Query results: aspects_aircraft_design

What a jour­ney. It took many weeks to recov­er from teach­ing the course and many more to be able to look back calm­ly. I view the course as a suc­cess, but there are sig­nif­i­cant weak­ness­es I would like to address.

• First and fore­most, the course is run at an insane pace and makes tremen­dous demands on the stu­dents’ ener­gy reserves and timetable. This goes direct­ly against the self-ini­tia­tive and explo­rative learn­ing that I want to encourage.
  This prob­lem has its roots deep with­in the edu­ca­tion sys­tem and in its engi­neer­ing sec­tor in par­tic­u­lar. The area is intense­ly com­pet­i­tive and the val­ue of cours­es (as well as the recog­ni­tion of their teach­ers and to some extent the choic­es of the stu­dents) is mea­sured in great part by their dif­fi­cul­ty. For me, work­ing at home or in class is a con­tin­u­ous bat­tle try­ing not to give in to the irra­tional and counter-pro­duc­tive fear that the stu­dents find the con­tent too easy; and there is no incen­tive what­so­ev­er to walk at a pace slow­er than the most extreme one stu­dents can sustain.
  With this in mind, it will be dif­fi­cult to remove con­tent on the premise that more will be learned — even though this is an obvi­ous truth and the most straight­for­ward path for me to improve this course. I will try.
• Sec­ond, the in-class time was not used optimally.
  By start­ing with the stu­dent pre­sen­ta­tions from the pre­vi­ous project, I mis-used the first 45 min­utes of each ses­sion, which is the prime slot for stu­dent atten­tion. Kick­ing in a new lec­ture with whol­ly new con­cepts and vocab­u­lary one hour into the ses­sion is mak­ing poor use of the student’s time and energy.
  As for the projects, they require sig­nif­i­cant ground-work and num­ber churn­ing before they yield inter­est­ing results. Late starts due to pre­sen­ta­tions and long lec­tures meant that the tru­ly inter­est­ing aspects of projects —new con­cep­tu­al­iza­tions, impor­tant deci­sions, con­clu­sions etc.— most often took place much lat­er dur­ing the week, and out­side the class. It is regret­table that I could not help steer and encour­age stu­dents in these moments.
  Next year, I will like­ly move stu­dent pre­sen­ta­tions to just after the lunch break and try to short­en the lec­tures. I also intend to hand the projects out very ear­ly on (per­haps even one week ahead), and —gasp— make the hand-outs a lit­tle more spe­cif­ic as to where the inter­est­ing parts are.
• I need to work on improv­ing stu­dent par­tic­i­pa­tion and well-being in class. My friend David lead by exam­ple and left me with many leads for nur­tur­ing class par­tic­i­pa­tion and involve­ment dur­ing lec­tures. I should also have much more time next year to address the team­work issues that under­mined so many projects.
  In the com­ing edi­tion, I will invest time in talk­ing about effi­cient team-work and prob­lem-solv­ing prac­tices — this course has shown me that here too, a lit­tle “top-down” the­o­ry helps in prac­tice. I will also ask groups to des­ig­nate group lead­ers, which I think will help with struc­tur­ing and report­ing progress.
• Final­ly, I will work on improv­ing mark­ing. Over­all the grades were not out­stand­ing, as I was often dis­ap­point­ed by the struc­ture and solid­i­ty of the stu­dents’ work (rather than the actu­al results). I went to great lengths to explain what I thought need­ed improve­ment in each report and pre­sen­ta­tion, but I felt some dis-sat­is­fac­tion and some­times even plain de-moti­va­tion among the stu­dents when they received their mark.
  This is under­stand­able. The key to effec­tive mark­ing is keep­ing a close rela­tion­ship between the grad­ed work and the obtained mark: a time­ly cor­rec­tion, trans­par­ent mark­ing cri­te­ria, and a human con­nec­tion to mesh and com­ment them. In this case, the times­pan for hand­ing in projects is one week, and I then need three to five days to cor­rect and mark them. So by the time I got to dis­cuss the mark of, say, project A with some­one, they would have hand­ed in project B and would already be work­ing on project C, each week with­in a new­ly-shuf­fled group!
  To ensure bet­ter con­nec­tion between the hand­ed-in work and the cor­re­spond­ing mark, I will ded­i­cate time with­in class ses­sions to de-brief­ing pre­vi­ous projects oral­ly with indi­vid­ual stu­dent groups. I will also “freeze” groups for sev­er­al weeks in a row so that feed­back can be gath­ered and act­ed upon more easily.

