Rejected takeoff no airspeed

[Jim Peace]

Taking off today noticed no airspeed approaching what should have been about 40+knots.......

 

Rejected.....

 

Sun going down in a non mx airport on a Saturday.......

 

Taxi off and decided to blow gently into pitot tube.....I know should not do that but what else can you do?

 

first time no indication.....

 

second time no indication then person monitoring the gage said it wound up all of a sudden past Vne

 

Plane was parked for the day in a high grass weed environment due to too many planes/full ramp on the asphalt......did not put pitot cover on, lesson learned.

 

Worked great for the 90 minute flight home.......

 

Now what?  leave it alone or tear apart dynamic system and look for anything wrong? fix something that is not broke?

 

1964 M20C

[RocketAviator]

Jim I would sure check it out. What if a bug or something is lodging in the system and the IAS comes and goes... just when you need it most....

I am quite sure you being a professional pilot and all would be able to fly the plane without the IAS but for me I would check it....

Fly safe

[carqwik]

It will get worse over time...mine would get "stuck" usually as I slowed up to pattern speed...and then would unstick...but then a few flights later it just got stuck at 100 kts all the way until shutdown on the ramp.  I decided to get it checked out at Berkshire Instruments.  They said there was a bunch of dirt in it...  Has worked great since...

[Jim Peace]

yeah I can see a lot of $$ being spent on this to make it right......my 2 year IFR check is due in about 8 months so I will probably just get it all checked out and recertified this month.....

 

If there is a bug in the line it can be anywhere correct?  even in the hose between the pitot and the indicator?  does it all have to come out to be checked?  even if they blow air into the line it does not mean the bug or dirt will come out.....

[N201MKTurbo]

It has happened to me twice. Always mud dauber nests. Both times I got airborne. Landing without airspeed is kind of unnerving.

[larryb]

The instruments can be damaged from too much pressure. So be careful blowing things out.

Sent from my iPad using Tapatalk

[Yetti]

It's tubing and ferrels and inspection ports. The tubing connections should be hand tight or a pair of pliers to loosen.  Blow away from the instruments.  Could be a seed or spider or a mud dobber. could have been water in a stuck drain hole.

[Guest]

Jim,

This should not be expensive to correct, unless you've damages your ASI. Does is sit at Zero now? You don't need to complete your two year early.

The pitot line at the airspeed indicator or past the airspeed safety switch for the landing gear needs to be removed and air blown through the line toward the pitot head. I would suggest placing a white cloth over the pitot head so you can catch what ever comes out. Once the line is clear and reassembled, place a length surgical rubber hose over the pitot head and slowly roll it around a clothes peg, the airspeed will rise, once it gets to 100 stop rolling and watch the ASI, it should not drop. If it is leak free unroll and remove the hose.

Clarence

[carusoam]

Things that come to mind...

1) power + attitude = performance.

2) GPS derived G/S is pretty close, re-double check twice to make sure you are landing into the wind.

3) the stall vane is an independent source of data. Know that it is working before relying on it.

4) having your mechanic take apart the pitot tube, clean, and reassemble sounds like a good idea. (Clarence's details above).

Doing this in a school C152 is easier. Doing this in your own M20X is a little more challenging. Padding the A/S turns into a long float in ground effect...

Be ready for the Go Around,

-a-

[ryoder]

I'd love to have two pitot tubes and static systems. Ideally I'd put in a ilevil and have the full AHRS on an iPad.

[carusoam]

A situational awareness pitot system...?

I saw a great video produced by a highschool student working on an aircraft control project, in his personal in-home wind tunnel.

The electronic pitot sensor was tiny compared to standard FAA compliant ones.

Next challenges:

-how to install and power it in a 'temporary' fashion...

-add wireless data communication back to the cockpit...

-some GoPro experience comes to mind...

Go Jr. Erik!

Best regards,

-a-

[N201MKTurbo]

The last time this happened I had to remove the pitot tube and soak it in water to get the bugs out.

It is fairly easy to remove the pitot. Use weed eater string to poke through the pitot, it won't hurt anything.

[ryoder]

A situational awareness pitot system...?

I saw a great video produced by a highschool student working on an aircraft control project, in his personal in-home wind tunnel.

The electronic pitot sensor was tiny compared to standard FAA compliant ones.

Next challenges:

-how to install and power it in a 'temporary' fashion...

-add wireless data communication back to the cockpit...

-some GoPro experience comes to mind...

Go Jr. Erik!

Best regards,

-a-

Wow great idea to integrate it into the camera and benefit from the battery and Bluetooth.

The ilevil2aw has a real AHRS with a real pitot tube and static system but you can use it on experimentals only.

[Jim Peace]

The ilevil2aw has a real AHRS with a real pitot tube and static system but you can use it on experimentals only.

Why can't a second pitot tube and static system be installed on a certified airplane for the ilevel system?

[carusoam]

It could be misused by an unfortunate person to injure themselves and other unfortunate people...

The FAA puts a lot of effort into making systems very known to minimize the really dangerous unknown risks...

Defining the risks of the iLevel system is possible, but the expense keeps people from doing it. Ability to sell a whole bunch helps a lot...

The expense is real life testing, documentation and legal support.

This is my experience from working on FDA related projects...

Best regards,

-a-

[Cruiser]

ryoder Posted today

Ideally I'd put in a ilevil and have full AHRS on an iPad

 

 Great idea,

 

just installed. Connected to AoA probe. Also just installed.

 

Works great

iLevil says "more accurate than certified"

I agree

[carusoam]

Tom,

Did I understand correctly...

Accurate digital A/S read out to go with AOA, while keeping a view of the runway (that sounds awfully good!)

Stall speeds for the O are known in 1/10ths of a KIA...

Error while reading the analog a/s gauge down on the IP is huge in comparison.

Still requires good power / attitude control experience to minimize landing roll out distance while maintaining adequate margin of safety.

We're going to need some photos...

[N201MKTurbo]

I'm a CB. So I don't run out and buy every gadget that comes along. I see no reason to go to the expense of installing a complex system to solve a problem that can be solved by actually putting on the pitot cover every time I park. I freely admit that both times my pitot got clogged was caused by my own laziness.

And, what makes you think that two bugs wouldn't clog both pitot tubes....

It is pretty easy to unclog a standard pitot tube, try to unclog a short port to a solid state pressure sensor! Just about any method I can think of would destroy the sensor.

[Steve65E-NC]

For the future.  A day glo colored tennis ball.  Cut x for pitot tube.  Cut smaller slit for knotted end of 1" x 24" strip of orange sunbrella fabric.   Five years later, still looking good and going strong.  I do a pre walk around removing:  Chain with prop lock, Intake plugs, pitot cover, tail hole bra (see my gallery).  I have a small bag that just hold all the above.  Keep right inside baggage door.  Reverse order at end of flight.  This walk around is just for the covers, avoids distraction.

[Jim Peace]

Jim,

Does is sit at Zero now? 

Clarence

yes and it worked for the 90 minute VFR flight home.....

[Immelman]

My 2nd-ever solo flight as a student, I hit a bee square on with the pitot tube. It made me glad my instructor made me fly the pattern and land once, with the panel covered, pre-solo.... its a valuable thing to be able to do, maybe with a safety pilot to peek for you to be sure you're safe.

[BigTex]

I remember one time flying a Cherokee 180 the airspeed stopped at around 65 knots. I continued the flight. On landing, I just maintained the same sight picture on landing and landed without any issues. Actually one of my better landings. Turned out to be just a bug in the pitot.