Cessna O-2A `Jade 07' The man meets the model.

[dcrfan]

Does any one have any idea if it will sit on its undercarriage without additional weight the nose?

[ericg]

Does any one have any idea if it will sit on its undercarriage without additional weight the nose?

Will let you know as soon as mine is at that stage.

 

A slight change of plans with the model. I really liked the look of the modified pilots window and sought Davids advice regarding doing an O-2 that he flew that had the larger window. The tail number of the one that he is standing next to in his portrait photo was 68-10999, in which he flew 20 missions and can be seen in a few entries in his logbook page as posted earlier. This was also the aircraft that features in the black and white video that shows David in action, also posted earlier.

David recounted to me a particularly interesting sortie that he flew in this aircraft, on 03 November 1969. Here is his story.

 

`The story of the electrics failure is interesting.

 

The O-2 had two alternators (on on each engine) and it was not unusual for them to be slightly out of phase. In this case we could have either on-line but not both together. It was usually a temporary problem.

 

On the day of the night strike I had flown my boss, Colonel Hobbs USAF, from Nui Dat to Vung Tau in that same aircraft and I was able to bring both alternators on line.

 

The aircraft was serviceable and prepared for a night air strike under a flareship. At night we always flew with two pilots - one to control the strike and the other to monitor the flight instruments. Phuoc Tuy province was as black as the proverbial cow's guts.

 

I was tasked to fly with Capt. Chis Neale (featured in one of the other pics). We started engines and had some problems with the alternators. Normally, I would have cancelled or changed to another aircraft but we were then told that there were Aussie troops in contact (TIC). 'Troops in Contact' meant that they were engaged with the enemy and we were expected to respond ASAP. I decided to take the risk and I expected that if one alternator failed, I could bring the other on line.

 

It was a windy night with unpredictable weather. We took off and headed on the direction of Nui Dat. It was as black as always. Then about 20 minutes into the flight, we were called to say that the troops were no longer in contact. Then the electrics failed totally. Neither alternator would come online. The O-2 was an electric aeroplane. The lights, radios, many instrument and navigation aids and flaps were electrically driven. I asked Chris to light his torch and shine it on my airspeed indicator. I had some residual energy in the attitude indicator before it wound down. I turned towards Vung Tau. I could just make out some lights of the village as I headed home. This was my only horizon.

 

We joined the circuit at Vung Tau and the runway lights were on. I couldn't talk to air traffic control and no-one knew we were there. As I lined up on final, (for a flapless landing, with no landing lights, in a 20 knot crosswind), an OV-1 Mohawk entered the runway in front of us.

 

I had to go around. That overshoot, climb, turn onto downwind and base to final was the most stressful period of my flying career. Chris was a new pilot but an experienced navigator (on RB-57Fs above 80,000 feet!). He bravely helped with the lookout and shining the torch.

 

The landing was okay and we rolled through. After touchdown, he patted my leg furiously. Then we taxied slowly, carefully and ignominiously to our flight line and shut down. No-one knew we were coming and it was quite a surprise to the ground crew.

 

I had to submit an incident report and the safety officer at Bien Hoa called me and apologised. He said that he could't decide whether to chastise me for flying an unserviceable aircraft or give me a citation for great airmanship. Nothing more was ever said!'

 

 

 

The problem (and solution). Now, those that follow my builds know that I like to get stuck into some pretty big modifications that could easily trash the kit. I was hoping to keep this one more or less lightly tweaked, but after seeing a few more pics of the window I thought I would give it a go and hopefully add to my skill set at the same time.

 

Here is the unmodified window opening. Notice that I have drawn a pencil line where the wing meets the fuselage.

 

 

I sketched where I wanted to cut to get a feel for how it would look and see if it was going to be feasible to perform the modification.

 

 

I took some measurements of the opening and drew a mask in Silhouette Studio.

 

 

This allowed me to start to work out how to get the new opening as neat as possible. The mask as above was placed over the kit opening to check for correct sizing of the bottom and side edges.

 

 

This then allowed me to modify the original shape. By double clicking on the original shape, it is very easy to manipulate it into a different shape by adding points and dragging them around.

 

 

The final mask over the opening.

 

 

I used a sharpie texta to mark out where the new opening would be.

 

 

No turning back now!

 

[ericg]

Now that the opening had been modified, I needed to work out how I was going to make up a new clear part to fit it. I am yet to work out exactly how I will do it, but I have started the process.

 

I carved a block of balsa to fit the new opening. The majority of the window is flat, so it wont be too much of a problem. It is the compound curve of the upper surface that will be. This will allow me to hopefully plunge mould a new window. Failing that, I will buy a vac form machine. I selected the end grain to carve, and have wicked thin superglue over the surface, filling the grain and allowing me to sand and polish it to a very smooth and hard surface.