So much for the crit­i­cism. I won’t elab­o­rate on the pos­i­tive points — these were eight intense, demand­ing weeks crammed with new knowl­edge. Also, a great deal of new mate­r­i­al was released under a Cre­ative Com­mons license for the ben­e­fit of all who wish to study it. The stu­dents’ feed­back was rather good and I think much was learned overall.

I set out to build this course with the hope of going by two pre­cepts: learn by your­self, and learn by doing.
“Learn by your­self” in the sense that I hoped to engage stu­dents in the set-up of the projects as well as the selec­tion of top­ics, and more so because I wished to let them choose and iden­ti­fy their areas of inter­est with­in projects, work­ing with­out a pre­cise set of instructions.
“Learn by doing” in the sense that I tried to have us work from real-life exam­ples (e.g. a 777 MTOW take-off) up into the under­ly­ing the­o­ry, instead of the oppo­site (e.g. “what real-life appli­ca­tion would illus­trate the use of that equa­tion?”). I hoped to pro­vide stu­dents with near-real-life prob­lems that they could solve with the ana­lyt­i­cal or method­olog­i­cal tools of their choice. Using a new tool or method because you need and chose it to do some­thing is a much more effec­tive learn­ing expe­ri­ence than start­ing from the tool and then look­ing for appli­ca­tions. Indeed, one of the great­est suc­cess­es of the course was that the stu­dents used, entire­ly upon their own ini­tia­tive, a great vari­ety of tools (hand-draw­ing, pro­gram­ming, spread­sheets, 3D-CAD, CFD, FEA soft­ware), even though there were many mis-uses and mistakes.

These two high-lev­el ped­a­gog­i­cal objec­tives would best be pur­sued with loose­ly-defined, ful­ly-cus­tomized, most­ly-impro­vised ses­sions in class.
Of course, any teacher will know that this is not a real­is­tic propo­si­tion. My employ­er will not hire me, the head of stud­ies will not allo­cate a slot for the course, the stu­dents’ future employ­ers will not give the diplo­ma cred­i­bil­i­ty, unless a detailed, ful­ly planned-ahead course cur­ricu­lum is writ­ten out. As a con­se­quence, when the course begins a very large amount of struc­ture and lim­i­ta­tion is already built-in, so that nat­u­ral­ly we nei­ther have com­plete­ly “learn by your­self” nor entire­ly “learn by doing”. I’ve lived with this lim­i­ta­tion ever since I want­ed to teach.

The one big thing that I have learned going through this course, how­ev­er, was that these prac­ti­cal require­ments are not the only obsta­cles to enabling true learn­ing. I have found that count­less small ele­ments not direct­ly relat­ed to the course con­tent have their impor­tance. Ensur­ing that groups com­mu­ni­cate effi­cient­ly, that they keep track of their progress, fero­cious­ly bat­tling stu­dent timid­i­ty and over-sub­or­di­na­tion, care­ful­ly sched­ul­ing ses­sions all the way down to 15-minute slots, all these seem­ing­ly insignif­i­cant things end up deter­min­ing whether or not most stu­dents will have a suc­cess­ful learn­ing expe­ri­ence, even if the con­tent is well-pre­pared and of high quality.
This dis­cov­ery trig­gers a series of thoughts and ideas about the process of learn­ing and the weight of social and cul­tur­al habits in our uni­ver­si­ties — but enough for now. “Aspects of Air­craft Design and Con­trol” been a ter­rif­ic expe­ri­ence. I look for­ward to next year.

Lec­ture 8 — Lon­gi­tu­di­nal stability
Project 8 — Design­ing Canards

The objec­tive of this eighth and final project was to explore the notion of lon­gi­tu­di­nal sta­bil­i­ty and the con­straints it impos­es on air­craft design and oper­a­tion. The accom­pa­ny­ing lec­ture is focused tight­ly on the con­cept of sta­bil­i­ty and the tools need­ed to solve the problem.

The lec­ture tack­les the notion of sta­bil­i­ty in a very pro­gres­sive and visu­al way. It is one great virtue of such infor­mal, project-based lec­tures that they let us focus on the essen­tial only. Here, all sub­tleties such as tail/wing inter­ac­tion, their respec­tive effi­cien­cies, ver­ti­cal off­sets, or dynam­ic effects are left aside, leav­ing us to work on the very con­cept of sta­bil­i­ty un-distracted.

The last part of the lec­ture is ded­i­cat­ed to answer­ing the ques­tion “how can canard air­craft be sta­ble?”, which if done cor­rect­ly, neat­ly cap­tures the con­cept of, and con­straints brought by, lon­gi­tu­di­nal stability.
As a whole, the lec­ture is short, neat, and leaves me very satisfied.

