Knots or Mph, re P-82

[airnutz]

Also, from the manual excerpt, we can see that the left engine powers hydraulics for the gear and flaps. From Chunks' pictures, we can see with no doubt whatsoever, that the right prop is feathered, hence he lost the right engine.

Thanks for your input W1 and thanks Chunks for the photos. W1, the feathered prop does not neccesarily imply
engine failure. If the oil supply dwindles to "nought" on the F-82 the prop "fails" to a feathered position,
as I understand.

What happens to the PIC's seat cushion if he suddenly experiences "0 prop" on one side at say about, 30 or 40 feet altitude
on very late short final?

[warbird1]

Also, from the manual excerpt, we can see that the left engine powers hydraulics for the gear and flaps. From Chunks' pictures, we can see with no doubt whatsoever, that the right prop is feathered, hence he lost the right engine.

Thanks for your input W1 and thanks Chunks for the photos. W1, the feathered prop does not neccesarily imply
engine failure. If the oil supply dwindles to "nought" on the F-82 the prop "fails" to a feathered position,
as I understand.

I did not know that the F-82 had automatic feathering props in the event of oil pressure loss. If the prop did lose oil pressure and it went to the feather position, though the actual engine was still good and running, the pilot would still be single engine, right? So, as far as the pilot is concerned, he still flies it utilizing single engine procedures because it is producing no power due to the feathered prop.

Thanks for pointing out that subtle difference, airnutz, I stand corrected.

My sentence should have read:

"Also, from the manual excerpt, we can see that the left engine powers hydraulics for the gear and flaps. From Chunks' pictures, we can see with no doubt whatsoever, that the right prop is feathered, hence he lost power to the right engine."

I still believe that the knots vs. MPH indicator argument I presented shows that it could have had a substantial impact on the airplane crashing. In other words, it's very plausible that that was the cause.

Thanks for your input, airnutz.

[airnutz]

If the prop did lose oil pressure and it went to the feather position, though the actual engine was still good and running, the pilot would still be single engine, right?

I still believe that the knots vs. MPH indicator argument I presented shows that it could have had a substantial impact on the airplane crashing. In other words, it's very plausible that that was the cause.

Sorry, I reckon a vestige of one camps arguement as to the "cause" of the accident crept in. Your correct, regardless of what attitude the aircraft was experiencing at the point the pilot was aiming for, if he was 14mph behind the proper speed the ball game is over at that point.

[Bill Greenwood]

Here is my guess. Lefty flew the plane with Ed that morning, maybe another time also. It is reasonable to assume that Lefty knew what airspeed to use for landing, and he knew that speed re the type of instrument that was in the plane. If it the ASI was in mph, Lefty would know that the speed might be 120 mph. If it was in knots it might be 105 k. EITHER WAY, it is likely that Lefty BOTH DEMONSTRATED and TOLD Ed the PROPER approach speed, in whichever unit the plane had. So all Ed needed was this figure, it seems unlikely that Lefty would say use 105 k, when he really meant 120 mph. So Ed would have the correct figure in mind, and I don't see this as a likely accident cause. The only catch would be if the Pilot Manual gave the figure in Knots and the plane was in mph. That seems unliklely.
My distant memory was that there had been engine or prop problems on the previous landing, glad I am not completely senile on this, as others agree now.
So it appears that the engine problem may have been the cause or as cause of the mishap, along with Ed's low time in type; more so than the ASI markings.

How about it Mustangdriver, go look in the cockpit and let us know what ASI instrument is in that plane. If it is in knots then the theory that the instrument fooled Ed seems to have no substance. I guess it could be marked in both, like a civilian one, but unlikely.

[b29flteng]

Is it possible one side was Kts and the other Mph?
Remember back then the CAF didn't have the best maintnenance.

[warbird1]

How about it Mustangdriver, go look in the cockpit and let us know what ASI instrument is in that plane. If it is in knots then the theory that the instrument fooled Ed seems to have no substance. I guess it could be marked in both, like a civilian one, but unlikely.

I don't know if that will definitely prove anything one way or another. The airspeed indicator could have been replaced or changed both at the ensuing years under partial restoration with the CAF/Ezell's, and/or the quick "restoration" that the NMUSAF did.

