Grob Tutor engine handling

[Thud105]

Howdy y'all, I'm visiting friends in Lincolnshire right now, and when a Tutor goes over the engine often seems to be howling in pain. Some of the throttle movements seem very abrupt, and it sounds as if the prop is jammed fully fine. My friend claims he's heard that the instructors don't teach the use of the prop control at all, but I can't believe that! Anyone out there know?

[Thud105]

What did they do with it when the engine failed? I'm intrigued - about the only thing you can do is pull it to 'Fully Coarse' to reduce drag.
He has mentioned their propensity to shed blades! Have other operators experienced this or is it unique to the RAF?

[BEagle]

When I instructed on the Bulldog, normal cruise was 2400/19" with best power mixture. We'd also stopped giving the 2400/15" vs. 1800/21" 80KIAS demo. However, I heard that the normal cruise was changed to 2600 rpm some years later so that, 'as in a jet', Bloggs normally only had one noise lever to worry about....:rolleyes:

Perhaps that's the same in Das Teutor?

I guess they're not too worried about engine life.... But when I flew in loose formation from Abingdon to St Mawgan for Summer Camp one year, I reduced rpm and increased MAP to the verge of 'parallel needles' and leaned the mixture as far as I could. I saved gallons of fuel, but the engine response was pretty dire.

[Thud105]

I've heard the 'as in a jet' argument before* - its remarkably specious isn't it, and also rather patronising of Bloggs. After all, how hard can it be? At least you knew what you were doing Beagle!

* Unless of course they are also flying the Tutors at the same speeds as a Tucano or Hawk, which doesn't seem very likely.............

[just another jocky]

Use of the rpm control is taught and practiced. Normally set to High for whole sortie, reduced if needing to set for range or endurance. Also set to Low for PFLs if needed.....it glides a LOT further!

Can't account for the noises you heard though.

[India Four Two]

about the only thing you can do is pull it to 'Fully Coarse' to reduce drag.

What kind of CS prop does the Tutor have? On the 182 I fly, an engine failure will put the prop to full-fine pitch. It's like an airbrake!

[cessnapete]

I too have noticed the noise produced by continuous high RPM on the Tutors operating near me from Benson. Other than for aeros etc a normal cruise for an I0-360 would be 22"/2200rpm or perhaps 23/23.They seem to operate at a continuous 2500 rpm, probably doesn't help prop life.
I also remember my daughter, when flying at her UAS, telling me that they leaned the mixture by setting a fuel flow before take off? My Lycoming Manual states that full rich should be used for take off, for engine cooling and increased life, except at high altitude airfields.
Perhaps the 180/200HP Tutor is so heavy and underpowered, with two pilots togged up with military gear and parachutes, that it needs to operate at max continuous power.

[DCThumb]

The Tutor has a constant speed propellor. When I flew it, before the latest prop change, RPM was full high for take off, then reduced to 2500 I think just before top of climb. It is then left there for the duration. In the event of an engine failure, it is normal to select RPM to low which should give the coarsest possible blade angle for least drag.

The mixture was set to 'Best power Mixture' before take off. Students were taught how to set up for best endurance but it was rarely used.

The engine is operated as per Lycoming/Grob procedures - what works for a Cessna isn't necessarily going to be correct for another type!

[G-KEST]

Now that the Tutors are operating from Wittering the tortured sound of an AEI-360 in continuous fully fine pitch offends my senses. The increased fuel burn and engine wear is costing the RAF a lot of money (out of my tax payments). I operate a Skybolt fitted with, essentially, the same power plant and a reduction to 2500rpm/25" after takeoff and for aerobatics is SOP if only to reduce the noise nuisance with 2200rpm/22" in the cruise. As for the "one power lever" argument, what about all the turbo prop RAF aircraft.

Trapper 69 :mad::mad::mad:

[Roland Pulfrew]

Now that the Tutors are operating from Wittering the tortured sound of an AEI-360 in continuous fully fine pitch offends my senses. The increased fuel burn and engine wear is costing the RAF a lot of money (out of my tax payments). I operate a Skybolt fitted with, essentially, the same power plant and a reduction to 2500rpm/25" after takeoff and for aerobatics is SOP if only to reduce the noise nuisance with 2200rpm/22" in the cruise. As for the "one power lever" argument, what about all the turbo prop RAF aircraft.

