SAS and ATT mode
The recognise bit is sometimes called fly through mode on some types (eg airbus)
i think 'spirited' angles of bank would have to be in excess of 30 degrees and much more than you would use IFR but I take your point. The Sea King Mk 3 was very noticeable when the ASE saturated in roll (no ATT mode on Mk 3) giving an exaggerated control response but that was effectively going from SAS mode to no mode instead of ATT to SAS.
Agreed, jumping from a 350 into a 412 requires a very different stick trim technique.
They joy of punching in heading on an early Sperry without centering the heading bug first was exhilarating too. Also if you were on a heading of say 090 and ATC told you to turn right to a heading of 300 you would turn the bug right and the aircraft would start to turn right but if you spun the heading bug too fast to 300 and the aircraft heading had not yet passed 120 Mr. autopilot would decide it would be quicker to turn left to 300 and reverse the turn. The Sperry wanted to turn the fastest way to the selected heading.
always entertaining when a student forgets...
Never ever experienced or heard of the "jump", never ever used the coolie hat other than to set a ROD, flew the 76 and 412 coupled en route and reverted to trim off when hand flying, VFR operation, cough, cough.
Due to my time teaching in Simulators....76 and 212/412.....It was plain that far too many Helicopter Pilots did not understand the Sperry System or in some cases have any clue as to how to fly instruments. They perhaps understood procedures and things that could be learned by rote memory.
In my Sim....if you failed to brief for the Missed Approach...it was dead certain you would not see the airport as with a click of a a button I made it dissapear from the visual display.
How many times did I watch two well qualified and experienced pilots kill themselves upon realizing they had to actually perform a Missed Approach.
They punched the Go Around Button and started scrambling to read the Approach Chart to figure out what to do.....and did not adjust the Collective to apply Climb power.
The pitch attitude changed....the VSI showed a climb....and their noses dropped as they both studied the Approach Chart....and some point the airspeed dropped to a point where the Autopilot threw up its digital hands and surrendered to Allah's Will.....and the pilots died a virtual death.
At that point...we broke for Coffee....I handed them a video cartridge and asked them to watch it while they had their Coffee and I would join them in a few minutes.
In variably the later sessions went much more smoothly as the teaching point. had been made.....the Simulator Training that their employer was spending lots of money was so they could learn....and improve on their skill levels.
We used to set the aircraft up for an ILS Approach...with the "Upper Modes" armed.....and we watched the aircraft fly right down the ILS without a bit of deviation....with an engine shutdown and a fire warning light showing on the other and several other Caution Lights illuminating with the Master Caution Flashing each time.
Teaching point....the machine can do it....why can you not?
Perhaps if you let the machine do it....and stay in the Loop by executing command authority over the machine....the machine would help you in flying the machine.
But.....you had to understand the machine before you could get full use of. it....and not cause yourself a problem.
Sometimes adherence to a set procedure but not fully understanding the aircraft systems could cause you serious problems.
Some Operators came to us thinking their Standard Procedures were very carefully thought out....but were not.
We had the advantage of seeing many different approaches to the same problems/issues plus having direct access to the Manufacturer's experts.
I sense some of that in this thread.
Sometimes one has to sort out the wheat from the chaff.
In my Sim....if you failed to brief for the Missed Approach...it was dead certain you would not see the airport as with a click of a a button I made it dissapear from the visual display.
How many times did I watch two well qualified and experienced pilots kill themselves upon realizing they had to actually perform a Missed Approach.
They punched the Go Around Button and started scrambling to read the Approach Chart to figure out what to do.....and did not adjust the Collective to apply Climb power.
The pitch attitude changed....the VSI showed a climb....and their noses dropped as they both studied the Approach Chart....and some point the airspeed dropped to a point where the Autopilot threw up its digital hands and surrendered to Allah's Will.....and the pilots died a virtual death.
At that point...we broke for Coffee....I handed them a video cartridge and asked them to watch it while they had their Coffee and I would join them in a few minutes.
In variably the later sessions went much more smoothly as the teaching point. had been made.....the Simulator Training that their employer was spending lots of money was so they could learn....and improve on their skill levels.
