Long Trip ended with a bit of excitement

[Tennisdogs]

I did a dog run today that ran from...

Marshall TX (ASL) to
Downtown S'port (DTN) to
Tallahasee Fl ( TLH ) to
Bainbridge, Ga (BGE),
to Marianna FL (MAI) to
Chatom, AL (5R1) to Laurel,
Ms (LUL) then home to ASL.

I don't mention this because it was special neccesarilly (many, many members here do and have done trips like this on a regular basis) but to highlight what a privlidge it is to be able to do this. Granted, I made the stops in GA, AL, and MS for the sole purpose of getting the states added to my map but still, it was a blast to be able to do it.

Now, imagine after 13 hours, most of it in the air, coming in on a left down-wind to runway 15 and you lower your gear and boom, boom, but no third boom! My nose gear would lock in! I did all the usual remedies, cycle the gear, try the emergency drop, bring the gear back up, try it again, Slow down to 65 kts, drop the gear with nose down... Couldn't get that little light to light up.

I made several low passes over the airport to get someones attention to see if the gear was actually down then made the softest landing I have ever made. (anybody that says you cannot hear the gear "fault bell" with noice canceling headphones may need a hearing aid... There's no mistaking that sound) That front wheel didn't hit the deck until I was at the end of the runway... and thank goodness it did not collapse.

Never a problem in the short time since I've had the plane, Did not have any indication of a problem throughout the day and there were a lot of landings.

I've got her parked so the Mechanic can look at it tomorrow but I'd love to have some suggestions to offer him if there are any to be had.

 

[rcastillo]

Re: Long Trip ended with a bit of excitement

Did you check the light to make sure it wasn´t just a faulty bulb? If the bulb is ok, check the micro switch to see if there is a broken cable right there. These are the easiest and most obvious troubleshooting items, if these 2 things are ok you may need to ask your mechanic to help you.

Good luck troubleshooting.

 

[skirunner4]

Re: Long Trip ended with a bit of excitement

Bryne
I had the same thing happen to me last August, I had owned my plane about 6 months & was working through a series of minor repairs - 2 days before going for my private, wheels down - 2 in the green!!! - do you know how to say pucker, I too did several fly-bys & finally got 3 green - turned out to be micro switch, the final one which we had not replaced, I also replaced springs which seems to have made a noticeable difference in thud factor

 

[bhogue]

Re: Long Trip ended with a bit of excitement

Same thing and the micro switch was the answer.

 

[Airotto370]

Re: Long Trip ended with a bit of excitement

I keep a copy of the emergency gear dump procedure on my knee board just in case the wheels all don't go down. Figured a high stress situation like you described wasn't a good time to test my memory on a rarely used procedure.

Only had to use it once so far, but it was nice to see it in print!

 

[michaelh]

Re: Long Trip ended with a bit of excitement

Main Gear Strut Assembly.

Just a heads-up. I found the pin/rod, FIG 2-15, #17 on the left main gear protruding slightly out of the yoke yesterday. Luckily, I was with my mechanic and he jacked up the aircraft and found that the screw, FIG 2-15, #18 had sheered.

Actually, he wasn’t too surprised as he had already seen this while working on Shane’s aircraft earlier this year. Quick and easy repair. Perhaps something to consider for some PM during annual.

 

[VGIAMPA]

Re: Long Trip ended with a bit of excitement

Good catch, Mike. I'll be checking mine very closely, and often.

 

[ksandrew]

Re: Long Trip ended with a bit of excitement

Folks,

I do not mean to brag, but the first flight of every month I have a check list that I go through, VOR check, tire pressure, ELT check, fluid in gear pump, and lots of other things.
I am so familiar with the "thud, thud, thud" that it is a none issue for me. Each month I perfect the rudder waggle and slow speed. I have almost got to the point where I remember to close the Em.Valve before I raise the gear again.
The better we understand our planes , the better pilots we are.

Life is a barrel of fun.

Ken Andrew

 

[wab003]

Re: Long Trip ended with a bit of excitement

Ken, with all that filling and testing you may be building up a nice pile of 5606 goo in your belly. If the reservoir is full to the brim and you perform a gear dump, the rapid repatriation of the gear fluid tends to push a stream out of the reservoir vent hole. Not a big deal for an occasional annual style gear dump but if you are doing them frequently w/ a full reservoir, you may want to either keep a rag under the pump to catch the excess or pull your port side step every couple of years and clean out the residue. (aft bulkhead scuppers will let it drain into that area)

 

[Airotto370]

Re: Long Trip ended with a bit of excitement

...you may want to either keep a rag under the pump to catch the excess or pull your port side step every couple of years and clean out the residue. (aft bulkhead scuppers will let it drain into that area)

Remembering Valdez...

 

[wab003]

Re: Long Trip ended with a bit of excitement

Now, there was a classic dump...


...pretty place though.

 

[ksandrew]

Re: Long Trip ended with a bit of excitement

Bill,

Explain this a little more. I only check the pump fluid with a drinking straw and never have to add. Never had any 5606 come out. I was a little concerned about the monthly thuds causing long term damage, but consulting with experts there would be no long term damage.
Life is a barrel of fun.

Ken Andrew.

