Know the aircraft systems?
Moderator
Thread Starter
Join Date: Mar 2003
Location: Orlando, Florida
Age: 69
Posts: 2,586
Likes: 0
Received 0 Likes
on
0 Posts
Know the aircraft systems?
Couldn't decide whether to go into Pro Training or Private Flying - you guys lost the toss as there may be many students and pilots lurking in here who have not yet admitted to themselves that they don't "know their aircraft systems".
There is some stuff you can, effectively, forget - like "What should the tyre pressure be in the main wheels?" (Provided you know where to look when you suspect that the pressure is too low) - but there's some very basic stuff that you really should know.
I've spoken to quite a few students who were putting themselves forward as candidates for 'skill tests'.
I ask many of them, "What does this gauge marked Suction indicate?" After they answer, I ask, "So what if it suddenly drops down to indicate zero whilst in flight? What would you expect to happen, or what would you do about it?"
Answers have included ;
"It shows the amount of cooling air flowing over the engine - if it dropped to zero the engine would overheat and I'd land in a field".
"It shows the fuel pressure from the main tanks to the engine (Cessna) - if zero, the engine would stop" (Had this TWICE in one week - both students had the same, instrument rated, instructor).
"It shows the amount of air from an engine driven pump - can't remember what it does. If it dropped to zero - forced landing in a field if not near an airport"
Asked one guy (an IMC candidate) to describe to me (on a white board), the layout and "power" sources (pitot/static, static, suction gyro, electric gyro) of the standard 'six pack' of instruments on his PA28 flight panel. He found it very amusing that he couldn't tell me - thought it was really funny (until I explained he was presenting himself for test).
These are some scary answers to very basic questions. There are harder ones like "How many fuel drains does this aircarft have?" or "What's this extra pitot tube thing sticking out of the cabin wall on the Piper Arrow?". "No idea", is the normal reply. Then why are you flying it??
"What does it mean (what can you say "for sure") if one of the little green lights doesn't come on when you select undercarriage down?"
How many said "A wheel hasn't come down". Think again.
Rant over.
There is some stuff you can, effectively, forget - like "What should the tyre pressure be in the main wheels?" (Provided you know where to look when you suspect that the pressure is too low) - but there's some very basic stuff that you really should know.
I've spoken to quite a few students who were putting themselves forward as candidates for 'skill tests'.
I ask many of them, "What does this gauge marked Suction indicate?" After they answer, I ask, "So what if it suddenly drops down to indicate zero whilst in flight? What would you expect to happen, or what would you do about it?"
Answers have included ;
"It shows the amount of cooling air flowing over the engine - if it dropped to zero the engine would overheat and I'd land in a field".
"It shows the fuel pressure from the main tanks to the engine (Cessna) - if zero, the engine would stop" (Had this TWICE in one week - both students had the same, instrument rated, instructor).
"It shows the amount of air from an engine driven pump - can't remember what it does. If it dropped to zero - forced landing in a field if not near an airport"
Asked one guy (an IMC candidate) to describe to me (on a white board), the layout and "power" sources (pitot/static, static, suction gyro, electric gyro) of the standard 'six pack' of instruments on his PA28 flight panel. He found it very amusing that he couldn't tell me - thought it was really funny (until I explained he was presenting himself for test).
These are some scary answers to very basic questions. There are harder ones like "How many fuel drains does this aircarft have?" or "What's this extra pitot tube thing sticking out of the cabin wall on the Piper Arrow?". "No idea", is the normal reply. Then why are you flying it??
"What does it mean (what can you say "for sure") if one of the little green lights doesn't come on when you select undercarriage down?"
How many said "A wheel hasn't come down". Think again.
Rant over.
Join Date: Sep 2004
Location: inner suburbia
Posts: 370
Likes: 0
Received 0 Likes
on
0 Posts
Not all aircraft of a particular type will have exactly the same systems.
eg. whilst most GA aircraft have their DI 'powered' by suction there are quite a few electrically-driven ones installed.
Golly.. is that system still been used ?. 
(I thought it had been disabled years ago.)
How much detail do you want ?
Are you expecting your students to have an intimate knowledge of the entire electrical system and the undercarriage mechanicals ?
I'm more content to simply know what I can and should do if a fault manifests itself during flight.
