What is involved in production testing helicopters?

[Graviman]

NB: Title changed, as i wanted to expand the thread to capture more...

I have often read with great interest the various tests machines are subjected to during the development phase. Naturally this then leads to the various manouevres a machine can be put through, to demonstrate the machines capabilities at say an airshow.

What i am curious about in this thread is what level of testing does each helicopter go through once it comes off the assembly line (R22) or out of it's production cell (probably everything else). Is it a question of slowly building up confidence in the machine, or are there various ground tests that prove different systems? What procedures are used to "snag" various faults that always exist in even the most meticulous assembly?

Mart

[SASless]

The first requirement is to be able to fly with your knees.

That frees up your hands so you can put your fingers in your ears and thus not hear the almighty BANG when you have a cast iron failure of some sort.:E

[Dave_Jackson]

How do you fly when your knees are trembling from fear? :)

[Shawn Coyle]

This is based on my experience working as a production line pilot at Bell (that was over 20 years ago, but watching the folks at Mirabel as recently as 3 years ago, it hadn't changed much). I also watched it being done at Agusta in the US and in Italy. Basically the same process.
The process for accepting a helicopter off the assembly line is obviously different for each machine, but in general will be a very disciplined process that involves checking every aspect of the machine for proper operation.
All snags will be noted and rectified prior to release. All the companies will have very tight quality control systems - it's their reputation that's going out the door!
It will start with ground runs to make sure things are right in general. Every system will be exercised, all temperatures and pressures have to be in the correct range, have to stabilize, etc. Radios will be checked for correct functioning.
Once all the things that can be checked on the ground are OK, then track and balance of the rotor is done. (obviously some things are done concurrently). Then the airborne systems checks for rigging, systems operation, and so on are completed. And when everything is OK, the aircraft may be flown for several hours to make sure it all keeps working. I think Bell insisted on 5 hours on the airframe prior to delivery just to make sure things are working properly. Everything that was a problem gets documented and fixed.
Now the customer comes in, and if they're smart, they'll go through everything with a fine tooth comb. Power assurance / topping checks, systems integration, and so on. Major customers often have a wonderfully detailed checklist and can (and should) be pretty demanding. They are after all spending quite a bit of money!
Hope that helps.

[NickLappos]

Shawn has it right, as usual. The flights take typically from 1 to 5 days, depending on how complex the equipment is (one hour for a dirt-simple vfr machine, 7 hours for a complex IFR bird).

A run through all the equipment, many in real situations - real navigation runs, instrument approaches, auto-hovers, etc. For complex military machines, a complete run-through the equipment might include a mine-sweeping exercize, for example.

Production pilots have to know the systems, and usually write the acceptance test procedures, they must be technically sharp, and are often engineers. It is a stepping stone to experimental and then research pilot for many manufacturers.

[Robbo Jock]

Nick,

What is the difference between Experimental and Research Pilot?

Ta,
RJ

[BlenderPilot]

Without specifing the Texas helicopter manufacturer, I picked up 2 new helicopters from the factory last year, and some of the "minor" discrepancies,

- Mast Seal Leaks that got all the cabin roof covered in oil
- Improperly installed seals in the fuel cap area which led to tons of fuel seeping to the space between the aircraft floor and the fuel cell having to pull out the fuel cells out and cleaning and regasketing everything.
- Improperly installed radios with non shielded wire having tons of problems with them before being usable.
- Smoking engines
- Main rotor blades that came with visible dings that had been poorly covered up
- Bad instruments
Plus other little things such as,
- Old rusty cables on the map lights
- Missing headsets
- And a ciclic grip which had been spray painted with glossy black paint. covering all the labels.

Fortunately the Bell people in Mexico are absolutely great and they worked hard at solving all these issues once the aircraft was here.

