New Wing Parts

Don and I picked up the abandoned Bearhawk project for $1500 from EAA Chapter 96, Compton, CA. The previous builders got pretty far on the wings, with components mostly complete and one wing partially assembled.
Tonight: began inventory. 0.2 hours.

With or Without You

Don ponders his favorite U2 song.

Chicago Knowhow

Illuminating visit from the Knaacks (pere et fils). The elder Knaack has built a Mustang II and is currently working on both a Stuart S-51 and a Harmon Rocket. He liked the Bearhawk, including our flush rivets and .040 wing skins.

Storage, Revised

Here is the new location for parts (and toy) storage. Note the temporary carpentry workbench at left. This will be used until we have built Chapter 1000 standard EAA workbenches.

Chin Ups

Hangar Storage

If DV is in agreement, this 8-foot shelf will move to the left-hand side of the back wall. Which currently houses most of the man's earthly posessions.

Phone Blogging Again

Finally fixed my phone E-mail settings, so I can blog in real time
from the hangar, like the old days (December 2009).
Mobile blog capability is crucial, given my short attention span and
numerous distractions waiting for me when I get home.
When I patched my default and backup SMTP servers, a whole bunch of
old E-mails went out immediately, including some posts intended for
this web log. Hence the several puzzling items that appeared
yesterday.

Painted.

Spent two hours painting the rest of the hangar floor.

We will come back later to touch up with brushes.

Looks really good!

Tamper Shrink Fit

Tamper has been fixed. We heat soaked the cast iron head at 325 deg. F. for one hour and then pounded in the handle.

Prep: the handle had been filed to a small end chamfer and greased at the chamfered edge with sewing machine oil.

We used a sheet of oak and a ten-lb barbell plate to protect the kitchen floor.

Project time = 0.3 hours.

2nd Time Around

A Mini Project

The wing strut attach point should be on the other side of the landing gear leg.

Mosquito Hawks

These big bugs ...
Removed over 160 carcasses the other day, but looks like very few live ones are still around now.

Wing Fixture Plans

Been designing jigs to facilitate installation and removal of wings.

Soul Searching in Montana

We have seen the airplane, and have some further questions to ponder.

It's -20 F right now.

False Alarm

Well, our ELT works.

I stepped out of the hangar and saw a guy in a city vehicle headed my way.  Uh oh.  Did a lightning-fast hangar scan for combustibles, etc.  If there were any I would have thrown them in the trunk of my car.

He rolled up next to me and asked how long I had been here today.  Since about 2:30 PM.  I looked at his conspicuously displayed antenna and he explained that he was trying to track down the source of a 121.5 MHz emergency beacon.  Probably somebody's airplane's emergency locater transmitter (ELT) had gone off accidentally.  Meaning with NO accident.

I volunteered to check my ELT.  I knew we have one for the Bearhawk, but I was relieved when I was actually able to run into the hangar and find the big orange ELT in the first cardboard box I laid my hands on.

I walked outside and cycled on my ELT, heard the warble of the DF equipment in his truck, and turned it off again, demonstrating that our hangar was not the source of the distress signal.  He thanked me and rolled on.

Afterward, I looked it over, and the date of manufacture was February 1975.  Battery had probably not been checked in several years.  It worked anyway.

Later I saw the city guy parked outside a hangar down the row on the other side.  I gave him the long distance thumbs up/down question, and he shouted the update to me: he had found the hangar that seemed be be the source of the radio beacon, and called the culprit at home.

As I left for dinner, it was my turn to roll by and interrogate him.  The U.S. Air Force Rescue Coordination Center was calling him from Langley (Virginia) every 10 minutes to find out if he'd found the beacon yet.  The dude whose hangar it was still hadn't shown.  "Yeah, he lives right nearby and he said he'd be right over, but it's been 40 minutes."

Nuisance ELT transmissions on emergency channel 121.5 are one of the reasons for the change over to the new, 406 MHz GPS-linked ELT standard.  For now, I can legally put this old one we already have in the Bearhawk (with a new battery of course), and it would probably start transmitting if I crash land, but there's a good chance that help would never arrive due to incidents just like this one masking my signal.  Oh, and 121.5 will no longer be monitored by satellite, so we'd be at the mercy of ground stations and passing aircraft that might be monitoring 121.5 or 243 MHz.  I know I don't do that often when I am out flying.  Much more likely to be on Flight Following or Flightwatch, or just the next frequency on my flight plan.

Yeah, maybe we should spend the money (~$1k) and get a new 406 MHz ELT, synched to our GPS.  Besides our precise position, data transmitted to "Langley" would include aircraft type, registration, and home phone numbers.

Bearhawk Crash Update

Thanks to the Bearhawk mailing list, I found out about an update to the only fatal accident involving the Bearhawk. The accident happened last year, and resulted in all three on board dying. Tests are starting to point to carburetor icing as the cause.

What is also interesting to me is that there is actual video from onboard the airplane. This is an excerpt from the report:

"The camcorder was largely destroyed by the accident; however, the tape (8mm video cassette) received only minor damage and was also sent to the Board's vehicle recorder for review..."

There are some interesting observations about the sounds they hear, and whether or not it came from the engine or the movement of the actual camera. It would be great if the NTSB had easy public access to this kind of evidence, and I'm considering filing an FOIA request for a copy when the investigation is concluded.

I'll post an update when the final report comes out, which should be in May of this year.

