Q4 Pitot Heat

[GoneWest]

Flying about - happy as can be - in your light training/touring aircraft.

Gorgeous blue sky (Florida winter, maybe) - pitot heat, ON or OFF??

If you vote for OFF - when would you use it??

[FormationFlyer]

OFF.

I use the pitot heat when OAT < 5degC or there is visible moisture in the air. Otherwise you are merely loading the electrical system for no real gain, and shortening the life of the element.

Thats my take.

[Julian]

I would still give it a burst anyway, ****** the element life!
Rather have to fit a new element than have a failure because the pitot has iced up!!!

Besides on a hire aircraft you are paying anyway so use the thing.

[FormationFlyer]

'give it a burst'? Its not carb heat you know!

Remember that your use of the heat when not required may cause someone else to suffer a failure when they need it...

...and I am speaking as someone who has had an ASI failure @ FL80 in IMC due to pitot heat failure & icing.

The real trick here is to understand the environment you operate in...its like people who turn the pitot heat on and off to see a charge on the alternator...duh....I suppose the fact its reading +20amps isnt a good enough indicator...

As for pitot icing up - yep below 5 deg C or visible moisture...that stops the problem - no a blast - just put it on and leave it on until such a time when those conditions no longer prevail...

And as for 'failure because the pitot has iced up' - well thats easy to solve - turn it on bye bye ice....its not exactly an issue....the problem comes when the heat fails in flight....so you DO want to preserve the element life...

[foxmoth]

Remember though, if you fly with it OFF, the compass is swung with it ON, and on some headings it can make quite a difference!

[Blue Hauler]

I don’t know about Florida but in sunny Australia where our winter temperature today (Queensland) is forecast at 8 min to 23 max degrees Celsius (and don’t all you Poms come rushing out here as we have enough of you already) the following is my philosophy:

VFR operations ‘OFF’ except as alluded to by Formation Flyer.

IFR operations ‘ON’ at line-up and ‘OFF’ vacating the landing runway.

Pitot heat on some turbines also triggers the Angle-of-attack heater. The A/A unit will get very hot and survive about three minutes without airflow. Many thousands of $US to replace! If over-use of the heater causes damage, the hirer ultimately pays because of the increase in maintenance costs!

Foxmoth, I have never detected even the slightest compass swing caused by the Pitot Heat ON/OFF position. Can’t say the same about the windshield heater (element types) that produce a massive swing of the compass when selected to ‘ON’.

[DFC]

The pitot is turned on whenever operating in visible moisture egardless of temperature.

So if in a cloud at +20C then pitot ON but if in a clear blue sky at -10C then pitot off.

DFC

[essouira]

Can someone explain clearly why it is advantageous to keep it switched off in flight ? I was taught to keep it on and don't understand other people's reluctance. As has been noted, the compass is swung with pitot heat on, so why not leave it on ?

[CaptAirProx]

essouira,

Because as said, using it reduces the elements life. Now, most aircraft owners will winge when they have to fork out for a new one, most clubs will winge and build it into their hire rates. So whether you are a private owner or a considerate aircraft hiring customer, it possibly is helping you and the club/owner to not put it on unless required.

Then you must consider element of risk by not putting it on and whether that out weighs cost of replacement. I would suggest that most VFR around the houses flying below the freezing level, day VFR chaps, it is possibly worth considering leaving it off till required. And as someone else posted, if you are going IFR, well sodd it, put the thing on and have done with it. You have lots of other things to be doing and are more likely to require it.

As for the compass swing, very true. They are swung with them on and again for "most GA around the houses", is 5-10 degrees going to break the bank? BUt again, if IFR or doing precision flying well then yes, put the Pitot on. Someone said they have not noticed a swing, well I have quite remarkable so - up to 15 degrees. So yes it must be valid.

[fireflybob]

Anyone got any statistics for how many pitot elements get "burned out" at organisations where it is SOP to fly with Pitot Heat On at all times?

I suspect that the heaters get burned out by those who rarely use the Pitot Heat and then omit to switch it off in the after landing checks.

If the SOP is to use Pitot Heat at all times then after landing checks will include Pitot Heat Off.

All professional pilot schools where I have either been a pupil or student have taught Pitot Heat ON. As has been said it's not just a question of ice dispersal but also precipitation.

The penalties for not using Pitot Heat can be high - remember the B727 that was lost which got into deep stall because they were on climb out with the heaters off!

[FormationFlyer]

Just as an aside...

Its interesting that the use of Pitot heat has been associated with FLIGHT RULES...and not the FLIGHT CONDITIONS...

Anyone heard of IFR in VMC??

If you are going IMC use the pitot heat - remember IMC is NOT just in cloud - but in conditions which do NOT meet VMC minima - so you can still be visual (say between clouds) but be in IMC conditions.

Just a thought....no wonder the eurocrats have started making statements about licence issue about hours flown under IFR....I mean you could fly 1000s hours IFR and NEVER see a cloud....let alone flight by sole ref to instruments....

[Sqwark2000]

OFF unless required.

You only need to use heat if you are in or likely to encounter icing conditions, which is <5'C and in/near visible moisture

Some of the previous arguments would suggest that they would rather fly with the Carb Heat on full time instead of having to remember to cycle it reguarly.

Pitot Heat is a anti/de-icing function. No need to have it on when not required. Not only are you protecting the elelment from premature failure but you are protecting the other parts of the electrical system which when it fails due to overloading, could really make your day.

S2K

[FormationFlyer]

In the last few days we have lost 2 pitot heaters on club a/c. They can no longer fly IFR now...and therefore we cannot perform IMC training in IMC conditions.....this has thus reduced the effective usuability of the aircraft.

Now if they have gone thru normal use fair do...but if it was through bad practice then it means people are having lessons or flights cancelled when the situation was avoidable.

Ho hum.

[fireflybob]

They only burn out when you sit on the ground for extended periods with the Pitot Heat ON.

If pilots are taught to switch pitot heat on just before take off and off after landing this is not a problem.

The problem arises when pilots are not taught to use the pitot heat on a regular basis. This means they do not incorporate switching it off in the after landing check.

[IRRenewal]

Pre take off checks on test:

pitot heat ............................not required

FAIL!

Pitot heat is always required if you want the compass to be accurate.

I don't normally, but on this one I blame instructors for not teaching properly.

Just switch it on in flight. It is only a resistive element and its life will not be shortened by using it when there is sufficient airflow about.

Cheers

[Chuck Ellsworth]

The dumbing down of flight training is evident on this thread by reading the posts.

Pitot heat is only required when there is a chance of ice forming in flight.

Pitot heat is an " as required item "

Sooner or later we will reach a point in flight training where the instructor will teach, do not think during flight, just follow check lists that are designed to relieve the pilot of any thought process.

You know real difficult decisions like is it cold enough for water to freeze?


Oh by the way as to compass error,, yeh IFR equipped aircraft all rely on using the magnetic compass and we never check DI reading after runway line up. Hell why would I bother to confirm the heading information against runway heading..

No, all I need do is turn on the pitot heat to ensure my magnetic compass is reading accurately set the heading and off I go..

DUH!!!

Cat Driver