View Full Version : Pitot heat check?


Krallu
8th Jan 2010, 07:08
I was flying in a C172 and saw that the pilot was doing this pitot heat check thing.

You needed to after startup put the pitot heat on and then check the amp meter and then turn it off again. You could see a little increase in amp usage when turning the pitot heat on.

Why on earth do you do this check?
And why using the pitot heat for this check?



Badente
8th Jan 2010, 08:26
A wild guess: to see if the pitot heat works? Think icing and no working pitot heat.

-- Badente

englishal
8th Jan 2010, 08:27
Well you check it to make sure it works. I check it by feeling whether it gets hot or not.

You can use the pitot heat to put a load on the alternator as it is a relatively high current device, and thus checking the alternator is working ok....

Krallu
8th Jan 2010, 09:50
Yes, but he told you can use landing light to check with as well if you don't see any indication on the amp meter.

And the alternator was not on, it was just battery on and startup and then checking the pitot heat with the amp meter.

You guys don't do this?

Intercepted
8th Jan 2010, 10:14
If the aircraft I'm flying has a reliable amp meter I use this to check that my pitot heat is working, if not I check if its warm.

The aircraft I fly at the moment has an amp meter that indicates all over the place, so I have to turn everything on to see any difference (still indicating all over the place but in a different pattern :))

Checking landing light and pitot heat with amp meter saves a bit of battery during your walk around (good at this time of the year).

Gertrude the Wombat
8th Jan 2010, 11:56
To be perfectly frank and honest not all pilots always bother to check that the pitot heat is working when intending visual flight - after all, if the pitot does ice up you can fly perfectly happily without the instruments, can't you, we've all practiced circuit and landing with the ASI covered up, haven't we.

To take off intending flight in cloud having not checked that the pitot heater is working would be another matter entirely.

Pilot DAR
8th Jan 2010, 12:22
I check it by feeling whether it gets hot or not

Well... with great caution! if it is working, it will get hot enough to burn you. I suppose that pitot heat for a VFR only aircraft has save a few lives over the years, probably those who have foolishly entered meteorlogical conditions they should have avoided. in more than 30 years of flying I have never chosen to use pitot heat in VFR flight unless it was a checklist item. I certainly have used it many times during flight in icing conditions.

I hold the opinion that it is installed on many light aircraft for two simple reasons: Marketing - it makes the pilot think he's flying a big plane, but more likely (in the case of Cessna) because it won't bend, and the maintainer does not have to keep aligning it with the airflow, as we had to do with the early ones, when people bent them!

As for checking the ammeter/electrical system, operating the landing light or flaps would be a better choice than the pitot heat, as each of those draw twice the current (amps) of the pitot heat. Even the flashing beakon draws more, and you can sometimes see its pulse on the ammeter.

Generally, aircraft electrical systems have a means to indicate the failure of the ammeter anyway, though there is one alternator circuit failure mode which will not trigger this indication in some C 150's, but not other Cessnas.

A2B Ferry
8th Jan 2010, 12:23
we've all practiced circuit and landing with the ASI covered up, haven't we.

Actually no I never have and I wouldnt have thought this would be common practice on safety grounds. In my humble opinion, airspeed is critical when in landing configuration on approach for obvious reasons. I once had a vacuum failure on an approach and was fortunate enough to have a G430 which displayed groundspeed so I made a faster than normal approach to give myself a greater margin for error but it wasnt something I enjoyed.

mad_jock
8th Jan 2010, 12:36
I used to teach it as well to the students.

Along with no altimeter circuits as well.

If they wern't fixated on instruments I might not have bothered but almost all of the FS 1000hour pilots got those lessons. And nearly all of them were shocked to find they were more accurate on everything with no instruments than they were with them available.

How do you think instructors fly an approach?

I certainly don't sit there looking across at the parallax error. Set the machine up by ear and look out the window. And when the student is to fast or slow you tell them not by looking at the ASI but looking out the window. It annoys the hell out of them when your looking at the wing tip and saying airspeed low/high. Does the picture look right.

1800ed
8th Jan 2010, 12:46
Well... with great caution! if it is working, it will get hot enough to burn you.I made this mistake on an SR22. The PA28 I normally fly gets warmish, but the Cirrus had some markings from burnt on rubber on the pitot. I should have known better really!

A2B Ferry
8th Jan 2010, 12:49
And nearly all of them were shocked to find they were more accurate on everything with no instruments than they were with them available.

Im not going to argue with an ex instructor but I dont fully understand how a pilot could say hold 1000ft in the circuit more accurately without an altimeter than with one and the same applies to say holding 70kts as an example over the threshold. I know there are a lot of old school pilots who subscribe to seat of the pants flying but I personally dont see how it could be more accurate then when flying on instruments, in fact again in my humble opinion I would say its simply not possible.

