Re: Forward Canopy geometry


Jerry Marstall <jnmarstall@...>
 

The next time I pull the cowling, I’ll take some pictures of the race car fire suppression system.  Unless I find pictures sooner.

Jerry

 

From: main@Q-List.groups.io [mailto:main@Q-List.groups.io] On Behalf Of smeshno1@...
Sent: Monday, March 22, 2021 7:03 PM
To: main@Q-List.groups.io
Subject: Re: [Q-List] Forward Canopy geometry

 

 Lot of good design and methods comes from the racing world. I look forward to what Jerry offers. I am grateful for your efforts and on another Blog dealing with aviation I suggest recording the build on thumb drive for the DAR and more especially a record for ones own memory support. Upload and store video is a boost to the Airworthiness sign off and later builders as myself. Also good was advising on overseas sign off. The Commonwealth Nations are particularly difficult. Delt with that a few times in my aircraft factory life, so I don't envy builders of Experimental in those parts of the world.

 

Vern   

 


From: main@Q-List.groups.io <main@Q-List.groups.io> on behalf of Jay Scheevel <jay@...>
Sent: Monday, March 22, 2021 3:17 PM
To: main@Q-List.groups.io <main@Q-List.groups.io>
Subject: Re: [Q-List] Forward Canopy geometry

 

Hi Vern,

 

Yes, I preserved almost the entire area of the original plexiglass canopy, by sliding it “around the sphere” of the original glass shape. The following two videos are time lapse compression of my fabrication of the doors and overhead beam/console.

https://youtu.be/0Ct7ZWoG3yE

https://youtu.be/MzFPIyD-_f0

 

Yours sounds like a good plan for gas tank evacuation, provided it does not blowout the edge seams of the tanks.

 

You should query Jerry Marstall for his solution to automatic cockpit fire suppression, adapted from the motor car racing world. It looks like it would be very effective and is essentially automatic. I will allow him to elaborate further.

 

Cheers,

Jay

 

From: main@Q-List.groups.io <main@Q-List.groups.io> On Behalf Of smeshno1@...
Sent: Monday, March 22, 2021 1:50 PM
To: main@Q-List.groups.io
Subject: Re: [Q-List] Forward Canopy geometry

 

 Excellent thought-out method, Jay. In a roll over you'd be without worry. I also see not much "sky" is blanked out for the needs of visual separation. I like your split design a lot. 👍

 

  That experience scared me enough to consider that Certificated ownership was (is) hampered by not being allowed to innovate legally! Even if it made logical sense to do mods. That being said; I owned and perfected N1100Y (1962 B model 150) as much as I could for over two decades.

 

My thoughts on the fuel eject is based on pressurizing the header tank to purposely blow a fuel jettison "fuse" just ahead of a jettison vent downstream from the main tank (at the lower "keel" and just forward of the shell joint seam); thereby both tanks are made empty in short order. Similar to how the pressure system works on some biz jets (Falcon 20 for one). For redundant seal protection, a manual valve is in front of the "fuse". Of course the dump handle is brite red, positive lockout, and placard indicated for it's use.  

 

 Once the decision is made to offload the benzine, there is for sure a dead stick landing on the way; but by that time PIC already has the chosen off field (or possibly with luck, an airport..) parking place.   

 

 Most of you guys know that I was very involved in the Engineering side of the 777 and 747 flammability program (affected all airliner new build fleets in all Nations from 2004 and on, not just America) and from that I learned a lot about what can be done under our cowling as well. 

 

 Not much weight or vast amounts of money to upgrade..and all of the mods are well known and tested to be effective. Just having the mental margin that you'd have a very good chance at surviving an in flight fire makes it worth the time and cost.

 

 There is no such thing as flight safety...but there is such a thing as risk management. As pilots, all of us (should) have training to back us up but if the airplane doesn't give us a chance to use it we would still end up taking a dirt nap needlessly.  

 

 After many millions in testing at the lazy B we made the grade by using Conolite and stainless or titanium details at all "penetrations". Also by capturing the joints (such as the IML of the cowling to the added Conolite firewall buffer) with cheap and lite fiberglass single adhesive tape (use 2" or 3" wide) under the panel attach fasteners, the structural elements are buffered from the heat once the tape adhesive gives up (about .5 seconds!). The fiberglass tape then "pillows" and an air pocket develops..so effective insulation happens at the joints automatically.  

 

 Using stainless steel screws and 1/2" long standoff tubes the thin Conolite sheet leaves a 1/2" air pocket from the original .025" thick stainless firewall, same thing happens with the Conolite, the resin boils out quickly and the fiberglass cloth remaining becomes effective flame block and insulation automatically. Because the fiberglass tape is on the inside of the cowling joints the fire cannot escape the aft cowling area junction at the fuselage. 

 

 Discharge a small Kidde foam fire extinguisher through nozzles located under the cowling and an oil fire no longer becomes a bad story for General Aviation aircraft on the 6 o'clock news. I have one in my Capella..it doesn't weigh much at all. 