 

 

 

Very rough and very dodgy, but it should work.

 

[Simmo.b]

Nice mate!!!

[Winnie]

Holy. I think once you have made all the masks you should be able to sell them... (or just the cutfile, i'd be in for a set),

 

I was curious on the "Jade" call sign and found that it is an Australian unit within USAF... curious but cool.

 

Have finished 3 different books on the FAC business, mostly based on the OV-10, but some mentions of O-2 as well. Those guys were nuts...

 

Oh and superb workmanship.

[ericg]

Holy. I think once you have made all the masks you should be able to sell them... (or just the cutfile, i'd be in for a set),

 

I was curious on the "Jade" call sign and found that it is an Australian unit within USAF... curious but cool.

 

Have finished 3 different books on the FAC business, mostly based on the OV-10, but some mentions of O-2 as well. Those guys were nuts...

 

Oh and superb workmanship.

Thanks a lot.

 

This book makes for a great read as well and is about the 36 Aussie FAC's that served during the Vietnam war. It includes many first hand accounts of the pilots time over there and is well worth it.

 

http://regimental-books.com.au/hit-my-smoke-targeting-the-enemy-in-vietnam-p-1110.html

[LSP_Kevin]

Terrific work, mate! Expert modifications.

 

Kev

[Gazzas]

Eric,

   Love the work you're doing!  Impressive and bold!

 

Gaz

[dodgem37]

Great use of materials and processes.  Excellent problem-solving.

 

Sincerely,

Mark

[Fancherello]

Very interesting way to deal with this mod.

I'm considering buying a silhouette cutter, and this is a new good reason to go ahead !

Fanch

[Nillus]

Captivating real life stories splined with the in progress modification processes make these posts exceptional reading.

Thanks Eric.

[shark64]

love the work. cool kit

[alaninaustria]

Wow! Eric - outstanding work! Damn impressive mate!

Cheers

Alan

[Guest Maxim]

Hi Eric, have you ever tried GRS-Thermo- Loc Sticks? They are used in the jewellery trade to hold rings etc while you work on them. The product is also good for molding shapes etc and you can vac over them. The sticks become pliable in hot water and set up at room temperature. You can use them over and over. Just thinking you could have used this stuff to push through the window opening and then trim to shape and use it as a mold. I have used them for years in the ship modelling to make multiple shapes. Just remember to pop it in the freezer before you vac form over it.

 

https://www.ebay.com.au/itm/GRS-Thermo-Loc-Sticks-1-4-Lb-Package-003-664-THERMO-LOCK/131269927855?hash=item1e904c23af:m:mhDgzi82XfJbCL7nC70PH0Q

 

Cheers

 

 

Now that the opening had been modified, I needed to work out how I was going to make up a new clear part to fit it. I am yet to work out exactly how I will do it, but I have started the process.

I carved a block of balsa to fit the new opening. The majority of the window is flat, so it wont be too much of a problem. It is the compound curve of the upper surface that will be. This will allow me to hopefully plunge mould a new window. Failing that, I will buy a vac form machine. I selected the end grain to carve, and have wicked thin superglue over the surface, filling the grain and allowing me to sand and polish it to a very smooth and hard surface.





 

[ericg]

I ended up constructing a Vac form machine. It was very easy to do and cost very little as well. I was initially looking at buying a dental type machine, easily sourced on Ebay etc but felt that it may have been a bit small for future projects. I went to the local hardware store and purchased all of the required materials and built it myself. The good thing is that I can now apply my knowledge learnt from this project into larger machines as required.

I used pine for the sides and MDF for the top and bottom. Glued together with liquid nails for the seal and screwed together for strength. I drew a grid on the top surface and hand drilled the holes and then made a 32mm hole in one side to allow for the vacuum nozzle to fit into it.

 

The master is blu-tacked onto the top. The small slide on the vacuum nozzle allows me to back off the vacuum pressure as required.

 

 

A $60 toaster oven with variable heat and a timer completed the set up.

 

 

I initially tried a double sided frame made from Aluminium L bar but found it was a little big and I was using plastic up at a great rate, so made up a smaller one sided frame and just clipped the plastic onto it rather than sandwiching it between two frames.

Once the plastic is bowing down in the oven, I pulled out the frame and placed it upon the box, notice that my placement is far from square! Also notice that the master is a bit different from the one on my previous post a week ago. I was sent some Ureol modelling board from a mate of mine (actually the son of the subject pilot of my O-1 Bird Dog build) and I decided to re-make it in that. Great stuff and much better than balsa wood.

 

 

The new window trimmed:

 

 

And fitted:

 

 

 

Much work went into producing that one window but I learnt alot from it! In the words of Borat, `Great Success!'

 

Edited February 9, 2018 by ericg