Dave's 2020 Almost-Gliding Report

A year we are all glad has passed...

This year I was able to start flying again. My plane, not so much...

I just couldn't help myself and fixed the stupid Antares. This after it failed during the 2018 18m nationals at Seminole, due to yet another Lange electronics engineering fuck-up which caused the precharger ballast resistor to burn. The glider was in storage since then. I tried to give it to the Smithsonian Air and Space Museum, but they didn't take it. Some of my friends said Get rid of the damn thing, you've had too much grief with the plane and Lange. But a few said A righteous engineer would figure it out and fix it, don't be a wimp, and Dave, we're the kind of folks that tackle problems head-on, not quitters. Perhaps I shouldn't have taken the bait... Took 70+ hours in shop plus time to reverse engineer, then engineer a fix and replace stuff. Engineering report here.

In January I went to Williams CA for a refresher and biennial (I hadn't flown since June 2018). After that I was ready to fly!

In February I took the Antares for a very cold test-flight at Orange, MA. Expected a quick test flight but found some wave and flew until my toes were just too cold. Some nice pictures from that flight (click to see full-size image):
Cockpit view Orange, MA Sun over wingtip

In March, down to the Seniors in Florida! It was really great to get back in the air, with some superb flying. And great to see all my friends at the Seniors.

Race day 2 was the stuff a soaring pilot dreams of: Cruise at 110 knots when I can see a pull-up under the next cloud will bring me at 5+ knots right back to cloudbase with no circling. Slow up to 100 knots when its a slightly longer gap, or even down to 90 when I have to make a detour between streets. Every turn area, turn onto the next task leg when a street lines up into the next area. Only a few nasty lying clouds and one 80 knot stretch. A few thermals below 4 knots to get back up and connected, but most circling climbs 5-7 knots and average climb for the flight 4.4 knots. And only slightly over-cooked the final glide. Computer says 44% of the time climbing, but much climb time was flying straight on course! 2nd fastest raw speed at 70mph over 220 miles, behind former national champ Jim Lee in his new 21-meter Jonkers. After handicapping silliness, 3rd behind New England buddies and USA team pilots Phil Gaisford and Bob Fletcher.
SSA 2020 Seniors Day 2 score
You'll enjoy the straight-ahead climbs (slide cursor across climbs and watch position on map)!

Just before launch Day 3, I extended and ran the engine and verified everything AOK, then stowed it and took a tow. At 500 feet I flipped the gear-retract switch. Nothing happened (other than the cute animation on screen). No noises, no gear retract. Towed to 2k and then climbed to altitude to debug. Repeat, power-cycle and try again, nothing. Try to extend engine pylon, nothing.

Complete hydraulics failure. Again. This was just as the pandemic was starting... Withdrew from the contest and returned home to Boston...

A couple months later I put in in the shop, and hydraulics were working again! Something intermittent worked after driving 1500 miles back from Florida, no doubt it got a good shaking over our 3rd-world highways.

Pulled the electric motor driving hydraulics out. Brushes were severely worn, with brush leads binding. Looked like the cause of failure, and manufacturer said from photos it absolutely needed a rebuild, so I sent it off to the motor manufacturer. Some months later it reappeared all nice and shiny, however...

A brushed DC electric motor like this has a big inrush current before it gets up to speed. Motor manufacturer advised me the inrush current would be higher with a new/rebuilt motor. I measured the inrush at 85A some years back, thought I'd better check (using a 12v car battery). Yikes!! 200 Amps !!

Now, some years back a bunch of Antares (including mine) had exciting fires because the original power supply for this motor burned up. First related AD from Lange added a fuse they'd neglected (!!), to limit the size of the fire!!!  Note burned hand-wired perf-board! Just the thing you like to find in a high-quality certified aircraft...
Burned hydraulic power supply

Then Lange provided an 'improved' supply, 'designed' and fabricated by an unqualified person, which failed intermittently. I engineered a fix (and I fixed all Antares in USA). Note: Axel Lange promised me he would make an AD, but failed to do so, some customers outside USA have made these fixes on their own - Engineering notes and ECO.

But... Lange's 'improved' supply still has a hard limit of 80 Amps. More, it blows up (hopefully no big fire as this time its fused). Lange failed to comprehend why the supply was blowing up and make the simple fix of limiting the motor inrush current! The original supply was big enough - it just needed a current limiter. Also, Lange had replaced the designed motor fuse with a piece of wire!
Fuse replaced with wire

Anyway, bottom line: powering up my Antares with the rebuilt motor and its 200 amp inrush would fry the power supply! For the second time!
So, I designed/fabricated/tested/installed a current limiter, and added a fuse (love FrontPanelExpress!). I do hope my German is OK:
Lange #23 Abgefuckten Box Scope picture of Lange #23 Abgefuckten Box current limiting
New Abgefuckten box checked out AOK! Ready to go fly except... another blown thermal fuse. Before putting the fuselage back in the trailer, I decided to pump up the tires so I'd be ready to fly. Dropped the landing gear, pumped up the tire and... wouldn't retract. Dead hydraulics again.

Never mind, repair the thermal fuse and come back to it fresh. Repaired the fuse, plugged in the wings, and powered up the plane to balance the battery (imbalanced because of the failed thermal fuse). Just for yucks, I flipped the 'gear up' switch, and as expected nothing happened.

Some hours later I go out to the shop to check on balancing progress, and... the gear is up!

By process of elimination, I narrowed the (latest) problem down to the HMM (hydraulic management module - electronics board). Studied the schematic and found ANOTHER Lange engineering error, this one stacked tolerances with temperature sensitivity (sorry, haven't finished the engineering write-up). This in October when its getting cold in New England. The gear retracted when the plane warmed up...

Designed and implemented a fix (changed a couple wrong parts on the HMM), and magic - it works again! Including COLD!
And finally, successful October test flight at Fitchburg:

So, in the last 12 months, I had to re-engineer around 4 Lange engineering fuckups. Plus 2 failed thermal fuses in the battery, and worn out hydraulic pump.
Good thing I'm semi-retired ;-)

Now's its had its annual inspection, and everything is packed away for winter. Snow has just started, expecting 1 foot...

Lets hope next year has more flying and less re-engineering. I really hope my new glider gets here soon!!

See ya, Dave "YO"