Unmanned Aircraft Systems

There was an article in one of the latest Aviation Week magazines about the British Mantis UAS (or UAV depending on who you are). It was amazing how fast it went from concept to development, and it seems that could potentially apply to experimental airplane design. That there are so many interesting designs for these craft, and several of them have the ability to stay aloft for long periods of time.

Bullet Proof?

While chasing that philosopher's stone of general aviation, the "bullet proof" piston engine, I ran across this stimulating post on aircraft engine reliability.

Based on the data posted, I estimated the fleet-wide odds.  Over a 25 year period this is the rough-order-of-magnitude fraction of aircraft engines (including automobile engine conversions) that experienced catastrophic in-flight failure:

Lycoming:         1 in 1000
VW:                  1 in 120
Ford/Subaru:     1 in 30
Mazda:              2 out of 3
Chevy:              4 failures each

This is based on actual NTSB accident investigations back to 1985, compared to aircraft fleet sizes currently registered (as of 2009).

The truth is probably significantly worse for the Subaru/Mazda because there were very few flying before 15 years ago or so.  People have been flying behind Fords since the 1930s (Model A) and the VWs since the 1970s and maybe earlier.  Chevy enthusiasts have been trying to fly the "big block" engines but most have been using the Corvair.  I am disappointed the Mazda engines did so poorly here, because I had/have high hopes for the Wankel (rotary) engine.

The VW conversions actually come out looking pretty good.  The Aerovee slated for use in our Sonex probably does better than above because the data includes ALL Volkswagen derivatives.

The poor record of the Chevy conversions may be slightly overstated, but then again maybe not, because if the author's data is to be believed, apparently there are currently NONE registered (I cheated and divided by one).  The first thought that springs to mind is that they all must have crashed or scrapped!

As a postscript, I will add that the engines that I found most often mentioned as "bullet proof" are the Lycoming O-235 and O-360.  That's encouraging news for our Bearhawk, which sports the latter.

Bearhawk CD

Got a package from Russ Erb today.  Hopefully it's more than just the back issues of Trials & Tribulations.  Oops, I mean "Beartracks."

Bearhawk Discussion Group

While the Bearhawk might seem to be on the more experimental side of the experimental airplane spectrum, that's not always a bad thing.

Yahoo's aptly named Bearhawk support group is a great resource. I mean, where else can you find people telling you how to position your pitot tube, put skis on your plane, and land it? Yeah, I thought so. I've been getting the daily emails, but really need to delve into the old messages.

One of our concerns is the fact that we need to find out what revisions have been made between the time this plane was originally worked on, and now. The people in that group are really helpful and intelligent, which is what we'll need to have on our side in the coming months...

Torrance Fire Department

Should be satisified with our hangar's new fire extinguisher: 2A-10BC rated.  $30 at Lowe's.

Jig Planning

Took measurements today for the wing installation jigs.

Where to start?

It's taking a while to absorb everything about the Bearhawk. Up until a few months ago, the Sonex was at the forefront, so all of my focus was on learning about a small aluminum plane. Catching up on the Bearhawk has been quite the challenge, with so many sources of information (the fairly simple plans, actual manuals, magazines, forums, and so on...). There's a sort of DIY/Wild West mentality about the Bearhawk vs. the structured factory plans that come with the Sonex. I guess that embraces the experimental nature of this plane. And with the changes made by the original builder of this one, it makes it that much more...interesting.

A few observations from what I've looked at so far:

1) The mods we were planning on making are probably a great idea, because they will get us that much more insight into the current structure.

2) We'll need to do a lot of material inspection and measuring to ensure that this thing ends up solid but not overweight.

3) One mod we discussed (large access panel on the empennage) is in the builder's manual, so I don't feel so guilty about the damage I did to the fabric during the horizontal stabilizer removal. Knowing that, I probably could have removed the four final screws in something less than the four hours it actually took me while lying on the ground in -6 F winter weather.

Next up we'll come up with a good plan of attack, and then systematically improve and complete the plane.

Manuals are Here

Just downloaded Eric Newton's Bearhawk builder manuals.  I already had the Fuselage volume, but Don plumped for the Wings and Finishing volumes.

Naturally, I am starting with Finishing.

My end of the bargain is to order Russ Erb's Bearhawk data CD.  Lisa will do it for me, since she actually has a PayPal account.

Cabin Configuration

We're not planning on using these Cessna 152 seats, but they're kinda useful for trying out seating scenarios.

Hands Clean For Now

We are WAY ahead of where we ever thought we'd be with a Bearhawk by now.  So far ahead that we really don't know what to do next!  I have not been able to meet my goal of getting my hands dirty every day with AIRPLANE BUILD, because I simply don't know what to work on.

Hence, there will be a period of "hands clean" progress (studying, reading, learning new skills), but I will still try to get my hands dirty as often as I can.

Inventory

Haven't been slacking on the airplane, just on blogging!  Been conducting an inventory and studying the plans.

Bringing It All Back Home

Bearhawk is in the truck.  Should reach home base today.

Ramps and Pulleys

Last few days have been spent making arrangements for the trip to Montana, and the inspection, disassembly, loading, and stowage of the aircraft once we get there.

Also convincing ourselves it's a good idea to cross the Monida pass in January in a 24-foot Budget truck.

Blogger Issues

Having trouble posting from my phone.  But hangar paint is almost completely dry.