Test Equipment Anonymous (TEA) group therapy thread

[Specmaster]

The first 3 are pretty good, not so sure about the 4th though

In terms of manipulating fabric I think that it's actually more impressive. Getting flat, stiff, fabric to conform to curves in 3D is the core skill of the fabric patternmaker's art. Anyone can get a bit of stretch jersey to fit, getting something as unyielding as that strange 'woven flat ribbons' type polypropylene that the Ikea bags are made out of to fit someone's nose, cheeks and chin is worthy of applause. Note that where the other ones have to fit something curvy the makers have resorted to a lot of gathering and scrunching up fabric.

You have a point, but it still is not as "appealing" as the others if you get my drift, no matter how technically superior the craftsmanship is.

Are you looking to deprive Med of his "Dirty old man of TEA" award? 

Who are you talking about, me    . I never knew that med held that award, he always seems so mild, meek and butter wouldn't melt in his mouth like.... 

[fpmacko]

[...]
The flames are bad enough but what is more alarming is the severe vibration.

If I was looking out the window at that engine I would be thinking that it's going to fall off at any moment.

The vibrations are likely why everything fell apart in the first place.  Wonder if there is an "engine vibration monitor" in the cockpit?

Normally yes on larger aircraft. I don't knw for sure on the PW4000 777 though.  They are intended to detect low level vibrations as an early warning. Not needed in this case as vibration and damage was obvious.
The early 737 vibration indicators were unreliable and when a BA crew on a later 737 had an engine issue their perception of this caused them not to use them in determining which engine was faulty. This contributed to a chain of events that resulted in the working engine being shut down and the aircraft crashing at Kegworth.

Most modern PW engines have telemetry.  I would assume that the pilots would have a suite of parameters available.  I also assume that the airline maintenance office and P&W would have near live telemetry to provide guidance to the pilot on what action to take to protect the engine before failure.  Any uncontained fault is going to get hard questions to the designer, manufacturer and maintainer.  As far as I am aware, something like a blade failure is required to be contained according to the regulations.

Essentially all turbine aircraft in Part 121 service (commercial air carrier) will monitor key engine parameters (e.g., fuel flow, RPM, temps, vibe, EPR) and send this info to the airline over the ACARS data link at scheduled intervals and when a key value has exceeded preset limits.  But I can guarantee you that company dispatch is not going to call the flight crew to ask how they can help with their imminent engine failure.  Besides, in this case it probably happened with no warning so no one could have seen it coming.  Compressor blades are binary...they're either attached to the hub and doing their thing or they've left the engine.

Welcome to TEA.
The new big jets mostly work as you describe but a lot depends on who owns the engines. Recording or transmitting engine parameters is not mandatory (except for accident data recording). Some systems record the data and transfer it by short range data link at the gate. Simplist system is a "quick access recorder (QAR) that records to  memory card or similar Smaller. aircraft and airlines may not even have QAR.
You are correct hat it will not hav given any warning in this event. NTSB have confirmed a loss of fan blade. Looking very similr to UA1175 incident a couple of years ago. That one had indications of a crack in the blade but they thought it was a paint defect!
 

Tnx for the welcome.  I've been lurking for quite a while and I'm proud to admit to being totally addicted to classic TE.  I got excited about this particular thread because I was on the ACARS development team at Arinc in the early years of the service in the 80s.  Coupla more data points...  Yes, a lot of engines are "rented".  The downlink engine data goes to airline ops and the mfr.  But that also applies to owned engines.  Also, it would be a very rare major airline (if any) who wouldn't have ACARS these days.  It's just too important for operating efficiencies.  Yes, many aircraft have a QAR but it's mainly used for the a/c data that can wait until a convenient time to gather it from the recorder.  But ACARS is used for a boatload of purposes in addition to engine data downlink.

Ahh ARINC 618-7 etc. Were you on hardware or protocols?
My TE includes ARINC 407 (synchro) kit, and a couple of ARINC 429 test sets. My day job is aerospace.

618 and 724, both of which are now very long in the tooth.  Hardware, software, and protocols.  Our team supported the AEEC standards activities.  We developed protocol enhancements in concert with Teledyne Controls and Collins that were then added to the standard.  We also developed our VHF ground station network and specialized RF monitoring eq for Arinc ops to use.  I also worked on the first attempt at HF ACARS that eventually became HFDL.  Later on I got involved in 741 and the ICAO SARPs for ACARS over Inmarsat.  Mostly as an independent rasputin to the FAA and industry.  I even got to do some flight test and got some sim training.  I have stories.