FWIW, here is a picture that Brad took at Midland, just prior to it's shipping to Dayton. This is from the other extensive P-82 thread:



That looks like it is in MPH, as the redline is at 505mph, I believe that is what the P-51D redline speed is, if I'm not mistaken. Can someone confirm?

I don't know which cockpit that is. When the P-82 is flown solo, which side is it flown from?

[warbird1]

Is it possible one side was Kts and the other Mph?
Remember back then the CAF didn't have the best maintnenance.

Excellent, excellent point b29flteng! That is entirely conceivable, as Lefty might have been checking out Ed and all of his numbers might have been different than Ed's cockpit!

FWIW, here is the other cockpit, again credit to Brad, from the other P-82 thread:

[Larry Kraus]

Normally,I'm not really supposed to post more than 10 pages from a manual,but the F-82 cockpit setup is so unique,that some additional pages are necessary for clarity.The solo cockpit is the left side.There are change over switches for some systems that have to be positioned in both cockpits to allow the pilot in the right cockpit to operate them.Several controls are only available to the pilot in the left cockpit.Incidentally,I'm not posting these pages in a larger format than normal on purpose.I've set everything the same as I always do and they post in this size.I'll admit that it does make the pictures and captions easier to make out.If anyone is interested in buying a copy of this manual,it's available on CD,along with a manual for the AJ-1 and a photocopy of a flight manual for the XA2J-1 for $19.95 from my friends at Flight Manuals on CD in New Zealand.It's listed under "NA-TWIN" for North American twin engine airplanes.Here's a link to their site:

http://www.flight-manuals-on-cd.com/

Here are the first 9 pages from the F-82E manual showing the cockpits:

[warbird1]

Thanks for that Larry.

An interesting item in that excerpt. It seems like the manual kind of contradicts itself. Direct quotes:

"However the co-pilot has no control over the following major items: landing gear and flaps (except emergency), ignition, water injection, surface control boost, or bombs (except salvo) and rockets. In the event of injury to the pilot, the co-pilot can, therefore assume control of the airplane and effect a landing."

Really, the co-pilot can "effect a landing" despite the fact that he can't lower the landing gear? I guess they should have said, "effect a gear-up landing". That's really odd the way they phrase that.

Despite having that excerpt, I still can't tell which cockpit is which in the earlier cockpit pictures from Brad that I posted. The clarity of the cockpit pictures from the manual is not the greatest, but it appears that both cockpits had a MPH airspeed indicator. From the other excerpt you posted earlier, it mentions the stall speeds in mph, so it makes sense that the cockpit ASI's would be calibrated that way as well. Of course, this all means nothing, since the CAF could have had virtually anything in the cockpit, just to make it fly.

Larry, any thoughts on this discussion or anything to add? Anyone else, for that matter?

[Bill Greenwood]

If the manual gives speeds in mph and the photos appear to show the instrument in mph, then it is reasonable to assume that Lefty and Ed had the correct number (speed) to use, that is perhaps 120 mph, irregardless of the units. There's no reason to think they transformed it to knots and thus flew too slowly. Note that a P-51 has an ASI marked in mph and the manual gives mph speeds. No reason to think the P-82 is different. If the ASI caused Ed to fly to slowly, why did it occur only on this flight?
So I'd guess that cause was more due to the engine/prop problem.
As to the gear and flaps, the co pilot on the right side may have been able to lower it in an emergency, it seems to say.

For some reason on my computer, photos won't display fully. It shows only the top part,sometimes if it sits long enough, it will fill in, mostly not. My scan says I don't have virus or spyware,just some "cookies".

[airnutz]

Both cockpits have the emergency L/G release at the lower right of the instrument panel. (legend #23 and #16 respectively)

Thanks Larrry for the additional manual pages. They answered a few questions, but created one more.
I don't see oil pressure guages for the propellers, am I missing something folks?

[warbird1]

If the manual gives speeds in mph and the photos appear to show the instrument in mph, then it is reasonable to assume that Lefty and Ed had the correct number (speed) to use, that is perhaps 120 mph, irregardless of the units. There's no reason to think they transformed it to knots and thus flew too slowly. Note that a P-51 has an ASI marked in mph and the manual gives mph speeds. No reason to think the P-82 is different. If the ASI caused Ed to fly to slowly, why did it occur only on this flight?

