Simulator trial of Take-Off Performance Monitor system at Cranfield University

[Jeremy Purry]

I am a bmi B737 Pilot doing an MSc in Human Factors at Cranfield and am looking for some willing volunteers who would like to take part in a simulator trial of a new invention of a monitor system for Take-off.
It is a simple exercise involving lots of take offs an RTOs taking about 11/2 hours.
There is no remuneration I'm afraid, volunteers only, and you will need to come to Cranfield University campus.
You will need to be relatively current and be experienced on any medium to heavy Jet transport aircraft.

If you are interested please contact me, Jeremy Purry, at [email protected] for more details.

The trial will run til 15th August 2003.

Thanks, look forward to hearing from you.

Jeremy Purry.

[747FOCAL]

What kind of system is this? Aircraft tracking? Noise?

:confused:

[Jeremy Purry]

Hi there,747Focal,

it is basically system that advises whether the aircraft is performing adequately on the take-off roll towards V1 and can sense whether the a/c is performing relative to the calculated scheduled performance.

If you want more info and want tp take part in a trial send me an e-mail to [email protected] and i can send you a briefing pack.

JP.

[747FOCAL]

What is the intention of this system if it is ever put into use?

[Jeremy Purry]

It would help prevent the sort of accident that occurred to the Air Florida B737 at Washington National in January 1982, where insufficient thuust was set and the aircraft was not accelerating adequately. Such a condition would have been "flagged up" by the monitor early in the t/o roll. It is very sensitive to subtle under-performance which could arise if say there was a binding brake unit or the aircraft was overloaded. There was a relatively recent case of, I believe a B747, which took off 10 tonnes over weight and consumed most of TORA just to get airborne - this also would be a classic situation in which the Take-off Performance Monitor (TOPM) could alert the crew that all was not as it should be, allowing an RTO from well before V1.

If you are interested in seeing the system in action and would like to take part in the trial please do get in touch and I can send you further information.

[john_tullamarine]

I suspect that you ought to do a bit more in the literature research side of the thesis workup .... such gadgets have been developed and researched in years gone by .... be a pity if your research were to be treated with disdain were it to replicate something which has already been published ...

[747FOCAL]

john_tullamarine, Then I would suggest certain parts of the study be impressive for the greens. If the software does what J. Purry indicates, it could be used to demonstrate how derate takeoffs and aircraft not maintained as well as others offend the airport communities noise wise much more often. If one can corelate noise monitor data with a specific takeoff you could demonstrate why airlines that choose to operate using derate or not maintain their airplanes as well should/could pay more noise related fees.

Noise certification for takeoff is done with AC off, mid cg and MAX thrust. It also uses a cutback procedure that would unsettle most passengers. How many airlines you know of operate in this configuration? Thats right, zero for the most part. I guess that means that the QC system is based on bogus noise numbers that are not achievable in normal operations.
:ok:

Kinda off topic, but the first post grabbed my attention along these lines. :E :E :E

[Jeremy Purry]

John,
I have read quite a lot about the previously designed systems including the one by John Grover, ex ground instructor and tech perf expert and author. His was flight tested by the FAA in the early 70's on a Coranado 880, if you remember those !!
Also the Dutch NLR system and the NASA system that was tested in their interesting B737 flying test-bed that they used for developing the first CRT displays. Had a cockpit back in the cabin near the centre section !
I believe the Cranfield system, which has only recently been patented, stands a far higher chance of success mainly because of its simplicity of display format and readily retrofittable design.
I have also looked at the system proposed by Khwata at Bristol which again has a complex interface.
Thanks for your reply, if you have knowledge of any other similar systems that may be worth comparing with, please let me know.

JP :ok:

[john_tullamarine]

JP,

I don't know of any others to those you have listed. We look forward to seeing your name up in lights in due course .... best of luck with the research ...... JT

[used2flyboeing]

This is an old idea - Boeing invented something like this years ago - IE the notion of takeoff perfromance monitor centered around what they called a "Chrondrasic Interval". The thing worked, was a nobel cause & good innovative engineering. I dont know why it never got implemented. I suspect for product liability reasons - IE Modern day aircraft flight deck & air carrier operations are centered around the FAR "The pilot is ultimately responsible for the safety of his aircraft", Now, this FAR basically shifts all the liability onto the pilot when it starts raining aluminum. However, if you have a takeoff performance monitor - then you start to shift the responsibility back onto the aircraft manufacturer, because this critical step of synthesizing dynamic info is done by the aircraft manufacturer & voila ! product liabilityconcerns !. Now, certainly you do not expect an American COmpany to take on additional risk do you ?? This thing will not get implemented in the US - unless, a foreigner makes it happen first . AIRBUS is much closer to this concept than stodgy old Boeing - IE with the full up envelop protection. That being asaid - this is takeoff performance in my humblest of opinions is somewhat irrelevant on modern jetliners - THE DIRTIER SECRET CONCERNING YOUR CONCERN WITH TAKEOFF PERFORMANCE is display data latency delays. IE The through put of dynamic data such as GS & CAS is delayed in modern avionics systems due to the latency getting from the enviromental sensor - through whatever conputer ( airdata, IRS etc ) down the data bus - into the display processor & upload onto the display - therefore, if the data you are relying on to make these natz-ass decisions is "late" - then what does it all mean ? - yes - Im saying your are always going to be at least faster then what your are indicating - by milliseconds - to seconds - depending on the aircraft your are flying. Put that in your fuse box !

[PPRuNe Towers]

As an indication of the latency mentioned external wind velocities are commonly 6 seconds out of date by the time they reach a symbol generator and thus your scan.

Rob

[Jeremy Purry]

used2flyboeing,

you make some good points. I am approaching this from a pilots and human factors angle and am not aware that the latency is as bad as mentioned. I note your comments re Boeing v Airbus in acceptability of such a system but would say that this system is still only advisory and so the pilot(s) still have the ability to make the decision to Stop or Go.
JP

[Jeremy Purry]

Reference the Simulator Trial of the Cranfield developed TOPM (Take-off Performance Monitor)

I have now closed the trial of the TOPM, as I am approaching hand-in of my thesis.

I would just like to thank all of you who took an interest in the system and those who came forward to take part in the trial.
Many thanks.

It is unfortunate that the study was hampered by poor serviceability of the sim.
It is hoped to run a larger more in depth trial at some time in the future after the sim has been modified.

The results so far show that the TOPM is a simple yet effective system to use and this is encouraging for future development.

regards,

Jeremy Purry.

[used2flyboeing]

Jeremy Purry - the plantifs lawyers will say - if it was only advisory - why put it on in the first place? ( some people will rely on it ) - I have some dead sea scrolls ( white papers ) on this topic - email me if you are interested in this ..