[tautech]

I even got to do some flight test and got some sim training.  I have stories.

Reminds me of our good friend and neighbour whom was foreman of maintenance watch at Air NZ and did rotational shifts for much of his career. In the dead of night when they were all caught up and all aircraft signed out as airworthy trips to the sim were fav time killers where he reckoned he'd crashed 747's in every major international airport. 

[Robert763]

Hi have stories too, Not allowed to tell most of them though. While a engineer / designer rather than flight test I've done a fair bit of flight test work over the years. Even with the current company who have a flight test department who are very protective of their role. Made me go for a pilot medical just to sit and -----CENSORED-----
Years ago there was the flight in a swept wing, rear engined biz jet. It involved stalling the aircraft. Well before the expected stall it dropped the left wing. rolled on it's back and fell out of the sky tail first. Fortunatly the captain had insisted on plenty of height and a forward C.G. Eventually the nose came down and we recovered. The flaps/slats were not rigged quite right apparently.

[SilverSolder]

Hi have stories too, Not allowed to tell most of them though. While a engineer / designer rather than flight test I've done a fair bit of flight test work over the years. Even with the current company who have a flight test department who are very protective of their role. Made me go for a pilot medical just to sit and -----CENSORED-----
Years ago there was the flight in a swept wing, rear engined biz jet. It involved stalling the aircraft. Well before the expected stall it dropped the left wing. rolled on it's back and fell out of the sky tail first. Fortunatly the captin had insisted on plenty of height and a forward C.G. Eventually the nose came down and we recoved. The flaps/slats were not rigged quite right apparently.

The most important equipment for a test flight like that might be a nappy? 

[tautech]

Hi have stories too, Not allowed to tell most of them though. While a engineer / designer rather than flight test I've done a fair bit of flight test work over the years. Even with the current company who have a flight test department who are very protective of their role. Made me go for a pilot medical just to sit and -----CENSORED-----
Years ago there was the flight in a swept wing, rear engined biz jet. It involved stalling the aircraft. Well before the expected stall it dropped the left wing. rolled on it's back and fell out of the sky tail first. Fortunatly the captin had insisted on plenty of height and a forward C.G. Eventually the nose came down and we recoved. The flaps/slats were not rigged quite right apparently.

The most important equipment for a test flight like that might be a nappy? 

Didn't save an a young Air NZ engineer we knew that was on that Air France check flight that went into the mediterranean. 

[bd139]

Hi have stories too, Not allowed to tell most of them though. While a engineer / designer rather than flight test I've done a fair bit of flight test work over the years. Even with the current company who have a flight test department who are very protective of their role. Made me go for a pilot medical just to sit and -----CENSORED-----
Years ago there was the flight in a swept wing, rear engined biz jet. It involved stalling the aircraft. Well before the expected stall it dropped the left wing. rolled on it's back and fell out of the sky tail first. Fortunatly the captin had insisted on plenty of height and a forward C.G. Eventually the nose came down and we recoved. The flaps/slats were not rigged quite right apparently.

I'd have shat myself instantly  .

Reminds me of a meeting I attended once. My "mentor" at the time said I should attend it to get some experience of high level planning sessions apparently. They had designed the floorplan of an aircraft so that all the equipment was on one side and the meat bags on the other side. Apparently this was a surprise for several of the design engineers who hadn't thought that was a problem because none of them had ever designed anything that went in anything that flew, only things on wheels. The consultant engineer from the airframe manufacturer made a facetious comment about their vehicles ending up in fields whenever they went round a corner  .

Edit: got to be honest I was surprised at exactly the disparity between how projects start off and end as clue is slowly built. I traded that for an industry where clue never arrives 

[fpmacko]

I even got to do some flight test and got some sim training.  I have stories.

Reminds me of our good friend and neighbour whom was foreman of maintenance watch at Air NZ and did rotational shifts for much of his career. In the dead of night when they were all caught up and all aircraft signed out as airworthy trips to the sim were fav time killers where he reckoned he'd crashed 747's in every major international airport. 