Having said that, I do agree that some basic systems-knowledge is vital, even for non mechanically-minded aviators.
eg. whilst most GA aircraft have their DI 'powered' by suction there are quite a few electrically-driven ones installed.
"What's this extra pitot tube thing sticking out of the cabin wall on the Piper Arrow?". "No idea", is the normal reply. Then why are you flying it??
(I thought it had been disabled years ago.)
"What does it mean (what can you say "for sure") if one of the little green lights doesn't come on when you select undercarriage down?"
Are you expecting your students to have an intimate knowledge of the entire electrical system and the undercarriage mechanicals ?
I'm more content to simply know what I can and should do if a fault manifests itself during flight.
Having said that, I do agree that some basic systems-knowledge is vital, even for non mechanically-minded aviators.
Join Date: Oct 2004
Location: UK
Posts: 32
Likes: 0
Received 0 Likes
on
0 Posts
Well said Keygrip, with you on that one 100%
Biggles in oz - where do I start?
You should know EXACTLY what feeds what in each and every aircraft you fly so you know what instruments you can rely on if your suction, electrics or pitostatic systems fail. Common sense!
YES!!
Although on many training aircraft, the gear lowering function has been disabled, that little horn and flashing light still operate, always handy to know what things like that are. There are also many aircraft with that system still fully operational.
If you fly an aircraft you should know exactly what all the levers bells and whistles do! A light aircraft isn't exactly a complex machine, a good understanding can be achived in only a few hours of study i.e READ THE POH.
If you don't know what it does, how do you know what effect it will have if it's broken????
......and there are those of us who realise that there is not a checklist for every eventuality, and realise that it's often aircraft knowledge that enables us to develop a solution to any given situation.
*** KNOWLEDGE = AIRMANSHIP ***
Biggles in oz - where do I start?
Not all aircraft of a particular type will have exactly the same systems.
Golly.. is that system still been used ?.
Although on many training aircraft, the gear lowering function has been disabled, that little horn and flashing light still operate, always handy to know what things like that are. There are also many aircraft with that system still fully operational.
If you fly an aircraft you should know exactly what all the levers bells and whistles do! A light aircraft isn't exactly a complex machine, a good understanding can be achived in only a few hours of study i.e READ THE POH.
If you don't know what it does, how do you know what effect it will have if it's broken????
I'm more content to simply know what I can and should do if a fault manifests itself during flight.
*** KNOWLEDGE = AIRMANSHIP ***
Join Date: Oct 1999
Location: Anywhere
Posts: 2,212
Likes: 0
Received 0 Likes
on
0 Posts
I'm with Keygrip.
All the questions he's posed are basic knowledge, which should be answered straight off the top of your head. Some of those answers, especially for the more experienced candidates (IMC type) are positively frightening.
Another sympton of the "know the minimum to get by, someone else will spoon feed me" society that we seem to live in these days perhaps? How many of these guys have actually picked up a book and done some study for themselves - I think that's a pretty obvious answer.
All the questions he's posed are basic knowledge, which should be answered straight off the top of your head. Some of those answers, especially for the more experienced candidates (IMC type) are positively frightening.
Another sympton of the "know the minimum to get by, someone else will spoon feed me" society that we seem to live in these days perhaps? How many of these guys have actually picked up a book and done some study for themselves - I think that's a pretty obvious answer.
Join Date: May 2003
Location: UK
Posts: 278
Likes: 0
Received 0 Likes
on
0 Posts
What's this extra pitot tube thing sticking out of the cabin wall on the Piper Arrow?
However, I hope to be flying an Arrow which I know has this “thing sticking out of the cabin wall” (port side). No doubt I'll be told when the time comes, but would be grateful if somebody could enlighten me as to its purpose now. Anticipated thanks.
Helicopter Pilots Get It Up Quicker
Join Date: Jun 2001
Location:
Posts: 885
Likes: 0
Received 0 Likes
on
0 Posts
Whilst I agree with what you re saying about basic knowledge of the type you re flying - particularly for a checkride...
Doesn't a large(r) part of the blame lay with the instructors, for signing off a student for the checkride when they clearly aren't ready and for not covering the basics during training?
I accept the responsibility is also on the student to LEARN the material but if they don't know the material exsists...
PW
Doesn't a large(r) part of the blame lay with the instructors, for signing off a student for the checkride when they clearly aren't ready and for not covering the basics during training?
