meanmf

That's not what I heard on the other thread, although I do not know if a new vendor constitutes a new design, for shafts or wheels.

jchris said the T-500 is a RAM 500, check the other thread.

Mark

David Gladwin

U2 fast and others,

I very much welcome another engine on the market but equally I would like to see fair and impartial treatement extended to ALL engine manufacturers, regardless of origin, no more no less.

The FTE site says the T500 has an improved (therefore changed) shaft and turbine wheel as well as electronics. Common sense suggests to me that the engine should have had a full assesment. That, however is AMA's decision.

However, the internals of the T500 must be much improved i. e. changed, over the RAM 500, basically a MW54, as it is VASTLY more fuel efficient than other model jet engine, further suggesting that this engine would require a full assesment. Perhaps someone more numerate than I can check these calculations.

FTE states that on his web site that the T500 burns 160 cc( ML) per minute at 12 pounds of thrust.

160 cc is, at a fuel (Jet A1) S. G. of .8, (airlines generally consider the SG of fuel at .793) 128 grammes per minute 2.133 gms per second.

At 12 pounds of thrust the engine is therefore producing 5.45 Kg of thrust = say, 54.5 Newtons. Therefore the SFC expressed in Gms/sec./Newton is .03913. The best SFC, expressed in identical values, produced at the last GTBA efficiency contest (see RCJI P 52) was .0530 so the T500 is 35% better, a remarkable achievement, and one which would require significant internal redesign.

In terms of the TEMs unit allowing all engine parameters to be adjusted that is not true.

The TEMs supplied with commercial engines such as the TJT and PST allow only limited adjustment as stated earlier, certainly mine does, although some TEMS units supplied for homebuilders allows the operator to change a number of parameters to suit the engine dynamics. No doubt use of an unapproved TEMS variant would disqualify the engines approval.

Gentlemen, I have no hidden agenda, and I am a rep. for NOBODY , except an impartial writer for RCJI but when I see the PST certification being delayed and another similar engine, being produced and marketed by someone well connected with the AMA, getting fast track treatment my curiosity gets the better of me.

Perhaps the AMA could make some comment and assure us that the PST WILL be cleared for operations at FJ as I know many such engines will be flown there if the clearance arrives in time.

BRG,
David Gladwin

ajcoholic

My Feedback: (10)

John Casey,
On my "AMA approved" JDE 54 engine, which came with a "JDE ECU" (in reality a Wren MW54 engine with FADEC ECU) there are many user adjustable parameters, the most critical being able to EXCEED the 160,000 top RPM if I so foolishly chose to do so, FYI....

How did that pass muster with the AMA powers that be??

Andrew Coholic

rjpilot

My Feedback: (5)

I plan to have my AV8R at Fla jets if my PST 600 is approved in time.
I spoke with some AMA reps at Superman this year, and was told at that time approval was only a couple of weeks away.
Don't know what is happening with the AMA, but others appear to be getting much faster approval.
Ron Jahnig

GerhardH

Hallo David,

Simjet is advertising 180 ml per minute for their 12 lbs engine running at 160.000 rpm. It would be reasonable to think that 160 ml per minute is correct for the T500 running at only 150.000 rpm since both engines are made pretty much from the same parts. Maybe you got your calculations wrong?

David Gladwin

Maybe I did but they are there for you to check and the results were derived from figures given on the FTE website ! Do the maths. yourself !

As a matter of interest Tom Wilkinson 's independant and impartial review of the SimJet 1200 (RCJI P 18-21) shows that at 12 pounds of thrust the engine consumed 1 liter of fuel in 4.9 minutes or 205 ml per minute, 14% greater than the manufacturers claim as given above ! At 160k RPM the graph shows 222 ml per minute i. e. 1 liter in 4.5 mins. which is 25 % more than the 180ml figure.

These are not my calculations, merely figures extracted from Tom's graph.
BRG,
David Gladwin.

jettset99

My Feedback: (7)

Hey guys,Heres one for ya, I asked for a name change approval and was told I needed full re-submittal, double standard! Im calling the AMA Monday to make sure all facts are true im mad for the PST guys too, it isn't fair period!

Jackjet

My Feedback: (1)

Paul .
see if AMA will certify that J-79 you got in your backyard........

Jackjet

EASYTIGER

My Feedback: (119)

It's strange, isin't it?


Under this same logic, can't the PST use the Wren approval?

bruce rattray

Adjusting the ATV's on the radio will not help.The TEMS will limit the pump delivery once the Max RPM is reached,and should this overshoot for any reason,the Turbine will be shutdown once the Shut RPM is reached.

The parameters which are not accessible on the TEMS are mainly the hold and shutdown EGT's and RPM's. All other parameters are limited by factory defined limits.
The ramping is freely settable, with minumum values to prevent a too quick a ramp up or down being set.
The idle RPM can be raised but not lowered(below 33K) , and Max RPM can be lowered,but not raised (above 126K) to allow the user to "derate" the thrust should he want to.
These values are for the TJT 3000, the PST has its own set of factory limits.