 

[K Walker]

Re: Long Trip ended with a bit of excitement

I am looking at the possibility of purchasing a Commander and the research I am doing has me wondering if gear failures are one of the features of this aircraft. Many of the Commanders listed on the market right now seem to have a "gear up landing" in their history. Is this any more of a concern than other retractable aircraft? It is one of those things that is causing me some pause in what seems a terrific aircraft for my purposes.
I would appreciate hearing any straight talk that any of you folks might offer on this subject.
Thanks

 

[alim]

Re: Long Trip ended with a bit of excitement

I am not sure if the Commander is special there in any way for more gear ups than other retracts. The warning bell blares at you if you put > 20 degrees of flaps with the gear up even at max power.

Even with the warning bell inop, a retract is a retract. Flown with procedures, i see no reason to gear up in one. There is no secret gotcha in the Commander that isn't applicable to any other retract (have flown Arrows, Senecas, Saratogas and some heavier iron).

Did you see "gear-ups" or did you see "nosegear collapse" ?

The original commander design did have a hollow nosegear pin which is susceptible to failure due to a hard landing. It was subsequently redesigned with a solid pin which can be retrofit to all models. Most commanders flying today have already gotten that retrofit done after watching some unlucky owners go through nose-gear collapse. You will hence see a fair number of "nosegear collapse" in the damage history of early commanders.

 

[Lawrence Rippon]

Re: Long Trip ended with a bit of excitement

I am looking at the possibility of purchasing a Commander and the research I am doing has me wondering if gear failures are one of the features of this aircraft. Many of the Commanders listed on the market right now seem to have a "gear up landing" in their history. Is this any more of a concern than other retractable aircraft? It is one of those things that is causing me some pause in what seems a terrific aircraft for my purposes.
I would appreciate hearing any straight talk that any of you folks might offer on this subject.
Thanks

Kevin

Most gear up accidents are caused by pilot error not aircraft failure, although there has been a couple of failures, it is no more common than in other types, the difference here is that there have been surprisingly few accidents from other failures so the gear related ones stand out.

Although tougher than most retractables, the gear on a Commander doesn't like running off the side of a runway very much.

You are more likely to have a false warning on an unlock due to an old microswitch being the cause, I guess they weren’t supposed to last forever and after 30+ years they can stick. They cost very little to change and are easily available.

This group discusses engineering issues in fine detail, there are few like it and we all share our mechanical issues for the common good. You may get the impression from reading through our pages that there seems to be a lot going wrong with Commanders which you don't hear about with other aircraft. That's true, you don't HEAR about the other types. Commanders have a lot of high hours private owners who, especially in the USA, carry out or take a close interest in their own aircraft maintenance. Here in the UK with Part M it is harder for us to get as involved, legally, with the engineering process, however having a good understanding of the processes involved keeps the fleet flying with the minimum down time.


Before the signature police get you, why not add a signature to your profile so we all know where you are, we can give you locally focussed answers.

 

[ksandrew]

Re: Long Trip ended with a bit of excitement

Kevin,

The Commander must have the most simple and reliable emergency gear extension of any aircraft.

As long as gravity keeps working they are great.
Simplicity it the thing, no co2 bottles. Just a plain open the valve and they drop.

Many designs have it where you can extend the gear in emergency mode just once, with the Commander and a bad switch you can Em Decend it as many times as you with. Also practice is very easy.

Life is a barrel of fun

Ken Andrew

 

[nruzic]

Re: Long Trip ended with a bit of excitement

Ken you are basically right pretty much always so perhaps with the exceptioon of cows (sorry couldn't help it there read too many emails by Messers Gary M, Scott S, Mark B, Jim B, Byrne, Lonnie and many others).

The Commander just has the gear free fall because the Em releases the hyd pr. The Hyd Pr keeps the gear up and so if removed gear just want's to fall and the springs help it fall & lock. The nose gear has to work against airflow so it takes longer. I suppose even if you had low or no fluid it works because as sioon as the fluid went below threshold the gear would fall due to lack of Hyd Pr.

The only simpler system was Mooney's Johnson Bar manual retract that didn't have to have an Em because it was a direct mechanical lever the pilot used to retract or drop the gear.

 

[K Walker]

Re: Long Trip ended with a bit of excitement

Thank you very much for your response
I will now try to figure out how to do the signature detail.
Cheers
Kevin

 

[wab003]

Re: Long Trip ended with a bit of excitement

Bill,

Explain this a little more. I only check the pump fluid with a drinking straw and never have to add. Never had any 5606 come out. I was a little concerned about the monthly thuds causing long term damage, but consulting with experts there would be no long term damage.
Life is a barrel of fun.

Ken Andrew.

I don't think you are likely to experience any damage from your monthly checks. If the reservoir is filled to the brim (visual check of fluid in the fill port threads... no straw req'd.) then there is no room left for the sum of the fluid displaced in the actuators to return to the reservoir via the emer dump valve bypass and so some will purge through the vent hole (assuming it hasn't been clamped shut by some over zealous maintenance procedure). If the reservoir is not full to the brim, it may be able to accommodate the fluid w/o overflow.

 

[Commander91gm]

Re: Long Trip ended with a bit of excitement

Bill

I was under the impression that the dump valve released the pressure which is holding the gear up but as it is displaced the other side of the piston is filling. This should mean that there isn't an overabundance of fluid going back to the pump. If there was then it would be from air being introduced into the system which does not happen.

After an emergency dump the system pressurizes normally and doesn't cycle any longer than usual to purge any air.

Do I have this right?