IMC flights - after start checks of instruments

[donkey89]

Hi,

Having recently re-started some instrument training after a long gap and change from my old flying instructor I just have a query about how in-depth the checks of the flight instruments/radio navigation equipment need to be after start/prior to departure.

The first instructor I had went into checking the OAT, AI, Altimeter, DG, TC etc etc etc as well as comprehensive checks of the VOR/ADF/Com radios.

My new instructor has not mentioned any of this and no checks are ever made (as indepth as above or of the Nav radios/displays) prior to departure until they are identified in the air.

Can any IMC/IR instructors or pilots out there kindly share their views or preferred method of pre-departure instrument checks before an IMC flight?

Thanks in advance, and apologies if this sounds like a stupid/basic question.

[IO540]

You should definitely check all avionics before you start to taxi.

Obviously some things can't be checked e.g. if there is no receivable VOR then you can't check that, but you should still tune in a VOR/DME if it is to be used after departure.

For an IFR flight, you need to start ahead of the plane and stay that way.

Also, in some scenarios you may depart from an airport which is below minima for getting back in right away, etc.

My new instructor has not mentioned any of this and no checks are ever made

:ugh:

[Cusco]

The more checks you can do on the ground (In-range VORs ADF etc.), the fewer you need to do when airborne when the work load will ramp up pretty quickly.

Similarly Compass/DI should be checked.

IMHO the instructor who lets you take off 'naked' with no checks is talking a big risk.

[foxmoth]

Basic instruments should be checked every flight anyway - I can go through them all if you want, but it would be fairly long winded and you should have learnt this in PPL training. ALL radios should be turned on after start and checked for sensible indications if possible but at some airfields this is not possible as there may not be suitable aids within range. I would have thought though, if you are part way through, YOU should be doing all these checks without the instructor having to say anything, though personally I would be correcting you if you were not.

[donkey89]

That's the sort of response I expected to be honest - I appreciate this is something I should be taught, and realise that I'm not being taught in enough detail what to check, but my instructor keeps coming out with "oh don't worry that's not necessary"

I'm actually only a couple of hours into my training, and those 2 hours were a year ago so I'm pretty much starting from scratch.

Basic checks I do on every flight, but I am not sure "how" to check each of the more important instruments (nav etc)...I haven't been told what I should be checking FOR.

Would someone mind giving me a brief rundown that I can at least discuss with my instructor?

Once again, apologies for the ignorance.

[IO540]

To put it simply, find yourself a decent instructor, who has flown somewhere for real.

Get some old ex airline pilot type, perhaps. Too many PPL instructors are just hour builders, and there are some real old space wasters hanging in there too.

You need to learn the basic principles of IFR, which means using navaids. Plus GPS too, which is today's main method of nav.

You also need to learn about cockpit organisation, which is important in keeping one step ahead of the plane.

[foxmoth]

For all radio navaids I use SID (Select/Identify/Display). So - tune your aid, ident it then check the display:-
VOR - check that the inbound to the VOR displays correctly with the bar centered and TO displayed, move the OBS 5 degrees, should get half deflection, 10 degrees and the bar should go full deflection (in the correct direction), check FROM as well if being thorough.
DME - check sensible distance

ADF - Needle pointing sensibly, check it stays sensible whilst taxying.

Use SID in the air as well whenever you use an aid.

For GPS - they will have their own checks which you should familiarise yourself with, but I will always check that the map display is sensible.

But as IO540 says, best is to find an instructor who takes all this seriously!

[justmaybe]

I assume this probably relates to IF trg in a single engine a/c. The majority of such a/c have single system IF fit, without any backup systems. It may not be a big deal to skip checks for sim IF, but it is extremely back practice. Flying actual IF in SE a/c can be fraught with difficulty and danger, and it is imperative that students are taught and disciplined in carrying out full and meaningful thorough pre-flight checks of both primary flight instruments and navaids. If it is not happening for you, seriously consider the quality and content of your course instruction.:confused:
Couldn't disagree with both Foxmoth and 10540 - practical and sensible contributions

[Cusco]

Where do you fly from and what navaids are 'in range' (VOR? DME? ILS? NDB?) when you're sitting on the ground going through your checklist?

