Grob Tutor engine handling
Thanks for the insight of tanker ops, a different animal to airline flying.
As regards piston engine operations, on every piston type with VP prop I have flown, it is definitely not recommended to take off and then climb to cruise altitude at max RPM. Usual recommendation is to reduce power and RPM to a recommended 'climb power' usually a few inches and 2/300 RPM, at 1000ft or so agl. Noise and engine life factors again.
I suppose a military operation is not so constrained by cost and economy, and I expect the heavy old Tutor does not have a sparkling performance in climb and cruise at anything less than max continuous power.
Having flown the IO-540 250HP version, that's a performer!
As regards piston engine operations, on every piston type with VP prop I have flown, it is definitely not recommended to take off and then climb to cruise altitude at max RPM. Usual recommendation is to reduce power and RPM to a recommended 'climb power' usually a few inches and 2/300 RPM, at 1000ft or so agl. Noise and engine life factors again.
I suppose a military operation is not so constrained by cost and economy, and I expect the heavy old Tutor does not have a sparkling performance in climb and cruise at anything less than max continuous power.
Having flown the IO-540 250HP version, that's a performer!
Last edited by cessnapete; 18th Jun 2015 at 13:16.
Quote cessnapete "Thanks for the insight of tanker ops, a different animal to airline flying".
OK, on that basis may I suggest you delete the provocative comment about innefficient AAR OPS! Or are you one of the TriStar bashing crowd?
OAP
OK, on that basis may I suggest you delete the provocative comment about innefficient AAR OPS! Or are you one of the TriStar bashing crowd?
OAP
Thread Starter
Autobit you say "At the TOC the RPM is reduced" while Roland says "The Tutor now leaves the RPM at max throughout the sortie (2700 RPM).
Which one is it?
They certainly sound as if they're being roundly thrashed (and some of the throttle movements also sound a bit ham-fisted). Not trying to pick a fight - genuinely curious.Interesting that others have heard the same thing though.
Which one is it?
They certainly sound as if they're being roundly thrashed (and some of the throttle movements also sound a bit ham-fisted). Not trying to pick a fight - genuinely curious.Interesting that others have heard the same thing though.
With the original Hoffman prop, the RPM was reduced.
The replacement prop is left high all sortie.
I'm not convinced that the RPM has anything to do with the prop failures.
The first failure was due to the torque on the hub nut not being tight enough.
Can't remember the reason for the second and third failures actually being positively determined (as in why the component failed) but they precipitated the change in prop manufacturer.
The replacement prop is left high all sortie.
I'm not convinced that the RPM has anything to do with the prop failures.
The first failure was due to the torque on the hub nut not being tight enough.
Can't remember the reason for the second and third failures actually being positively determined (as in why the component failed) but they precipitated the change in prop manufacturer.
Originally Posted by Dominator2
A better solution would be to get rid of the Tutor and EFT (and many of the QFIs).....
Gosh you sound like lovely chap.
Chip perhaps?
I know, let's let all the knowitalls run everything because they clearly know better than anyone else.
Laugh? I nearly cried.
Thread Starter
"Sorry I don't see the analogy. Reducing the RPM at TOC isn't really like changing up through the gears is it? It just reduces the max available RPM."
OK - when you pull away in a car its the same as taking off, you want max rpm. In the cruise you don't need max rpm (car or airplane) so you change up/coarsen the pitch.
Previously, you said that "The Tutor now leaves the RPM at max throughout the sortie (2700 RPM)".
Essentially, it is the same as driving a car and never changing up.
(Explanation from Wiki below)
"A shallower angle of attack requires the least torque, but the highest RPM because the propeller is not moving very much air with each revolution. This is similar to a car operating in low gear. When the driver reaches cruising speed they will slow down the engine while still producing enough power to keep the vehicle moving. This is accomplished in an airplane by increasing the angle of attack of the propeller. This means that the propeller moves more air per revolution and allows the engine to spin slower while moving an equivalent volume of air, thus maintaining velocity."
Hope this helps.
OK - when you pull away in a car its the same as taking off, you want max rpm. In the cruise you don't need max rpm (car or airplane) so you change up/coarsen the pitch.