We used to set the aircraft up for an ILS Approach...with the "Upper Modes" armed.....and we watched the aircraft fly right down the ILS without a bit of deviation....with an engine shutdown and a fire warning light showing on the other and several other Caution Lights illuminating with the Master Caution Flashing each time.
Teaching point....the machine can do it....why can you not?
Perhaps if you let the machine do it....and stay in the Loop by executing command authority over the machine....the machine would help you in flying the machine.
But.....you had to understand the machine before you could get full use of. it....and not cause yourself a problem.
Sometimes adherence to a set procedure but not fully understanding the aircraft systems could cause you serious problems.
Some Operators came to us thinking their Standard Procedures were very carefully thought out....but were not.
We had the advantage of seeing many different approaches to the same problems/issues plus having direct access to the Manufacturer's experts.
I sense some of that in this thread.
Sometimes one has to sort out the wheat from the chaff.
Ah, the joys of Go Around mode on a three-axis (ie no collective) autopilot where there is no speed protection. A certain recipe for unexpected death in an IFR go around for the unpracticed. The really annoying bit is that generally the go around mode is linked to vertical speed. So your left hand is not actually controlling the rate of climb but rather your airspeed. And naturally of course your focus at low altitude IMC is on the altimeter and not the airspeed. You see the initial pitch up from the GA and then you get onto other things and miss the speed washing off .
I personally teach (on a three axis system) that you've got four options (GA (lethal), ALT ACQUIRE (not much better), IAS and reverting to ATT). The latter seems the most natural (power directly related to going up) but IAS works the best overall for a 135 at least.
On the topic of workload in the go around, due to having access to a decent FMS/GPS (GTN750) I teach to use the GPS coupling for the missed approach and just wait until your in the (automated) hold before even thinking about what's next. Needs practice though
I personally teach (on a three axis system) that you've got four options (GA (lethal), ALT ACQUIRE (not much better), IAS and reverting to ATT). The latter seems the most natural (power directly related to going up) but IAS works the best overall for a 135 at least.
On the topic of workload in the go around, due to having access to a decent FMS/GPS (GTN750) I teach to use the GPS coupling for the missed approach and just wait until your in the (automated) hold before even thinking about what's next. Needs practice though
Where a force trim release button is fitted the sudden release of the force will oftencause the control to ‘jump’ as the pilot changes the amount of force he is applying. In the case of the cyclic this is known as stick jump. To the pilot this can become irritating, as it is not possible to make small changes to the datum trim position. To test control jump, the control is displaced from the trim position, the release operated and the reaction of the control noted. The amount of displacement used for this test is a realistic amount that an operational pilot might employ before operating the release. After ground tests, an airborne assessment is made to determine if any control oscillations cause an undesirable aircraft response.
It is no more than a mild irritation though and becomes almost imperceptible when you become accustomed to it.
Personally, I never fly stick trim off, even ASE out as I much prefer a 'datum' position to work around rather than a floppy stick. It helps prevent overcontrolling, especially IMC.
I was flying a Wessex yesterday which has no ASE at the moment and with stick trim on you can at least relax your grip on the cyclic a little.
Personally, I never fly stick trim off, even ASE out as I much prefer a 'datum' position to work around rather than a floppy stick. It helps prevent overcontrolling, especially IMC.
I was flying a Wessex yesterday which has no ASE at the moment and with stick trim on you can at least relax your grip on the cyclic a little.
Gipsy,
One can always lead with power.....when the decision is made to go around you invariably want to fly up....adjust collective to climb power....adjust the pitch attitude either by means of the GA Button or as you suggest....manually using force trim on and ATT Mode.
After you are established in a climb....the rest of procedure can be dealt with.
A note....the canned Missed Approach is fine if that is the same as the clearance you were provided as there can be non-standard instructions given.
Now some Sky God shall come along and want to argue which action should be "first"....but either pitch or collective is fine...but for sure the collective must be adjusted to climb power or all the other actions will not matter much.
It worked in the Huey with no SAS or AFCS....and every other dinosaur aircraft.
One can always lead with power.....when the decision is made to go around you invariably want to fly up....adjust collective to climb power....adjust the pitch attitude either by means of the GA Button or as you suggest....manually using force trim on and ATT Mode.
