BeechTalk - BT

Username Protected · **Posted:** 05 Jan 2019, 08:08

Username Protected wrote:

The P-38 has contra-rotating propellers. Bot engines turn outboard so both are critical... The Cheyenne 400 does as well.

And the Aerostar 700...

Username Protected · **Posted:** 05 Jan 2019, 10:18

[quote="Doug Rozendaal"]As Doug undoubtedly knows, the same applied to the XP-82 in reverse. It was originally designed with outward rotating props (blades going up in the middle) but couldn't take off. The propwash was increasing the AoA on the center section so much that it was stalled. They swapped the engines to blades going down in the middle and it flew beautifully. Story is that a junior designer had predicted that and made a bet with the chief designer (he paid up, amount unrecorded).[/quote]

I read this as well. Fascinating. Why does swapping rotations not cause the same effect on the outboard wings?

Username Protected · **Posted:** 07 Jan 2019, 01:16

Username Protected wrote:

As Doug undoubtedly knows, the same applied to the XP-82 in reverse. It was originally designed with outward rotating props (blades going up in the middle) but couldn't take off. The propwash was increasing the AoA on the center section so much that it was stalled. They swapped the engines to blades going down in the middle and it flew beautifully. Story is that a junior designer had predicted that and made a bet with the chief designer (he paid up, amount unrecorded).

I read this as well. Fascinating. Why does swapping rotations not cause the same effect on the outboard wings?

Username Protected · **Posted:** 09 Jan 2019, 06:58

Found this on reddit this morning.

Attachment:

0D324F7D-AAC1-4B44-BA5A-501D402DA336.jpeg

Photo credit: https://inspire.eaa.org/2019/01/03/xp-8 ... -the-shot/

Username Protected · **Posted:** 10 Jan 2019, 13:45

Username Protected wrote:

From one of the great books in my aviation library...

I need to get a library card for Sven's library!

Username Protected · **Posted:** 11 Jan 2019, 00:32

Good idea !

Username Protected · **Posted:** 11 Jan 2019, 00:48

Username Protected wrote:

From one of the great books in my aviation library...

I need to get a library card for Sven's library!

Username Protected · **Posted:** 12 Jan 2019, 08:00

I cannot believe the description of the FAA requirement for the “taxi test”
If there was ever a perfect recipe for wrecking the airplane that is it. it’s not a new untested design. if the CG is right and everything is bolted on it should fly. Heavy taildragger twin Adding full flaps after pulling it to idle to abort a high speed taxi? With geared supercharged engines....

Glad he just took it around the pattern. Smartest decision of the year.

There was an accident back about 2002 here at AVP with a Hawker Hunter. The pilot went by Shark Bait, Tom Delashaw. he was flying airshows with the Civilian F-104 group.

From what I remember the Feds would not allow a light local test flight. Only a single ferry flight to Burlington VT. The airplane had sat outside on a taxiway at AVP for years. They did engine runs and a lot of maintenance, brake adjustments before his flight. After takeoff it started losing thrust and he put it into a unpopulated area instead of the toll road highway which is off the departure end but was busy. Possibly tried to eject and the seat failed.

I believe if he was allowed to do a light weight test flight local area and check it out first before filling it with fuel. I believe it also had drop tanks installed, he would have been able to bring it around and land

Who writes these test programs?

I always wonder about phase 1 homebuilt test programs because everything recommended goes against the engine break-in procedures. I see the reasons for each item to be tested but it’s not designed with engine life in mind.

Username Protected · **Posted:** 13 Jan 2019, 20:54

Username Protected wrote:

The P-38 has contra-rotating propellers. Bot engines turn outboard so both are critical... The Cheyenne 400 does as well.

And the Aerostar 700...

Username Protected · **Posted:** 17 Jan 2019, 23:48

P-82 holds the record for longest flight by Piston Fighter.
Hawaii to New York. 14 hrs. 5000ish miles.
The one that did it is on display in Dayton.

Username Protected · **Posted:** 18 Jan 2019, 10:18

Username Protected wrote:

I didn’t think you could have 2 critical engines on a Twin?

One of them failing is either worse, or it isn’t. If it is an “isn’t,” then could it really be critical?

Does critical mean "worse," or does it mean "the rudder can stall before the wing does"?

I thought it was the latter, which would make a situation where both are critical.

Username Protected · **Posted:** 27 Jan 2019, 19:44

And the Aerostar 700...[/quote]

I didn’t think you could have 2 critical engines on a Twin?

One of them failing is either worse, or it isn’t. If it is an “isn’t,” then could it really be critical?[/quote]

The 700P has a big rudder and flies great on one engine.