As an additional story I once went to pick a brand new business jet to Wichita Kansas, my boss wanted to delay delivery for "unspecified reasons" so he told us to go and pick up the aircraft but that we couldn't leave the factory until the aircraft was in perfectly good shape and everything was working properly, with the aircraft sitting on a beautiful hangar, placed on a red carpet, delivery ceremony standing by, we found 64 discrepancies with the aircraft that had to be taken care of, we spent 14 days at the factory and before everything was perfect we had flown it about 5 times and still couldn't get everything working, that thing just kept on going into the red carpeted hangar and coming out to the plant!!

When you go pick up an aircraft to the factory never trust it to OK just because it just got out of the factory.

[NickLappos]

Test Pilot Heirachy, IMHO:

Maintenance Test Pilot - Fleet pilot with extra training to do maintenance tests (usually not at all critical)

Production Test Pilot - OEM pilot trained to do acceptance testing of type designed normal aircraft. Tests are similar to maintenance tests. Often writes the acceptance test procedures, and often tests new pieces of gear that do not affect fundamental airworthiness (radios, hoists, etc.).

Experimental Test Pilot - OEM or Military customer test pilot - Trained by OEM or military to fly unapproved newly built or modified aircraft, those mods can include those that affect airworthiness (transmissions, blades, structure, controls). These aircraft are usually the first of a series to be produced, so by nature their design is less radical than a "research" aircraft. The tests performed can be quite difficult, and can be hazardous, such as a structural demonstration to critical limits, or a height-velocity test. Note: Military test pilots do not often fly unapproved aircraft on envelope establishment flights, these are usually first flown by OEM pilots, the data reviewed by military engineers, and then flight clearance is given for mil pilots to fly within that envelope.

Research Test Pilot - Experimental TP who flies aircraft that have been modified or special built to examine new and unique properties where production is not anticipated for the design. Such aircraft are designated as X in their model series, if military, but can have other names if purely civilly funded. Such aircraft as the XV-15, XH-59, CarterCopter are examples.

Most manufacturers have the TP staff that meets these definitions, although the difference between Experimental and Research is blurry, and sometimes non-existant.

[Graviman]

This is great stuff, thanks all! :ok:

In general how do Maintenance/Production/Experimental/Research pilots find their input contributing to design improvements? Albeit not aerospace, i find the hardest thing in assessing a design is getting good technical feedback about performance - i often find myself trying to interprete the feedback i do get. I will freely admit to being a great believer in the "bums on seats" philosophy, since FE and accelerometers will only tell you so much.

Any specific examples about problems which wer resolved by pilot feedback? I read the S92 thread with great interest Nick, but was never sure when the need for horizontal stabiliser reposition and control was identified.

Mart

[NickLappos]

At Sikorsky, a TP is assigned by the Chief Pilot to the design team at the outset, and he/she represents the customer operationally. Similarly, a Customer Service rep is assigned to represent the future maintainer. Generally, the TP must sign off on design features that affect the pilot, as well as top-level systems logic and cockpit design.

Your observation about the horizontal stab position is bang on. The pilots were not happy with the nose-up at low speeds and so a major redesign was undertaken, as well as a flight test program to place the tail (I understand that NO helicopter has gone into production with the same tail it first flew, at least not in the last 20 or so years!) At Sikorsky, the TP's are all engineers, and pretty savvy technically and politically, so there is good give and take to get things done right without major head-butting (but sometimes....!)

I worked on the design teams for about a dozen helos, and it was always interesting. For several models, I was the PDT leader for a section of the aircraft, so the pilot's inputs were always strongly considered! The same is true of the Black Hawk and Comanche, where the pilots had strong say.

I can't say what other manufacturers do about their pilot's opinions, we should let them post to tell us.