After you are established in a climb....the rest of procedure can be dealt with.
A note....the canned Missed Approach is fine if that is the same as the clearance you were provided as there can be non-standard instructions given.
Now some Sky God shall come along and want to argue which action should be "first"....but either pitch or collective is fine...but for sure the collective must be adjusted to climb power or all the other actions will not matter much.
It worked in the Huey with no SAS or AFCS....and every other dinosaur aircraft.
Ah, the joys of Go Around mode on a three-axis (ie no collective) autopilot where there is no speed protection. A certain recipe for unexpected death in an IFR go around for the unpracticed. The really annoying bit is that generally the go around mode is linked to vertical speed. So your left hand is not actually controlling the rate of climb but rather your airspeed. And naturally of course your focus at low altitude IMC is on the altimeter and not the airspeed. You see the initial pitch up from the GA and then you get onto other things and miss the speed washing off .
I personally teach (on a three axis system) that you've got four options (GA (lethal), ALT ACQUIRE (not much better), IAS and reverting to ATT). The latter seems the most natural (power directly related to going up) but IAS works the best overall for a 135 at least.
On the topic of workload in the go around, due to having access to a decent FMS/GPS (GTN750) I teach to use the GPS coupling for the missed approach and just wait until your in the (automated) hold before even thinking about what's next. Needs practice though
I personally teach (on a three axis system) that you've got four options (GA (lethal), ALT ACQUIRE (not much better), IAS and reverting to ATT). The latter seems the most natural (power directly related to going up) but IAS works the best overall for a 135 at least.
On the topic of workload in the go around, due to having access to a decent FMS/GPS (GTN750) I teach to use the GPS coupling for the missed approach and just wait until your in the (automated) hold before even thinking about what's next. Needs practice though
Gipsy,
One can always lead with power.....when the decision is made to go around you invariably want to fly up....adjust collective to climb power....adjust the pitch attitude either by means of the GA Button or as you suggest....manually using force trim on and ATT Mode.
After you are established in a climb....the rest of procedure can be dealt with.
A note....the canned Missed Approach is fine if that is the same as the clearance you were provided as there can be non-standard instructions given.
Now some Sky God shall come along and want to argue which action should be "first"....but either pitch or collective is fine...but for sure the collective must be adjusted to climb power or all the other actions will not matter much.
It worked in the Huey with no SAS or AFCS....and every other dinosaur aircraft.
One can always lead with power.....when the decision is made to go around you invariably want to fly up....adjust collective to climb power....adjust the pitch attitude either by means of the GA Button or as you suggest....manually using force trim on and ATT Mode.
After you are established in a climb....the rest of procedure can be dealt with.
A note....the canned Missed Approach is fine if that is the same as the clearance you were provided as there can be non-standard instructions given.
Now some Sky God shall come along and want to argue which action should be "first"....but either pitch or collective is fine...but for sure the collective must be adjusted to climb power or all the other actions will not matter much.
It worked in the Huey with no SAS or AFCS....and every other dinosaur aircraft.
If you pull power while still coupled on the approach, you merrily accelerate towards the ground. "PITCH MODE->POWER is very much the mantra we have to use. I have seen some spectacular collisions with the runway when power is pulled first, the pilot language deteriorates to ever stronger expletives, then they fail to step back through the automation gracefully (ie they fight the modes).
It may not work or be necessary for some AFCS installations (particularly those where collective always controls vertical modes) but in earlier Airbus 3 axis machines or later machines in 3 axis mode, the mantra is essential in my opinion.
But this is really thread creep. Back to SAS and ATT!
Gipsy.....what airspeed do you use for an ILS Approach?
One single set speed for all approaches or do you use different speeds for different conditions?
How do those approach speeds compare to Vbroc and Vy airspeeds for your aircraft?
We also have to consider all of the possible ways an ILS Approach may be flown...hand flown using raw data right on up to by means of a full capability four axis autopilot system.
That can bring you back to your desire to talk only of SAS/ATT.....is one mode better than the other for a raw data approach or while using an uncoupled FD?
One single set speed for all approaches or do you use different speeds for different conditions?
How do those approach speeds compare to Vbroc and Vy airspeeds for your aircraft?