The project prob­lem can be solved rather eas­i­ly (only three sets of two sim­ple equa­tions need be solved) but leaves room for exper­i­men­ta­tion and ini­tia­tive; the bal­ance was struck in the right place.
I want­ed to alle­vi­ate the work load on the stu­dents, who were caught with­in mul­ti­ple dead­lines, as well as has­ten the pub­li­ca­tion of the final results (my expe­ri­ence is that when marks can­not be avoid­ed, giv­ing out marks prompt­ly is one of the most effec­tive ways of keep­ing stu­dents moti­vat­ed and enabling them to improve). There­fore, I pro­posed that the project be com­plet­ed in-class with­in four hours, and the class accept­ed. Work­ing with a close-by dead­line tremen­dous­ly increas­es pro­duc­tiv­i­ty but this comes at the cost of the seren­i­ty and slow-pace explo­ration that char­ac­ter­ize true learn­ing. Cut­ting-off stu­dents in their work at the end of the ses­sion sim­ply rein­forces the teacher-judge/­taught-judged cleav­age, and everyone’s frus­tra­tion. I will not do this any­more next year.

All in all, a nice­ly con­struct­ed lec­ture and project. To me, the ses­sion was spe­cial in two ways. First, lon­gi­tu­di­nal sta­bil­i­ty had been a devour­ing, part­ly-unsolved cen­ter of inter­est ever since I stud­ied it in uni­ver­si­ty, and the first top­ic I ever desired to teach. Sec­ond and most impor­tant, it was the last ses­sion that I would be able to spend togeth­er with a class I’ve known for three years and with whom I’ve spent many an inter­est­ing or intense expe­ri­ence. Work­ing on the design of a great-look­ing, ter­rif­ic-sound­ing hypo­thet­i­cal air­craft was a nice way to part.

Lec­ture 7 — Air­craft Trim
Project 7 — Air­craft Trim

The aim of this project was to explore the con­cept of lon­gi­tu­di­nal equi­lib­ri­um (“trim”) in flight, and the ways in which it can or can­not be attained in prac­tice. The lec­ture far exceeds what is required to solve the prob­lem and indulges into a dis­cus­sion of the design choic­es, pilot tech­nique, and human inter­ac­tion facets of the top­ic. The result of the inter­ac­tion of two pas­sion­ate close friends, the ses­sion was the most suc­cess­ful of the course.

The lec­ture was one of two parts. My objec­tive was to explore trim thor­ough­ly in this ses­sion before div­ing into lon­gi­tu­di­nal sta­bil­i­ty in the fol­low­ing, eighth and final ses­sion. It was a wise propo­si­tion and I think the dis­tinc­tion between the two con­cepts —which both are affect­ed by the same para­me­ters— real­ly came through.

The ses­sion starred long-time friend and air­line pilot Hamas­sala David Dicko. We pre­pared the lec­ture and project togeth­er over three days, and shared the session.
David focused on the top­ic of trim from the point of view of the pilot (as we found out, pilots and engi­neers do not even define trim in the same way!), explain­ing how things are felt and account­ed for in the cock­pit. It was a fan­tas­tic con­tri­bu­tion, cul­mi­nat­ing in a dis­cus­sion about the human/machine inter­ac­tion impli­ca­tions of the trim man­age­ment automa­tion on airliners.
I also learned a lot from David by see­ing him inter­act­ing with the stu­dents in a way I had not thought was pos­si­ble. This prompt­ed very inter­est­ing dis­cus­sions after­wards and I think I will improve great­ly in this regard.

The part I took charge of is a very basic quan­ti­ta­tive intro­duc­tion to trim. The equa­tions are cer­tain­ly intim­i­dat­ing, and I took care in class to focus us all on the impor­tant parts only. Despite the minor caveats, things went well.

The project is not exact­ly bril­liant — to me it is more of a rid­dle than a true learn­ing frame­work. Giv­en the time invest­ed in the prepa­ra­tion for the lec­ture, the length of the in-class ses­sion, and the con­text with­in the course (this was the sev­enth week and sixth dead­line day in a row), I think this can be for­giv­en. I will try to re-mold it entire­ly this year.

Over­all, not even with­stand­ing the sheer joy of work­ing with my good friend, the ses­sion was the high­light of the course and a suc­cess by almost any met­ric, includ­ing the most impor­tant of all, stu­dent moti­va­tion and enjoy­ment. I am look­ing for­ward to invit­ing David again =)

Lec­ture 6 — Propulsion
Project 6 — Tur­bo­fan design

The aim of this project was to review the physics gov­ern­ing the oper­a­tion of tur­bo­fan engines, as well as begin explor­ing a few of the many com­pro­mis­es asso­ci­at­ed with jet engine design and instal­la­tion. The lec­ture reviewed the main notions need­ed in the project in a rather light and illus­tra­tive way.