I logged an hour of dual inst. and six takeoffs and landings at SYD in a Qantas B-747 sim.  A good mate was a Qantas captain and got me a slot in the schedule.  I was in town for a meeting and had arrived the morning after the big party at the opera house after Sydney won the 2000 Olympics.  (Such a mess.)  They had the Olympic venues in the sim just like when they gave the Olympic suits sim rides to showcase what it would look like if they were awarded to Sydney.  I even flew the a/c under the Harbour bridge and it knocked off my vertical fin.  Good memories.

[tautech]

I even got to do some flight test and got some sim training.  I have stories.

Reminds me of our good friend and neighbour whom was foreman of maintenance watch at Air NZ and did rotational shifts for much of his career. In the dead of night when they were all caught up and all aircraft signed out as airworthy trips to the sim were fav time killers where he reckoned he'd crashed 747's in every major international airport. 

I logged an hour of dual inst. and six takeoffs and landings at SYD in a Qantas B-747 sim.  A good mate was a Qantas captain and got me a slot in the schedule.  I was in town for a meeting and had arrived the morning after the big party at the opera house after Sydney won the 2000 Olympics.  (Such a mess.)  They had the Olympic venues in the sim just like when they gave the Olympic suits sim rides to showcase what it would look like if they were awarded to Sydney.  I even flew the a/c under the Harbour bridge and it knocked off my vertical fin.  Good memories.

Sims are in much greater demand it appears these days (pre Covid) and our daughter captain gets a slot weeks in advance to do her 2x/year checks. She flys the 50 seater Dash 8's.
In Auckland we apparently get quite a few fly in's to use it and I know it was extended and further sims added. Pretty neat place to have a poke around as daughter got us in there once.

[tggzzz]

Hi have stories too, Not allowed to tell most of them though. While a engineer / designer rather than flight test I've done a fair bit of flight test work over the years. Even with the current company who have a flight test department who are very protective of their role. Made me go for a pilot medical just to sit and -----CENSORED-----
Years ago there was the flight in a swept wing, rear engined biz jet. It involved stalling the aircraft. Well before the expected stall it dropped the left wing. rolled on it's back and fell out of the sky tail first. Fortunatly the captin had insisted on plenty of height and a forward C.G. Eventually the nose came down and we recoved. The flaps/slats were not rigged quite right apparently.

I've had fun times doing this; I still remember the first time, back in 1976



BTW, that aircraft also falls out the sky backwards

[med6753]

I hereby rescind my UPS fail from earlier this morning. They delivered. On time. 

These are the capacitors for the 3456A PSU. But I can't start until I get the C5 adapter board which is still in a USPS black hole. 

[Cerebus]

Edit: got to be honest I was surprised at exactly the disparity between how projects start off and end as clue is slowly built. I traded that for an industry where clue never arrives 

Oh it does, but it takes one look around the door, sees what's going on and goes "Sod this for a game of soldiers, I'm off down the pub!". 

[nfmax]

The problem with having two benches is that the tool you want is always on the other bench. That is all.

[med6753]

The problem with having two benches is that the tool you want is always on the other bench. That is all.

Which is why I have two benches with duplicate tools. 

[Robert763]

I even got to do some flight test and got some sim training.  I have stories.

Reminds me of our good friend and neighbour whom was foreman of maintenance watch at Air NZ and did rotational shifts for much of his career. In the dead of night when they were all caught up and all aircraft signed out as airworthy trips to the sim were fav time killers where he reckoned he'd crashed 747's in every major international airport. 

I logged an hour of dual inst. and six takeoffs and landings at SYD in a Qantas B-747 sim.  A good mate was a Qantas captain and got me a slot in the schedule.  I was in town for a meeting and had arrived the morning after the big party at the opera house after Sydney won the 2000 Olympics.  (Such a mess.)  They had the Olympic venues in the sim just like when they gave the Olympic suits sim rides to showcase what it would look like if they were awarded to Sydney.  I even flew the a/c under the Harbour bridge and it knocked off my vertical fin.  Good memories.

Sims are in much greater demand it appears these days (pre Covid) and our daughter captain gets a slot weeks in advance to do her 2x/year checks. She flys the 50 seater Dash 8's.
In Auckland we apparently get quite a few fly in's to use it and I know it was extended and further sims added. Pretty neat place to have a poke around as daughter got us in there once.