Previously, you said that "The Tutor now leaves the RPM at max throughout the sortie (2700 RPM)".
Essentially, it is the same as driving a car and never changing up.
(Explanation from Wiki below)
"A shallower angle of attack requires the least torque, but the highest RPM because the propeller is not moving very much air with each revolution. This is similar to a car operating in low gear. When the driver reaches cruising speed they will slow down the engine while still producing enough power to keep the vehicle moving. This is accomplished in an airplane by increasing the angle of attack of the propeller. This means that the propeller moves more air per revolution and allows the engine to spin slower while moving an equivalent volume of air, thus maintaining velocity."
Hope this helps.
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Oh, was that a bite?
Jaj, I must apologise but could not resist to see if anyone was nibbling.
I do, however, feel very strongly that RAF pilot training has been taken in the wrong direction over many years. From the introduction of Mirror Image money has increasingly become the over whelming driver. I contend that the bean counters have been allowed to reduce the output capability of RAF pilots to an unacceptable level.
EFT should be Elementary and not be a substitute for BFT. The Tutor may be adequate for 20 to 30 hours of ab initio training but it’s capability is too limited to provide top quality training beyond that point.
The RAF owes it to all of it’s trainee pilots to complete BFT and then stream. We can argue how many hours BFT should be and how much should be included within the course syllabus? That may depend on the aircraft that were to be used? The present streaming procedure is, IMO, far too early and unfair to many. More importantly, the RAF often does not get the right pilots in the right roles.
I feel very sorry for the multi engine students as they are really short changed. Apparently, the majority do incredibly well at AFT on the limited number of quality flying hours that they have previously been given. The lack of a basic grounding in the many facets of Military Aviation may only surface years later!
The Air Forces around the world that have addressed this conundrum have generally reduced the number of types of training ac in their inventory. Cheap does not necessarily save money. Quality training provided by quality instructors using quality training aids, both live and synthetic, are the way ahead.
Jaj, I must apologise but could not resist to see if anyone was nibbling.
I do, however, feel very strongly that RAF pilot training has been taken in the wrong direction over many years. From the introduction of Mirror Image money has increasingly become the over whelming driver. I contend that the bean counters have been allowed to reduce the output capability of RAF pilots to an unacceptable level.
EFT should be Elementary and not be a substitute for BFT. The Tutor may be adequate for 20 to 30 hours of ab initio training but it’s capability is too limited to provide top quality training beyond that point.
The RAF owes it to all of it’s trainee pilots to complete BFT and then stream. We can argue how many hours BFT should be and how much should be included within the course syllabus? That may depend on the aircraft that were to be used? The present streaming procedure is, IMO, far too early and unfair to many. More importantly, the RAF often does not get the right pilots in the right roles.
I feel very sorry for the multi engine students as they are really short changed. Apparently, the majority do incredibly well at AFT on the limited number of quality flying hours that they have previously been given. The lack of a basic grounding in the many facets of Military Aviation may only surface years later!
The Air Forces around the world that have addressed this conundrum have generally reduced the number of types of training ac in their inventory. Cheap does not necessarily save money. Quality training provided by quality instructors using quality training aids, both live and synthetic, are the way ahead.
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Dominator,
I must wholeheartedly disagree. The RAF doesn't 'owe' anyone more hours, least of all trainees that, with the advent of entirely more comprehensive trg solutions (and directed selection!) than years gone yonder, it can objectively determine a career path for. 'Unfair' is purely a subjective term but I am entirely intrigued to determine with what evidence you state that the RAF 'often does not get the right pilots in the right roles'? Do we have wrong pilots in the right roles? Or perhaps the right pilots in the wrong roles?
I concur that Elementary Fg trg should be exactly that, but it is entirely correct that streaming could, and should occur at the point it does. I have been around long enough to observe streaming from BFT and the current system, as a QFI, and now as a front line operator the calibre of JP has never been higher; arguably much more professional and knowledgeable than 'back in my day'. Ps- for an excellent read, try the Swedish Fg trg method as described in a recent Air Clues (I believe). An excellent argument for the modern methods of teaching and, dare I say it, 'Performance Analysis'...