Trapper 69 :mad::mad::mad:

Well no it's not! It's a PFI to start with so its not costing you any extra. The Tutor now leaves the RPM at max throughout the sortie (2700 RPM). The fuel burn isn't that much different from any other setting given the sortie duration. Not for nothing the AEFs are known as the "20 minuters"

[BEagle]

Hi RP - you wrote: The Tutor now leaves the RPM at max throughout the sortie (2700 RPM).

Why on earth do they do that when giving Space Cadets their 20 min of air experience? Or when 'teaching' the odd UAS student? Unless it's how NOT to operate c/s prop SEP aircraft?

[Thud105]

Good God! So they leave the prop at 2700rpm for the whole trip? That explains a lot (and also possibly why the blades kept falling off!).
Are the AEFs known as the '20 minuters' because that's how long the engines last? It seems to me that perhaps a little airmanship needs to be learnt regarding how to operate an IO-360 with a CS prop (irrespective of the airplane its bolted too).
I haven't seen the POH for a Tutor, but I'd be amazed if Lycoming say "oh, just leave it fully fine."
I've never heard such bullcr@p!

[Dominator2]

Gentlemen,
I have followed this thread with interest. I was lucky enough to have been trained to fly by the Royal Air Force when they could afford jet training aircraft. In the following 40 years I avoided being tainted by props or turbo props. I find it inconceivable that a disorganised bunch of QFIs cannot agree on how to operate an aircraft. Does the RAF not have some central organisation that enables and encourages Standardisation? I would assume that there is a CORRECT way to operate a variable prop ac?
If it is required to bastardise how to manage the engine to facilitate future fast jet pilots maybe the RAF should stream prior to EFT. - No, I was only joking! A better solution would be to get rid of the Tutor and EFT (and many of the QFIs) and get a proper basic trainer. You could then give ALL pilots an adequate amount of training and then stream them. Thus all pilots would be trained to the same Basic standard and not “short changed” by the present system.

Thud105 - I have just seen your comments - well said!

[Onceapilot]

Must be a sign of the times.:oh:

OAP

[Roland Pulfrew]

Gentlemen

Before you all get on the outrage bus, you are asking the wrong person (I don't know why the changes were made) but the changes were made after the introduction of the new prop following the blade failures:=. I assume Lycoming have approved the use of the engine at 2700 because it is the "max continuous" for the engine - not saying that there aren't different, maybe better ways of operating the engine but it's all been tested and approved by the owners of the aircraft.:hmm:

[cessnapete]

I have never heard of a civilian/ private operator flying their Lycomings continuously at max RPM. The obvious factor being engine longevity, reliability and fuel costs. Normal SOP for a 2700rpm engine would be 25/25 for the climb and perhaps aeros, and 22 or 23 squared for the cruise with appropriate leaning at cruise power.
Leaning the engine before takeoff, again never seen that recommended in any manual for cooling reasons,except for high altitude take off, not many of those in UK.
Presumably any MOD contract does not include civilian cost operation saving in their calculations.

[NutLoose]

Does the RAF not have some central organisation that enables and encourages Standardisation? I would assume that there is a CORRECT way to operate a turbo prop?


Err, it's not a turboprop.

[NutLoose]

With you on operation at Max continuous RPM Cessnapete

Engine TCDS ( AEIO-360-B1F )

http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgMakeModel.nsf/0/cb8eb266e5683e5b86257a09004d8f38/$FILE/1E10%20Rev%2024.pdf

Regulations re overspeed and the rated continuous RPM of the engines

http://www.lycoming.com/Portals/0/techpublications/servicebulletins/SB%20369C%20(04-18-2012)/Engine%20Inspection%20after%20Overspeed.pdf


I would recommend you read this, especially if you fly or operate a piston aircraft engine

http://web.archive.org/web/20081021015206/http://www.lycoming.textron.com/support/tips-advice/key-reprints/index.jsp



A. GENERAL RULES
1. Never lean the mixture from full rich during take-off, climb or high-performance cruise operation unless the Pilot’s Operating Handbook advises otherwise. However, during takeoff from high-elevation airports or during climb at higher altitudes, roughness or reduction of power may occur at full-rich mixture. In such a case, the mixture may be adjusted only enough to obtain smooth engine operation. Careful observation of temperature instruments should be practiced.


