Knots or Mph, re P-82

[RyanShort1]

This is a cool thread. I wish we had more like it on WIX (except for the circumstances)!

One point I think I can add. It looks that while the right engine propellers appear to be feathered, the prop was still turning with sufficient speed to bend up those blades pretty good. That would make me wonder - did the prop lose oil pressure and feather a relatively short time before the accident? Would it not have been standard procedure to go ahead and shut down the engine if the prop was feathered so as to not stress the engine as well as the blades?
Sounds to me more like some sort of distraction or lack of experience, coupled with the aircraft's apparently good handling characteristics right down to stalling speed, and the lack of warning of an impending stall.
As far as the airspeed indicators, and the not-so subtle comments about CAF maintenance, I'm not going to say I'm any kind of expert, but that seems unlikely as a major cause of the stall. The engine might be a bigger factor. We now know that there was an issue in a previous flight, but that does not mean that they were wrong to take it up again. Even in my limited experience, there have been times when we've had an issue, the mechanics have looked at it and tweaked something, and then we've flown it again to see if anything else shows up. That's not necessarily a dangerous practice.

Ryan

[Obergrafeter]

Yes Ryan, maybe that is why I keep saying both engines were running (for once) when he returned, maybe I saw him on final and they were running, only to quit nano seconds later,

[RyanShort1]

Without knowing more facts, it looks like an "almost" successful test flight, with the props losing pressure right before the landing, or during the landing, and he either didn't notice it in time to shut down the engine, was commited to landing anyway and didn't have time to react, or it just happened right there. A sudden loss of thrust from the props going feathered could also account for a loss of airspeed.

Ryan

[Chunks]

Ryan I like these threads as well. I wondered the same about the prop. It was obviously rotating but at what point in the approach did all of that happen? We'll never know for sure, but it's a cool discussion. I can only imagine that Ed was an extremely busy dude for a relatively short period of time. With limited experience in that particular model and what I think was an inflight mechanical failure (at what point of the flight I don't know) there was a relatively short period of time between flying and riding...

Considering the range of warbirds Ed had flown, and the rarity of the airplane, he still may have been one of the most qualified to fly it at the time. I'll have to quote my favorite Lefty comment of all time (although it was made in reference to the zero) "It's in reasonably good flying condition, and I think we should fly it"

I can't remember how many times we went to the airport to see the "first flight" that didn't take place for one reason or another. At least I did get to see it fly a number of times before the accident.

Chunks

[Chunks]

Ryan said

and then we've flown it again to see if anything else shows up. That's not necessarily a dangerous practice.

I definitely agree, however I may be more inclined to make that test flight on a day without 35,ooo witnesses

Chunks

[RyanShort1]

Ryan said

and then we've flown it again to see if anything else shows up. That's not necessarily a dangerous practice.

I definitely agree, however I may be more inclined to make that test flight on a day without 35,ooo witnesses

Chunks

Fair point, but it looks like it's plenty safe of an aircraft single-engine, and was successfully landed, possibly with him in the cockpit and Lefty in the other earlier in the day in single engine configuration. Here's my guess... If the prop had gone to feather a minute or two before, he might have been able to shut down the engine and fly it as a single-engine approach. However, if it had the hiccup right on final, that may have been proverbial straw that broke the camel's back. The one time went you don't want to find something new out.

Ryan

[bluehawk15]

I was there, but I didn't see the accident, so I can't say if both were turning or not. HOWEVER, if you look at the photo, you might say it looks like the right one was feathered as the blade angle is different than the left one. REMEMBER though that the props rotated in different directions, so the angles would not look the same even if a prop was not feathered. When I looked at the photo beside the PBY "Seabitch", it looks to me like the right prop blades are the same degrees from feathered as the left prop...just in the opposite direction.

I need to dig through my old slides, I think I might have some better angles on the props.

This kinda reminds me of "Cold Case"!

[warbird1]

Without knowing more facts, it looks like an "almost" successful test flight, with the props losing pressure right before the landing, or during the landing, and he either didn't notice it in time to shut down the engine, was commited to landing anyway and didn't have time to react, or it just happened right there. A sudden loss of thrust from the props going feathered could also account for a loss of airspeed.

Ryan

I agree with the previous comments, I also find this thread extremely fascinating. I just wish we had more participation from warbird pilots, mechanics and anybody who is familiar with the Twin Mustang and/or the incident in question.