Hope this clears it up

Bruce Rattray
GB Hobby Electronics

JetFever

I asked the same question on AMA deal in the "T-500 Delivery" thread. Still very confuse and sure would like to see the documents and video for T-500 certifications. Standard engineering practice..."no double standard". Let's make things right, fair and square!

I am looking forward to get the J600 and fly at FJ. With RTI taking care of the service in the USA, that makes the choice more attractive!

Kevin C.
20 years in Material Design Engineer

B777

Just want to confirm that PST TEMS ecu is NOT fully programmable or OPEN as per GB's TCU for homebuilders. You cannot set the critical values to exceed safe design parameters. Its impossible to set the ecu to fail the turbine. The ecu is also specially pre-programmed for the J600 only.

For our destructive test for AMA, we have to disable the ecu and use override mode (which is not possible thru TEMS ecu) to bring the rpm above safe sustainable speed of 160,000 rpm. This simulates total ecu failure and putting maximum available voltage (7.2V 6-cells Ni-Cad) to the fuel pump. Result: the J600 spinned to maximum of 179,000 rpm and cannot increase any further regardless of the fuel pump's output. The J600 can sustain this over speed to almost 20 minutes when the rear bearing would overheat causing the turbine inalignment and the rotor assembly just simply freezed. Turbine remained intact with no catrastophic failure or particles thrown out. The said test result can be expected for any turbines built per design..nothing special.

To make the J600 fails by programming the ecu is just not possible.

Thanks for all the support.
B777

BMT

I have had the oportunity to deal with a number of the AMA officials and can say that they do not play any favours. They are however sticky and with good reason with regard to inadequate/incomplete documentation. Especialy when they change distributor and sub suppliers several times in the process. It is up to the applicant to get these in order and in good time. The rules by with the T-500 was approved has been around for a while. Modifications that claim improved performance in thrust, regardless of RPM increase/decrease can be accepted without the obligatory destruct test. This being up to the AMA comitee. Changes to quality levels and other non-structural changes is allowed at any time. The destruct test has been revised such that if the ECU fails and the pump/battery combo will not allow an overspeed failure that is acceptable. Our BMT120KS settles at 138K until the typical max fuel load of 5 litres run out or the battery dumps at the high load under these conditions when submitted to test. Simultaneously this approval also warrants legacy BMT80's to be recertified to 120N using our new compressor.
I have been told by sources close to the commitee that many applicants submit data which is wholy inadequate and are non-responsive when asked for supplement data. Typically this process does not take more than 4-6 weeks. Our own application was delayed almost a year due to my busy schedule preventing my submitting suplelemental data and not due to any laxness of the AMA safety comitee.
The success of FJ and Top Gun suggest a professional person at work, perhaps why the AMA approval was timeous and complete in his case.
Andre Baird

David Gladwin

John Christensen of FTE was good enough to call me with his version of events and they are as follows:

The T-500 IS a RAM 500 X with changes allowed under AMA rules which did not require an engine re-certification. Seems fair enough and if FTE played within the rules good luck to them BUT I received an email this morning from one of the most respected names in model gas turbine engineering and he says :


In a recent mail Joe Amato said “I talked with Ilona at AMA, and the XX will have to go through the entire process for acceptance. Since the engine is coming from a new/different manufacturer/distributor, a new "file" is created, and all pertinent info has to be included in the file.”

As the T-500 is not manufactured or distributed by the original RAM company this policy was clearly not applied to the T-500 but WAS applied to another engine which is very well known and highly respected simply because the manufacturers wished to change distributor without ANY changes to an engine which had been certified !

To be polite, there is very serious inconsistency here.

John Tells me that the PST approval has been delayed because initial paperwork was incomplete and the burst test video was very late. He explained the workings of the AMA committee explaining that it meets only a few times a year so there can be delays in certification until the results come before the volunteer committee even though all tests are complete. I do hope PST approval is dealt with expeditiously to clear the air on this matter and give PST and their many US customers a fair chance at FJ.

I think it time the AMA explained this inconsistency described in para 3.

At 160 ml per minute at 12 pounds of thrust I questioned the extraordinaryily good SFC of the T-500. John told me that this figure was copied from the original RAM specs. They will test the engine next week to check the figures. If the engine can repeat that fuel burn then it is exceptionally good and the 500X is clearly a brilliant design.

However, judging by the facts before me, I vcan only conclude that the AMA does not apply its own rules with fairness and consistency. That is wrong.

BRG,

David Gladwin.

jettset99

My Feedback: (7)

Hey Jack you mean L-39 It just arrived back from paint here she is you need to be nice and stop getting in trouble if you want a Ride!