Ahh the heady heights of the Lincolnshire mountain range :p


.

[AutoBit]

My word there is some nonsense being posted on here.

Firstly the engine is operated as per the manufactures recommendations, not because we want to teach students to fly a prop like a jet engine. Thats done on the Tucano, not the Grob. Every light aircraft with a VPP that I have ever flown has always been 'RPM MAX' for take off,climb and landing. At the TOC the RPM is reduced. As for mixture admittedly this is the first a/c I have flown with 'BPM' but again that is as per the manufactures advise for best engine handling.

In reply to cessnapete the reason you came back in the low 20's was, I suspect, because you were utilising one of the Radar Corridors that allow mil a/c to transit from each side of the country. A tanker doesn't necessarily know when its going to come off station and so they can't just file for the RTB at FLXXX, additionally they have no idea what their Gross weight will be when they RTB (depends on offload). Try picking up a clearance with London for an RTB from the North Sea to Brize at FL 350, straight through the airways out of the south east and see how much luck you have. Thats why the Radar Corridors are used.

Whilst we don't work to profit margins I can assure you that mil aircrew understand and utilise max rec and econ speed as much as possible.

[Onceapilot]

Cessnapete: Can you give more details of that AAR experience, where, when and who?

OAP

[cessnapete]

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!

[Onceapilot]

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

[Thud105]

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.

[cessnapete]

No TriStar basher, PFM in my airline!

[DCThumb]

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.

[Thud105]

Wow! So (to use an automobile analogy), you drive everywhere in first gear? Astonishing.

[Roland Pulfrew]

Wow! So (to use an automobile analogy), you drive everywhere in first gear? Astonishing.

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.

[just another jocky]

A better solution would be to get rid of the Tutor and EFT (and many of the QFIs).....

Really.

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.

[Thud105]

"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 (https://en.wikipedia.org/wiki/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.

[Dominator2]

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.

[barotraumatized]

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

[AutoBit]

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.

[Thud105]

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.

[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.

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.

[NutLoose]

In one Thud....

[just another jocky]

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.

It's pointless m8.

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.....:rolleyes:

[DCThumb]

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!

[A and C]

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.

[Thud105]

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.

[A and C]

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.

[Thud105]

But surely A&C, at this stage of their training we're trying to find out how good they are. Wouldn't seeing if a student could manipulate 3 levers correctly be a good test?
And c'mon - its not really that hard, is it?

[A and C]

I agree with you but clearly the RAF has decided to focus on other things, probably because this is the first and last time these pilots will see red & blue levers.

[Onceapilot]

Thud, a CS prop is far better over a wide range of airspeeds than a fixed pitch. You know that.
Maybe the RAF should buy back some Chippies?

OAP

[Thud105]

Of course OAP - but only if you actually adjust the blue lever! If you don't its the same as a fixed pitch prop.
Never flown one but that sounds like an excellent suggestion - should at least teach some airmanship.

[BEagle]

Onceapilot, the standard CFS-spiel for the CS prop was indeed that it offered better efficiency over a wide range of airspeeds.

There was only one thing wrong with this as far as the Bulldog was concerned - it was bolleaux! 80-125 KIAS was hardly a sufficiently 'wide range' of airspeeds to warrant the fitment of an expensive C/S prop!

To my mind, the real reasons were:

It made aeros much simpler! We set a little less than max rpm (was it 2650 ? I forget) and didn't have to worry unduly about engine overspeed, so could keep your eyes out more. Whereas in the Chipmunk you had to fiddle constantly with the throttle to keep the rpm in limits, which also required a lot of rudder work.
It made navigation easier as the rpm stayed constant with IAS, so setting the desired cruise IAS was a doddle as the only adjustment needed was to MAP.


When I did some civil instructing, aeros on the T-67A reminded me what a pain it was to have a fixed pitch prop on such aircraft. As it was to have a fixed pitch prop on the PA28 - students took ages to settle the IAS at the correct value as every time the IAS changed, so did the rpm! It was easier (but poor practice) to set 2250 and accept whatever that gave you.

[Dominator2]

Thud,

Why would you think that the RAF would want to operate their aircraft correctly when they can make it "Simple", even if wrong. Even though the aircraft is fairly easy to fly everything is simplified to make it easy.

Even if the student will never fly a piston again why not challenge them slightly?

Thud, I totally agree with Wouldn't seeing if a student could manipulate 3 levers correctly be a good test?
And c'mon - its not really that hard, is it?Thud105

You will not convince those who apparently know better!

[Wander00]

Re the suggestion of the Services buying back Chipmunks - may well not be feasible, MAA and all that, but a modern "Chipmunk" in modern materials and a modern engine, but all the Chipmunk's aerodynamic qualities and handling...........(and the "smell", but might be more "curing GRP/carbon fibre"!)...................

[Cows getting bigger]

Of course OAP - but only if you actually adjust the blue lever! If you don't its the same as a fixed pitch prop.

Err no. In fact you couldn't be further from the truth. Blue lever sets RPM which is directly related to blade AOA. If you advance the black lever (power/throttle) the prop governor will increase the prop blade angle (pitch) to retain the blade AOA you require. Conversely, reducing power will reduce prop pitch to retain the blade AOA. A fixed pitch prop will only meet optimum blade AOA at one particular airspeed for a given RPM. A CS prop will achieve optimum blade AOA for a broad range of speeds at a given RPM.

CFS/22Gp/The CFI's Pet Hamster has decided that the optimum Blade AOA for the task they are doing is achieved when the prop RPM is set to a particular number (2700?). Considering that the Tutor fleet rarely spends any significant time straight & level I suspect that, in good old aerobatic fashion, they have elected for a high RPM which gives better (less worse, in the case of an overly heavy two seat aircraft ;) ) response to changes in power selection.

PS. I actually think the way the military train students to fly the Tutor is very refreshing. They realise that there is absolutely no requirement for graduates to fiddle with red and blue in their future steeds and have adopted a technique which emulates the SLPC scenario which the majority will ultimately be operating; this is no different to CPL/ATPL students being trained on the DA40/DA42 where they are presented one lever per engine. I also think setting BPM during power checks, regardless of Density Altitude, is possibly a lesson we should all learn.

[Thud105]

Well, each to his own. I was taught to fly the aircraft I was flying, but for what its worth (and only IMHO) to fly an aeroplane with a C/S prop in which you simply set it on max rpm/fully fine/whatever and never touch it again just smacks of poor airmanship - at least to me.
But one thing I've learnt for sure - in Lincolnshire you can indeed safely disregard Density Altitude!

[Dominator2]

What about RAF Binbrook - 360ft AMSL!

[Cows getting bigger]

Each to their own. You were taught badly as you clearly weren't taught that the main advantage of a CS prop is that you can set and maintain a constant AOA for the blades. In other words, for a given RPM you get maximum efficiency at that RPM, regardless of airspeed. Once you have selected an RPM, you can change speed knowing that the prop will maintain a constant blade AOA. The RPM you choose to set is dependent upon what you want to do. Sure, it may not be intuitive choosing to fly around in 2nd gear when there are options of a 3rd or 4th but that that largely depends upon what you are wanting to do.

One last thing, the fact that the military set BPM for each and every departure means that they are one of the few who actually consider Density Altitude, even in Lincs. :)

(Written as a civilian instructor/examiner)

[BEagle]

Blade AoA depends on blade angle, TAS and rotational velocity. If the optimum blade AoA is a known value then, for a specific IAS/FL, RPM may be set to achieve the optimum value from a table of values, with MAP just sufficient to enable the conditions to be achieved and with mixture leaned as far as can be achieved within CHT limits.

