Flying

My first ever app I made and sold...

I was digging through a cupboard today, when I came across the package shown below.

I was initially flabbergasted that I still had a copy on hand, but that soon gave way to feelings of nostalgia that took me back 30 years (yes, that is 3 decades) to when I first created this.

It is basically the first time I had “scratched my own itch”. Being a commercial pilot at the time, I was finding paper based logbooks to be painful to manage, so I wanted to use my programming skills to create a computer based one which would make it easier to tally up certain entries, especially looking at the recruitment process, where pilots would be asked questions like “How many hours do you have on multi engine aircraft?” or “How many in-command hours do you have on a certain aircraft type” etc.

I wanted to create a simple logbook app which could answer that, and so Sabre Personal Logbook was born sometime in 1990.

I wrote this using Clarion 2.1, which is still the most productive and useful application creation framework that I have ever come across to date. I think the original app took about 3 months to create, including the creation of the boxwork art, printing the manuals etc. I even created it using the IBM PS/2 shown on the box art!

There was no such thing as Paypal or Stripe back in those days, heck, even the internet was in its infancy, so everything was done via magazine ads (mainly in Australian Aviation magazine), or pilot specific BBS’s (Bulletin Board Systems), and payments were via people sending you cheques to bank. Wow, there was surely a lot more trust in those days (plus less scammers too, so I guess it all evens out). We even had one of the first online shops in Australia called PC Aviator as our distributor for a bit there.

We had a good run for a year or two, and sold several hundred copies of the app, and we had senior check and training pilots from airlines like Qantas and Cathay Pacific using it and giving us feedback. We had plans to create a “Professional” version for companies and flying schools which could track multiple pilots (hence the moniker “Personal” on this first version), but that never eventuated, as I got distracted with other aspects of the business, and life in general.

Eventually, we just stopped promoting and selling the app, and it simply died a natural death. I did experiment with creating an online version using ColdFusion for a while there, which would have been the first online pilot logbook, but web technology was in its infancy back then, and hosting was super expensive, and online payment gateways took a long time to become mainstream here in Australia, so I abandoned that project.

It was good to come across this today though. Funny to see that the passion to create apps still runs deep within me. These days, I run a very successful app that makes far more in one day than I made in 2 years of selling my Logbook app (indeed, the executable file for the logbook app was smaller than just the CSS file in my current app), but this was my first foray into selling something to total strangers, and I am still excited by it.

There have been many many apps in between, but you never forget your first.

Dambusters - on triangulations and forgotten boffins

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Last week was the 77th anniversary of the famous “Dambusters” raid on German dams in the Ruhr valley. There are many sources of stories online describing Barnes Wallis’ innovative ‘bouncing bombs’, and the bravery of Wing Commander Guy Gibson and his 617 squadron crew. However, I wanted to shine the spotlight (pun intended) on the unnamed ground crew who had to prepare the Lancaster bombers for these crucial missions.

As you might know, in order for Wallis’ bombs to ‘bounce’ properly on the surface of the dam waters, they had to be dropped precisely from an altitude of 60 feet above the smooth body of liquid.

Early attempts used a low level altimeter from EMI, but that proved to be unreliable and not accurate enough for the purpose.

Legend has it that Guy Gibson himself (or one of his crew) had a brainwave to use two beams of light to triangulate the altitude of the bomber above the water. If you watch the famous black and white movie from the 50’s, it shows an aircrew member being inspired by going to a West End show and observing the two spotlights on either side of the stage focusing on the performer.

However research shows us that it was Benjamin Lockspeiser, the Deputy Director of Scientific Research at the Ministry of Aircraft Production who designed the actual light fitting for the bombers. Unlike Wallis and Gibson, his name is a little more shrouded in the history books, as most of the ‘boffins’ working in the labs often were. Here are his plans for the lighting system installation on the Lancasters:

Image courtesy of RAF Museum

Image courtesy of RAF Museum

The idea was that there would be two Aldis lights mounted on the nose and midships under the bomber. They would both shine a narrow beam spotlight downwards and off to the right of the aircraft. The two beams would meet at an exact point 60 feet below (and to the side of) the aircraft.