 

Vern        

 


From: main@Q-List.groups.io <main@Q-List.groups.io> on behalf of Jay Scheevel <jay@...>
Sent: Monday, March 22, 2021 11:12 AM
To: main@Q-List.groups.io <main@Q-List.groups.io>
Subject: Re: [Q-List] Forward Canopy geometry

 

Great story, Vern.

 

The fuel dump idea had occurred to me when I was building (and probably several others on this list), but I could not find a way to make it happen expeditiously, especially from the header tank, so I did not do that. I did make sure that if the tanks stay intact on a roll over, they will not dribble fuel all over me, but there is no guarantee that everything stays intact in such a circumstance that flips you over. Exiting the aircraft is a bit easier in my configuration, as the overhead console is very stiff (I have had two people sitting on it without any deflection, so will serve to keep the cockpit from being crushed. If you are inverted, once you push the door over center, it stays full open. Here is a photo of my configuration (taken immediately after my first flight).

 

Cheers,

Jay

 

 

From: main@Q-List.groups.io <main@Q-List.groups.io> On Behalf Of smeshno1@...
Sent: Monday, March 22, 2021 9:01 AM
To: main@Q-List.groups.io
Subject: Re: [Q-List] Forward Canopy geometry

 

 Ala.. Spitfire or perhaps P-51?  The addition of a carbon hoop "roll bar" already was in my build plan. I would like to see your split canopy method chosen. If in case of an unexpected Frankenbird "inverted parking position" I also planned on a simplistic fuel purge to be used prior to emergency touchdown. Offloading all the fuel possible would offer time to exit before a bar b cue event. 

 

 I've personally "enjoyed" an inflight fire. I had just soloed also. Had about 6.5 hours in my student pilot log book. 

 

 The transponder was removed for the inspection (the 152 was IFR equipped) and the remover (my instructor at the time) unknown to me failed to tie back the transponder co-axial cable behind the instrument panel. 

 

 Mr. Murphy stepped in on my solo flight (as he is quite apt to do in aviation) after the removal of the avionic unit, and the loose co-axial shielded ground cable welded itself to the positive buss bar behind the instrument panel. Sparks ..LOTs of sparks! The carpet was set afire...so I had the rather unpleasent experience of the WW1 "hot foot" and the single fuel selector valve near the flames in THICK acrid smoke.  Opened the window and hit the main "off" electrical..but still had flaming carpet only now with more oxygen on hand!!  Not a good situation.

 

 Altitude was about 1500 ft since I had just departed runway 18 so I was flying over a dense metropolitan part of North Little Rock at the time. I had my E6B available ( 1980 Jeppesen..metal and analog..no batteries required) and proceeded to stamp out the flaming carpet. Obviously, I made it back to the field.  On roll out I un-buckled,exited the aircraft at the point of a fast walking speed, and let her roll on. 

  

 Walked in shaken but otherwise ok to the FBO and promptly called the local FSDO office and the investigation later ended up being rather unfortunate for my flight instructor since he was also the aircraft owner. The co-axial was melted all the way back to the antenna on the belly...close to the lowest point fuel drain. Too close according to FAR's.

 

 So some of the ideas I intend to add are perhaps just stem from logic. Fuel dumps on Biz jets and Airliners are standard industry items for good reason..and for me this part of aviation systems safety is something I learned at 6 hours in my pilots log book.  Should be included on my homebuilt Experimentals. Cessna and Piper don't seem to think the same as I do on this topic. 

 

As the comedian Mr. Richard Prior once said "Fire is Inspirational!" I'll vouch that it is indeed.

 

 The canopy drag fairing and addition of the hoop are going in the build also. To emergency exit I plan on cutting the canopy from inside.           

 

 Any photos of your canopy mod?

 

 Vern 


From: main@Q-List.groups.io <main@Q-List.groups.io> on behalf of Jay Scheevel <jay@...>
Sent: Sunday, March 21, 2021 8:30 PM
To: main@q-list.groups.io <main@q-list.groups.io>
Subject: [Q-List] Forward Canopy geometry

 

Hi Vern,

 

I built a transition like you describe into my forward canopy. It was partially to cut that draggy transition you describe  and partially to facilitate my split canopy. The forward portion of my canopy is permanently mounted, so that gave me the option of modifying the transition area.

 

Cheers,

Jay

 

 

On Mar 21, 2021, at 5:54 PM, smeshno1@... wrote:



 

 

 Jay.. I was reviewing the high pressure areas on the Q2 plot and perhaps an addition of a fairing in front of the canopy/cowl location could be worthy of the effort. Jim Patillo in his tour video convinced me to rework the present forward hinged canopy on my shells (purchased the partial kit that way..but I was never comfortable with the workmanship..a bit ruff how the previous owner hinged it) to a parallel mechanism..but perhaps by canting the aft up..the canopy can fit behind a new blended fairing.

 

 Think how we insert a foot in a slip on shoe.  The old blonde joke.. TGIF.. Toes Go In First. Anyway..that is the visual. 

 

 The transition appears too blunt at present. 

 

Vern       

 










Ron







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