Fine if you need to cross the pond in a Stratocruiser. But the RAF's requirements are rather different. The primary reason for the CS prop in military trainers has little to do with cruising efficiency, but has more to do with bestowing 'carefree' engine handling in dynamic environments.

If it was necessary to divert in the Bulldog, instructors could set 17" / 2200 and best economy mixture. At FL40 this gave 86KIAS and about 14.7 ANMPG in still air. Students were told to use 19" / 2400 and 2½ psi fuel flow, which gave them a more comfortable 100 KIAS at FL40 and 13.7 ANMPG in still air. But over a 50nm diversion, it would only add another ¼ gallon to the fuel required, so everyone normally used 19" / 2400 / 2½ psi if max range was needed.

[greenedgejet]

Engine leaned off before take off and rechecked in climb according to Grob placard.

This was done to compete with t67m260 in late 1990s procurement competition. Slingsby was run fully rich unlike USAF version which had auto mixture control.

Claim at the time was Grob used less fuel but actually had much poorer climb rate so used more fuel on a spinning sortie.

Old prop did not achieve service intervals so was likely to changed regardless of prop loss issues which had nothing to do with rpm but fundamental design.

New prop very efficient. So much so it revealed further design flaws in the aerobatic oil system that was solved by tremendous efforts of some highly experienced contract engineers and pilots alongside manufacturers.

Rpm high is for best climb and aerobatic performance. All students are taught how to operate all the levers including the blue one to achieve best range or endurance or glide performance with windmilling prop.

Downloading training and streaming onto the humbler machinery is still the most cost effective method.

[Thud105]

Autobit said that "At the TOC the RPM is reduced" while Roland said "The Tutor now leaves the RPM at max throughout the sortie (2700 RPM).
Cowsgettingbigger said that “CFS/22Gp/The CFI's Pet Hamster has decided that the optimum Blade AOA for the task they are doing is achieved when the prop RPM is set to a particular number (2700?)” but Greenedgejet said “All students are taught how to operate all the levers including the blue one to achieve best range or endurance or glide performance with windmilling prop.”

Does anyone actually know which one it is?

And yes Cowsgettingbigger it does not seem intuitive to choose to fly around in 2nd gear when there are options of a 3rd or 4th. And to stick with the gear analogy (and to take us right back to where we came in) during my visit to the Lincolnshire highlands I have noticed (and others seem to agree with me) that when a Tutor flies overhead it often sounds as if its in the wrong gear.

[just another jocky]

Autobit said that "At the TOC the RPM is reduced" while Roland said "The Tutor now leaves the RPM at max throughout the sortie (2700 RPM).
Cowsgettingbigger said that “CFS/22Gp/The CFI's Pet Hamster has decided that the optimum Blade AOA for the task they are doing is achieved when the prop RPM is set to a particular number (2700?)” but Greenedgejet said “All students are taught how to operate all the levers including the blue one to achieve best range or endurance or glide performance with windmilling prop.”

Does anyone actually know which one it is?

And yes Cowsgettingbigger it does not seem intuitive to choose to fly around in 2nd gear when there are options of a 3rd or 4th. And to stick with the gear analogy (and to take us right back to where we came in) during my visit to the Lincolnshire highlands I have noticed (and others seem to agree with me) that when a Tutor flies overhead it often sounds as if its in the wrong gear.

M8, why should we give a toss whether folk on the ground think the ac is in 1st, 3rd or 18th gear?

To answer your questions above, yes, I know which it is.....Autobit was incorrect, everyone else correct.

Can you not, for a second, think outside your own box? Try to figure out why (there have been enough clues so far) we don't mess around with the rpm lever very much. Just because it's right for you doesn't mean it's right for us. Don't forget we have differing requirements of the ac than you do so we each operate according to our own requirements.

Just because you don't understand it doesn't mean it is incorrect or a bad habit.

[Dominator2]

Thud,
I admire your persistence but I fear that you will not get through. The Tutor world has for a long time been a self-regulating, self-licking lollypop. The fact that you have disclosed such lack of standardisation is not surprising, however, slightly worrying.