Gertrude the Wombat
8th Jan 2010, 13:02
Actually no I never have and I wouldnt have thought this would be common practice on safety grounds.
Sigh. Apologies for leaving out the obvious:

"Don't try this at home on your own, children, take a grown-up with you in the right hand seat."

BackPacker
8th Jan 2010, 13:09
A2B, holding perfect altitude in the circuit is only needed when other traffic is around, and holding the perfect approach speed is only needed when flying into seriously short strips.

All other occasions, it's very well possible to fly a full circuit with zero instruments. Yes, you will not fly at the perfect 1000 feet and will not have the shortest landing roll possible, but you will have gained valuable experience in controlling the aircraft when things go pear-shaped. That's what's learning to fly is about, for a significant part.

Of course if you have a for-real pitot/static failure you're not going to fly into a situation where altitude holding is critical, or into a seriously short strip anyway.

A2B Ferry
8th Jan 2010, 13:12
Im not making a point about whether a safety pilot or indeed an instructor is present. The point I am making is that airspeed is critical when on approach and in landing configuration. I am questioning the wisdom of intentionally covering up the airspeed indicator in this critical phase of flight and indeed making a landing with it covered up. Now any training I have ever done always saw whatever was covered up, removed before making the final approach and I can see the good reason in that. If there are other schools of thought, then I personally havent come across them. I dont see the logic in it but thats just my opinion. I know in the UK we are health and safety barmy but I would actually think this wasnt conducive to safe practice.

A2B Ferry
8th Jan 2010, 13:15
Backpacker I suggest you read the previous posts to which I was referring. Of course its safe to fly a circuit on visual judgement. No one is disputing that. What I questioned was mad jocks comment stating he witnessed a majority of pilots flying more accurately to specific parameters by the seat of the pants judgement as opposed to when using instruments and that is what I disputed. Maybe you was a little quick to get your response in?
Now flying a fast approach with loads of runway is fine but your maybe not taking into account the perils of flying too slow and approach which is certainly more likely when going into a shorter strip.

mad_jock
8th Jan 2010, 13:27
Current instructor but unfortunately somewhere that you can't fly GA.

Its all to do how you were taught the first exercises. Personally I am anal retentive about attitute flying and trimming. You are not flying by the seat of your pants when you are doing this by looking out the window.

In the circuit you get the student to stick a bit of the plane on the runway on the down wind and look at the picture. On the PA38 and that sort of type its the wing tip and on a C172 its the tie down bolt on the wing strut.

Then to get the circuit height you just get the picture to match what you want it to be. Power you set by ear then adjust and thats it.

Same on approach get the picture right and configuration right and everything works.

Its pefectly normal for a student who was chasing needles with +- 5 knots and +-100ft in the circuit to get within +- 2 knots and 20ft all in a couple of circuits with no instruments. After that if you are horrible you can throw a bad wx circuit at them at 600ft and 9 times out of 10 they will be bang on 600ft without even showing them the new picture. PFLs again it comes into its own being able to judge your height and speed off attitude and is further refined in that exercise to the point that when you start doing land aways the student can do it with an unfamilar field and still get it pretty much spot on with one quick glance at the alt to confirm that its right.

After they can do this the amount of released capacity is huge. No more panic on the downwind, base etc and all you have to do is get the flare sorted and you throw them off solo.

Day VFR in a fixed prop aircraft in class G it really won't bother me two hoots if all the instruments packed. And for my ex students I don't think it would bother them to much either.

If you can go and do a CRI course at ontrack and it will become very obvious what I am on about after a couple of hours in the RHS.

mad_jock
8th Jan 2010, 13:38
O and to answer the orginal post. There is a theory out there that if you test the heating without air going over the tube you reduce the life of the tube.

Also its meant to check that your alternator circuits are regulating the voltage properly. So if you switch it on and see a increase in output and no low voltage light come on your hunky dorry to go.

Persoanlly I didn't used to bother checking it unless I was doing night ratings.

Poltergeist
8th Jan 2010, 14:18
OK, As a GA pilot and airline Safety Manager, Quite simply, what does the manual/sop/checklist tell you to do? then do it! simple. It doesn't matter what you think you know, these publications are provided for a reason. If you disagree with the publication then challenge it correctly, it may save someone else. Sadly, all to often people ignore them then I end up getting statements like 'with hindsight........'

Pilot DAR
8th Jan 2010, 14:29
Thread drift I know, but;

Learning to "feel" the aircraft as you fly (an approach and landing in particular) is vital. Dependance on an airspeed indicating system in anything other than a very high performance aircraft is to me foolish.

During the early phases of my night training (1970's) more than half the circuits flown were with absolutely no instrument lights at all - thus no instrument information available (yes, I had a flashlight, but it's use was not permitted for training). The object was to learn to feel the plane in it's approach configuration. This has eased my remaining flight many times over that years, as bugs in the pitot tube will cause odd errors in indications (ever seen an ASI read negative once airbornre?) and numerous cockpit lighting failures over the years have meant that you're feeling your way down, not reading instruments to do it, and at night, with fewer visual cues.

I once flew an instructor home after his delivering an aircraft. I purposely flew an extra slow curved approach, while watching and waiting for traffic to clear. Peeping stall warning, 'cause that's what it's there for. Once on the ground, the instructor reported to anyone who listened that I was an "idoit" for "flying around below stall speed". His boss correctly asked him if I was below stall speed, why did I not stall? (He had no answer for that). The truth is, I was looking out the window, and had no idea what speed I was flying, and as long as the approach felt safe and with an adequate margin for safety for the conditions, I really don't care what the airspeed was in numbers - it's AoA and G that matters really.

Several times I have had to "help" with an approcah in its latter stages from right seat. most GA aircraft do not have two ASI's, so I'm not looking at one in front of me. When we're slipping over trees into a small sheltered bay in a lake, I'm not looking over to the left panel in any case! I'm just going to feel my way to the appropriate approach attitude.

Those pilots who depend on indicated numeric information to the exclusion or obliviousness (if that's a word) of flying their aircraft with respect to "feel", in visual conditions, are overlooking their resonsibility to fly as safely as possible, and should refresh themselves with some very basis skills. Those skills are equally valuable for most any aircraft they would fly.

It is certainly possible for the characteristics of an aircraft to change in flight (airframe ice) such that flying an approach by adhering to flight manual speeds would be very dangerous. The pilot must "feel" that the aircraft must be flown faster to be flown safely in that condition. I hold the personal opinion that a Dash 8 400 would not have crashed in New York State last year if the pilots were simply "feeling" the plane.

I know that the flight training community puts a lot of thought into what are appropriate things to train new pilots, but the thought that elementry flight training does not leave a pilot able to confidently land without referring to indicated airspeed alarms me.

ChampChump
8th Jan 2010, 15:31
Continuing the thread drift, when I learned in gliders, a circuit without instruments was mandatory before solo. Everyone, bar none, performed better.

Yes, I have taken off in an aeroplane with the pitot cover on and it's no big deal. Circuit, land, remove cover, hope no one noticed that one inevitable result of an interrupted pre-flight...:uhoh:

Similarly, once when the little flappy pitot cover on the Champ didn't flap enough when airborne, it didn't really occur to me that I shouldn't carry on to France as planned. We found another cause to land en route, though, so I did sort it out before carry on.
I might have thought differently without any of my very basic instruments, but the fact is the aeroplane doesn't know what it has inside and will fly nicely if allowed to do so by the klutz inside.

I'm surprised if students aren't given that training anymore.

bookworm
8th Jan 2010, 16:16
I check it by feeling whether it gets hot or not.

Can I ask a different question? Has anyone ever detected a pitot heat failure where the expected current draw was observed, but the pitot tube didn't get hot?

mad_jock
8th Jan 2010, 16:44
once. The thermal cut out was shot so it used to chop the current after about 30secs so a quick flick on and check and off again wouldn't have spotted it.

David Horn
8th Jan 2010, 19:21
1. Turn on.
2. Touch gingerly.
3. Yelp and jerk hand away.
4. Turn off.

Seemples.

Maoraigh1
8th Jan 2010, 22:18
"I once had a vacuum failure on an approach and was fortunate enough to have a G430 which displayed groundspeed so I made a faster than normal approach to give myself a greater margin for error but it wasnt something I enjoyed."
How does vacuum failure affect the ASI?

Cusco
8th Jan 2010, 23:27
I check pitot heat and heat to gear auto-extend mast by hand with battery only at initial walk around. (along with nav lights. landing light , strobe and stallwarner)

20-30 seconds max: not time enough to burn my hand or flatten the battery.

Ammeter after startup with landing light.

Works for me.

Without an airflow over it pitot heat element runs risk of burning out.

Cusco

amostcivilpilot
9th Jan 2010, 07:50
Be very careful when pre flighting and confirming that the pitot heat cover has actually been removed. It will depend on the aircraft type and the checklist, as you can easily end up with a very expensive piece of egg on your face :rolleyes:

I recently started to taxi out from the ramp having been given an immediate takeoff clearance by ATC ahead of a landing heavy jet and as I began to transit from the hover to forward flight I noticed that there was an unusual orange flag flying in front of the windscreen :confused: I happened to be flying an AS350B3 Eurocopter Squirrel, which according to the standard Eurocopter checklist requires that the Pitot heat is switched on as the caution panel will show an amber "Pitot" caution if left off.

Ordinarily I live with the caution warning but I decided to switch it on for that flight as I was doing some low level work and didn't want the distraction on the panel.

I immediately switched off the Pitot, told ATC I was aborting and made a fast return to the ramp. One of our engineers ran up and saw the flag and started to remove the cover. He left a trail of molten plastic over the pitot, but luckily there was no major melting and the pitot opening was unaffected.

I had done a walk around in the hangar and another just prior to start while having a chat with the engineer and we both missed the cover :ugh:

If I had actually gotten airborne and had not immediately noticed that the cover was on there would have been a large lump of molten plastic in the pace of the cover!!! Try explaining that to your chief pilot and senior engineer.

Always CHECK!!!!!!!!!!!

A2B Ferry I would not take any of the comments given personally but I am with mad_jock, ChampChump, Poltergeist and Pilot DAR on the need to learn to fly by feel and visual references.

And I would apply it to both fixed wing and rotary. I certainly do not regard myself as a dinosaur using old fashioned instructional techniques but I was taught by my instructors to fly by feel and alway taught my ab-initio students and expected my experienced pilots on annual or recurrent training to be able to fly without reference to the panel, both Day and Night. It is not a black art, but good airmanship.

If you intend to gain an instrument rating you will also be expected to be able to fly partial panel approaches, under the hood with multiple instrument failures.

Go and do a couple of hours with a competent instructor and practice circuits and PFL's by feel and visual clues and you will leave with a smile on your face and your flying skills greatly enhanced :ok:

Black Jake
9th Jan 2010, 08:57
Mao 1

I think the vacuum failure ASI incident must have been confused with the day he/she had a pitot static problem. On that occasion the DI and AI were all over the place and it was impossible to maintain straight and level flight. Fortunately the GPS still worked, thus avoiding imminent danger to schools and hospitals.

Warning to instructors - do not ever attempt to cover the flight instruments with stick-it notes or similar to show your students that flight by reference to the horizon is possible. It is not. Modern aircraft require, as a minimum, the following:

Glass panel PFD and MFD (e.g. Garmin 1000/600/500)
Autopilot
Twin G430/500
FADEC
and failure of any of these is not possible because the manufacturers guarantee their 100% reliability.

;)

www.aaib.gov.uk/cms_resources.cfm?file=/Dornier%20328-300,%20G-CJAB%2009-09.pdf

BJ

Stratus Fractus
10th Jan 2010, 02:42
FFS. Only on ******e can such a simple thing run on to 2 pages: The pitot heater is supposed to keep your ASI working. It stops you losing control and crashing. alternater is fairly far down the list compared to ASI. Aviate Navigate Communicate etc. Wet and cold=Ice= ASI might not work: so check it goes warm when you want it to in the pre flight checks. touch it ( It takes about a minute before anything happens), highly unlikely to fatally burn yourself unless you get seriously distracted. Then it gets slightly warm. Turn it off before you drain the battery. Go Flying. Turn it on if you might go into some cold cloudy stuff. Use your superior flying skills to avoid such complications. Live another day to speak s*it on pprroone private flying section.

Pilot DAR
10th Jan 2010, 03:42
I know that I'm on the left side of the Atlantic and everything, and so lack the English sense of humour so valuable to appreciate many of these posts in context, but;

The pitot heater is supposed to keep your ASI working. It stops you losing control and crashing.

Really?

In any plane I'm flying, I stop me from loosing control and crashing, the ASI provides just a bit of information, which at times is helpful...

alternater is fairly far down the list compared to ASI

Well, yes, I agree, most of the time, but I have certainly flown many long legs over unwelcoming territory where if I had to loose one, I'd much rather loose the just ASI, than the alternator. During a long leg of IMC in ice, if you loose the ASI, you loose airspeed information. Loose an alternator, and you'll loose the pitot heat (so ASI), plus a whole bunch of other equipment you'd like to have, once the battery goes flat.

But, as I said near the beginning, the use of pitot heat, and checking the function of an alternator, are, in my opinion, not closely associated.

Pilot DAR

Chuck Ellsworth
10th Jan 2010, 03:47
Flying by attitude is something that every pilot should be comfortable with.

If you can not fly an accurate safe approach without an airspeed indicator I would not let you fly my airplane.

Nor would I allow you to rent an airplane from any flight school I were in charge of.

What happened to basic flight training?