Talking of Dash 8's I designed a system for and spent a fair bit of time on this one a few years ago.
https://youtu.be/huJDDGyWDYU

[med6753]

The first 3 are pretty good, not so sure about the 4th though

In terms of manipulating fabric I think that it's actually more impressive. Getting flat, stiff, fabric to conform to curves in 3D is the core skill of the fabric patternmaker's art. Anyone can get a bit of stretch jersey to fit, getting something as unyielding as that strange 'woven flat ribbons' type polypropylene that the Ikea bags are made out of to fit someone's nose, cheeks and chin is worthy of applause. Note that where the other ones have to fit something curvy the makers have resorted to a lot of gathering and scrunching up fabric.

You have a point, but it still is not as "appealing" as the others if you get my drift, no matter how technically superior the craftsmanship is.

Are you looking to deprive Med of his "Dirty old man of TEA" award? 

Who are you talking about, me    . I never knew that med held that award, he always seems so mild, meek and butter wouldn't melt in his mouth like.... 

You don't know me very well, do you? 

Dirty old man until I'm a dead old man. 

[mnementh]

Awsesome! Looks like end-users have already done the alpha testing and we're now well into the beta testing phase! 

I might get by with just adding a fusible link to the test jig and and a better FET! And that diode... and zener on the gate... and... and... 

@Robert - Thanks for the pointers. I'll try that along with the recommended zener. In a month or two.

mnem
*tinker-ily*

Keep us posted. I ordered one too 

I think that as long as we actually give the FET some protection as Robert sez... we'll be easily able to get more than our money's worth out of it.

The ATORCH listing recommend to substitute a IRFP260N for full 180W operation, but some of the feedback I see on the unit says it comes with a IRFP260N of dubious origin; either reclaimed or counterfeit.

What I'm seeing so far is that the modders have been subbing single higher voltage and higher continuous current FETs (IXTH130N20T & FDH44N50), adding the base resistor and zener diode to clamp the oscillations from that op-amp, and some suggestions of replacing that TO252 diode with something in a TO247 package. I'm still digging tho.

The listing's 1000W claim is utter fiction; the manufacturer's suggested path to that is to sub a VMO400-02F megaFET module (~$200 list) for the original FET, or to parallel FETs but offers zero recommendations. The latter will still probably be the path I take, however, especially as the IRFP260N is designed with that in mind, at least according to the datasheet.

My desire for this is to have something cheap that can dump 4S regular & HV  packs at ~20A discharge to terminal or storage voltage, so ~17volts/300Watts. The specs of the IRFP260N say that is the max dissipation, so I'm guessing at least 2 pass transistors to get there unless I do change to one of the other FETs, then I still need to figure out how to wick the heat away from the FET(s) and that diode fast enough.

Don't think I'm gonna connect any of my big LiPos to it without a 30-ish amp fuse in the test jig, fo sho. 

Short version: It wasn't obvious at first cuz I'm math-defective; but I think getting more than 10A out of these in my application is going to require some money spent on FETs and maybe a TO-247 Schottky. Nowhere near what a real 300W load would cost, just not the "Holy fucking asscrackers!" deal this thing looks like on the surface. As is the case with most such cheap, China-direct electronic gadgetry.

I think that if you look at these bare-board units as a somewhat buggy "control module" with serial output to LabView, etc, that you have to build the final pass element of yourself... you'll be going into it with eyes open, and at $28 delivered, that's still a pretty good deal.

mnem
 

[mnementh]

Hi have stories too, Not allowed to tell most of them though. While a engineer / designer rather than flight test I've done a fair bit of flight test work over the years. Even with the current company who have a flight test department who are very protective of their role. Made me go for a pilot medical just to sit and -----CENSORED-----
Years ago there was the flight in a swept wing, rear engined biz jet. It involved stalling the aircraft. Well before the expected stall it dropped the left wing. rolled on it's back and fell out of the sky tail first. Fortunatly the captin had insisted on plenty of height and a forward C.G. Eventually the nose came down and we recoved. The flaps/slats were not rigged quite right apparently.

I've had fun times doing this; I still remember the first time, back in 1976



BTW, that aircraft also falls out the sky backwards

*blerk!*   I think a little pee just came out of me...

mnem

[Specmaster]

You don't know me very well, do you? 

Dirty old man until I'm a dead old man. 

I see nothing wrong in that at all  , if a man has given up all interest in the opposite sex, he's either gay or not long for this world I reckon 

[nfmax]

The problem with having two benches is that the tool you want is always on the other bench. That is all.