The lec­ture relies strong­ly on notions and con­cepts that I stud­ied togeth­er with the class in the pre­vi­ous year, in my course on engi­neer­ing ther­mo­dy­nam­ics. Here we work with stag­na­tion (a.k.a. “total”) prop­er­ties for the first time, and then pro­ceed to air­craft propul­sion specifics.
In the last sec­tions of the lec­ture, I indulge into explor­ing some of the main para­me­ters and per­for­mance indi­ca­tors of jet engines, as well as the com­pro­mis­es relat­ed to their installation.
The notes lack an intro­duc­to­ry exam­ple that is not extract­ed direct­ly from a ful­ly-copy­right­ed book, as well as CC-licensed media to illus­trate tur­bine cool­ing tech­niques and prin­ci­ples. I will work on this next year.

Frankly, there is noth­ing extra­or­di­nary here — what you get is your stan­dard third-year overview lec­ture about propul­sion. I sim­ply took plea­sure tak­ing the ther­mo­dy­nam­ics stud­ied in the pre­vi­ous year one step high­er. It was a short and com­fort­able session.

The project was con­struct­ed direct­ly with the feed­back of the stu­dents, who had asked for a more straight­for­ward, lit-up path to a solu­tion. Straight­for­ward it is — three hours of late-night work using any thermodynamics/propulsion man­u­al at hand are enough to crack the project. In this sense it is more of a tuto­r­i­al exer­cise than a true project requir­ing group work and sig­nif­i­cant ini­tia­tive. Nev­er­the­less, in order to make progress, one is forced to think care­ful­ly about the types of flow with­in the engine, to trans­late them into ener­gy equa­tions. A lit­tle room for stu­dent ini­tia­tive and explo­ration is pro­vid­ed right at the end of the project, in the choice of the fan.

The project was suc­cess­ful. With known mate­r­i­al, no sur­pris­es, no pit­falls, and bet­ter marks, we all found an oppor­tu­ni­ty to breathe, six weeks into the course. I am left with much small­er sense of achieve­ment but I think it is a fair price to pay.

Project 5 — Wind tun­nel design
Lec­ture 5 — Scale and testing

The aim of this fifth project was to work with the main flu­id mechan­ics notions and phe­nom­e­na at play in a small, sub­son­ic wind tun­nel. The accom­pa­ny­ing lec­ture was a review of the impor­tant notions (the­o­ret­i­cal flow, the effects of fric­tion, and scal­ing tech­niques) need­ed to work on the project.

This was by far the rich­est and most ambi­tious lec­ture of the course. I set out to sweep across a very large amount of mate­r­i­al in a lec­ture that was struc­tured as though it was a review of the entire flu­id mechan­ics dis­ci­pline. In ret­ro­spect it is easy to see that this was rather fool­ish, per­haps in part because the cov­er­age can be nei­ther thor­ough nor com­plete (and indeed impor­tant parts such as com­put­er flu­id dynam­ics or com­press­ible flow are not even men­tioned), but espe­cial­ly because the lec­ture then lacked focus.
The stu­dents were not helped by this lack of clear pur­pose. I too had dif­fi­cul­ties, as I was tak­en aback by how lit­tle con­nec­tion I could make with the student’s exist­ing knowl­edge. Final­ly, because of the sheer vol­ume of mate­r­i­al, the Eng­lish lan­guage was a par­tic­u­lar­ly heavy over­draft that day.

Nev­er­the­less, I believe the lec­ture was a decent attempt at putting togeth­er the puz­zle pieces acquired over the semes­ters. Indeed, I am con­vinced that the largest short­com­ing of our flu­id mechan­ics and deriv­a­tive cours­es are that they fail to explain where and how the dif­fer­ent types of analy­sis fit togeth­er in the big pic­ture. For exam­ple, com­press­ibil­i­ty effects and bound­ary lay­er the­o­ry are always taught entire­ly sep­a­rate­ly, so one may nev­er find out in uni­ver­si­ty that they in fact may both togeth­er be use­ful for the study of a par­tic­u­lar flow. I hoped to present famil­iar con­cepts under the light of their use­ful­ness (or not) in study­ing sim­ple real-world applications.