[S64_fan]

A few years back, Nick Lappos gave me a 28-min ride in a just-off-the-line helo. There were a couple of relatively minor events, and something Nick said toward the end of the flight went deep, prompting me to effect a 45.deg. change in career track (experimental FT) and forcing me to spend many a sleepless night trying to reconcile what he'd said with what I'd been led to believe by some highly-regarded pilots and engineers.
I'm now working as a consultant to Agusta (Milan, Italy) and prior to this was on the A-380 program: I'm beginning to think that Nick was right. (It's close to midnight, so in case my argument seems out-of-thread or incoherent, let me know.)
In the late 60's, Asimov predicted that it would take 600 yrs for mankind to map and control our DNA. It took less than 40. Around the same time, the U.S.Navy stated the need to vertically lift 25.000 kilogram payloads from ship to shore, but 41 years later, we are still at least ten years away from meeting it. With the raw technology available (a high-end computer can now perform 350 billion calculations per second) there is the potential to solve some *really* challenging problems. For example, designing a VTOL aircraft which outperforms the -609 by a good margin, having per-FH safety levels on a par with the 777, and costs under $2M is *not* in the "Really Challenging" category. So why hasn't anyone done it? Think for a minute. Looking at the past 140 yrs of technology history, developing a new and improved gadget has usually required the backing of at least one individual with deep pockets, and a few friends in high places.
Now, however, it's two orders of magnitude more difficult. The Eclipse 500 team thought that it was all downhill when they landed Raburn as a backer: well over $1B behind a small, $900K vehicle with low technical risk. But every three weeks, the financial community forces them to go sharpen their pencils. So what chance does a smaller team, with only a $200M backing, have?

Back to the thread.
In 2001, the Eurofighter Typhoon team hired some of the best minds at BMW and Toyota to do design their QA systems. Less than two years later, they li

[SASless]

Nick has that effect upon people. I watched one of his presentations at a Safety Seminar and was impressed with some of the concepts he presented for discussion. After too many years flogging about the skies in 1950's techology and 1950's FAA rules designed for Airplanes and not helicopters, his concepts make a lot of sense. His views on the way we train, the way we ignore "helicopter IFR" and cling to other outmoded concepts ring very true.

[Brilliant Stuff]

I have to agree Nick's articles in that New Zealand publication are real Eye-openers. And it doesn't take much for him to bring the point across.

Robinson also use 5hrs for test flying.

[S64_fan]

. . . .(that was over 20 years ago, but watching the folks at Mirabel as recently as 3 years ago, it hadn't changed much). I also watched it being done at Agusta in the US and in Italy. . . . .

Mr Coyle: I would really appreciate the chance to learn more about your exp. in Italy (and those of other pilots, FE's or FTE's who've worked over here). Please contact me at [email protected]

- - - - - - -

That's my point! Or a part of it, anyway. Bell had a significant head start in the VTOL/tilt-rotor domain, and they blew it. In the mid-70's, several prominent engineers made a good case for the quad tilt-rotor vs. a twin rotor (agility, safety, c.g. range, no self-induced IFR) but
somehow the V-22 prototype wound up with just two. It would be too easy to point the finger at the various company and DoD PM's. One of the guys I worked with at Edwards AFB explained it this way: in many cases, the ball starts rolling in a certain direction, despite the lack of a significant body of technical, financial or market data. As the ball rolls, it accumulates mass. In a matter of weeks, there are a hundred or two hundred people assigned to the program. Once it's large enough to appear on the radar scope at corporate, it starts getting managed, and at that point, its rolling too fast to stop it.
In 1991, I presented a fairly solid argument for increasing the area of the Eurofighter's foreplane by 7%, and calculated that it would cost the program $2M. A couple weeks later, they told me that the overall impact would be over $200M, and a delay of up to 15 months. So if the age-old art of "going back to the drawing board" is no longer an option, then we'd better make sure that the guys doing the conceptual and early trade studies have an extra-sharp set of pencils. And much more importantly, we have to make sure that they have ample time and money to drive around the neighborhood, and see what the backyard mechanics are up to. I am not easily impressed, but the other day, a 40-man design firm operating out of a run-down building blew me away with their work in swarm technology.
The term "innovation" is used alot these days; where I come from, "innovative" means that you found a feasible solution to the problem in a just a few days, using very limited resources. At McDonnell Douglas and at Lockheed, the company culture stifles most of the true innovators. The situation is twice as bad at Airbus, and ten times worse at Agusta.
The production sites of Bell, Boeing, Agusta, and Airbus have one thing in common: the percentage of Toyota's in the parking lot.
One colleague tells me that on the Toyota Camry, between '96 and 2002, they managed to cut in half the number of hours spent in post-Final Assembly testing.