Which is why I have two benches with duplicate tools. 

Doesn't work, they just spend all the time visiting their friends 

[mnementh]

 

'strewth... I spend more time separatin' muh miscegenatin' tools an' puttin' 'em back where they belong than I do usin' em. 

mnem
 

[tggzzz]

Hi have stories too, Not allowed to tell most of them though. While a engineer / designer rather than flight test I've done a fair bit of flight test work over the years. Even with the current company who have a flight test department who are very protective of their role. Made me go for a pilot medical just to sit and -----CENSORED-----
Years ago there was the flight in a swept wing, rear engined biz jet. It involved stalling the aircraft. Well before the expected stall it dropped the left wing. rolled on it's back and fell out of the sky tail first. Fortunatly the captin had insisted on plenty of height and a forward C.G. Eventually the nose came down and we recoved. The flaps/slats were not rigged quite right apparently.

I've had fun times doing this; I still remember the first time, back in 1976

BTW, that aircraft also falls out the sky backwards

*blerk!*   I think a little pee just came out of me...

Pah, there are yootoob vids of 10yo girls doing that!

What comes out when you watch this, especially from 1minute on?



Then we could move onto aerobatics while being towed

[mnementh]

   *eeeep!* fly away, fly awayyyy!!!

Sorry... lemme get some wipes and I'll clean that right up...

mnem
no, the irony is not lost on me.

[cyclin_al]

...

618 and 724, both of which are now very long in the tooth.  Hardware, software, and protocols.  Our team supported the AEEC standards activities.  We developed protocol enhancements in concert with Teledyne Controls and Collins that were then added to the standard.  We also developed our VHF ground station network and specialized RF monitoring eq for Arinc ops to use.  I also worked on the first attempt at HF ACARS that eventually became HFDL.  Later on I got involved in 741 and the ICAO SARPs for ACARS over Inmarsat.  Mostly as an independent rasputin to the FAA and industry.  I even got to do some flight test and got some sim training.  I have stories.

Where I work now, I get to hear the stories from the engineers, designers, flight test pilots and flight test engineers.  The best stories were from a particular couple where he was the flight test pilot and she was the engineer; the two different perspectives made the stories much more poignant.  Lately, a lot of the activity is related to RTCA/DO-326, which is rather dry stuff.

Excitement can be found closer to home.  I am in a rural area where the neighbour farmer divides the field into strips with different crops.  This makes a perfect runway shape for practising approaches and go-arounds.  They get rather close but not too close; corn is not gentle on the undercarriage.  Anyway, one day I had the well pump experts over to replace the submersible well pump.  I told them to look up at just the right moment.  I knew the attitude and sounds to time it just right for maximum effect.  There was a student pretty much directly overhead of us entering into their first-ever spin-stall.  It took almost 3 rotations until recovery.  The pump experts just about ran away....  A couple of tries later, it was under 1 1/2 rotations and the instructor must have had enough as I did not see that plane again for a few days.

[tautech]

I even got to do some flight test and got some sim training.  I have stories.

Reminds me of our good friend and neighbour whom was foreman of maintenance watch at Air NZ and did rotational shifts for much of his career. In the dead of night when they were all caught up and all aircraft signed out as airworthy trips to the sim were fav time killers where he reckoned he'd crashed 747's in every major international airport. 

I logged an hour of dual inst. and six takeoffs and landings at SYD in a Qantas B-747 sim.  A good mate was a Qantas captain and got me a slot in the schedule.  I was in town for a meeting and had arrived the morning after the big party at the opera house after Sydney won the 2000 Olympics.  (Such a mess.)  They had the Olympic venues in the sim just like when they gave the Olympic suits sim rides to showcase what it would look like if they were awarded to Sydney.  I even flew the a/c under the Harbour bridge and it knocked off my vertical fin.  Good memories.

Sims are in much greater demand it appears these days (pre Covid) and our daughter captain gets a slot weeks in advance to do her 2x/year checks. She flys the 50 seater Dash 8's.
In Auckland we apparently get quite a few fly in's to use it and I know it was extended and further sims added. Pretty neat place to have a poke around as daughter got us in there once.

Talking of Dash 8's I designed a system for and spent a fair bit of time on this one a few years ago.
https://youtu.be/huJDDGyWDYU

Nice, bit flasher than the Q300 Dash 8's we have in NZ. Looks a bit bigger to, ~70 seater ?