Rgds
I must wholeheartedly disagree. The RAF doesn't 'owe' anyone more hours, least of all trainees that, with the advent of entirely more comprehensive trg solutions (and directed selection!) than years gone yonder, it can objectively determine a career path for. 'Unfair' is purely a subjective term but I am entirely intrigued to determine with what evidence you state that the RAF 'often does not get the right pilots in the right roles'? Do we have wrong pilots in the right roles? Or perhaps the right pilots in the wrong roles?
I concur that Elementary Fg trg should be exactly that, but it is entirely correct that streaming could, and should occur at the point it does. I have been around long enough to observe streaming from BFT and the current system, as a QFI, and now as a front line operator the calibre of JP has never been higher; arguably much more professional and knowledgeable than 'back in my day'. Ps- for an excellent read, try the Swedish Fg trg method as described in a recent Air Clues (I believe). An excellent argument for the modern methods of teaching and, dare I say it, 'Performance Analysis'...
Rgds
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Apologies all
I didn't realise that the RPM settings had changed. A few years since I flew the a/c, however the MoD has a reasonable amount of experience of operating CSU VPP aircraft and I'd suggest that if the RPM is now left at 2700 there's a very good reason for it, and both a/c and engine manufacturer would have bought into it.
Dominator I have to agree with baro here. What evidence do you have in a reduction of quality reaching the front line? Its certainly not my experience from both my time on the FL, and instructing on an OCU. The guys and girls we had coming through when I was instructing were top notch.
Inevitably you are going to get one or two people who could have gone FJ and didn't, or went FJ and get chopped. I don't think any system in the world will reduce this and at some point you have to make a choice. Additionally, and having been involved in streaming boards, its not just about the scores on the doors. A whole raft of factors are considered to give the best possible assessment of a students potential. Is it perfect? No, but I think it does a fairly good job.
I didn't realise that the RPM settings had changed. A few years since I flew the a/c, however the MoD has a reasonable amount of experience of operating CSU VPP aircraft and I'd suggest that if the RPM is now left at 2700 there's a very good reason for it, and both a/c and engine manufacturer would have bought into it.
Dominator I have to agree with baro here. What evidence do you have in a reduction of quality reaching the front line? Its certainly not my experience from both my time on the FL, and instructing on an OCU. The guys and girls we had coming through when I was instructing were top notch.
Inevitably you are going to get one or two people who could have gone FJ and didn't, or went FJ and get chopped. I don't think any system in the world will reduce this and at some point you have to make a choice. Additionally, and having been involved in streaming boards, its not just about the scores on the doors. A whole raft of factors are considered to give the best possible assessment of a students potential. Is it perfect? No, but I think it does a fairly good job.
Last edited by AutoBit; 18th Jun 2015 at 22:48.
Thread Starter
Actually, I'd suggest that if you have a C/S prop which you never adjust you
A) Don't understand what it does and
B) Might as well not have one.
Think about it.
A) Don't understand what it does and
B) Might as well not have one.
Think about it.
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You know what you're right Thud. CFS, 22Gp, the manufacture and the MAA, as the airworthiness regulator, clearly don't know what an aeroplane is. Give 'em a call as Im sure they need to hear how wrong they are.
Come on mate, I don't know why the RPM is left at 2700, but Im fairly sure it isn't because they couldn't be bothered to do the research.
Come on mate, I don't know why the RPM is left at 2700, but Im fairly sure it isn't because they couldn't be bothered to do the research.
Last edited by AutoBit; 18th Jun 2015 at 23:22.
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In one Thud....
Originally Posted by AutoBit
You know what you're right Thud. CFS, 22Gp, the manufacture and the MAA, as the airworthiness regulator, clearly don't know what an aeroplane is. Give 'em a call as Im sure they need to hear how wrong they are.
For the most part, these posters have no experience of the current air force. They have some experience at some point in their past which they deem relevant and so are happy to make sweeping statements which include insulting the professional intelligence of those currently serving.
And all because they don't understand. And because it was clearly better in their day.
They all know better.
Maybe they should make those calls.....
It's NOT like driving everywhere in 1st gear!!!! The Tutor has an RPM lever not a PITCH lever.
