Preflight Checks, What do you find?

[dazza 38]

I was mainly wondering because puncture repairs are usually easier with tubeless tyres. You can buy a nice little kit from the 4WD shop that takes care of them. With tubes, it's a bit different.

Yep I agree.I carry a full repair kit made in Australia from Tyrepliers.(on my motorbike).It has a handpump that also can be fitted with little CO 2 bottle.I carry about 3 bottles.I also carry 3 tyre levers, alot easier than using just 2 tyre levers.Especially on the rear tyre.

Then I looked at the tubless kit.How easy is that to use. A-find hole, B-screw in the screw piece, to clean out and make hole to correct size.c- Place tyre plug in its tool and them insert. D- pull out insert tool, then pump up tyre.

 

The down side of tubless is if the whole is bigger than the plug.Then you are up S^&T creek with out a paddle.Well not realy, if you carry a tube , you can throw the tube into the tubless tyre.

 

 

[dazza 38]

www.tyrepliers.com.au is where I bought my tyre repair kit.Probably about 10 years ago.Top quality stuff.If your life is on the line.By that I mean stuck in the middle of no where with a flat.This quality kit is what people want.Not some chinese crap.

[Sapphire]

How many people check the air speed indicator preflight? To lightly blow into the pitot tube and view my ASI at the same time is a gymnastic manoever I can't do. Was flying out of Kununurra to remote strips and the ASI was not working. Returned to an irate boss who said "If it ever happens again, just keep going". I eventually kept going-out the door.

 

 

[motzartmerv]

Don't they say not to blow into a pitot tube?

 

 

[Sapphire]

In gliding circles they do it all the time-lots of time to check the a/c before the thermals start. How would you check it otherwise??

 

 

[motzartmerv]

Check that the tube is free of obstructions and check the ASI is active on the takeoff roll. The bellows inside the instrument are incredibly sensitive and your likely to damage them if you blow too hard, which isn't hard at all ;)...

 

 

[motzartmerv]

Just found this..

 

a. Airspeed check: Slip a long rubber hose

 

over the pitot mast (surgical tubing is recommended).

 

As one person reads the airspeed, the other should

 

very slowly roll up the other end of the tubing. This

 

will apply pressure to the instrument. When the airspeed

 

indicator needle reaches the aircraft’s approximate

 

recommended cruise speed, pinch the hose shut,

 

and hold that reading. The airspeed needle should

 

remain steady for a minute if the system is sound.

 

A fast drop off will indicate a leak in the instrument,

 

fittings, lines, or the test hose attachment. NEVER

 

force air in the pitot tube or orally apply suction

 

on a static vent. This will cause damage to the

 

instruments.

 

From this advisory circular.http://www.faa.gov/library/manuals/aircraft/media/ac90-89a.pdf

 

 

[Wayne T Mathews]

Don't they say not to blow into a pitot tube?

They sure do! Blowing in a pitot tube is a no no. For several reasons.

 

1/ While it's not such a problem for us blokes with basic aircraft, and/or gliders, many aircraft have heated pitots which if its ON and you wrap your lips around it... Well you've just given yourself a perpetual pucker.

 

2/ When you blow into a pitot, you stand a better than average chance of introducing spittle to the system... Not a good thing.

 

3/ ASIs are delicate instruments. When you huff and puff into them, you've a good chance of causing expensive damage.

 

I know people do it. I've even done it myself when I had to check I'd cleared the bug out when I was in the bush. But I have never once seen it as a technique called for in a maintenance manual or a POH.

 

 

[motzartmerv]

Yea, I've been asked by engineers to do it while they check stuff, which is accompanied by a big lecture on just using the pressure of your mouth and not actually blowing into it.. Very surprising that just the slightest pressure can produce an IAS of 100 kts.

 

 

[Sapphire]

I think I'll pass on the smacker around a heated pitot tube. Blowing from a distance [3"] was the usual way to do it but saliva and bad breath are out. I like the idea of pushing a plastic tube over the pitot tube and rolling it up until "cruise speed" is reached. After you have done it once you know how far to roll up. Each preflight, roll it up and hold it in place with a clamp. Go around and check the ASI. Don't forget to remove before flight. Checking the ASI on the ground run is faster though and very rarely would you have to power off and taxi back, but not practical for a glider.