What needs to happen, in industry or in govt, before companies listen as much to their senior pilots and engineers, as they do to their financial people? Before the engineers are given the freedom to contract directly with the smaller shops?

(btw, can anyone suggest a more appropriate forum?)

[delta3]

S64_fan

I known plenty of stories of good engineering advise not being followed.
The snow-ball effect you quote is true and has too do with inherent conservatism (call it healhty sceptisism) present not only in business and finance but -believe me- even in academia. It is sad, but from another view point, it should be accepted that people at the helm are seldom rewarded by taking bold actions because they really cannot evaluate/predict succes rates, and may not have the time and perseverance, or gather and keep the concensus it takes to put the idea to work. So it is safer to stay 'in the middle' and move by small increments. History tends to show that it takes always longer than anticipated to make things work, even be it because of self full filling conservatism.

Focussed 'smaller shops' are perhaps better to start change, that is until they are noticed, bought and maybe silenced by the bigger ones. Only very few will pull it off, all the way to industrialisation. But that is life I am afraid.


d3

[CopterD]

Does anyone of you know how many test pilots are working for Eurocopter? And what the requirements are for the job?
CopterD

[Shawn Coyle]

Blenderpilot (and everyone else too)
Your experience is unfortunately all too common - at nearly every manufacturer. It pays to have someone go over the machine with a fine-tooth comb (or other appliance of your choice).
The story of the FW is also all too common.
There are those who make a living from accepting aircraft from manufacturers. For some reason the manufacturers hate to see them coming -when you'd expect them to love to find a way for manufacturing to be improved!
I just wonder what will happen when a helicopter manufacturing company really, truly pays attention to quality processes...

[idle stop]

To work at EC(F) Marignane as a tp there is one overriding qualification, I suspect: be French!
But EC(D) have a native Englishman as their CTP.
Otherwise, graduate tp or FTE of recognised tp school.

[Dave_Jackson]

S64_fan,

I believe that the fundamental answer to your question is founded more within a societal culture then within its individual companies. Everything is cyclical and it is appearing that the current style of 'capitalistic democracy', which is prevalent in the western world, is on the backside of the Bell curve. There is a preoccupation in the short-term gain, which will result in a long-term pain,

The following statement should add credence to the above. It was recently said that the US has 75,000 university students in Engineering, of which approximately 1/3 are foreign nationals. It was said that China has 900,000 university students in Engineering.

How is the direction of a culture changed? By evolution? By revolution? ......

[212man]

Idle Stop is correct in general, but they are breaking the mold now as they have recently begun training in house their first non TP school graduate. He's the former Chief instructor of the training school and is effectively doing a modular course of on the job training, with TPs/FTEs, and short course visits to EPNER (which is just down the road)

[bugdevheli]

http://img.photobucket.com/albums/v28/eboki/not%20sophs%20stuff/hover.jpg

Whats all the fuss! Design your machine, knock it together in the shed, climb in, make sure your head and nuts are well protected, tie her down, and GO FOR IT.:D :D

[Graviman]

Hey that's pretty cool, BugDevHeli! Is it your own design or based on a kit?

Trouble is in production when the assy guys are spitting out one a day, to earn everyones keep, things get missed - parts shortages, engineering changes etc. I have a great deal of respect for the guys who can consistently throw a new design together, but noone is perfect and everyone has to learn. The five hour test (say) keeps those mistakes inhouse, where they belong...

