The Long Way Round...

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That was a great story! Thanks for posting !

 

I have read that incredible story and it is a lesser known saga of WW2.

 

Reading this for 30 minutes was time very well spent.

 

Bob,
Are there any Clippers remaining, anywhere?

 

No. They scrapped the last airframe and now there is a group with thoughts about brining up a clipper that ditched in the Pacific. It's hard to understand the thinking sometimes. At one time there were two clippers that could have been kept, also the first 707 could have been kept but that was scrapped, too.

 

The 'Flying Boats' were just incredible aircraft... they are truly fascinating...still.

Wonderful story!

 

From what I have read, they were a bear to fly. If you look at all the lateral area ahead and below the wing it would require a lot of fin and rudder , neither of which it had. Only a cruise ship matched the comfort.

 

So probably had to be 'hands-on' all the time...?

Interesting about the full fuel load in the wings bending them enough to bind the aileron controls... wow...

 

Boeing was getting into the big bird game in 1935-1937 and they went through a steep learning curve but they put enough good engineering together and worked their way out of it. They had to make a lot of fixes on the B314 before it was in service. Some aero and maritime (sponsons) problems. When I started at Boeing in 1950 I worked in the building on the Duwamish River where the clipper was built. There were some lofting templates still in the building but soon disappeared.

 

I should have used the term "hydrodynamic " instead of maritime. They had designed the sponsons without enough span, too low an angle of incidence, and the water rudder was inadequate. Somewhere I have a photo of number one with the right wing under water and the airplane going in circles . I think it was in a crosswind and got dunked.

 

I know it's come up here in the past- they had three different tail configurations before settling on the production version.

 

so glad I clicked in this forum today, and even more glad that NYC Fred posted this story. What a great read. Thank you.

 

The 314 originally used the wing and tail of the experimental XB-15 bomber, as is shown in the first photo above, though with more powerful engines. The directional stability was lacking, so the vertical fin was removed and replaced by twin vertical tails, with rudders, near the ends of the horizontals. That still wasn't enough, so they added a central fin back in, with the same shape as the original but with no movable rudder.

 

George Schairer was the Boeing engineer responsible for how to calculate tail volume and before he quantified the process, it was always a Scientific Wildass Guess in configuring the tail assembly. His most visible result was the fin on the B-17E versus that on the B,C,and D models. It was based on wing span, tail arm, and lateral area of the fuselage. A short explanation, I guess.

 

I always thought that the fin on the early B-17s (and 307s) looked too small. I believe that the fatal crash of an early 307 was attributed to directional instability, which must have forced the revision on both aircraft types.

Of course, the fin on early KC-135s and 707s was also too small, and I believe that the crash of a Braniff 707 before delivery was what precipitated the redesign to a taller fin (and, for a time, a ventral fin).

 

Actually the culprit was the partial hydraulic power to the rudder that didn't kick in until there was a healthy displacement of the rudder by unassisted input. I think if I remember, it was 15 or 20 degrees of displacement before there was any hydraulic boost. The incident has several explanations of how it happened but the one that I got from engineering was that the trainee Braniff pilot was being put through an engine out simulation when he was in a climb out. He was too late with corrective rudder and the airplane yawed into the dead engine and then did a snap roll, throwing off two engines on one side. The Boeing pilot took over and followed the airplane through and effected a recovery. In the process another engine came off and he came to full power on the remaining engine, ordered everyone else into the rear of the airplane and made a controlled landing in the Skagit River, a rock strewn river bed. He did not survive but the others did. he was able to fly the airplane because it had the larger J-75's on it and it was just enough to keep it under control. The ventral fin was an effort to help with directional control at high angles of attack. All 707's and 720's were equipped with the ventral fin for a while until full hydraulic rudder power was adde to all airplanes.

 

I failed to mention that the Braniff pilot was not big enough and strong enough to get adequate rudder quick enough to stop the yaw. The airplane was a 707-227, a shortened 707 powered with J-75's and at 100 % thrust that helped to fly the airplane in those final moments. I did some of the drawings that added the new hydraulic system and ventral fin to the empennage. I also worked on the struts to add thicker skins to contain the higher side loads in a possible repeat of the Braniff incident.

 

I found it interesting that Braniff was the only Boeing customer to order the original aircraft with the JT4/J75 engines, the 707-220, but Douglas sold a lot more of their JT4/J75 variant, the DC-8-20. The first plane I ever flew was an Eastern DC-8-20 (which they advertised as a "DC-8B").

 

Jim, the Braniff airplanes were a shortened version of the 707-120 and equipped with JT-4's so that they could operate from high altitude airfields in South America. I can't recall the location of the highest one right now..

 

Probably La Paz, Bolivia... 12k feet ASL and 100 degrees f.

I think I read that at one time, Braniff used JATO with their DC-6 planes on occasion.

 

Yes, La Paz. It popped into my head a little while ago. Thanks.

 

Of course, Qantas used a different approach for a "special performance" 707 - instead of bigger engines they just took 10 feet out of the airplane. But then their goal was longer range, not better high-altitude airport performance. One could argue that their 707-138 was different enough that it should not have been considered part of the -120 series, but since it was the only one, Boeing opted to keep it in the series. Anyway, we're getting increasingly off-topic here.

 

Amazing ! We start out with a great story about the Boeing 314 and end up on a mountain in Brazil. That's what makes this forum so much fun....at least for me.