 

 

[Mick]

Have had an L2 blow into the pitot while we were setting up an air-switch to cut in at the correct airspeed. With the length & girth of the pitot on the Sportstar this definitely fitted into the "things you see when you haven't got a camera" category! We did have a trial run on an unservicable ASI to get a feel of just how little pressure was required.

 

 

[Sapphire]

length & girth of the pitot on the Sportstar this definitely fitted into the "things you see when you haven't got a camera" category!

 

I think some planes are sold just on the size of their pitot tube:wink:

 

 

[motzartmerv]

Yes, and you have to know that 'blow' is just a figure of speech...;)

 

 

[Mick]

Mmmmmm pitot envy!,,

Hi Met,

 

That was someone we both know at Gympie so you can imagine how much we payed out on him!

 

 

[Ballpoint 246niner]

Hell knows what will happen when you guys start onto vacuum gauges!!

 

 

[Mick]

Hell knows what will happen when you guys start onto vacuum gauges!!

Did I tell you about the other day when I was balancing my carbies...................

 

.

 

 

[eightyknots]

1/ While it's not such a problem for us blokes with basic aircraft, and/or gliders, many aircraft have heated pitots which if its ON and you wrap your lips around it... Well you've just given yourself a perpetual pucker.

OuCh!

 

 

[Sapphire]

Hell knows what will happen when you guys start onto vacuum gauges!!

I don't think I want to go there.

 

 

[eightyknots]

....what will happen when you guys start onto vacuum gauges!!

As members of the younger generation so often say: That SUX!

 

 

[Sapphire]

As a result of the above "discussion" we can conclude there are three ways of checking your ASI preflight. First is to check it on the ground run, second is the rolled up rubber tube method, and third is to wrap your lips around the pitot tube "using the pressure of your mouth". That requires some precautions as listed above, including anyone around intent on photographing it [for educational purposes of course]

 

 

[facthunter]

The main 2 ways of having your ASI fail would be a wasp filling the opening with mud, and one of the connections pulling off a pipe. If you aren't carefull with putting pressure in the pipe ypu will need your instrument repaired or recalibrated. In some ways a completely failed instrument might be safer than one that has been altered and therefore the error is not detected initially. Pilots should practice a circuit with no ASI preferably with an instructor. Over the years I have seen a few ASI failures and experienced several myself. It is not a dangerous situation if you are aware and trained for it. Nev

 

 

[M61A1]

As a result of the above "discussion" we can conclude there are three ways of checking your ASI preflight. First is to check it on the ground run, second is the rolled up rubber tube method, and third is to wrap your lips around the pitot tube "using the pressure of your mouth". That requires some precautions as listed above, including anyone around intent on photographing it [for educational purposes of course]

It has always been my understanding, that ,IF, you are going to blow into a pitot, the you do it gently from a distance, like gently blowing on your cuppa. Still, this is of little use unless you have an assistant to check for asi indication. Although I know this is more of a maintenance process,I have seen a test kit made up using a water manometer calibrated and a large syringe. I have attached it below, note that at low speeds not much pressure require, you could set up with your tube at a calibrated incline for greater accuracy .

Manometer.pdf

 

Manometer.pdf

 

Manometer.pdf

[Sapphire]

Most gliding clubs have this device. Will give you errors in your indicated air speed over your whole speed range. The blowing bit from a distance was just to get the needle to twitch, but not recommeded by many here.

 

 

[mAgNeToDrOp]

(luckily?) I had an asi failure during my training with my instructor, he made me continue with the circuit and showed me as long as the power and attitude are correct you will be fine, also helps if you know the aircraft. Glad it happened then and not on first solo or something, major pucker factor and possible wrong decision if I hadn't already experienced it...

 

 

[Yenn]

Another way to check ASI is to make a "U" of plastic clear pipe and put some water in it, connect one end to the pitot and bu moving the other end up and down you can vary the presssure at the pitot. Somewhere i have the speed / Water heights in a magazine. You can check the static lines byconnecting a rolled up pipe to the line and unrolling it will cause the altimeter to register height.