Vintage Vega and P&W ads

General information about the Wing42 Lockheed Vega.
User avatar
Tailspin45
Posts: 216
Joined: 16 Jun 2018, 18:28
Location: San Diego California, USA

Vintage Vega and P&W ads

Post by Tailspin45 » 23 Jun 2018, 22:02

Open image in another tab (right click) and click to enlarge so you can read

The "Side Slips" columns are humorous if not funny.

Image

Image

Image

Image

Image

Image

Image

Image

Image

Image

Image

Image

Image

Image

Image

Image

Image
Blue skies and tailwinds - Tailspin Tommy (aka Tom)

User avatar
Vitus
Posts: 366
Joined: 17 Jul 2017, 15:19
Location: Görlitz, Germany
Contact:

Re: Vintage Vega and P&W ads

Post by Vitus » 24 Jun 2018, 10:52

I'm always amazed how you keep finding this stuff...
Image Wing42 | The Simulation Company

User avatar
Tailspin45
Posts: 216
Joined: 16 Jun 2018, 18:28
Location: San Diego California, USA

Re: Vintage Vega and P&W ads

Post by Tailspin45 » 24 Jun 2018, 17:54

They help. I asserted somewhere that the Vega probably had Hayes drum brakes. But ad above clearly shows they chose Bendix. Remains to be seen if they were mechanical or hydraulic.
Blue skies and tailwinds - Tailspin Tommy (aka Tom)

Jarek
Posts: 104
Joined: 18 Jun 2018, 21:31

Re: Vintage Vega and P&W ads

Post by Jarek » 24 Jun 2018, 18:26

Looks like they were mechanical. 1928 article here:

https://www.flightglobal.com/FlightPDFA ... 200213.PDF

Description in the upper right corner - and lever with an attachment could be seen. Probably parking brake is pulling both links simultaneously by a wire and an pulley wheel.

User avatar
Tailspin45
Posts: 216
Joined: 16 Jun 2018, 18:28
Location: San Diego California, USA

Re: Vintage Vega and P&W ads

Post by Tailspin45 » 24 Jun 2018, 21:42

Right you are! NC3242 had mechanical, NC365M and NC674H had hydraulic.

They all worked about the same in practice, except the way 3242 was rigged you could get your toe caught behind the brake with the ball of your foot on the rudder. So when the rudder was all the way down and you desperately need some brake to help keep her going straight you had to take your foot off the rudder!

We had a US Navy Test Pilot School graduate that flew for us discover that the hard way. Didn't break anything, but he discovered a new aircraft behavior!
Blue skies and tailwinds - Tailspin Tommy (aka Tom)

Jarek
Posts: 104
Joined: 18 Jun 2018, 21:31

Re: Vintage Vega and P&W ads

Post by Jarek » 25 Jun 2018, 22:00

Hydraulic brakes description - and how they interact with rudder:

Lockheed hydraulic wheel brakes are provided, being built into the fairing of the wheels in such a manner that no additional head resistance results in their use. Steering action is provided by means of the rudder pedals which increase the braking action on one side and proportionately decrease it on the other when operated while the brakes are engaged. Provision is also made for locking the brakes when starting or warming up the engine.

Source: https://ntrs.nasa.gov/archive/nasa/casi ... 090644.pdf

User avatar
Tailspin45
Posts: 216
Joined: 16 Jun 2018, 18:28
Location: San Diego California, USA

Re: Vintage Vega and P&W ads

Post by Tailspin45 » 25 Jun 2018, 23:33

Odd terminology, isn't it? I presume "head resistance" means drag? Interesting that they refer to Lockheed brakes because later versions used Bendix mechanical brakes and because Allan Loughead was a successful automobile brake inventor and businessman. That's where the money came from so he and Jack Northrop could start the Lockheed company, after all.

No clue what the next sentence means because there was no connection, as far as I know (and pictures prove), between the rudder and the brakes.

I think what they're getting at is what I described above: as you apply more and more rudder with the ball of your foot your toes begin to also apply brake. Careful rigging of the pedals was required so they were in the right place or you could get your toes behind the brake with dire consequences. While flying, of course, if you put your heels on the deck and the ball of your foot on the rudder pedal your toes wouldn't reach the brakes. Usually.