And what Nav/comm equipment do you have: For example do you have two VOR/CDI/GS or one? One altimeter or two?

This might answer the question on how to check whatever Navaids you have available to you.

But , to be brutally frank, as others have said, you need a change of instructor.

[HighFlyer75]

I was taught to do taxi checks as follows (making very slight turns while taxiing);

Airspeed Indicator- Indicating correctly (usually zero during slow taxi)
Attitude Indicator - Erect, stable and no errors
Directional Gyro - Free moving and turning in correct direction
Turn Coordinator - Moving in opposite direction of the turn
Altimeter - Within 75 feet of airfield elevation with pressure set
Vertical Speed Indicator - Reading zero (or whatever represents zero)
Magnetic Compass - Proper fluid levels, moving in correct direction, no leaks

I was also taught as part of the pre takeoff checks to set the nav frequencies for the first leg of the flight in NAV1 and to set the appropriate frequency for my departure airfields runway in NAV2 (and have the approach plates handy) in case I need to turn back for any reason and do an instrument approach shortly after takeoff.

[Contacttower]

My new instructor has not mentioned any of this and no checks are ever made (as indepth as above or of the Nav radios/displays) prior to departure until they are identified in the air.

Have you put it to him that when you come to the flight exam the examiner will expect you to do those instrument checks which he seems to think are unnecessary?

I mean come on he must of sat an IMC/IR flight exam at some point himself?...I find it hard to believe he never did any instrument checks on the ground during his training...

Are you doing IMC or full IR? Reason I ask is that I'd be very surprised if an instructor employed by an FTO offering full IR training would not teach instrument checks. For IMC rating the instruction can be surprisingly dodgy though...

[Genghis the Engineer]

I'm with IO540 and Cusco. Get a new instructor, 2 sorties of instrument training with no teaching or demonstration of instrument checks this idiot is bad news.

Check everything that can feasibly be checked, before brakes-off.

DME - ident, check for sensible reading
VOR(S) - ident, check for sensible reading(s), cross-check if multiple instruments, check 5 and 10 degrees off radial and on reciprocal
ADF - ident, check for sensible reading, switch to ANT, check points at antenna wing (normally port)
GPS - check receiving and giving appropriate position report
Displays - flags out if idented
AI - erect and caging (unless venturi driven)
DI - stable
Altimeters - cross-checks, within 100ft of each other and airfield elevation correct at airfield QNH

Then when taxiing, check during turns:

- ADF tracking
- DI & compass tracking in turn
- Turn needle into turn, slip ball out of turn
- VOR displays remaining stable
- AI remaining stable

To be honest, I'd do all of this and teach this for VFR flights as well. If the kit is in the aeroplane, the pilot should know how to use it and whether it is serviceable or not. It is merely more important for IMC flight.

G

[Big Pistons Forever]

If you are not doing an instrument check before an IMC flight (pretend or real) you might as well skip the runup too...after all what you don't know can't hurt you right :rolleyes:

I second the advice about firing your instructor.

A few more points on instrument checks and please note these are meant for your average club fixed gear simple trainer with a standard basic 2 NavComs, ADF, and transponder radio package. First off at the risk of being a bit pedantic, there are actually two separate and distinct pretakeoff IMC checks. Instruments (flight and flight system) and radios. They should IMO be handled as two distinct checks to avoid missing things.

So for Instruments additional considerations

1) AI: yes check for erect and stable but also note on your walk around what the resting attitude of the aircraft is. Most little Cessna's and Piper's sit on the ground at 2 to 3 degrees nose up. The horizon bar should reflect this. Also if the aircraft is sitting on level ground the roll index (the little orange marker at the top of the instrument) should be exactly at zero bank. When the AI's get old, or are carelessly mounted out of level then you get a permanent bank error. Unnoticed this can be disconcerting as the aircraft will start to turn every time you level the wings.

2) DG: comparing the mag compass is not much help if the compass is off which in my experience is pretty common. So a parallel taxiway is a good double check and of course the line up check will give you a last chance to make sure the DI is properly set.