I accept the responsibility is also on the student to LEARN the material but if they don't know the material exsists...
PW
And, beating the drum about one of my pet hates - how many clubs treat operators manuals as if they were classified documents, where the pilots are never told they exist, and if they find out are only allowed to read them in a locked room?
G
G
Guest
Posts: n/a
Keygrip,
I'm a little puzzled. You can't say anything "for sure" if there isn't a green light can you? I mean multiple things can prevent the light from glowing regardless of the gear position. I would have though that the only thing you can practially say for sure, is that the gear is down and locked if the green light is on. This one needs explaining to me I fink 
"What does it mean (what can you say "for sure") if one of the little green lights doesn't come on when you select undercarriage down?"
How many said "A wheel hasn't come down". Think again.
How many said "A wheel hasn't come down". Think again.
Join Date: Nov 2000
Location: Cambridge, England, EU
Posts: 3,443
Likes: 0
Received 1 Like
on
1 Post
When I first got my PPL I knew something the examiner didn't, something slightly obscure along the lines of whether or not the oil pressure gauge would continue work in the event of certain types of electrical failure.
He said it wasn't fair because I only had to learn the systems of one aircraft, whereas he had to know several and his day job involved having to have a vastly more detailed knowledge of a Herc (or Tristar or whatever it was) than he needed of a 152.
He said it wasn't fair because I only had to learn the systems of one aircraft, whereas he had to know several and his day job involved having to have a vastly more detailed knowledge of a Herc (or Tristar or whatever it was) than he needed of a 152.
Potentially not a good excuse, the aviation gods don't care whether it's fair or not when something ceases to behave in the air and you need to make your best judgement on what to do.
That said, we'll never any of us know our way round any aeroplane as well as we'd like - but we have to keep trying.
G
That said, we'll never any of us know our way round any aeroplane as well as we'd like - but we have to keep trying.
G
Bravo Keygrip! 
High Wing Drifter, what you can say for sure is that the light isn't on when it should be on. That's important because that leads directly to the next question: 'Why?'
Then comes the fault finding. Is something causing a the light to be dim? In a Piper that would be the nav lights are on, in a Cessna the 'eye' on the light is closed. Is the bulb blown? Swap the lights around. Maybe it's the consequence of another system's problem eg alternator failure & flat battery. Is the gear really down? Did you really move the lever like you thought - or forgot. Use whatever equipment is installed to verify eg mirrors, mechanical indicators, LOOK(!) and of course the alternatate extension mechanism(s).
-----
4. Corrosion resistance
High Wing Drifter, what you can say for sure is that the light isn't on when it should be on. That's important because that leads directly to the next question: 'Why?'
Then comes the fault finding. Is something causing a the light to be dim? In a Piper that would be the nav lights are on, in a Cessna the 'eye' on the light is closed. Is the bulb blown? Swap the lights around. Maybe it's the consequence of another system's problem eg alternator failure & flat battery. Is the gear really down? Did you really move the lever like you thought - or forgot. Use whatever equipment is installed to verify eg mirrors, mechanical indicators, LOOK(!) and of course the alternatate extension mechanism(s).
-----
4. Corrosion resistance
Join Date: Aug 2000
Location: Norfolk
Posts: 1,966
Likes: 0
Received 0 Likes
on
0 Posts
4. On certain aircraft it lets you know exactly where to park them in the hangar as all you need do is sit them over the corresponding marks on the floor?
On a more serious,
on analysis can give a clue to the state of the internals.
Stik
On a more serious,
on analysis can give a clue to the state of the internals.
Stik
Guest
Posts: n/a
Englishal,
I would venture that the missing item is the constant speed unit.
Tinstaafl,
Thanks for your input. I was more puzzled by Keygrip saying that you know something for sure if the light isn't on. FWIW, faulty microswitches seem to be a very common, but as you have said there are a veritible multitude of possible problems.
I would venture that the missing item is the constant speed unit.
Tinstaafl,
Thanks for your input. I was more puzzled by Keygrip saying that you know something for sure if the light isn't on. FWIW, faulty microswitches seem to be a very common, but as you have said there are a veritible multitude of possible problems.
Moderator
Thread Starter
Join Date: Mar 2003
Location: Orlando, Florida
Age: 69
Posts: 2,586
Likes: 0
Received 0 Likes
on
0 Posts
High Wing - Tin. had the answer.