JetFever

I just simply want to see fairness in all these processes for all manufacturers and not anyone in particular. BTW, I still cannot find the approval for RAM500X on AMA publication. Isee 500 and 500R. I will leave it just as that because posting facts and comments here may constitute as bashing and will be removed.

Respectfully yours,
Kevin C.
Electric or glider?... silence and peaceful...

meanmf

Are you the guy from LA that I heard won the lottery?


Mark

GerhardH

Dear David Gladwin,

I have been a longtime reader of RCJI, and really like your articles, because I believed them thrustworthy. Now however, seing how you shameless ly promotes PST and trashes other products it is very clear to me that you must have economic gain from helping PST. Maybe free engines, maybe commision? Who knows. You wrote a glowing article about the PST engines. Now unfortunately we must all conclude that this was nothing but paid advertising. I will be writing my concerns to Simon Delaney, editor of RCJI also.
Respectfully

EASYTIGER

My Feedback: (119)

That's NASTY, Gerhard. If you had REALLY read what Mr. Gladwin has written over the years, you would take his word at face value. He has always played fair and square, has never hesitated to criticize flaws in products, but has always done so in a gentlemanly way.
I do not beleive for a second that he has any fiscal interest whatsoever in selling anyone a PST600, I think he just tested it and loved it. You have absolutely zero basis to doubt the man's integrity.
Come to think of it...YOU, Gerhard, seem to be one of the handful of people who ONLY post when you feel it necessary to defend Frank Tiano and his Enterprises. YOUR motives and words are much more suspect than David Gladwin's.
DG's writings, and posts here, have always been interesting and informative and articulate, and I have always found him trustworthy, and for that matter, in Gerhard's words, THRUSTWORTHY. And he is right about this. One engine gets treated one way, and another quite differently. Let's find out WHY.

ajcoholic

My Feedback: (10)

Hey Gerhard - hey just gave the AMT engine in the latest RCJI a good review too, so I guess he is a rep for them too? Come one, give the fellow a break. If what he says (regarding the converstaion with the AMA) is indeed true it is a crock. I havent heard one negative thing regarding the PSTJ600 so maybe the fact is it IS a great engine. He is only concerned (as many more are obviously) that there are inconsistancies with the AMA approval process.

AJC

GerhardH

So maybe I was a little rough on old David. But please keep magazine reports and personal interes separated

Jackjet

My Feedback: (1)

Paul .
I'll be good - I promise !

Jackjet

B777

Dear friends,

Refer to the statement made by GerhardH to David Gladwin.

PST Jets Thailand can confirm that the statement is FALSE . David bought the loan engine for the review and decides to purchase another engine. The same deal is offerred to JetMag (German Jet magazine) for the review.

In addition, David is travelling and flying his jets on his own expenses just from shear pleasure in the jet modelling.

Kraivuth S.
B777

BMT

Gerhard,
Suur druiwe man! Your comments are wholly inappropriate.
Strange how people with the best of motives and doing wheatever they can to promote this hobby gets targetted. Don't take it too seriously David, been there done that....
Andre

David Gladwin

Gerhard,

Your comments are interesting but hopelessly, hopelessly, wrong.

I wrote a glowing article on the PST (and JetCat 80, 120, 160, AMT Pegasus HP , Ram 500 and JPXs, I bought examples of all engines because they were good, very good. That is why I BOUGHT these engines, bought because I value quality above all else, except honesty and integrity. The little PST delighted me, so much I bought, BOUGHT with my OWN money, another and they are running beautifully. It is a gem which gives me great pleasure and I have handled more engines than most of you with thrust levels from 8 to 60,000 pounds.

I have yet to receive a free engine ( I did receive a JPX as a gift from JPX for a favour I did to Jaques Buchoux and his son which was nothing to do with model engines and was totally unexpected, that engine will never be sold) or commission (I wish, but in fact would not be accepted, I do not need to sell my integrity).I do pay trade prices for engines but with ten engines, from five manufacturers in my collection the small reduction helps offset my costs. It actually COSTS me to do a review for RCJI.

What concerns me is this : the T-500 is a RAM 500x and it received its approval without further test (ref. John Christensen FTE) even though parts are now manufactured by different companies and the engine is now marketed by a different company. However, when Wren wanted to change their distributor, even though the engine was identical to the example tested, AMA wanted a full, new assesment, quite different to the way FTE's engine was processed. That in my view is discrimination and WRONG !

I am sure FTE's engine is excellent (my purchased RAM 500 works beautifully ) but so is the Wren and that received very different treatment, that is what deeply concerns me.

I am NOT trashing the T-500, far from it, but I am highly crtitical of the way Wren have been treated and I am advised that the PST submission has been overly delayed for whatever reason.

Please step forward all of those manufacturers who pay me commision or supply free items, don't all rush now !

BRG,

David Gladwin