India Four Two
10th Jan 2010, 04:36
Chuck,

I absolutely agree with you. Everyone should try flying circuits by attitude. I've had two ASI failures.

Once in a 182, at Red Deer, due to a mud-wasp's nest, when I didn't notice the lack of needle movement until after takeoff :uhoh:, so a quick circuit was required.

And once in a Scout at Claresholm, where I noticed it during the takeoff run, but because I had a ballasted Open Class glider behind me, I decided that continuing was a better option than risk having the glider run into me during an abort. It turned out to be water in the pitot line, which cleared itself during the tow.

BoeingMEL
10th Jan 2010, 06:01
...you lost ASI because of vacuum failure? "Vacuum" as in gyro power?

OK, I'm getting old here..but how does that cause ASI failure? :confused:

IO540
10th Jan 2010, 08:16
I would not depart with a faulty pitot heater, except for a low level flight in the summer.

Sure one can fly without the ASI but why chuck away a damn useful instrument even before departure? Why not chuck out the GPS while you are at it, on the grounds that one can follow roads, lakes, etc? Actually one could unscrew the yoke and chuck it out of the window also, because one can roll with the rudder and do the pitch with the elevator trim :)

ExSp33db1rd
10th Jan 2010, 08:51
Took the Turb. out of the hangar to check something - forget what now - but no intention of going flying, getting dark, anyway.

The VW is always difficult to start, as I've already discussed, but thought I might have learned a new technique so gave it a swing - and it started ! no one more surprised then me, so what the Hell, let's do a quick circuit, let's not waste one !

Full power, keep it straight, speed rising and then airborne - with a speed of 160 kts i.e. full scale deflection on the ASI. I couldn't see it, but I just knew that the pitot tube flag was gaily waving in the breeze under the wing. Still, wasn't stalling, so lowered the nose a bit to gain a bit of fat, continued climbing until the cows looked the right size, reduced to cruise power and completed the circuit, set the normal approach power and attitude - no sweat, but a lesson learned, never change one's mind and rush into flight !

austerwobbler
10th Jan 2010, 08:52
I am not a licensed aircraft engineer but in the PPL training didnt we have to show a basic understanding of the operation of instruments ? I can remember after my skills test while still sat in the aircraft having to explain what pressure's worked each instrument.

ASI operates on dynamic pressure from the pito head and static pressure "depending on aircraft type" the static is a small hole on the side of the plane which is small and can get blocked easily,
It is part of pre flight checks to inspect for blockage's on the static hole as well as the pito head "both equally important"

Austerwobbler :ugh:

Croqueteer
10th Jan 2010, 08:56
:ok: A2B, the secret of flying is "Power plus attitude equals performance" Your training has been a bit lacking.

amostcivilpilot
10th Jan 2010, 09:11
Stratus Fractus

FFS. Only on ******e can such a simple thing run on to 2 pagesive another day to speak s*it on ******e private flying sectionWhile I appreciate that this thread may seem a little less than relevant to some, what is wrong with having a debate about the original topic and the other thread drift points that have been raised.

I fly commercially for a living but I read the private flying section to enjoy the varied grass roots and interesting posts that are generated here. There are a lot of low time and keen pilots and students who can and do learn from what is published here. There is also a lot of drivel but that is the internet.

After almost 9000 hours of aeroplane and helicopter flying I am still learning and want to learn. And if I can advise or help someone else to do the same then where is the issue? The pitot is a simple thing but it has generated a lot of interesting debate so I cannot see your argument against this thread?

AMCP

bose-x
10th Jan 2010, 10:54
My Auster does not have a pitot heater, does this mean I cant go flying?

Final 3 Greens
10th Jan 2010, 11:12
My Auster does not have a pitot heater, does this mean I cant go flying?

Only if the vacuum cleaner isn't working. :}

mad_jock
10th Jan 2010, 12:07
What the discussion does show though is that there are two groups out there.

First group the failure of an ASI or Alt is a problem proberly worthy of a pan maybe a mayday change of pants and many a story in the bar afaterwards.

Second group its mearly a bit of pain but not something to go screaming telling the world about. The only people that get told are the engineers.

Now given that the PPL course is pretty much the same in most countrys how has this come about?

bose-x
10th Jan 2010, 12:13
Because PPL flying seems to attract two types, the live for the moment crowd who recognise that there is risk in life and still know how to have fun and the analyse everything crowd with skills matrices and risk identification paperwork with a chain that starts with an assessment on how safe it is to get out of bed. Options A, stay in bed and possibly get sores, gangrene and die, Option B get up but run the risk of stubbing toe on way to bathroom, get gangrene, die. The risks assessment goes on...

I am the former camp, jump out if bed stand on puppies toys, go flying. I guess that's why I will fly a 70 year old with no pitot heater!11

:p:p:p

xj8driver
10th Jan 2010, 12:19
Smug remarks aren't necessary, Wombat

bose-x
10th Jan 2010, 12:26
Smug remarks aren't necessary, Wombat

Was that aimed at me? I thing it was probably more facetious than smug?
;)

facetious |fəˈsē sh əs|
adjective
treating serious issues with deliberately inappropriate humor; flippant.

smug |sməg|
adjective ( smugger, smuggest)
having or showing an excessive pride in oneself or one's achievements : he was feeling smug after his win.

However I really prefer:

humor |ˈ(h)yoōmər| ( Brit. humour)
noun
1 the quality of being amusing or comic, esp. as expressed in literature or speech : his tales are full of humor. See note at wit .
the ability to perceive or express humor or to appreciate a joke : their inimitable brand of humor | she has a great sense of humor.
2 a mood or state of mind : her good humor vanished | the clash hadn't improved his humor.
archaic an inclination or whim.
3 (also cardinal humor) historical each of the four chief fluids of the body (blood, phlegm, yellow bile [choler], and black bile [melancholy]) that were thought to determine a person's physical and mental qualities by the relative proportions in which they were present.

xj8driver
10th Jan 2010, 12:40
Thankyou for the lesson bose-X, but no, it wasn't aimed at you; if you look back along the thread there's another contributor or two, one of whom is named 'Wombat'

:ok:

IO540
10th Jan 2010, 12:44
What the discussion does show though is that there are two groups out there.

That may be an over-simplification.

There are purely-VFR pilots, and IMHO most of those don't fly if the weather is less than pretty nice, so they won't worry about the pitot heat.

In fact, I don't think a single plane I flew in for my PPL training had a working pitot heater; I always checked the thing for getting warm (as I was told) but it was never significantly warm, whereas my TB20 pitot tube will literally set fire to the plastic cover on it in under a minute or two, and after 30 secs cannot be touched by hand. The schools obviously don't want to spend the 200 on a new tube.

Then you have IFR pilots, most of whom won't fly with significant defective equipment, and rightly so. Single pilot IFR can be hard enough work without putting a banana skin under your feet before even departing...

There is also the slight legal issue of departing with faulty equipment which is a required carriage in the flight manual for night VFR or IFR.

A pitot tube is really cheap to replace so should be fixed without question.

Sure one can fly and land without the ASI but one can get significant errors at temps approaching 0C even in VMC, but these won't initially be obvious so why mess with this at all? I can't see the point. Would one depart with a load of cockroaches bunging up one's static vents? One doesn't need an altimeter to fly and land, either.

mad_jock
10th Jan 2010, 13:02
I think its a bit more than risk assement bose.

It seems there are pilots who have grasped the whole concept of flying. What your actually doing, how your actions alter how the aircraft fly's, why the plane does what it does when you do tamper with it. What you are actually doing with a control input, what the limits are and what is limiting them. They can be 45 hour pilots or 1000 hours pilots it does seem to make much difference.

And then there is another group where flying is a series of rules and regulations with a bit hand eye foot stuff. The reason behined those rules and regulations is not understood. There is a fixation on getting everything "right" the mathamatical solution to a wind correction must be applied to a hold or for that matter a nav leg to the degree in planning. The fact that you have to wag it later on in flight and you will hardly ever fly the heading you planned is missed. The thread on holding is a good example of this.

Again with the say lack of instuments in certain conditions in this thread. There is a group which obviously don't trust physics to continue working after a failure. The instruments are controlling them controlling the aircraft. It is also well known IR problem of fixation on 1 instrument instead of taking the full picture of all the information sources.

I had a stick shaker in the climb one sector. I quickly looked at the attitude and the power settings and the ASI. All were reading that I wasn't anywhere near the stall. So I didn't change anything and asked for the spurious stick shaker QRH card. After the Capatain had run it he was very complementry about the fact I hadn't done a stall recovery which had done to him previously. FO had manged to get them at +20 Vmo with the stick shaker still going and 20degs nose down before he took control. The previous FO had been in the mind set stick shaker equals stall, book says put nose forward until stickshaker stops.

Flying is part science and part art and part rule following. In a perfect pilot I presume they will all have equal bias. But more and more these days the rule following is taught and not really understood leaving the science and the art the disabled siblings.

BackPacker
10th Jan 2010, 13:08
IO540, I think it's even simpler. I think all the pilots on here will not take-off in an airplane while knowing that a certain bit of essential kit is inop. Of course, what one considers essential may vary a bit from pilot to pilot, from flight to flight, and the POH has a few things to say on that as well. And some of us have maybe skipped an item or two (pitot cover anyone?) on the pre-flight check and come to regret that afterwards.

What does differ is the amount of drama we make when discovering something is just not right, in-flight. There's one camp that will make an informed decision about the consequences of the failure and continue or abort the flight as necessary, flying the airplane by feel if necessary, and tell the engineers afterwards. And there's a camp that treats every failure as a mayday scenario, and once safely on the ground they tell the people propping up the bar first, and the engineers later.

I guess one of the differences between the two camps is the amount of training they've had, and the experience they've accumulated. If you've never been trained to land an aircraft without instruments whatsoever, then every instrument failure is an emergency. Just like if you've never been trained to read a map, your GPS failure will constitute an emergency.:ugh:

PH-SCP
10th Jan 2010, 13:13
Always check your pitot heat, no matter if you're planning IFR or VFR.
I usually have a buddy feel the probe while I switch on the pitot heat and look for an ampere load..
A prolonged period of pitot heat with engine off is not good for your battery, specially in the winter weather that is striking Europe right now.
Having your flying buddy feel the heat also avoids burning one's hands..:ouch::ouch::{ These things get very hot.. Be cautious :ok:

IO540
10th Jan 2010, 13:50
The other thing is that the wires to the pitot heater go past the fuel tank, so if the heater is not working, can sure can you be the wire hasn't come off and is about to make a nice spark right where there is a little fuel leak?

;)

Final 3 Greens
10th Jan 2010, 13:53
There are purely-VFR pilots, and IMHO most of those don't fly if the weather is less than pretty nice, so they won't worry about the pitot heat.

True, but if one has a night rating it is pretty foolish to depart into the dark skies without a working pitot heater, even if you do not intend to enter IMC conditions, as inadvertent penetration is easier at night than day.

So depending on the time of the flight, as a VMC limited pilot, I may take a different view about the pitot heater, as I would want a full panel available to get out of IMC safely with my limited instrument skills.

bjornhall
10th Jan 2010, 14:08
Checking the pitot heat for a day VFR flight is neither a requirement
, nor a necessity. It is an opportunity, and a service to the next pilot.

If you discover it to be inop before a night VFR or IFR flight, the flight is no-go (unless you can get it fixed immediately, which you usually can't). If you discover it to be inop before a day VFR flight, you can write it up, the flight is a go anyway, and there is a chance for maintenance to fix it before the next IFR or night VFR flight.

Regarding the two groups theory, it is rather simpler than what is being said. One group looks at new ideas as something to be looked into, assessed, and then adopted or disgarded after careful consideration; or as something to be ignored, at their own pleasure. The other group looks at new ideas as something that is different from what they do, therefore wrong.

One group thinks they are the only ones who know how to have fun, and look with contempt at those whose idea of a good time differ. The other group couldn't care less what the first group thinks. :p

And most significantly: One group is focused on their own flying, and the other group is concerned with how others fly. I'm in the first group! :ok:

edited to add: it might be a requirement depending on jurisdiction, but since a few previous posters take a rather dim view on regulations, maybe we can leave that out... ;)

mad_jock
10th Jan 2010, 14:10
as inadvertent penetration is easier at night than day.

Wise words 3Greens ;)

austerwobbler
10th Jan 2010, 14:46
"you should know an Auster dont go quick enough to block a pito head"


"and bugs av time to fly out the way" :ok:

yeeha Austerwobbler "roll on summer"

Big Pistons Forever
10th Jan 2010, 17:39
I routinely cover the ASI when I fly with students as it is a great way to make the point that attitude + power really does equal performance. This is especially effective on final as students are continually amazed at how well they can judge the airspeed just by assesing the attitude and noting the power setting.

As for checking the pitot heat before a day VFR flight..... I would suggest that care should be taken to ensure that one has not fallen into the trap of treating every check action as having an equal importance to safe flight, which is absolutely not the case, and making sure there is full understanding on "why" you are doing something not just on "what" you are doing.

IO540
10th Jan 2010, 18:25
This is especially effective on final as students are continually amazed at how well they can judge the airspeed just by assesing the attitude and noting the power setting.

One hopes that none of your students stalls and spins on the base to final turn and kills themselves - while trying to work out what speed they have from the power and pitch :)

mad_jock
10th Jan 2010, 18:57
How can they stall if they have the correct attitude?

Big Pistons Forever
10th Jan 2010, 19:29
One hopes that none of your students stalls and spins on the base to final turn and kills themselves - while trying to work out what speed they have from the power and pitch :)

Sigh.....

Ok for those especially pedantic I will amplify my comment.

1) Since I have to be in the aircraft to cover the airspeed indicator I am hardly going to do in an attitude/configuration where there is any chance of the aircraft stalling. In the .000000001 % chance of a stall there will be no spin because I emphasize the importance of controlling yaw from the very beginning of stalling exercises

2) I cover the airspeed indicator with a little yellow sticky. It can be easily ripped off if it becomes desirable to see the ASI.

3) Since the point of the exercise is to convince the student that they can in fact make a very accurate estimate of the airspeed by looking out the windshield at the attitude and noting the power, in practice I show them ASI at regular intervals after asking them to tell me what they think the ASI is reading. They very quickly will be within 2 or 3 knots of the actual airspeed

4) Like everything else in flight training there is a time and a place for every exercise. If the student is allready overloaded with heavy ATC or other issues there is no value to this exercise. I wait for low traffic density and smooth air before introducing this exercise.

dillardrg
10th Jan 2010, 19:44
Sorry about continueing the thread drift, but I agree with flying by attitude awareness.
Most of my clients come out of "spam cans" ie Cessna, Piper, and Cirrus. Virtually all of them chase the airspeed indicator and altimeter and invariably do better when flying attitude alone. They are much smother and less choppy on the controls, and all are surprised at how much information is outside the window.
I like to think that they all go home a better pilot. I know they have more fun.
I don't mean any slight to the aircraft mentioned above, they all do a good job at what they were designed to do.

Ron
advancedtailwheeltraining.com

Chuck Ellsworth
10th Jan 2010, 20:48
Please don't make fun of an old man just short of being senile, but when we are talking about Pitot heat in a simple airplane and the risk you face if it is not working how do you get enough ice to block the airspeed indicator?

If you are slow enough in your thinking process to actually get in that situation would you rather have a heated pitot or wing anti/de ice?

If an airplane needs heated pitot/'s would it not follow it should have wing ice protection also?

IO540
10th Jan 2010, 21:06
I think Chuck that the pitot can accumulate some ice - enough to affect the reading - long before any significant amount appears on the lift surfaces. I have seen ASI effects when there was no visible ice on the wing leading edges, and in apparent VMC.

Big Pistons Forever - I get your drift and don't disagree, but while it is trivial to establish the speed/power/pitch relationship in level flight, it is less obvious when e.g. descending especially if descending steeply, and with various flap settings, and turbulence. Sure one can do it, by applying heavy margins, but I would still not knowingly deprive myself of the ASI. It remains a vital instrument, and more so if one is going to do a max performance landing on a runway which is anywhere near close to the lower limit.

SpannerInTheWerks
10th Jan 2010, 21:19
How do you think instructors fly an approach?

I've always used the 'Luke Skywalker approach'.

Just close your eyes and let the Force be with you!!!

SITW :}

Chuck Ellsworth
10th Jan 2010, 22:36
I think Chuck that the pitot can accumulate some ice - enough to affect the reading - long before any significant amount appears on the lift surfaces. I have seen ASI effects when there was no visible ice on the wing leading edges, and in apparent VMC.


Icing can come in many forms, I have had ice build up so fast I was unable to maintain altitude in less than three minutes from the time it started until I could not maintain, and yes there are times when ice can affect the airspeed indication but it is unlikely youn would be flying a 172 in those conditions anyhow and even if the A/S did quit working you can or still should be able to safely fly it.

Pilot DAR
10th Jan 2010, 22:45
Some in the group talking about not really needing an ASI (which includes me), are offering up "attitude" as an appropriate supplement to ASI information. Yeah I agree. However (noting a remark about attitude not being so useful on extremely steep approaches) brings me to point out that attitude is only a part of the "feel" technique of flying I promote. letting alone the seat of the pants thing, it's very simply a pitch force you feel in the controls.

Haven't we all noticed that while flying, (trim and power remaining unchanged) It requires a pull to fly more slowly, and a push to fly faster? All cerified planes are the same in this respect, it is a certification requirement. For this very reason. In unacellerated flight ('cause you can't get into accelerated flight without pulling on something), no matter what your attitude, you're not going to slow down, unless you pull! Worried about stalling? Push, and you're worries (about stalling) are over! No matter what the attitude or speed. (Caution, other worries may become rapidly appropriate!).

If you're hurtling along in the mighty spam can, the the ASI quits, don't start pulling ans pushing on things a lot, you'll be fine! When you finally have to approach and land, take it slow and easy, be aware of your attitude by what ever means you have, and pay attention to the pull force you're putting in. If it's increasing, you're going more slowly! If you're afraid of stalling while doing this, I suggest that recurrant training is a good idea.

ASI not vital to flight safety for a compotent pilot - try it before you knock it!