We also have to consider all of the possible ways an ILS Approach may be flown...hand flown using raw data right on up to by means of a full capability four axis autopilot system.
That can bring you back to your desire to talk only of SAS/ATT.....is one mode better than the other for a raw data approach or while using an uncoupled FD?
It may not be strictly on topic but is a valuable topic of conversation.
A common theme seems to be that not enough pilots seem to know their autopilots as well as they should - if you're not sure exactly what is going to happen when you push a button - then don't do it or find out before you do.
On a 4-axis AP you have more straightforward options providing everything stays coupled - GA or ALTA would be my preferred options to initiate the Go around.
With 3-axis or hand flying, as long as what you do gets you going safely away from the ground, does it really matter?
I imagine most pilots fly ILS at speeds well above Vy/Vbroc (same thing different terminology) so a speed reduction is probably needed at some stage - especially if you are OEI.
A common theme seems to be that not enough pilots seem to know their autopilots as well as they should - if you're not sure exactly what is going to happen when you push a button - then don't do it or find out before you do.
On a 4-axis AP you have more straightforward options providing everything stays coupled - GA or ALTA would be my preferred options to initiate the Go around.
With 3-axis or hand flying, as long as what you do gets you going safely away from the ground, does it really matter?
I imagine most pilots fly ILS at speeds well above Vy/Vbroc (same thing different terminology) so a speed reduction is probably needed at some stage - especially if you are OEI.
Gipsy.....what airspeed do you use for an ILS Approach?
One single set speed for all approaches or do you use different speeds for different conditions?
How do those approach speeds compare to Vbroc and Vy airspeeds for your aircraft?
We also have to consider all of the possible ways an ILS Approach may be flown...hand flown using raw data right on up to by means of a full capability four axis autopilot system.
That can bring you back to your desire to talk only of SAS/ATT.....is one mode better than the other for a raw data approach or while using an uncoupled FD?
One single set speed for all approaches or do you use different speeds for different conditions?
How do those approach speeds compare to Vbroc and Vy airspeeds for your aircraft?
We also have to consider all of the possible ways an ILS Approach may be flown...hand flown using raw data right on up to by means of a full capability four axis autopilot system.
That can bring you back to your desire to talk only of SAS/ATT.....is one mode better than the other for a raw data approach or while using an uncoupled FD?
Anyway, we fly approaches at 100 kts except one particular type where an aircraft limitation holds us to 90kts. The speed is chosen to maximise speed (commercial need), minimises drift from wind and maximises stability without going up into Cat B minima. Nowhere near Vy. Climb out is different though.
Sadly the flying of approaches in a predominantly VFR operation is not easy to practice. There is generally little opportunity to practice when operational flying and every other proficiency check has to have a manually flown ILS in it. So people might fly one ILS automated in 12 months. So building confidence in the various options is difficult. I make everyone fly one either in recurrent training or in test. The whole enforcement of a manually flown 3D approach every rating revalidation is a bit daft. For a 4 axis multiple redundant AFCS there are quite a few failures in a row (or one very sneaky failure that the TRE knows about).
Originally Posted by [email protected]
It may not be strictly on topic but is a valuable topic of conversation.
A common theme seems to be that not enough pilots seem to know their autopilots as well as they should - if you're not sure exactly what is going to happen when you push a button - then don't do it or find out before you do.
On a 4-axis AP you have more straightforward options providing everything stays coupled - GA or ALTA would be my preferred options to initiate the Go around.
With 3-axis or hand flying, as long as what you do gets you going safely away from the ground, does it really matter?
I imagine most pilots fly ILS at speeds well above Vy/Vbroc (same thing different terminology) so a speed reduction is probably needed at some stage - especially if you are OEI.
A common theme seems to be that not enough pilots seem to know their autopilots as well as they should - if you're not sure exactly what is going to happen when you push a button - then don't do it or find out before you do.
On a 4-axis AP you have more straightforward options providing everything stays coupled - GA or ALTA would be my preferred options to initiate the Go around.
With 3-axis or hand flying, as long as what you do gets you going safely away from the ground, does it really matter?
I imagine most pilots fly ILS at speeds well above Vy/Vbroc (same thing different terminology) so a speed reduction is probably needed at some stage - especially if you are OEI.