Bill, I don't think you can be so quick to come to that conclusion for several reasons:

1) Lefty may not have had a manual to fly with. Lefty may have had a manual for a later model only, which perhaps used knots, after the Air Force transitioned to that unit. Lefty may not have used manual speeds at all, but instead used approach speeds based off of stall tests, similar to your first post here on this thread. We don't know what happened.

2) You are assuming that the aircraft had the original instruments in it as displayed from the manual. We can't assume that. Remember, this aircraft was taken off the parade ground at Lackland AFB where it was on outside static display. It's entirely probable that the aircraft was cannibalized of many usable parts by the Air Force, including the airspeed indicator, prior to it's display there. The ASI is one of the most common instruments around that have compatibility with many other planes. It's highly probable that it was taken out prior to display. If that was the case, the CAF almost certainly replaced it. The question remains, what did they replace it with? I find it interesting that from the picture that Brad shot, that one of the cockpits has a P-51D ASI in it. Is it merely coincidence that the P-82 has exactly the same redline airspeed as the P-51? HHHHmmmm, interesting. Remember, during this time, the CAF was a poor organization who scrapped together whatever resources they could to put airplanes in the air. It's entirely possible they put a different ASI in that cockpit, perhaps even putting two different ones in each cockpit, with one calibrated in knots and the other in mph. We just don't know what happened in this respect.

So I'd guess that cause was more due to the engine/prop problem.

It might have been, but we can't say that with authority because we don't have enough information. There are still lots of unknowns. For example, I would still like to know how much warbird multi-time that Ed had. That might have been a factor.

For some reason on my computer, photos won't display fully. It shows only the top part,sometimes if it sits long enough, it will fill in, mostly not. My scan says I don't have virus or spyware,just some "cookies".

There could be several reasons for that. That sounds like the old days of dial-up when it took forever to load pictures. If you have high-speed internet, test your downloading by visiting another forum that has lots of pictures. If it downloads them slow also, then the problem might be on your end. If it downloads fast, then it might be on WIX's end. This forum is having some issues and is slow at times.

BTW, don't place all of your trust on virus scans. There are some programs which are great and others which are very, very ineffective, and they all span the gamut. Just remember you get what you pay for. The free ones, are mostly only partially effective, with the paid ones being much more effective.

[airnutz]

test

[airnutz]

4th time the charm today?

Comparing the panel of "Betty Jo" at uscockpits.com, it appears Brad's photo of the one with the most missing
instruments and the call sign placard is the left-side one.

Ya' know, if one suscribes to the different mph/knots ASI guage theory one question begs an answer, why didn't they
paint telltales on the guage face or fix a placard with the values next to the ASI? "Let's-go-flyitus"?

As Chunks related earlier..one down, 8 more to go...

[Larry Kraus]

Bill,

I'll try to clear up the emergency gear and flap question without posting additional pages from the manual.For the emergecy flap extension,the manual states:

Paragraph 1-82

"WING FLAP EMERGENCY SWITCH

A wing flap emergency switch is located on the left side of each cockpit forward of the throttle quadrant.(See figure 1-3,reference 15;figure 1-6,reference 11.) Movement of the switch to "ON" position diverts pressure from the aileron boost system to the down side of the wing flap actuating cylinders.The resultant momentary pressure drop in the aileron boost system has no appreciable effect on aileron control action.The flaps lower approximately 10 degrees per second and may be stopped at any position desired by turning the flap emergency switch "OFF".

WARNING

The flaps cannot be raised by operation of the flap emergency switch."


The following paragraph covers emergency landing gear release:

Paragraph 1-87

"EMERGENCY LANDING GEAR RELEASE

1-88. The emergency landing gear release handle (See figure 1-2,reference 23;figure 1-5,reference 16) is located at the right side of both cockpits below the instrument panel.Pulling the emergency release mechanically unlocks the gear and fairing doors,and actuates a hydraulic dump valve which allows trapped fluid in the landing gear and wheel door cylinders to return to the system reservoir.This then allows the doors to open and the gear to extend by gravity without hydraulic pressure."


I hope that the above helps.There are definitely a few non-standard features to the F-82 that would make flying it,especially in an emergency situation,a potential handful.That would go double if there had been a few modifications to make a flying airplane of a long time static display.Things can go south in a hurry if you expect a specific result from moving a control and something else (or maybe nothing) happens as a result.I can attest to that from past experience with other aircraft.