There's a "gotcha" with some hydraulic brake systems wherein if you accidentally don't push the parking brake all the way off and also apply brakes in flight the pressure slowly increases and produces a nasty surprise when you land. That happened to my Dad and I in a Cessna 120 at La Aurora airport in Guatemala City when I was a kid, and I saw an instructor flip a Waco YMF-5 I used to fly here at KCRQ the same way. (The aircraft was totaled; the flip broke her back not just the tail and upper wing.)

Image
Last edited by Tailspin45 on 26 Jun 2018, 15:20, edited 1 time in total.
Blue skies and tailwinds - Tailspin Tommy (aka Tom)

Jarek
Posts: 104
Joined: 18 Jun 2018, 21:31

Re: Vintage Vega and P&W ads

Post by Jarek » 26 Jun 2018, 13:40

Interesting story! It teaches a lot.

Head resistance refers to the hydraulic pressure (fluid dynamics term) so when fluid is not able to compress it starts to engage brakes. But this is easy part. But brake function on Vega it is a new mystery for me.
When I compared pictures that we have collected, it created a lot of confusion. Basically I don't know if lower pedals are for rudder or for brakes. I would expect that upper is for brake and lower is for rudder as in "normal" airplane.
But:
It seems if you push this big right-hand side lever with wooden ball fully BACKWARDS, then this LOWER section of pedals hide in these shoe-shaped holes. In this position ball is at the edge of the bench.
If you push lever FORWARDS then whole section of lower pedals moves BACKWARDS. I'm lost here without help of someone familiar with this airplane again :/

User avatar
Tailspin45
Posts: 216
Joined: 16 Jun 2018, 18:28
Location: San Diego California, USA

Re: Vintage Vega and P&W ads

Post by Tailspin45 » 26 Jun 2018, 15:18

Concur that upper pedal should be brake...but it is also true that some aircraft have heel brakes. They're generally small levers attached directly to the brake master cylinder and situated slightly to the side, but they're only in small aircraft such as a Cub AFAIK.

You say that when the parking handle is engaged the bottom pedal moves--you mean in the current version of this add-on, right; not in a video? I think it is simply modeled incorrectly. The top ones should move.

The way hydraulic parking brakes work is you apply pressure to the brake and then engage the parking mechanism which traps the brake fluid and holds the brake on. When you release the parking level it releases the pressure.

What we don't know for sure is what brakes should be modeled. Mr. Laughead was famous for his hydraulic brakes, but we've seen ads that tout Bendix mechanical brakes as the Lockheed choice for the Vega. The tangs on the outboard edge of the pedal in the pictures support that--that's where the cable would be attached and there is no master cylinder behind the pedal.
...built into the fairing of the wheels in such a manner that no additional head resistance results in their use.
This seems to say the opposite of what you wrote above, doesn't it? You say additional pressure applies the brake, but this says no additional pressure is required. Head pressure is a hydraulics term I'm familiar with, but not head resistance, which is why I think they mean drag, especially when they're talking about how they're built into the fairing of the wheel. Remember, any kind of brake was still a new thing in the late '20s, so concern about them adding drag (but not when they're hidden in the fairing) makes sense. Many aircraft, including Vegas, still had tailskids, for that matter.

My, my. So many unknowns. I'm thinking I need to see if Kevin Kimball, the guy who restored Kermit Weeks Vega, can shed some light on these issues. Problem is he's an expert on that aircraft which, as we've seen, isn't necessarily the same as others.
Blue skies and tailwinds - Tailspin Tommy (aka Tom)

Jarek
Posts: 104
Joined: 18 Jun 2018, 21:31

Re: Vintage Vega and P&W ads

Post by Jarek » 26 Jun 2018, 16:59

"no additional head resistance" for me is when pressure is put on one side, at some point brake fluid cannot compress itself anymore, so it starts to push the thing on other side of the hydraulic line. So it is normal operation described with complicated words :)

I found one picture (Amelia's Vega at Smithsonian) where lower left pedal is pushed max forward and left goes backward. So it must be the rudder. At the same time upper pedals both have the same level. Right Lever is at max forward position.
But compare this:
viewtopic.php?f=6&t=10&start=40 (please scroll down to the last picture on this page - Right Lever is max forward, both rudder pedals exposed)
With this:
https://airandspace.si.edu/explore-and- ... 60030000_1
(Right Lever max backwards - both rudder pedals seem to be hidden in the "shoe bays")

Post Reply