You're right it doesn't matter which way you go around but given how infrequently outside your six month check ride you actually do a go around, it needs to be slick as it's high workload. With that in mind I highlight all the options but offer my preference. But I make sure the pilot briefs how he is going to automate his go around at the pre approach brief. Then they have a vague chance of doing the right things . I also push that automation (eg FMS or Garmin) are used to guide the lateral navigation in the go around. That is as long as it's a standard missed approach which is in the database, is not a missed approach which is just climb on a heading and is not non-standard.
There is much benefit to going outside of just the SAS/ATT questions posed originally....so I am not being critical of anything you have said in that regard....as you and Crab both brought up good points of interest.
Technology is both a blessing and a curse.....as it adds new layers of benefit and problems both.
The key as always is knowing as much as you can about it all.
We can look to our fixed winged friends who almost very last words were something akin to "What is it doing now?" referring to the the AFCS.
Personally, I would prefer to see this discussion continue and broaden its scope as I am of the opinion it would be a nice change.
Technology is both a blessing and a curse.....as it adds new layers of benefit and problems both.
The key as always is knowing as much as you can about it all.
We can look to our fixed winged friends who almost very last words were something akin to "What is it doing now?" referring to the the AFCS.
Personally, I would prefer to see this discussion continue and broaden its scope as I am of the opinion it would be a nice change.
Could not agree more with SAS, Crab,GM. Ther were a couple of factors in play here, historically ( maybe more than a couple? ). A lot of the “old heads “ considered SAS. AFCS etc as unnecessary, expensive, claptrap. Then, as those features appeared anyway, the ground school teaching syllabi and flight manual information was purposefully dumbed down to the extent that pilots understanding of how the systems worked was impossible. “ Oh, the pilots don’t need to know that “ was a phrase I heard, not infrequently. But they do, and if the subject is presented properly, it can be made both understandable and interesting. Just an opinion.
Airbus has recently started reacting to the demand from the coal face for more information about the AFCS. There are some excellent Flight Operations Briefing Notes (FOBN) for the AFCS on Helionix types. It's the manual that should have come with the aircraft in the first place. However we have still had to put in a form you can actually deliver in a classroom and we still have to add stuff from the FLM, the original (mostly rubbish) training manuals and things we have found out ourselves.
I remember on a slightly earlier variant of the airbus AFCS on a different type we found that there was an entirely undocumented sub mode of the AFCS that led to the roll channel adding a roll boost command to assist with rolling wings level when the stick was centred. Unfortunately in certain conditions the stick was close to centre when at significant angles of bank...the undocumented mode led to a gremlin seeming to grab the stick and roll you level. Took ages to work out what was going on!
Basically manufacturers should be putting as much as possible out in the documentation - well done Airbus for the FOBN (within the bounds of commercial sensibilities of course).
I remember on a slightly earlier variant of the airbus AFCS on a different type we found that there was an entirely undocumented sub mode of the AFCS that led to the roll channel adding a roll boost command to assist with rolling wings level when the stick was centred. Unfortunately in certain conditions the stick was close to centre when at significant angles of bank...the undocumented mode led to a gremlin seeming to grab the stick and roll you level. Took ages to work out what was going on!
Basically manufacturers should be putting as much as possible out in the documentation - well done Airbus for the FOBN (within the bounds of commercial sensibilities of course).
It seems to me like manufacturers love to load their AFCS with so many extras, maybe to try and out-spec the competition that they forget that a good AFCS does all the basics well through a simple, uncomplicated interface.
A pilot on a high pressure IMC go around shouldn't need to remember umpteen modes and sub modes, engagement parameters etc - if it says GA on the button, it should do exactly that and it should work seamlessly with the FMS.
Unfortunately I get the impression that engineers design AFCS/FMS forgetting that pilots need to be able to use it easily.
A pilot on a high pressure IMC go around shouldn't need to remember umpteen modes and sub modes, engagement parameters etc - if it says GA on the button, it should do exactly that and it should work seamlessly with the FMS.
Unfortunately I get the impression that engineers design AFCS/FMS forgetting that pilots need to be able to use it easily.