The navigator of the bomber, could look out of his blister window on the starboard (right hand) side of the aircraft towards the surface of the water in order to ascertain height. From this, he would simply convey the verbal instructions “Down, down, down” to the pilot until the beams met at a single point of light. The pilot then had to maintain a steady 232 knots and hold the aircraft level until the bomb aimer released the rotating drum bomb (and that method of judging the release point is another exercise in clever triangulation that I might discuss in another post).

Using my dimly remembered high school trigonometry to work out some details, I tried the following calculations.

The two beams were shone down from points underneath the bomber, and from the rough sketch above, it looks like the light under nose (X) was shone down at a right angle with respect to the airframe. The second light (Y) was mounted just ahead of the bomb bay about a third of the way along the aircraft and was angled to meet the forward beam at a distance of 60 feet. Because a Lancaster is just over 100 feet long, my estimations were that these two light were approximately 25 feet apart.

This gives us some starting points for a right angled triangle. We know the distance between X and Y is 25 feet, we know that the distance from X to Z, which is the point on the water surface is 60 feet, and that X is a right angle, so we have enough information to work out the angle α at Y.

Lanc - Side.png

Well - nearly enough. We need to find out the length of the hypotenuse of the triangle. The distance from the light at Y to the surface of the water at Z. Let’s call this length h. Using simple trig given X-Y (25 feet) and X-Z (60 feet):

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This gives us a result of 65 feet for the beam length from Y to Z. And from this, we can use an arcsign function to find the angle α of the light at Y:

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This gives us an angle of 67.38° that the light needs to be mounted at in relation to the body of the aircraft

But wait! We have said that the lights had to be canted sideways as well, to enable the navigator to see them on the surface of the water. From pictures (and illustrations) I’ve seen, it looks like the beams meet in line with the inboard engine on the starboard side. A rough approximation from Avro Lancaster schematics shows me that this is approximately 15 feet from the fuselage centreline.

Lanc - Front.png

Hence the actual distance from X to Z is slightly longer than 60 feet, and we need to find the new distance to the surface of the water based on this offset.

Based on the same formulas above, I get that the new distance to the water h will be:

gif.gif

which gives me 61.85 feet beam length to the water. Both of these lights will also have to be canted 14.04° from the centreline of the aircraft.

So plugging all that back into the top two equations, we get:

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Which gives us a rear light angle of almost exactly 68° - that is more than 1.5 degrees difference from our original, based purely on canting the light towards the side a little.

And here is the thing - for every 1 degree that the light is out, this will translate to a nearly 3 feet of difference in the convergence point. For instance, if the rear light was inadvertently set at 70°, then the beams would converge at 68.7 feet - more that the height of even the tallest crewman (in terms of difference from the required 60 feet).

For this reason, the mounting and calibrating of these lights have to be absolutely precise. They would have to be mounted at a set 90 degrees and 68 degrees, PLUS both be angled sideways at 14 degrees. If the sideways angling was not the same, then the two beams would not meet at all!

Sir Benjamin Lockspeiser

Sir Benjamin Lockspeiser

All this on a pair of lights on flimsy metal brackets, exposed to the whipping slipstream and turbulence and the jolts of heavy landings and incoming enemy fire.

I could not find any photos of the mounting brackets or adjusting mechanism for these lights, but it is all hats off to those anonymous ground crewmen who spent possibly many back breaking hours ensuring that the light were set perfectly before each mission. If not for these forgotten guys, Wallis’ bouncing bombs would have either sailed well over the dam walls, or not travelled enough length to reach them.

Finally, all credit to Sir Ben Lockspeiser (1891-1990), for inventing the lighting altimeter system, and who later went on to become the first President of CERN, which is home to the Large Hadron Collider today, and continues to push the bounds of human research.

Designers, please stop doing this...

Spotted this thread on Twitter today, these are the thoughts of a designer, retweeted by another designer I follow:

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Given the pithy responses to the original tweet, I will give the designer the benefit of the doubt that he was just yanking everyone’s chain with this thread, but I have seen designers who post stuff like this without irony.

To those that do this - Just. Stop. Please.

I applaud that you perceive that there may be a problem with something you see in the universe, and that you think it could be better. But before putting your critique’s hat on, please take the time to become more familiar with the domain of the thing/concept that you are critiquing.

To cover the above scenario: I used to be a pilot, and had to learn morse code as part of my studies to obtain my license. I initially thought the same as above - what a confusing jumble this seems. But guess what? When I actually started to USE morse code, I realised what an incredibly efficient method of communication it is. The series of dots and dashes are not seemingly random, as pointed out by one of the replies above, rather they reflect the frequency of usage (‘E’ is the most commonly used letter in the English language, and is denoted by a single dot), and are also designed to prevent ambiguity of similar sounding letters.

To suggest that the series of dots and dashes are dependent on the ‘numerical position within the set’ is flawed thinking. Quick - who can tell me the 16th letter of the alphabet? The 11th? As you can see - this is a pointless strategy.

(On the other hand, morse depiction of NUMBERS uses a flowing pattern system that is logical and consistent).

I was blocked on Twitter last year by a certain ‘high profile’ designer who is considered a darling of the Twitter Design community. She raised questions about something that is commonly used in the aviation industry, and when I (politely) pointed out the flaws in her thinking, based on my actual real world knowledge of the topic, she immediately Tweet shamed me and blocked me to prevent any further discussion on the subject.

This was quite an arrogant and myopic stance to take, and I hope that she is still not considered a role model for new up and coming designers in the field. (Note that she raised questions, but like the above example, didn’t actually use her designer expertise to come up with any sort of solution for the problem).

I know plenty of great designers. Some of them have even worked on my own creations and made them better than I could have ever envisaged.

Questioning something is perfectly valid. But before you voice your opinions on a particular facet of the existing design, please take the time to study the history and immerse yourself in the context of that design, and ask yourself WHY it is as it is currently? There are always forces that hold things in place, and sometimes those forces exist for a good reason, and shouldn’t be bent or altered unless your way forward is significantly better.

Proud to be sinister

sinister - (a) of, relating to, or situated to the left or on the left side of something especially being or relating to the side of a heraldic shield at the left of the person bearing it (b) of ill omen by reason of being on the left


I’m left handed. Have been so for as long as I can remember.

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But what I also remember is that when I was about in grade 1 or 2, my teachers in my primary school in Malaysia tried to force me to be right handed. I do recall the raps across the knuckles and the teacher standing over me while I did my writing practice to ensure I kept using my right hand.

It was at this point that my maths grades started to suffer. I was getting 0% on tests, and all my teachers were baffled, as were my parents. No one could explain why I went from a fairly average to good student, to a poor one at this one particular subject.

And it would have remained that way if not for my habit of drawing on everything with chalk, as I loved to do around the house. One day, I used chalk to number all the stairs going up to the second floor of our home. My mum noticed this when she was carrying a basket of clean laundry upstairs, and her annoyance at me on the first flight of stairs turned to concern and realisation by the time she reached the second flight.

You see, I had numbered everything from stair 1 to 11 perfectly fine, but after that, instead of 12, 13, 14,1 5… etc., they were written as 21, 31, 41, 51 and onwards.

The forced transposition from one hand to another also resulted in a transposition of the placement of those numbers, and I was unconsciously writing the numbers back to front.

A quick check of my old maths tests from class showed the same thing. I actually had got the sums correct, however my answers were written back to front, resulting in a cross instead of a tick. To this day I am alarmed that no teacher ever looked deeper at my answers and realised what was happening. Had I not numbered our house stairs with chalk that day, who knows how long this would have gone on, and what impact this would have had on my learning to date.

Conversely, many years later in flying school, one of my proudest moments was when I scored 99.9% on a fiendishly difficult navigation examination. Only three of us in the class (of 12 students) passed that exam and I was chuffed to be one of them.

What makes this even more special is that when I asked my instructor where I had lost the 0.1%, he said that is was because I had copied down one of the numbers from the original question sheet onto my working sheet wrong. But I had come up with the right answer at the end using that wrong initial figure. That was where I had lost the 0.1%!

But the fact that my instructor didn’t just mark my answer wrong because the end result wasn’t what he expected, like my grade 2 teachers did, but instead went through the effort of completing the 2 pages of calculations with my input figures and see that I understood the problem and could come up with a solution - well, that meant so much to me, and showed me the difference between a good teacher and a bad one.

Addendum: I am actually not a strict left hander per se. I do a lot of one handed things (writing, bowling at cricket, playing tennis, eating with a spoon) left handed, but two handed things (playing guitar, batting at cricket, playing golf etc.) right handed.

Actually, I think in guitar playing especially, it helps to have my most dexterous hand doing all the hard fiddly bits on the neck and not just holding the pick and moving it up and down!