As you move the throttle, the propellor changes pitch to maintain a constant RPM - effectively an infinitely variable gear ratio!
The aircraft are not owned by the RAF and are on the G reg. The RAF would not be permitted to operate them contrary to the manufacturers advice and documentation - for this very reason, when we first got the aircraft, the permitted aerobatics were limited to those listed on the cockpit placard and we had to jump through many hoops to get extra manoeuvres added!!!!
The current MAA/RAF culture also simply wouldn't accept not operating IAW manufacturers advice!
As you move the throttle, the propellor changes pitch to maintain a constant RPM - effectively an infinitely variable gear ratio!
The aircraft are not owned by the RAF and are on the G reg. The RAF would not be permitted to operate them contrary to the manufacturers advice and documentation - for this very reason, when we first got the aircraft, the permitted aerobatics were limited to those listed on the cockpit placard and we had to jump through many hoops to get extra manoeuvres added!!!!
The current MAA/RAF culture also simply wouldn't accept not operating IAW manufacturers advice!
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Not prohibited but not good
The RAF has a mission for this aircraft that is to train pilots for single power lever aircraft and so sees no need to confuse low time student pilots with the extra complication of good piston engine operating practice, so the blue and red levers stay at the full forward position and the red one shuts down the engine........... Simples ! As my friend Alexander Orlov would say.
The down side to this is extra engine maintenance, higher fuel consumption, more centrifugal strain on the propellor and more noise for the locals to endure.
While not being good practice from a piston engine operating point of view it might well be the best and most economic way to train people who are never likely to fly a piston engine aircraft in military service, as the skills of matching RPM, manifold pressure and leaning the mixture to optimum are simply not required by the RAF. ( unless you are lucky enough to fly for the B of B memorial flight !)
The aircraft & airframe manufactures would not advise the aircraft to be operated in this way but there is no reason to prohibit it as it is not dangerous and with the increased maintenance costs that it brings the extra income in terms of increased parts sales is welcome.
The down side to this is extra engine maintenance, higher fuel consumption, more centrifugal strain on the propellor and more noise for the locals to endure.
While not being good practice from a piston engine operating point of view it might well be the best and most economic way to train people who are never likely to fly a piston engine aircraft in military service, as the skills of matching RPM, manifold pressure and leaning the mixture to optimum are simply not required by the RAF. ( unless you are lucky enough to fly for the B of B memorial flight !)
The aircraft & airframe manufactures would not advise the aircraft to be operated in this way but there is no reason to prohibit it as it is not dangerous and with the increased maintenance costs that it brings the extra income in terms of increased parts sales is welcome.
Thread Starter
Sorry guys - still not getting it - and some of the arguments as to why its so hard to move the prop/rpm/pitch lever (delete as per your desired interpretation of what the blue lever does) are somewhat fallacious. As I said previously, not trying to start a fight, just trying to wrap my head round it!
So;- if you have a C/S prop that you never adjust (for whatever reason) why bother fitting one? Serious question.
CFS/22Gp and the MAA may well have a very good reason why the best way to operate an AEIO-360 with a C/S prop is to just treat the prop as if it were fixed - but for the life of me I can't work out what it is.
So;- if you have a C/S prop that you never adjust (for whatever reason) why bother fitting one? Serious question.
CFS/22Gp and the MAA may well have a very good reason why the best way to operate an AEIO-360 with a C/S prop is to just treat the prop as if it were fixed - but for the life of me I can't work out what it is.
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Thud105
I an guessing that your last post was written at the same time as mine and you did not get to read it.
You are quite correct that both the red and blue levers staying forward is not a good way to operate a piston engine and I have tried to give an insight into why the aircraft is operated in the way it is.
This lack of what would seem to be common sense is not limited to the RAF....... After all the USAF cut up a fleet of T67 trainers for no good reason at all.
It all goes to show that the military have different goals and perspective to the rest of us.
You are quite correct that both the red and blue levers staying forward is not a good way to operate a piston engine and I have tried to give an insight into why the aircraft is operated in the way it is.
This lack of what would seem to be common sense is not limited to the RAF....... After all the USAF cut up a fleet of T67 trainers for no good reason at all.
It all goes to show that the military have different goals and perspective to the rest of us.