The project focused on applied aero­dy­nam­ics, and required mix­ing ele­ments of design, scal­ing tech­niques, the­o­ret­i­cal flu­id mechan­ics, and approx­i­ma­tion tech­niques. I hoped to give stu­dents a taste of the aerodynamicist’s job by com­ing to grips with the shock­ing amount of restric­tions inher­ent to wind tun­nel test­ing, as well as the over­whelm­ing pres­ence of empir­i­cal, expe­ri­ence-based rather than the­o­ret­i­cal work.
The project pur­pose­ly left a lot for the stu­dents to decide by them­selves, and I nev­er thought they would hate this as much as they did! I could not con­vince any­one that there is no opti­mal wind tun­nel design at all, lest even that the objec­tive was to get a grasp of the main notions at play, not pro­duce cut­ting-edge data. Clear­ly the thresh­old that must be over­come to reach the most inter­est­ing parts of the project was too high.

I think the main miss­ing ingre­di­ent in this ses­sion was fun. The path through the lec­ture and project is full of dis­com­fort, as none of the beau­ti­ful the­o­ries, neat-and-unique results, and usu­al cer­tain­ties hold — real aero­dy­nam­ics is hard!
In the next edi­tion I will cut down as much as I can on the lec­ture and project con­tents so that the key aspects of the project can be han­dled ear­li­er on. I will work on get­ting more of my enthu­si­asm for the top­ic through. Stu­dents report­ed that they liked this project least of all although they felt it was inter­est­ing and impor­tant. That’s a good start­ing point for improving.

Lec­ture 4 — Cruise performance
Project 4 — The mar­ket for winglets

This project’s objec­tives were to explore the notions of and rela­tions between cruise speed, fuel con­sump­tion, weight, and eco­nom­ics. The lec­ture focus­es on ordi­nary flight mechanics.

This is a very short and light­weight lec­ture: we focus on a sim­ple mod­el for the rela­tion between lift and drag, and we derive the Breguet Range equa­tion in class (first part of the projet).
Once this is cov­ered, the project lets stu­dents explore air­line eco­nom­ics by them­selves, con­cep­tu­al­iz­ing, esti­mat­ing and research­ing val­ues for sec­tor length, air­craft usage, and so on. My feel­ing is that they tru­ly enjoyed this.

Over­all the lec­ture and project are far less demand­ing than any of the three pre­vi­ous ses­sions, a very dras­tic step down. This was prompt­ed by the cor­rec­tion of the Project 2 hand-ins in the week lead­ing to this lec­ture, which as I dis­cussed ear­li­er unam­bigu­ous­ly showed that I had been aim­ing too high.

Prepa­ra­tion for this lec­ture was thus impro­vised in a cou­ple of days (I recy­cled the pay­load-range dia­grams from anoth­er course). In ret­ro­spect, reduc­ing the dif­fi­cul­ty of the lec­ture and project was a wise idea. There was decid­ed­ly more enjoy­ment among the stu­dent groups, in class, in the reports and presentations.
At the start of the lec­ture I bet crois­sants and cof­fee with stu­dents that they would find that project much eas­i­er. No-one ever claimed any­thing but I didn’t get any cof­fee, either.

Lec­ture 3 — Wing geometry
Project 3 — Wing loads

This project has the rather broad aim of study­ing the design of an air­lin­er wing by inte­grat­ing con­straints relat­ed to aero­dy­nam­ics, over­all design fit­ness, air­craft oper­a­tion, and struc­tur­al efforts. Con­trary to most oth­er projects in the course the lecture’s scope exceeds what is strict­ly need­ed for solv­ing the project problem.

The lec­ture square­ly tries to answer the ques­tion “why do air­lin­er wings look the way they do?” in terms that will sat­is­fy an engi­neer already a lit­tle famil­iar with aero­nau­tics. In doing so I hoped to con­nect with exist­ing stu­dent knowl­edge, extend their Eng­lish aero­nau­ti­cal vocab­u­lary, and cov­er impor­tant notions in aero­dy­nam­ics in a rather light and visu­al way.

The first part (“2D Lift”) fur­thers the notion of two-dimen­sion­al lift that was already explored in the first two projects. None of the fig­ures are quan­ti­ta­tive but they give, I think, good insight on air­foil selection.
The sec­ond part (“3D Lift”) tack­les the very, very tough task of going from two- to three-dimen­sion­al lift, and I am left with the intense­ly sat­is­fac­to­ry feel­ing of hav­ing done it right. I did lose stu­dents along the way for not relat­ing close­ly enough to a project or in-class appli­ca­tion, however.
The last chap­ters cov­er wing design in a loose, very graph­i­cal way —great, stress-free fun.

