that comes out of it, namely more emphasis on monitoring of the low voltage light and/or voltmeter. Becuase this is such a critical part of the 914, i would think a recommendation would be to have voltmeters fitted to those aircraft that don't have, as a cross check of the low voltage light incase it fails. I know I want one asap. Anyone know where I can get a flat mounted LCD type? I don't have the space behind my panel for the MGL type.

[Magnifan]

Hi Len, The TCU controls the wastegate on your turbo at all times when the motor is running to ensure that the airbox pressure is within a suitable operating range for the carbs. A TCU failure can have much more serious consequences than a lack of "full turbo" performance. In fact, when you engage the turbo by fully opening the throttle you simply instruct the TCU to close the wastegate and keep it closed, during this period the TCU is not doing anything.

I mention this because, in my opinion, any sign that the TCU is not functioning correctly should ground the aircraft and if the TCU light comes on in flight one should land ASAP. I always watch the wastegate cycle open and closed again when I turn on the master switch as part of my pre-flight inspection.

[Gyronaut]

Good point Jonathan

The lesson I have learned is NEVER to fly with ANY light on, or any abnormal indication, no matter how harmless it may seem.

Now, moving on to the TCU...
I also check that it cycles all the way through when I put the master on. Which, of course, it was doing.

My question though, as a self confessed non-technical person, is this. If the waste-gate is open during normal operation and only closes when instructed to do so by the TCU for turbo boost and the engine continues to function normally then are you saying the risk is that it may fail to a closed position causing over boost? Surely this will deliver too much power and can be picked up both on the engine RPM and/or MAP gauges? (nevermind the kick in the pants you will feel under your ass?) Will merely throttling back reduce the RPM/MAP?

I am assuming of course that it (the waste-gate) is open under 5 400 RPM or 35MAP. I dunno...

I have been advised that it is better to go to full boost (5 800rpm, 39.9MAP max) rather than partial boost when operating the turbo or the TCU will hunt constantly for the ideal pressure setting you have selected. Correct?

Perhaps I should go read up some more, unless you want to enlighten us ill-informed non-techies more fully?
I'd sure appreciate a comprehensive description of its function exactly and what can go wrong for future reference.

Rgds

Len

[Spatzi69]

Every accident is the result of a series of events that went wrong! There are always a number of factors that contribute to a disaster!

Just be safe out there guys and don't take any chances! Its not worth it!

[Magnifan]

Hi Len, the TCU is constantly adjusting the amount that wastegate is open whilst the engine is running, so when the power requirement is low it opens it a lot and as the power demanded goes up it closes it down, but at all times it will be slightly open, just varying from fully open to almost fully closed as determined by the computer in the TCU. When you go to 115% power setting (throttle past the stop) the TCU closes the wastegate completely and boosts the engine to 115%. The engine can only safely maintain this power output for five minutes. There seems to be a throttle and wastegate combination between 100% and 115% where the TCU can't control the wastegate properly and Rotax advise the installer to provide a stop at 100% power and another at 115% and the engine should not be operated between these two throttle positions.

[Magnifan]

I had another look at your post and I am not sure how the engine would behave if the TCU stopped working. It would depend if the wastegate stayed at the last position called for by the TCU, and what that position was, or if it failed to fully closed or fully open. In the latter case you would definitely have a serious lack of power even with the throttle wide open. If it failed fully closed it may be very difficult to control the engine with it over revving with the throttle slightly open and cutting out with it slightly closed.

Perhaps someone has some experience?

[FO Gyro]

On a previous gyro, I had a situation where I was in the climb with 35" and 5500 RPM, all of a sudden the MP shot up to 49", and the engine screamed to 6300 RPM

Upon investigation on the ground, I found one of the plugs to one of the sensors were a bit corroded. After cleaning it out, it behaved itself again. Through the bad connection, the TCU has commanded the wastegate to close completely, overboosting the engine.

After checking out the manual, and phoning the agents, they said there wouldn't have been any damage if it was only for short duration. Caught my attention though. If it was a constant speed prop, I would have thought it was a runaway prop.

[Magnifan]

Hi Glen, how did you manage to control the engine? Did it behave OK at a lower throttle setting or did it sort itself out and start running properly again?

[Gyronaut]

Hi Glen, how did you manage to control the engine? Did it behave OK at a lower throttle setting or did it sort itself out and start running properly again?

Snap, thats what I'd also like to know please!

[FO Gyro]

I immediately closed the throttle completely and then everything returned to normal. I quickly landed back at the airfield expecting to see a damaged engine behind me, but everything was ok. There must have been a bad connection for a second which made the TCU all confused resulting in the wastegate going crazy.

What I learnt from this is to unplug some of those connectors now and then and check for any corrosion.

[Gyronaut]

What I learnt from this is to unplug some of those connectors now and then and check for any corrosion.

Thats going to be standard routine every few months for me from now on. Especially at the coast. It seems those plug-connectors just sometimes decide enough is enough if they arent kept clean and Q20'd.

[John Boucher]

Len.... I hear what you are saying re. being a better pilot but I do think you are being really tough on yourself here! All accidents have a sequence culminating in a catastrophic event! This sequence ended with prior to that happening - job well done!

Firstly, you performed a perfect forced landing without any damage to your aircraft (my goodness we can really call it a precauitonary in this case if the engine didn't choke!)

Secondly, you demonstrated good airmanship (as George said... wow keeping left on the N1) This goes to show that your you were situation aware! An excellent example to bare in mind for anyone, especially your students.

Now the technical bit.... this problem should have been picked up earlier and if you never had this occurence probably never would have been. This now has the path that other owners (all types alike, especially Sycamores in same configuration) will go out and check their aircraft and make sure that they don't fall into the same trap!

This is a lesson for all with an excellent outcome and possibly saving a few lives in the process!