Ryan, that's entirely a plausible scenario. He might have lost the engine on short final, and had little time to react. Remember from the previous posts, losing the engine is a double whammy. First you lose half your power, then your stall speed increases by 5 mph. So, unless you react fast enough, you might be in a world of hurt very fast. It also has the potential of being a triple whammy. This part I don't know about and will defer to Larry so he can look up in the manual of what I'm about to say next.

I've flown a fair amount of multi-engines and in a lot of the ones I've flown, if you lose the engine on short final like that and intend to land without going around, you must very quickly raise the flaps to something less than the full flap or landing flap configuration. The reason is that with the loss of half your power, you won't be able to overcome the drag from your flaps. The idea is you want just enough flaps to provide increased lift and lower your approach/landing speed, but not too much as the added lift will be offset by the increased drag which you can't overcome on one engine. In other words, you want more lift than drag out of the flaps, prior to that "breakeven" point, so to speak. I don't know if the P-82 has that consideration. Is it possible that Ed was utilizing full landing flaps, lost the engine on short final/low altitude, and wasn't able to raise the flaps partially to lessen the drag while losing half his power? The result of all this would be a high sink rate right into the runway.

Calling Larry!

[RyanShort1]

I was there, but I didn't see the accident, so I can't say if both were turning or not. HOWEVER, if you look at the photo, you might say it looks like the right one was feathered as the blade angle is different than the left one. REMEMBER though that the props rotated in different directions, so the angles would not look the same even if a prop was not feathered. When I looked at the photo beside the PBY "Seabitch", it looks to me like the right prop blades are the same degrees from feathered as the left prop...just in the opposite direction.

I need to dig through my old slides, I think I might have some better angles on the props.

This kinda reminds me of "Cold Case"!

On further view, it does look like there's still some angle on those props. Hmmm... I guess maybe my theory is also wrong.

Ryan

[airnutz]

Ryan, that's entirely a plausible scenario. He might have lost the engine on short final, and had little time to react.

I believe that's what I inferred earlier when I noted lack of thrust on the right side. The NTSB report says he "flared too early", not
"he lost power and stalled". We really need to get ahold of the original FAA report to see what the NTSB doesn't say in order
to shed possible additional details on the incident.

Is it possible that Ed was utilizing full landing flaps, lost the engine on short final/low altitude, and wasn't able to raise the flaps partially to lessen the drag while losing half his power? The result of all this would be a high sink rate right into the runway.

In the photos I ran across last week, she is where she came to rest in the sod just off the runway. Flaps are down a fair bit...about 40-45 degrees.
No telling what damage may have occurred to alter the apparent degrees.

EDITED

[airnutz]

Another thing came to mind after viewing the manual in reference to propeller control...if he is
bleeding-off prop pitch due to loss of oil how does he know it in time. Appears the control is
locked in a detent, so there may be no movement there. RPM drop? Would it be possible the
pilot would respond with throttle trying to recover thrust? More lost time while fate approachs?

[Larry Kraus]

For whatever reason, the F-82 flight manual doesn't give any specific instructions for a single-engine go-around. The only go-around reference is in Paragraph 2-58 "GO-AROUND" on Page 28. This is in the first set of pages from the manual that I posted on Page 1 of this thread. It's on the same page that shows the stall speed chart. This is under the instructions in Paragraph 2-51 "NORMAL LANDINGS". Here's what it says about flaps,among other things:

Paragraph 2-58
GO-AROUND

a. Propeller controls full "INCREASE RPM".

b. Open throttles to take-off power.

c. Landing gear "UP". When gear is up and locked,return handle to "NEUTRAL".

d. When sufficient airspeed is attained,gradually raise flaps.


The single-engine landing instructions are given in Paragraph 3-19,which begins on Page 30 in the Emergency Procedures pages, in that same posting of pages from the flight manual. I don't know if they didn't expect anyone to attempt a single-engine go-around or if they assumed that the normal procedures would automatically be used by the pilot. At any rate,there are no additional references in the manual on go-arounds,single-engine or normal.

I'm posting one additional page from the manual here showing the limits on engines and flight instruments. If nothing else,this confirms an earlier question concerning the 505 mph VNE speed limit marked on the airspeed indicator. Also,someone mentioned not being able to see the entire pages posted from this manual. All that I can suggest is to either shrink the web page display to around 75%. if that's an option or to scroll right to see the rest of the page.The manual on the CD shows up initially as 204%, which is apparently the way that it was originally scanned by the vendor. However, I have to print the original pages and rescan them prior to uploading them to Photobucket, so I don't really understand why they show up in such a large format on WIX.

Anyway,here's the page: