The value of carefully inspecting aircraft before flight.

[Vance]

Sometimes people want me to teach them to fly in a gyroplane they already own.

I have a firm policy that it needs to have a current annual condition inspection done by an A&P mechanic that I know.

I have seen too many sloppy annual condition inspections to assume a stranger has done a good job.

I am not a professional mechanic and do not want to rely on my mechanical skills for our safety.

The client had trailered his gyroplane from out of state and the first thing we found was a problem with the steering stem. We felt it was bent beyond our ability to make a field repair. We found another part and she is now back on her wheels. I suspect if we had flown her things would not have gone well. I like to think I would have noticed during ground operations but I am not certain.

As we were assembling the rotor blades and hub bar the A&P mechanic noticed the rotor blade retention bolts had marks on them he could catch his fingernail on indicating that the blades had been moving in flight. They only had about 15 hours of flight time.

As I torqued them down to 44 foot pounds they just didn’t feel right to me.

On further inspection I found the bolts were just a little too long or the washers too thin and the nuts bottomed out on the base of the threads reducing the clamping force. I used three thinner hardened washers to get the correct length. The difference in how they feel when they are torqued down is significant. It is not unusual to find this with aircraft hardware because they are trying to keep the threads out of the hole. There are actually several different thickness of AN washers available for this very reason.

I ordered a castle nut for the teeter bolt because I did not feel comfortable with the elastic stop nut in that application per FAA AC 43.13-2B.

The A&P also found a stainless braded line trying to saw through a radiator hose. The hose was new.

The last bit of potential trouble was an on-off valve on the fuel tank breather that was sort of hidden behind the seatbelts. I don’t know what would have happened if I had left it closed. I suspect we would have run out of gas. It was mentioned in passing in a call to the previous owner over something unrelated. It was not on the preflight check list.

I take preflight and conditions inspections very seriously and this is not the first time it has mitigated a potential hazard.

This aircraft had some of the best log books I have seen. The person who owned this gyroplane previously is a first rate mechanic and had flown her recently; yet these problems were present when the aircraft reached Santa Maria, California.

I am working with the client on a more comprehensive pre and post flight check list. He is a high time Vietnam era helicopter pilot with over ten thousand hours in Rotorcraft and he believes in the rigorous use of check lists. I am proud to work with him.

Please, this is about condition inspections and pre-flight inspections and what we found. It is not about a particular brand of anything. If you have a negative opinion about a particular brand pleas keep it to yourself as it diminishes the focus of the post. I fly all gyroplanes and love them all. I have yet to have a condition inspection done on any brand of gyroplane that didn’t find something amiss.

 

[ventana7]

Vance i think one of the challenges is that most A&Ps are used to working on certificated aircraft they are familiar with;, Cessna, Beech, etc that come with very detailed inspection protocol. Many are not familiar with Rotax, rotors, pre-rotators, experimental aircraft, etc. I know my A&P has increased his expertise over the 10 years he has been doing my Xenon and also his knowledge of Rotax engines has increased as more and more of them come to reside at our airport.

I think you are wise to have an A&P you know look at client owned aircraft before you put your life on the line.

Rob

 

[Kolibri]

extremely bent nosewheel spindle (seems the older/inferior OEM RAF part, and never upgraded to their newer part)
nyloc nut on the teeter bolt
incorrect hardware for blade retention
braided SS line touching lower radiator hose​

This aircraft had some of the best log books I have seen. The person who owned this gyroplane previously is a first rate mechanic and had flown her recently;

I fly all gyroplanes and love them all. I have yet to have a condition inspection done on any brand of gyroplane that didn’t find something amiss.

Yeah, but those were some very alarming (and basic) errors, especially from a "first rate mechanic".

Glad you've pointed out the wisdom of having a known A&P in the loop.
Good post, thanks,

Kolibri

 

[Vance]

No Title

As a follow up to my pre-flights are important thread I was doing a preflight on a very nice gyroplane and found this oil line that had been abraded by a cable tie.

The damage is hard to see because it was covered up by the cable tie.

I grounded the aircraft despite having a compelling reason to fly.

 

[JEFF TIPTON]

That so good catch. I find Tyraps also securing items to engine mounts and found these to damage the mount to the point of repair. Always good to use something like the Adle clamps instead. MS21919 series.

 

[Vance]

Good advice Jeff! Thank you.

I was just talking to a friend on the phone about this and I realized why I checked that particular wire tie. I thought the philosophy behind it might be helpful.

When I am doing a pre-flight inspection there are certain things I examine more closely.

An example of priority items are the oil lines, fuel lines and coolant lines. I follow the lines the best I can looking for kinks or abrasions. Check the oil lines was on the preflight check list and yet somehow the damage had been missed.

I could not see the damage but I felt the damage. Once the wire tie was removed the damage was easy to see. I like to touch and move things during preflight inspection.

When I am teaching someone to do preflight inspections I remind them that the item on the list directs them to look around in that particular location. There was nothing that said to check the wire tie on the oil line.

There is more to a good preflight than just checking things off of a list.

 

[anthom]

Vance,
The methodical way you conduct the preflight check is commendable. There is a lot one can learn by spending some quality time with you.

 

[DavePA11]

I found a broken bracket that is used to attach the vertical stablizer on my Vortex M912 by physically checking it. Visually could not see it, but could tell it was loose when touching it. I think it broke in flight since there was new vibration that I couldn’t figure out. I thought it was the rotor, but found this on preflight.

 

[Vance]

Thank you Dave; that is just the sort of procedure I am trying to promote.

It is easy to see the pre-flight inspection as a delay in getting to the fun of flying.

Sometimes people get complacent because they seldom find anything wrong.

For me a pre-flight check list is a living document that helps me to not miss things. I update mine at least once a year.

I learn from my clients about what sort of things are easy to miss and how to get them to take it seriously.

I always do the pre-flight inspection before the client arrives at the hangar because I can't do a good job and teach it at the same time.

The problem that can create is the client usually doesn't find anything so they can get complacent. If I find something I sometimes leave it and make a note of it so they have a chance to find it or an example of how easy it is to miss something.

If a client brings their own aircraft we often expand the check list as the training progresses.

Sometimes I feel the check list is not satisfactory for an aircraft I am about to fly and I use the one I have written for The Predator to make certain we have touched on the important points.

Writing in the most general terms the quality of the aircraft I see at Bensen days is improving. I am pleased to see that.