As an outsider it is interesting how the Rauceby Lane Flying Club (Cranwell) react to being challenged. You will argue with A1 or A2 QFIs who are masters of their trade, or so they tell me. It is interesting as an “all jet pilot” to observe your challenging of how the RAF operates it’s Tutor ac.
I still maintain that with the correct Basic Jet Trainer the RAF could do away with the Tutor. Maintaining a fleet of aircraft for AEF and UAS cannot be justified in the present climate. Just think how many QFIs could be returned to the Front Line.

[Cows getting bigger]

Point of order - I've never personally been a member of the "Rauceby Lane Flying Club". := As a CAA Examiner I have flown with DFTS at Barkston and can equivocally say that their standards and standardisation is by far the highest order I have seen in 30+ years of flying.

Perhaps the dogmatic attitude is actually on the other side of the fence.

[Thud105]

Well Jusanotherjockey, greenedgejet seems to contradict Roland and Cows too - so either everyone else isn't correct, you've missed something or I've missed something. Anyway, as my teenage grandson would say - 'whatever'.
I bet you all think QFE is a great idea too!
Gotta go guys, mustn't miss my flight! It was real, and it was fun - but it wasn't real fun.

[DCThumb]

Dominator, of course the training could be done with the correct jet. We did it for years with the Long course on the Jet Provost. This was replaced with a turbo prop on the grounds of operating costs. We could still have a long course on the Tucano if we wanted, but it is cheaper to do elementary exercises on a piston.
In fact, under MFTS, the Tutors will be replaced, with a Turbo prop.

The intention I believe is to keep the Tutors for AEF/ UAS. They cost (comparative) peanuts to operate, are largely flown by 'free' volunteers and offer a tangible benefit to both the services and meet the government youth policies!

And to reiterate!!!!

Old Prop - RPM reduced to 2500 at TOC
New Prop - RPM left at high.

No ambiguities, no standardisation issues, just answers from people who flew the Tutor at different times!!!!!

[NutLoose]

Engine leaned off before take off and rechecked in climb according to Grob placard.

This was done to compete with t67m260 in late 1990s procurement competition. Slingsby was run fully rich unlike USAF version which had auto mixture control.

Claim at the time was Grob used less fuel but actually had much poorer climb rate so used more fuel on a spinning sortie.

Old prop did not achieve service intervals so was likely to changed regardless of prop loss issues which had nothing to do with rpm but fundamental design.

New prop very efficient. So much so it revealed further design flaws in the aerobatic oil system that was solved by tremendous efforts of some highly experienced contract engineers and pilots alongside manufacturers.

Rpm high is for best climb and aerobatic performance. All students are taught how to operate all the levers including the blue one to achieve best range or endurance or glide performance with windmilling prop.

Downloading training and streaming onto the humbler machinery is still the most cost effective method.

I seem to remember the Grob wasn't the first choice of those testing them, they didn't think they were the best for aeros?



Fascinating discussion btw

[just another jocky]

Well Jusanotherjockey, greenedgejet seems to contradict Roland and Cows too...

No he doesn't. Movement of the rpm lever is taught (setting Range & Endurance) but the rpm lever is not routinely moved from Max (2700).

Dominator, of course the training could be done with the correct jet. We did it for years with the Long course on the Jet Provost. This was replaced with a turbo prop on the grounds of operating costs. We could still have a long course on the Tucano if we wanted, but it is cheaper to do elementary exercises on a piston.
In fact, under MFTS, the Tutors will be replaced, with a Turbo prop.

The intention I believe is to keep the Tutors for AEF/ UAS. They cost (comparative) peanuts to operate, are largely flown by 'free' volunteers and offer a tangible benefit to both the services and meet the government youth policies!

And to reiterate!!!!

Old Prop - RPM reduced to 2500 at TOC
New Prop - RPM left at high.

No ambiguities, no standardisation issues, just answers from people who flew the Tutor at different times!!!!!

Nicely put. :D

[Onceapilot]

But what about CTM and ATM? :)

OAP