3) The Turn Coordinator. When you first turn on the master as part of the walk around listen for the sound of the instrument spinning up. No noise means the instrument is U/S so you find out right away. If it is making nasty grinding noises then you probably do not want to fly actual IMC as it is the only thing keeping you alive if the vacuum system fails.

4) ASI, ALT, ROC. I think these checks have been adequately covered in previous posts

Flight Instrument Systems. That is the systems that power/affect flight instruments. These are the vacuum system, electrical system and the alternate static source. IMO this is one area where flight schools do not generally do a good job. Things to check are as follows

5) Vacuum system. The AI and DG only work if they get vacuum air at the right pressure. Checking that the suction gauge is reading the right value is a vital pretakeoff and regular inflight check. It is important to note that too much suction is almost as bad as too little.

6) Electrical system. Your average club trainer has no electrical system redundancy so every part of the system has to be healthy. In particular
the battery should be at or near full charge before taking off in IMC conditions. If the battery is showing a high rate of charge on the ammeter than you should wait on the ground until the charge rate has dropper to normal before taking off. It the charge rate does not come down than you should not takeoff. Also obviously, any indication that the charging system is not charging (ie a negative value on the ammeter) would also be a no go item.

7) alternate air: Make sure you know where the control is, that it actually moves and that it is in the normal position

Radios:

8) A full VOR check is
- a clear ident is heard
- needle centered from with the radial cross checked to your geographic
- needle full deflection both ways with a 10 deg OBS change
- to/from flag flips at 90 deg to the radial you first centred the needle
- to flag with needle centered with OBS turned 180 deg
- No more than 4 deg needle split between two VORs with the same OBS value.
- The localizer and glideslope is not checked when you check the VOR so if available tune and identify the approach aid and make sure the needle deflections are sensible ( ie GS up and loc needle in the direction of the runway centerline).

9) ADF: A full ADF check is:
- Select "Ant" and listen for a clear and relatively static free ident and needle parked pointing at left or right wing tip
- Select ADF for a station ahead of the aircraft and needle moves to bearing and steadies
- repeat for a station behind you
(Note if there are no nearby aeronautical stations a commercial AM radio station works as well although the needle will usually not be a steady)

10) Comms:

- start by using the test switch to break the squelch and then set the volumes
- comm check both radios.

11) Transponder:

- check the response light (ie the little orange or green light that blinks every time the transponder is interrogated) illuminates when the transponder is switched to the test position

12) GPS: (Non IFR approved system)

- Observe system test pages, data base validity date and verify flight plan waypoints, if loaded in flight plan page

[GeeWhizz]

Not much I can add here, however I've not too long ago completed IMCr training and test.

In line with what all others have suggested so far, I would check as many of the instruments as possible prior to taxi. If for nothing else than to reduce the amount of instrument set-up time during vital actions, thereby reducing time of the ground (especially significant if costs are brakes off to brakes on!). Also if as many nav aids/radios are checked and set prior to taxi the vital action of recapping and vocally stating what will need to be identified when within range IMO shows a little planning nous. That said there are one or two things that I'd like to suggest.

During the after start/prior to taxi checks, should a VOR be out of range whilst on the ground, perhaps your airfield has an ILS you could set and check that the instrument is actually working? Notwithstanding normal tune/ident/check/use procedures, if it does correctly pick up the ILS then I would believe there's a greater liklihood that it will work when within range of a VOR (a sanity check).

Remember also that NDBs are not line of sight. If your airfield doesn't have one perhaps a nearby airfield will? Again whether it was able to be checked or not during pre-taxi, a vocal 'ADF tuned to xxx, to be identified once airborne' is all that is needed during vitals.

My final nugget of inexperienced wisdom is that DME will tune to many aids: ILS, TDME, military TACAN. Thus for example if your ILS is on maintanance and hence nil positive ident, tune to something else for your static check if possible, re-set to a useful frequency with a vocal sanity-check as above.

As for taxi checks all of the advice has been given already. I'm only to add that the aircraft checklist, if a comprehensive post-start instrument check has been completed (something like I'm suggesting here), should be adequate. A big but... be prepared to carry out extra checks as you see fit if you are left unsure of any piece of equipment.

