Anatomy of Failure

So the title sounds a little foreboding – but we actually had a very successful run at the Maker Faire this past weekend! Over 50 people got to ride in the Dropship during the two-day event.

We had a situation where paying customers (one of who was autistic) were trapped for a couple minutes in the simulator, in the dark, with no AC, and no way to communicate, and no way to open the door. They handled the situation fine and gladly accepted a full refund but troubleshooting and responding to a potential emergency at the end of a long weekend is not something I ever want to deal with again.

Sequence of events:

  • 2015-06-27 18:24:24.732 – Simulator secured for the night, GNC on generator power
  • 2015-06-27 20:07:54.035 – Generator was manually switched off (unknown, unauthorized individual).  Event (“shore”) power was unavailable so GNC switched to internal battery
  • 2015-06-27 21:35:11.666 – Last entry before GNC was forced to shut down due to battery depletion (90 minutes later, as designed)
  • 2015-06-28 09:58:56.476 – GNC was force-ably* brought back online, internal battery now trickle-charging due to GNC operating load
  • 2015-06-28 17:16:28.796 – Last ride of the day started almost 20 minutes past the published operating hours
  • 2015-06-28 17:19:10.630 – Shore power was shut off, GNC switched to internal battery with only 4 minutes run-time estimated
  • 2015-06-28 17:19:28.063 – Last entry before GNC was forced to shut down due to battery depletion

Recommendations:

  • Advise Maker Faire of the security incident at 2015-06-27 20:07:54.035 (complete)
  • Install some kind of shield or screen on the front of the generator to prevent unauthorized access (PENDING)
  • *Do not override the UPS “minimum charge” to restart (when I arrived ~9:15 AM there was very little condensation on the ground from the AC indicating that the power hadn’t been on for very long… I became impatient for GNC to boot so I actually forced the UPS to come back online). There was a discussion that a delayed start to the day was a possibility and actually wouldn’t have impacted our revenue since the event was slow to start on Sunday.
  • Indicate the low remaining run-time in amber (15 minutes) and red (5 minutes) on the electrical synoptic page (PENDING)
  • Environmental CAS message regarding low remaining run-time (less than 15 minutes since the current scenario is never more than 10 minutes) (PENDING)
  • With 5 minutes or less run-time remaining we should initiate the shutdown (PENDING)
  • Advise Maker Faire that they disconnected power with paying customers still in the box (previous day they came around and made sure that it wouldn’t be a problem) (complete)
  • Do not operate the attraction after the published hours OR switch to generator power before operating outside of published hours

Spring Update

We are rapidly approaching our “soft-launch” date of April 11 and “drop-dead” date of May 9. I haven’t had a moment to spare until today to update everyone on our progress!

First and foremost – our first Groupon campaign is live!

wpid-screenshot_2015-03-29-09-06-36-576x1024

In the interest of rapid development of new missions we started construction of an Adaptive Scenario Engine or ASE.  It uses a basic XML scripting language to cue different bus commands (starting engines, closing the door, visual help, and more) as well as waiting for conditions (button presses, stable flight) and step-by-step aural instructions. Here is a snippet:

xml version=”1.0″ encoding=”utf-8″?>

<Scenario players=”2″ assistLevel=”10″ recommendedAges=”8-12″ minimumExperience=”0″ allottedMinutes=”10″

description=”Introductory flight from one platform to another. Starts with a drop and then we give them a choice of going through rough weather or dealing with a TCAS RA.
Ends with an approach and landing.”>

<Step name=”WelcomeAboard”>
<Command name=”Read” vmu=”You are about to experience:” />
<Command name=”Read” vmu=”Weather or Not” />
<Command name=”CloseDoorRequest”></Command>
Dropship. Brought to you today by…” />
<Command name=”Read” vmu=”Jake’s Birthday Party” />

 The Flight Director “command bars” are now overlaid on the Artificial Horizon as part of the Attitude Indicator. This will provide simple guidance for players based on real aviation technology.

Flight-Director-GFC-700-526x135[1]

The Ground Proximity Warning System (GPWS or “jip-wiz”) module is wired up.  Although CFIT will never be an issue, there are many features GPWS such as bank angle, altitude loss after departure, and obstacle detection features that will be connected in short order.

GPWS_Signalfluss[1]

Units of Measure

Knots%20Speed[1]

Aviation is a hodge-podge of English, metric, dimensionless, and nautical units of measurement.

  • Distance (nautical miles, nautical)
  • Altitude (feet, English, and FL which is in 100’s of feet instead of thousands, very English)
  • Airspeed (knots, nautical, and Mach, dimensionless related to the speed of sound)
  • Temperature (centigrade, metric)
  • Pressure (inches of mercury, English, and millibars, metric)
  • Visibility (statute miles, English, and RVR in feet, English)
  • Fuel quantity (pounds, English)

Our operational regime is initially 35 km above Venus to 60 km above Venus. Each kilometer would make for a good “flight level” and Aliens (the movie) made reference to “clicks” which is slang for kilometers.

However, as a former airline pilot, I like flying with knots indicated speed… and I am used to nautical miles for distance. So when I sat down to port over the altimeter, I took a pause… what units should it be in?  Feet is unwieldy at 35 kilometers (114,829 feet aka FL 1148, whatever).  Why not measure distance vertically the same that we measure it horizontally?  35 km is 18.8985 NM (60 km is 32.3974 NM) … and it gives us better resolution (the separation at tenths of NM is less than 1000 feet) so we could do a FL-type system (FL 188 to FL 324).

Doing a little research, I found that the retired space shuttle could display altitude in feet up to 400,000 depending on the phase and was also capable of showing altitude in miles from 40 to 165 (always based on static pressure).

Then again, our universe framework is metric based – it allows for faster and more accurate conversions between scales (i.e. meters to kilometers).  Similarly, Rise was metric: Rise used meters and kilometers for everything – indicated speed, vertical speed, altitude, and distance.