The only thing you know for sure is that the light isn't on. The gear may be down, locked and happy - could be the bulb/lamp (*delete as appropriate for your own country) or any one of numerous things that kick you into trouble shooting.
Student in a PA44 saw two greens, immediately went for circuit breakers to check "all in". When advised that they don't have INDIVIDUAL breakers (per wheel) he then immediately assumed that the gear was locked up. No other option. Lamp not lit must equal gear not down.
Was just a loose bulb/lamp. Anybody remember Eastern Airlines flight 401?
Pilotwolf - ABSOLUTELY the instructors fault - IMHO. (I was waiting for somebody to point it out - you win the first prize).
Genghis - also agree 100% (though MOST of the US schools make the students buy their own copy of the Pilot Information Handbook [unnoficial copy of POH]).
The only thing you know for sure is that the light isn't on. The gear may be down, locked and happy - could be the bulb/lamp (*delete as appropriate for your own country) or any one of numerous things that kick you into trouble shooting.
Student in a PA44 saw two greens, immediately went for circuit breakers to check "all in". When advised that they don't have INDIVIDUAL breakers (per wheel) he then immediately assumed that the gear was locked up. No other option. Lamp not lit must equal gear not down.
Was just a loose bulb/lamp. Anybody remember Eastern Airlines flight 401?
Pilotwolf - ABSOLUTELY the instructors fault - IMHO. (I was waiting for somebody to point it out - you win the first prize).
Genghis - also agree 100% (though MOST of the US schools make the students buy their own copy of the Pilot Information Handbook [unnoficial copy of POH]).
Grandpa Aerotart
Ok how about this;
What does MP indicate?
Which engine control/s effect mixture?
Which engine control controls power from 0-100%.
First action after complete/sudden power loss?
Gotta agree that not knowing the emergency auto gear lowering system in an Arrow is pretty bad...have an engine failure and suddenly the gear goes down doing awful things to glide ratio....and when no knowledge of said system is evident just crash I guess.
At the big end of town the amount they want us to know about systems in the Boeings etc is truly scary...virtually nothing...driven it seems by product liability concerns...don't think just do what we tell you too in the QRH.
Perhaps that mentality has trickled down to GA?
What does MP indicate?
Which engine control/s effect mixture?
Which engine control controls power from 0-100%.
First action after complete/sudden power loss?
Gotta agree that not knowing the emergency auto gear lowering system in an Arrow is pretty bad...have an engine failure and suddenly the gear goes down doing awful things to glide ratio....and when no knowledge of said system is evident just crash I guess.
At the big end of town the amount they want us to know about systems in the Boeings etc is truly scary...virtually nothing...driven it seems by product liability concerns...don't think just do what we tell you too in the QRH.
Perhaps that mentality has trickled down to GA?
Join Date: Apr 2002
Location: Farnham
Posts: 130
Likes: 0
Received 0 Likes
on
0 Posts
quote:
--------------------------------------------------------------------------------
What's this extra pitot tube thing sticking out of the cabin wall on the Piper Arrow?
The Arrow I am flying at the moment hasn’t got one, although it looks as if there used to be one.
However, I hope to be flying an Arrow which I know has this “thing sticking out of the cabin wall” (port side). No doubt I'll be told when the time comes, but would be grateful if somebody could enlighten me as to its purpose now. Anticipated thanks.
----------------------------------------------------------------------------------
The 'sticky out thing' is a pitot tube for auto gear deployment system. Once the airspeed drops below a certain value, the wheels drop. There is an override down by the flap handle, although this system may have been disabled in many G registered aircraft (cant remember the exact ruling on this one)
--------------------------------------------------------------------------------
What's this extra pitot tube thing sticking out of the cabin wall on the Piper Arrow?
The Arrow I am flying at the moment hasn’t got one, although it looks as if there used to be one.
However, I hope to be flying an Arrow which I know has this “thing sticking out of the cabin wall” (port side). No doubt I'll be told when the time comes, but would be grateful if somebody could enlighten me as to its purpose now. Anticipated thanks.
----------------------------------------------------------------------------------
The 'sticky out thing' is a pitot tube for auto gear deployment system. Once the airspeed drops below a certain value, the wheels drop. There is an override down by the flap handle, although this system may have been disabled in many G registered aircraft (cant remember the exact ruling on this one)