Edit:

Very quickly on OAT and 0deg isotherm: At some point during the checks, be they start/after-start/taxi/vitals, when 'pitot heat as required' comes up this is the perfect opportunity to explain to an examiner/self brief at what altitude the 0deg isotherm is. At this point you can state whether you can or cannot fly into icing conditions, is there any visible moisture, what FL/alt could you fly to before airframe icing could realistically occur, and what icing checks you will carry out in the air. ;)

[Duchess_Driver]

I'm actually only a couple of hours into my training, and those 2 hours were a year ago so I'm pretty much starting from scratch.

Whoa..... Before we start hanging, drawing and quartering IMC instructors lets just take a step back. WHILST I WHOLEHEARTEDLY CONCUR with the carrying out of flight instrument checks before departure and checking of the nav stack as best you can I do believe in not overloading my students too early.

With my students, second sortie is still developing basic IF skills on full panel and partial/limited panel and intro to completing the basic climb,cruise and descent checks whilst still keeping the plane under so sort of control. All of this is done (where possible) in VMC under VFR without reference to any VOR's, ADF's, DME's or GPS. I do, however, avail myself of a traffic service when operating OCAS.

3rd hour is unusual attitudes, compass turns, timed turns, ATIS etc .... still nowhere near the nav stack.

Any IMC student who is asking what checks they should be undertaking for the basic flight instruments / electrial systems prior to departure, IMHO, should not really be embarking on the IMC course - rather they should be seeking out their PPL instructor and asking for a refund.

[IO540]

Any IMC student who is asking what checks they should be undertaking for the basic flight instruments / electrial systems prior to departure, IMHO, should not really be embarking on the IMC course - rather they should be seeking out their PPL instructor and asking for a refund.

Well, yes, that's also true, but there would be an awful lot of refunds going on :)

[foxmoth]

With my students, second sortie is still developing basic IF skills on full panel and partial/limited panel and intro to completing the basic climb,cruise and descent checks whilst still keeping the plane under so sort of control. All of this is done (where possible) in VMC under VFR without reference to any VOR's, ADF's, DME's or GPS. I do, however, avail myself of a traffic service when operating OCAS.

That is fine, but this is a student who had already covered this aspect so should be encouraged to continue with this. It also worries me that when queried about this the instuctors reply seems very offhand "oh don't worry that's not necessary", if the instructor when questioned been saying "We will be covering that when we get to the radio nav phase" that would be fine - though as a good example it would be better if he was at least doing these checks himself.

[Lightning Mate]

Good grief....................................................... .......................
............................................................ ...............................

[RodgerF]

If the training is being done in real IMC not checking the instruments and aids is simply unacceptable. I do not see how doing the radio aids checks from the start of the course will overload the student, as the aircraft is not flying. I think that some instructors just want to get flying and therefore earning as quickly as possible.

Not sure if it has been mentioned already but the OAT gauge should be cross checked against the ATIS.

The GPS checks should include checking the satellite status page ensuring the EPE is less than 50ft. DOP less than 4, if HUL is calculated less than 0.3nm. On the Garmin 430/530 the first test page should be cross-checked against the CDI or HSI presentation to verify the halfscale deflections, the annunciator lights and that the bearing is consistent with that selected and changes with the OBS.

I have encountered IMC rated pilots who do not know what a Radar Vectored ILS is and did not know what circle to land procedures were. I also know of instructors qualified to teach the IMC rating who will not fly in IMC.

[GeeWhizz]

Not sure if it has been mentioned already but the OAT gauge should be cross checked against the ATIS.

What an excellent point. Hold my hands up to this, I'd not thought about it before. Maybe due to there being extremely little difference between gauge ATIS and met briefings, but then probably due to ignorance. But thanks to RodgerF for sharing that now, before it catches me out later! :=

I have encountered IMC rated pilots who do not know what a Radar Vectored ILS is and did not know what circle to land procedures were.

This is really surprising. In my mind if everything goes wrong in IMC I'd gladly let a controller do the navigation whilst I fly the aeroplane in the direction I'm told to. Even go one better and let them navigate all the way to DA/H on an SRA or PAR! Vectors is vectors :ok: