Warbird Information Exchange

In the topic on the CAF P-82, it is said that the cause or a factor in the accident was that the pilot was used to airspeed indicators in either knots or mph and this plane was the opposite. I don't know how much if any this affected the landing problem, which is said to have been due to flaring too high. I was at Harlingen when Lefty flew the plane with no problem,I think with ED in the second seat, then Ed went up and had the mishap. I recall that by the time Ed flew it was fairly windy, not extreme, but not an ideal calm morning. I can't recall if there was a problem with one engine.
If you were aiming for perhaps 100 mph on final, and actually had 100 knots (115 mph), then you might balloon as you flared. I don't know if this was the case. The opposite way might cause you to stall too soon.

You just need to use the proper number, no matter how the indicator is marked. I have flown different T-6,SNJ, Harvard, etc, some in knots, some mph. I know I prefer a certain speed at the runway just before flaring for a 3 point landing. I just use whichever figure is right for the way that plane is marked, that is 80 mph or 70 knots. Think what it would be like in a ME 109 which might use 130 kph for final!

How do you know what that desired speed is? The pilot notes, the manual, may give the figure and you may have to do some calculation or allow for lighter weight. You can ask a pilot who has experience in the same plane. This is not foolproof, as some pilot might say he uses 120 mph in his P-51, but that might refer to when he is turning final, not close in where he may be about 95. The most accurate method would be to go up high and do a landing type stall, VSo, gear and full flaps so that you know how the plane handles that day at that weight, then use 1.3 times that speed for short final. In my plane the figure is VSo of 62 knots, so 1.3 X gives 80 knots for short final at the runway. Going into a short runway, with an obstacle, in the Russell Group Spitfire, I think it is marked in mph, so I used 80 mph the last time I looked, and slowed to about 60 mph as you touch down. That situation demands more accuracy than some long paved runway.

Ed's mishap was unfortunate, not a big crash, but did some damage. it might not have grounded the plane for long if there was a replacement prop available. I don't know if he had much flight time in a comparable type, perhaps P-38, B-25, A-26 or similar, and that may have been the biggest factor in the accident. I don't know if he had ever flown the P-82 before, but since there were no dual control ones, one had to start somewhere. I do recall that when I first came into CAF back then, Ed was friendly and welcoming to me.

_________________
Bill Greenwood
Spitfire N308WK

Some of those questions can be answered from the official NTSB report, located here:

http://www.ntsb.gov/ntsb/GenPDF.asp?id= ... G01&rpt=fi


From the report, it states the winds were 350/5 knots with no gusts while using 17L. That's about a 5 knot tailwind, not enough to be a contributing cause. The report does not mention any mechanical problems with the engine.




I agree with what you said earlier about having to adjust the speeds. Most modern warbirds are much lighter than their combat counterparts because they don't have the armor plating, guns, and heavy military equipment in them. Both Lefty and Gary flew the F-82 prior to Ed flying it and I would be absolutely shocked if they didn't give Ed some flying advice, particularly in relation to flying speeds to use that worked for them.




According to the report, Ed had 2 hours total time in the F-82. It also mentions that he had a multi-engine land rating, but does not mention the number of hours of multi time he had.

The report mentions the probable cause as:

FLARE..MISJUDGED..PILOT IN COMMAND
LACK OF RECENT EXPERIENCE IN TYPE OF AIRCRAFT..PILOT IN COMMAND

while the contributing factor was:

STALL..INADVERTENT..PILOT IN COMMAND

It does not mention anywhere in the report about the human factors issue of MPH vs. KNOTS for the airspeed indicator, but I have heard that theory from several CAF members over the years. Does anyone know which airspeed indicator the P-82 had in it at the time of the accident?

Thanks, as for the wind, I thought it was about 15, but that may have been after the flight or I may be way off on this.
I am not at all sure about an engine problem, but have a vague idea that Lefty might have had some trouble with one on the morning flight.
There's not much in the report to know more about why he stalled too high, no mention of the airspeed indicator markings.
Also not enough detail on his multiengine time to assess how much carryover there'd to a P-82.
I don't know what the wing loading or stall behavior is like in a P-82, it might have been a lot different than a light civilian twin, for instance

_________________
Bill Greenwood
Spitfire N308WK

I agree, lots of questions left unanswered. I would like to know more about this, not to place blame, but to learn. I'm sure we have some CAF members here who know a lot more about the story. Anyone care to give input?

Some questions:

1) Did the CAF P-82 have a knots or MPH airspeed indicator in it at the time of the crash?

2) How much multi-time did Ed have prior to this incident? Was any of it in warbirds, or just light stuff?

3) What is the stall behavior like in a P-82?

4) Were there any engine problems on that day, prior to when Ed took it up?

5) When did the "airspeed indicator confusion" issue arise? Was it right after the time of the accident or years later? Why wasn't that mentioned in the NTSB report? I would think that would be important information to put in the final report.

6) How much difference in airspeed is there between Vmc and approach speed in the P-82? Is it possible he got a little slow, perhaps below Vmc during the high flare?

7) Were both props turning when it impacted the runway? Were both props in a "non-feathered" position?

8. Was Ed injured at all during this incident?


I don't put 100% faith in any NTSB report, especially older ones. This is probably the best information source we have, but NTSB reports are notorious for leaving out bits of information by NTSB investigators who are not familiar with "specialty" airplanes such as warbirds and ex-military jets. I think there is more to this story than what is published on the NTSB website. I would like to hear others' perspectives on this, particularly from anybody who was there at the time and has first hand information about the event.

Can only tell what I saw. On at least two occassions before the crash both Lefty and Ed went up and returned each time on on engine. Both engines were running at the time of the accident. Ed had lots of warbird time, but not sure about multi. Seems the best way to land one is on one engine.

It's been many moons, but my recollection was that the accident landing was on one engine as well. I have pictures I took after it was moved behind the fighter hangar. I'll try to scan them this weekend when I get home.

Disclaimer: Less than 600 hours, low performance aircraft, so this is an uneducated personal opinion based on irrelevent experience...

I have trouble believing that the units of measure of the airspeed indicator significantly contributed to the accident, but I guess the difference between flying and a stall is only 1 knot

Also, I don't remember a high flare on approach, I remember a low altitude stall and the plane simply dropped to the runway. What I remember means little as I get older because the fog seems to be setting in I also thought I saw Reg do a dirty roll on take off one year at Ellington, but I just can't imagine that being true...(as I remember/imagined, it was very cool though )

Chunks

_________________
Jack McDonnel

T-6/SNJ Hoarder

Thanks Ober and Chunks, I appreciate your input here.



We have two conflicting recollections. Can anyone remember definitively? I would think that if Ed was doing a single-engine landing that would have come up on the NTSB report, but it's omission wouldn't surprise me as they have made mistakes before.


Yes, I would love to see those! Thank you in advance for going to the trouble to upload them.



It depends on what phase of flight you are talking about. If it's a landing speed and he's a little slow thinking he has a buffer of 5 to 10 knots before stall, when in reality he is already 12 knots slow, he might very well be deep into the stall at that point. It could definitely make a difference.

Anyone else have any recollections? Did the CAF ever do an internal investigation, above and beyond the NTSB one or did they just settle for the explanation of their report?

I was there, didn't see the accident, but heard he stalled it at about 30 feet. I did hear him, personally, say in the O-club afterwards (after too many beers) that he would spare no expense on getting her back in the air...

I was there and saw it happen, but it appeared to be higher than 30ft, and saw the one wing drop.

I was also at the O club for the survivors party and heard him make the same statement, along with the obligatory applause. It took two beer coupons to get a Fosters Lager, and you didn't dare wear your cap in the club, or else.

_________________
If God had wanted man to fly behind a flat motor, Pratt Whitney would've built one.

I don't know if it will help,but here are some pages from the F-82E flight manual that pertain to stall characteristics and engine out procedures.Paragraph 2-39 states that there is little or no stall warning in the landing configuration.Figure 2-6 gives the indicated stall speeds and Paragraph 3-15 in the Emergency section says that the stall speed in a single engine landing will be about 5 mph faster than normal.

Test

_________________
He bowls overhand...He is the most interesting man in the world.
"In Peace Japan Breeds War", Eckstein, Harper and Bros., 3rd ed. 1943(1927, 1928,1942)
"Leave it to ol' Slim. I got ideas...and they're all vile, baby." South Dakota Slim
"Ahh..."The Deuce", 28,000 pounds of motherly love." quote from some Mojave Grunt
DBF

Maybe third times the charm..tho shorter post this time...
Left props were at "normal" positions afterwards..three bent aft..one appearing unscathed.

NTSB sent no one since there were no fatalities or injuries. As I've understood it, they skimmed
the FAA's report and rubberstamped the upshot, but not the details. FAA repository time with
an FOIA request, I reckon. As I've heard over the years, one of the issues was with a leaky
oil supply line to the right prop.

Hope this works, cause I'm not doning it again today mon chers..

_________________
He bowls overhand...He is the most interesting man in the world.
"In Peace Japan Breeds War", Eckstein, Harper and Bros., 3rd ed. 1943(1927, 1928,1942)
"Leave it to ol' Slim. I got ideas...and they're all vile, baby." South Dakota Slim
"Ahh..."The Deuce", 28,000 pounds of motherly love." quote from some Mojave Grunt
DBF

Oh and one other thing Bill, much ado has been made about the props, but IIRC it took them
quite a while to find a replacement for the right main landing gear. I believe the forging for
it was destroyed in the accident.

_________________
He bowls overhand...He is the most interesting man in the world.
"In Peace Japan Breeds War", Eckstein, Harper and Bros., 3rd ed. 1943(1927, 1928,1942)
"Leave it to ol' Slim. I got ideas...and they're all vile, baby." South Dakota Slim
"Ahh..."The Deuce", 28,000 pounds of motherly love." quote from some Mojave Grunt
DBF

I had a little trouble with the scanner, so the first pic is cut off. This photo album was dated '87. The worst part about finding these is the fact that as I thumbed through the album I counted 8 aircraft that have been destroyed since

Roll out after landing with right engine shut down and prop feathered...



Being towed back to the flight line...



It was too far away to get clear pictures during the recovery so I didn't post those.

As it lay behind the Fighter Hangar. Right prop appears to be feathered...



Another shot...



I have to be honest...at the time I really didn't appreciate what I was seeing fly. It was cool, but my favorites were Fortresses and Mustangs. Wish I would have enjoyed some of the more rare ones at the time.

Chunks

Thanks Chunks for the pictures, that confirms that the right prop was indeed feathered prior to the crash. Thanks Larry for the Dash 1 excerpt. That was tremendously helpful. A few interesting tidbits caught my eye from the pilot manual. The manual references are quoted verbatim in blue:

"However there is little or no stall warning with the flaps and gear down, power on or off, and flaps and gear up, power off."

Depending on where Ed lost the engine, he might have had little warning about an impending stall, with little time to react, especially if he was close to the ground.

"Should engine failure occur either on takeoff or during flight, control forces required to hold a constant heading are relatively light, and complete control is easily maintained down to stall speed."

It sounds like this is relatively easy to fly single-engine, PROVIDED one is above stall speed. I haven't seen the rest of the manual, but the omission of any problems with Vmc issues in the single-engine emergency section implies that it is not an issue at all. At the beginning it even remarks that "single engine control characteristics of this airplane are exceptionally good".

"Estimated single-engine stalling speeds are approximately 5 mph higher than normal."

This is key. In this scenario, we can refer to figure 2-6, page 28 of the pilot manual that Larry scanned. Let's also assume that the CAF aircraft was a lightly loaded one with no armament, combat equipment, etc. In that table, I will use the following conditions: flaps down, power on, normal rated power, level flight, and 20,000 lbs, which is exactly half-way between the 18,000 and 22,000 lb columns (a light weight aircraft), so we can interpolate half-way. The stall speeds for 18K and 22K weights are 97 mph and 108mph respectively. Interpolating, we come up with a 103mph stall speed for the conditions which most closely approximate a two-engine landing at Harlingen. The manual (see above quote) states that for single-engine, the stall speed increases by 5 mph. So, 103 mph + 5 mph = 108 mph stall speed for a single-engine condition.

So, his actual single engine stall speed is 108 mph, which converted to knots equals 94 Knots indicated air speed. Thats a difference of 14 units between the two measurements. Whatever he thinks he is using, he is going to be off by 14 units on what he thinks his stall speed is. If he thinks he has until 94 knots until he stalls, but in actuality, he is flying 94 mph because the airspeed indicator is calibrated in mph, rather than knots, he will actually be 14 mph too slow and fall out of the sky. So, from this perspective, it is very easy to see that confusion between mph and knots calibration on the airspeed indicator is very critical.

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. Losing that side will not affect his ability to lower his landing gear or drop the flaps like he normally would do. So, no distractions there for Ed when he was configuring for landing.

Using normal rated power on single engine, altitude can be maintained up to 10,000 ft with airplane gross weight of 21,000 lbs, up to 5000 ft with airplane gross weight of 23,000 lbs

With our scenario of using a 20,000 lb aircraft, he should be able to maintain level flight above 10,000 ft. Harlingen is nearly at sea level, and will come nowhere close to that. Utilizing the weather observations from the weather data in the NTSB report, I calculated the density altitude to be no greater than approximately 1500 ft, worst case scenario. So, Ed should have had plenty of excess power to not only maintain altitude, but also enough to climb in those conditions on one engine.



That makes sense airnutz. The NTSB report is terribly incomplete and leaves out a lot of very important information - not the least of which is he lost the engine! The other interesting item is that as Chunks' picture shows, Lefty lost the same right engine on an earlier flight in the day, but he successfully recovered the aircraft. You would think that losing an engine would be a semi-serious thing and they wouldn't want to risk sending the aircraft up so soon without extensive engine ground running. I don't know, maybe they DID do that. I wonder if the CAF or mechanics felt pressured to put the P-82 back in the air that day because Airsho' was going on?



So, in my analysis, we can probably conclude the following things above and beyond the NTSB report:

1) Ed lost the right engine.

2) Losing the engine should not have distracted him from flying the aircraft, as all the normal systems required for configuring the aircraft were available, and the single engine flight characteristics were excellent. He should have had no directional control or altitude holding issues, assuming his piloting abilities were commensurate with his experience level, unless he lacked complex multi-engine experience - something which we still don't know yet.

3) The weather was not an issue.

4) The stall warnings were very quick, insidious and without warning after Ed lost his engine. He had virtually no time to react to the stall.

5) Confusion arising from utilizing an airspeed indicator calibrated utilizing mph vs. knots could have had a substantial impact on his ability to maintain control of the aircraft and prevent a stall.


I know there are many other people on this forum who know what happened. I still would like to hear their input, particularly the CAF members who have first hand info on the event.

Any Mustang pilots care to vet my analysis? Anything I am missing or overlooking? I'm open to suggestions, but based on the information so far - provided it is accurate - this is what I have come up with.

Comments?