Any of the bigger players do production tie-down testing? Are any of the sub-assys tested, eg rotors in whirl-tower, or is quality inspection to drawing relied upon?

Mart

[I Build 92's]

Not sure about the other guys, but here at the big Sky we test everything! New production runs gear boxes, blades, etc to the breaking point. Then we put it all on the new airframe, tie it down and run that to death too! When that all checks out we biuld 2 or 3 prototype aircraft and beat them up too! Needless to say, we try our best to root out all the issues before we sell our first production aircraft. Do things come up after the fact? of course, you can't possibly cover every scenario but we sure try!

[Graviman]

"I Build 92's",

I'd like to learn more about your inhouse design/development/test procedures. Nick Lappos has helped me a great deal in obtaining a very practical perspective on heli design. Is there anywhere on the web i can delve a little deeper, since i live in fear of annoying pro heli pilots? :}

Mart

[I Build 92's]

Well if you have been talking to Nick, you've talked to the best!! I have had the pleasure of working with Nick here at Sikorsky since we were both new hires. The stories I can tell!! But I digress....I did some searching thru our company intranet and didn't come up with a whole lot of information for you. Of course I did come up with a slew of process's and procedures that are listed but company private and all so I couldn't forward those to you! There is quite a bit of info on line just by searching "engineering flight test" on Google, and of course there is always Nick....if he can't answer it for you, no one can!

[Graviman]

Thanks for the sound advice "I build 92's", Sikorsky sounds like a great place to work. When i first looked at GKN Westlands (original degree) they still seemed to be suffering from the WG30-300 development costs. :uhoh: I looked again when they became Agusta Westlands, but they were actually laying off...

This way i can compare the engineering experience i have gained with my favourite subject. ;)

Mart

[Graviman]

One thing that has not been mentioned here is any development that the pilots contributed to the EH101. I would be curious to expand that to Lynx too, since i understand this was the first production helicopter to have the electronic version of Lockheed's gyro stabilised system fitted (thanx Lu).

DM, any flight feedback ever get used during development? This thread is absolutely NOT going to become a Westland bashing event (FMECA or otherwise)...

Mart

[NickLappos]

Grav,
My experience with the Westlands TPs is that they are first class engineers and pilots, and they contribute mightily to the development of their helos. Certainly the adjustment of systems during flight trials is key to the system's success, and the pilots are strong inputters to this process. In the design phase, prior to flight, the pilots are often consulted and are also influential.

[Graviman]

Thanks Nick. I guess none of the Merlin TPs are going to bite :sad: . Shame, since as a professional engineer my interest really was just to improve my practical understanding of rotorcraft design.

Mart (C.Eng,M.I.MechE - honest guv! :} )

[dangermouse]

WHL use a joint approach with TPs and FTEs each having an input during the design and devlopment process, WHL use those inputs like any other company. the types of testing that useful feedback can be generated on are fairly self explanatory (handling, vibration, HMI etc)

Unlike some companies WHL have no real distinction between experimental/development/production test crews, all FTEs and virtually all pilots do all aspects of the test job, mainly based on experience, ie I believe the more experienced the individual the more likely to be involved with the experimental type stuff. on the other hand all get involved with production testing (which appears to be pretty run of the mill)

From memory the FTEs represent the core engineering view with the TPs putting in the handling and in-service view of the product, all the TPs are probably ex UK military services whilst most of the FTEs are not(it seems to work OK).

(it appears to be a British trait to remain quiet on a subject like this which is why you won't get many replies)

DM

[Graviman]

it appears to be a British trait to remain quiet on a subject like this which is why you won't get many replies

Very true, so i am even more appreciative of your taking the time to help me learn. :ok:

I would be extremely interested to learn about any handling characteristics which benefited from your experience. WHL products have a reputation for spot on handling - i guess your rotor dynamics guys are pretty experienced.

Mart