Over­all the lec­ture is a suc­cess. It assem­bles an enor­mous amount of use­ful media (there are weeks’ worth of draw­ing furi­ous­ly on Inkscape in these slides) and does, I believe, a good job of answer­ing its mis­sion­ary question.

The project prob­lem is rather sim­ple, even if it is buried beneath rich and tor­tu­ous phras­es. A rough sketch and cal­cu­la­tion for a work­ing answer might only take two hours to come up with. The project pro­vides a good oppor­tu­ni­ty to fine­ly explore the notions of bend­ing moment and shear force, as well as their inter-rela­tion. I also trust­ed stu­dents would take advan­tage of their struc­tures and mate­ri­als knowl­edge, which far exceeds mine.
There was also room for exper­i­men­ta­tion (wing lay­out, load cas­es, safe­ty mar­gins, etc.). My favorite propo­si­tion is ask­ing why, if the wingtip con­tributes more weight than lift, it is not sim­ply suppressed…

In prac­tice the project did not go very well. The long and rich lec­ture took its toll on the time bud­get and once again we start­ed late. I felt there was enjoy­ment and explo­ration in some groups but I found out in the fol­low­ing weeks that most had left the ses­sion with­out a clue as to what the final result should look like. We were also in the wake of the pre­vi­ous project which had engulfed con­sid­er­able amounts of ener­gy. None of the groups obtained a result that was cor­rect or even remote­ly realistic.
This project suf­fered most strong­ly from poor work tech­niques and human resources man­age­ment with­in the class. I have a share of respon­si­bil­i­ty for that, and will be much more active in the future to ensure bet­ter learn­ing can happen.

Over­all then, a good project and lec­ture; here too bet­ter exe­cu­tion is needed.

Lec­ture 2 — Run­way performance
Project 2 — Run­way performance

This lec­ture focus­es on the tools and knowl­edge required to study and pre­dict an aircraft’s per­for­mance on take-off. The project’s aims were to prac­tice ana­lyt­i­cal tech­niques in New­ton­ian mechan­ics by work­ing on an applied and high­ly visu­al aero­nau­ti­cal prob­lem, and to gain famil­iar­i­ty with the com­plex oper­a­tional con­cepts involved in a typ­i­cal air­lin­er take-off.
It was by far the most inter­est­ing and dif­fi­cult project of all. It met only very mod­er­ate success.

The lec­ture, I believe, had merit.
The first part (“Prob­lem-solv­ing tools in mechan­ics”) focused on two tech­niques for solv­ing New­ton­ian mechan­ics prob­lems — but I lost many stu­dents in this chap­ter by not giv­ing detailed con­crete exam­ples of their use. It is under­stand­ably hard for a third-year stu­dent to be attract­ed by a sec­tion titled “Newton’s sec­ond law”! In the in-class project ses­sion that fol­lowed, I end­ed up com­ing back mul­ti­ple times to points I brought up in this chap­ter but that were sim­ply over­looked. So this sec­tion will need re-work.
The sec­ond part (“Def­i­n­i­tions”) was sat­is­fac­to­ri­ly suc­cinct and clear.
The third part (“A take-off”) was frankly good. I took the approach of explor­ing the impor­tant flight mechan­ics con­cepts at play dur­ing a take-off by nar­rat­ing an imag­i­nary one. This was ter­rif­ic fun. I also like my way of tack­ling the notion of Bal­anced Field Length.

The project was split in two parts. The first one, a pure­ly in-class ana­lyt­i­cal exer­cise, took too long. I blame the lack of per­spec­tive and appeal of the lecture’s first chap­ter for that: I should have giv­en exam­ples, as well as real hints towards how to start when stuck. Hope­ful­ly and if any­thing at all, the exer­cise was an effec­tive demon­stra­tion of the some­times immense dif­fi­cul­ty of com­ing up with the rather triv­ial math­e­mat­ics that describe ordi­nary problems.

As for the sec­ond part, the only word that comes to mind to describe it is “epic”. To be frank, I feel it was extreme­ly good, in that it pro­vides a good frame­work for true learn­ing: con­cep­tu­al­iz­ing new notions (V1, the Bal­anced Field Length, Rota­tion, etc) instead of hav­ing them fall from the sky, and solv­ing a chal­leng­ing, real­is­tic problem.

In prac­tice, the stu­dents had great dif­fi­cul­ties with that part. Not only is there no obvi­ous path to a solu­tion, but one is also forced to make sim­pli­fi­ca­tions and esti­mates if s/he is to obtain any result at all. This clash­es spec­tac­u­lar­ly with the learn­ing pat­terns and habits with­in the school. I made sev­er­al mis­takes in hand­ing such a chal­leng­ing project.
First and fore­most, I should have invest­ed more effort in describ­ing prob­lem-solv­ing tech­niques. In par­tic­u­lar, we are used to pro­ceed “from the top down”, work­ing our way from an all-encom­pass­ing, most-gen­er­al heavy math­e­mat­i­cal expres­sion down to a spe­cif­ic appli­ca­tion case. By con­trast, in such cas­es it is much more effi­cient to work “from the bot­tom up”, start­ing from a dum­my, extreme­ly-sim­pli­fied case, and grad­u­al­ly adding lay­ers of com­plex­i­ty whilst mon­i­tor­ing the san­i­ty of the calculations.
Sec­ond, I mis-man­aged our ener­gy dur­ing the ses­sion and with­in the course. We were only able to get in the heart of this project very late in the 6- or 7‑hour ses­sion, which makes for an un-wise con­text for hard-core think­ing. The project came too ear­ly with­in the course, the ses­sion was slight­ly over­loaded, and then too much was left for the stu­dents to do by them­selves afterwards.
By then, the stu­dent team­work and work plan­ning issues that I described in the back­ground remarks on the course had ful­ly kicked in.

The result was that the class, whose gen­eros­i­ty and moti­va­tion keep amaz­ing me year after year, threw in tremen­dous amounts of effort and ener­gy into the project with­out most stu­dents obtain­ing mean­ing­ful cal­cu­la­tions, sat­is­fy­ing results, and indeed, much moti­va­tion feed­back. That is hard­ly a suc­cess­ful learn­ing expe­ri­ence and I feel that most of the respon­si­bil­i­ty for miss­ing this oppor­tu­ni­ty is mine. Many improve­ments come to mind for next time with­out mod­i­fy­ing the core. Great project, per­fectible implementation.

Lec­ture 1 — Basic Flight Mechanics
Project 1 — Flight Domain

This first lec­ture focus­es on the notions of lift and lift coef­fi­cient as they apply to ordi­nary flight. The project’s aims were to explore the very pecu­liar way in which drag con­strains flight, as well as the notions of ener­gy and pow­er, through the explo­ration of the flight domain of an aircraft.

The lec­ture approach­es the main notions in a prac­ti­cal, explorato­ry way: we make many small thought exper­i­ments in class to come up with the main phys­i­cal trends (which results in the numer­ous graph curves shown in the hand-outs). This makes for a rather intense, and I hope, pro­duc­tive time in class; how­ev­er as a result the notes are less effec­tive at guid­ing the read­er through.

The project looks some­what like a puz­zle at first sight, but once “cracked”, pro­vides a great plat­form for the stu­dent to play with the data (for exam­ple, “what hap­pens if the wing sur­face is shrunk?”).

Only one hour into the lec­ture it became clear that there was a sig­nif­i­cant gap between my pace and the stu­dents’, and sub­se­quent­ly a lot of effort went into bridg­ing it. The Eng­lish lan­guage was not, I believe, pre­vent­ing under­stand­ing, but it made the lec­ture so much more demand­ing for the stu­dents that lit­tle ener­gy was left for participation.
It was also the stu­dents’ first encounter with the unusu­al for­mat of the lec­ture and hand-outs, so the lec­ture took longer than it should have. I still think it went well.

The project, too, took too long. My hope was for the first sketch­es of the flight domain to come up with­in the sec­ond hour of in-class work, so that the rest of the time could be ded­i­cat­ed to explor­ing the many inter­est­ing impli­ca­tions of the results. Unfor­tu­nate­ly, by the end of the day many teams were bare­ly on track, and most stu­dents obtained their results very late in the project cycle.
Next time I will spend much more time and ener­gy explain­ing that the project shouldn’t be han­dled as a puz­zle, and that most of the com­plex­i­ties of the mod­els, data, and avail­able tools are just dis­trac­tions from the analy­sis that makes the core of the project.
I will also be much more active in mak­ing sure the stu­dents work effec­tive­ly — there were great mis-uses of everyone’s time in class, that I thought would solve them­selves pro­gres­sive­ly but in fact nev­er did.

All in all, I think, a good project. It will not take much to make it great.

So how did the course go?

All in all this has been the most demand­ing project of my short career. I sig­nif­i­cant­ly under-esti­mat­ed the ener­gy that would be required to run the ses­sions and projects. There are many rea­sons for this.

First, for many stu­dents, lec­tures that were built as mere reminders and overviews most­ly failed to con­nect with exist­ing knowl­edge. Signs of acquain­tance or recog­ni­tion were rare dur­ing the lec­tures, which thus took a slow­er pace than expected.
I can­not blame the stu­dents for this. As teach­ers we still have to embrace the fact that with our manda­to­ry-pres­ence, heav­i­ly mark-based, 35-hour a week lec­ture sys­tem, only a small frac­tion of what is taught is tru­ly learned. It is my first uni­ver­si­ty course which strong­ly depend­ed on knowl­edge and skills acquired in oth­er parts of the cur­ricu­lum, so I most­ly dealt with this prob­lem live “on air” dur­ing the lectures.

Sec­ond, there were clear­ly great prob­lems with the way stu­dents worked among them­selves. I failed to antic­i­pate rather pre­dictable issues with time man­age­ment and dif­fi­cul­ties with keep­ing on track. Much worse, how­ev­er, was the com­plete inabil­i­ty of most stu­dents to solve inter­nal con­flicts or move past per­son­al rela­tion­ships: the class­room was split in two un-mix­able parts. Clash­es thus occurred when­ev­er we tried to cre­ate new work groups by mix­ing lists randomly.
Unfor­tu­nate­ly, I could nev­er real­ly afford the time and ener­gy that solv­ing this prob­lem would have required. This aspect remains one of the largest weak points of the course.

Third, it took time for us, I believe, to feel at ease with the for­mat of the lec­tures, whose pro­gres­sive, explo­rative slides and hand­outs con­trast sharply with the more top-down, author­i­ta­tive for­mat that is cus­tom­ary with­in the school cur­ricu­lum. Many stu­dents would nev­er tru­ly embrace this way of work­ing — indeed note-tak­ing (even under­lin­ing or high­light­ing) was rare all through­out the course.
Despite this, I still think the for­mat was appro­pri­ate and a worth­while expe­ri­ence for all of us.

Fourth, the projects were dif­fi­cult. Most exer­cis­es in uni­ver­si­ty cours­es are con­struct­ed as “here are A and B, find C” and they come after a lec­ture focused on all the quan­ti­fied rela­tion­ships between A, B and C. By con­trast, most of these projects sim­ply stat­ed “eval­u­ate C” with­out giv­ing much hint as to the process (and some­times not even giv­ing any data). This was inten­tion­al — most real-life engi­neer­ing prob­lems have mul­ti­ple solu­tions and do not come with an instruc­tion man­u­al. Most impor­tant­ly, the learn­ing process is much rich­er when one asks “which A and B does C depend on?”. The result­ing dis­com­fort and some­times even dis­ar­ray in the class took time and many efforts to dissipate.
Many stu­dents’ “nav­i­ga­tion-in-the-dark” tech­niques (how to know whether one is on the right track, how to make sol­id approx­i­ma­tions, etc) were rather weak. I read things in reports that no would-be engi­neer should allow him/herself to write.
In ret­ro­spect now I real­ize that the one-week span avail­able to tack­le each project did not pro­vide room enough for the serene learn­ing and exper­i­men­ta­tion that I hoped to encour­age, espe­cial­ly with­in the con­text of a time slot deep into the semes­ter and mul­ti­ple con­cur­ring dead­lines for the stu­dents. This, unfor­tu­nate­ly, will be hard to change.

Nat­u­ral­ly, I spent great efforts to adapt the course as these issues —all of them com­pound­ed by the Eng­lish lan­guage— unfold­ed. The top­ics stud­ied, the dif­fi­cul­ty of the projects, all the way down to the way work groups were select­ed or the for­mat of the ses­sions, every­thing from the third ses­sion onwards has been tai­lored to that spe­cif­ic class with vary­ing degrees of success.

Final­ly, it should be men­tioned that many aspects of the course made it stand out a lit­tle in the cur­ricu­lum, which nev­er helped. The course has been “ordered” from me and then “sold” to the stu­dents very ear­ly on (this can do noth­ing but need­less­ly raise expec­ta­tions), and was then taught as it came in the midst of a finan­cial and inter­nal pol­i­tics dis­pute with­in the school. Most nat­u­ral­ly, just as any oth­er teach­ing course, it was con­struct­ed and run with an avail­able time bud­get that was much small­er than what is required to do a good job, which is about one gazil­lion hours. C’est la vie.

This lengthy set of remarks should pro­vide con­text for tru­ly under­stand­ing how the slides and projects that fol­low were con­struct­ed and used. In the next post I shall final­ly start pub­lish­ing con­tent =) , and once done, I will con­clude briefly on the whole course.