How slow can a P-51 fly

[Bill Greenwood]

Vlado, what is the stall speed in your plane, both Vs and Vso? See, us old guys know some fancy av terms also, even if I think a glass cockpit is a place to put a nice flower display.

[Bill Greenwood]

As for as the brakes on the Mk V, or early Spitfires, remember they have the smaller 10 1/4 inch tires so the brake area is also probably smaller than my 12 inch ones.

I have read that the brakes may have some fade if used hard, but in a Mk V I'd guess you ought to be touching down no faster than 55 mph, so how much braking do you need?

I don't know this speed for sure, as I have not flown a V, but from talking to pilots who have, like Stu Dawson, I think my guesstimate is correct. I sure would like to do some hands and feet on research for this.

[mlenoch]

Bill wrote:Vlado, what is the stall speed in your plane, both Vs and Vso? See, us old guys know some fancy av terms also, even if I think a glass cockpit is a place to put a nice flower display.

I can't remember. Its cold & frozen here and I haven't flown for months! I'll get those numbers to you when I get warm!!
Vlado

[Bill Greenwood]

Vlado, you should be out here. It is sunny and warm, really probably 40 in the sun today, almost not needing a coat weather. The downside is that our snow is getting a little thin, except the manmade stuff. It gets down to 4* or so at night,but warm in the daylight. Howard and Carolyn came in today, they'll love the Texas like weather, except the Texas weather last week was more like Chicago in the winter, with all time lows.

[avenger2504]

Wow a Fokker Triplane and P51D Mustang in formation??? Now that would be a sight to see! Closest I've seen was Tim Wallis' MKXVI Spitfire in formation with a Sopwith Camel! The Spitfire was decidedly nose up!!

[Hawkeye]

I ask because we were talking in the Vintage section about trying a formation flight with a Fokker Triplane and a P-51. I think the Triplane will do 110 mph in level flight, so maybe it would be possible at altitude in a shallow turn with the P-51 on the outside?




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I don't think any I've heard of any Fokker Triplane that could do 110 mph in level flight, I think the average for a replica today is 80 or 90. The closest I've seen to something like that is the video of the Camel and Spitfire.

[Baldeagle]

This Triplane will, it averaged about 100 mph in cruise from Denver to Dayton and back last September, and I watched it the whole way.



and it will be at Oshkosh this year...


(I will say that I was also surprised that it went that fast)




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Last edited by Baldeagle on Sun Jan 17, 2010 9:45 am, edited 2 times in total.

[Dave Hadfield]

I wondered about 110 straight and level in a Triplane, too. That may require a shallow descent -- though that's not a real problem.

You could substitute a P-40. Much more of a high-lift wing. It'll fly into the 90s without much trouble.

Dave

[Dudley Henriques]

I wondered about 110 straight and level in a Triplane, too. That may require a shallow descent -- though that's not a real problem.

You could substitute a P-40. Much more of a high-lift wing. It'll fly into the 90s without much trouble.

Dave

110 is doable in a 51 even with the wing. I've been stacked behind a Breezy once. The poor guy kept looking back at me as I S'd behind him. I have no doubt he was having visions of a Hamilton Standard eating him alive. He was a lot slower than 110 and I don't think I could have hung in there with him formation wise, but I didn't have all that much trouble avoiding over running him. The Mustang was nose heavy and trying hard to take me left but I had rudder enough to hang in there without killing the poor guy anyway.
I'll admit that the final result was ATC changing my runway for me, but all in all, it was a routine deal throughout.
110 should be ok for a decent 51 driver.

[Baldeagle]

Now all we need is a camera plane (T-6?) and a P-51 pilot (with P-51) who will be at Oshkosh... any volunteers??




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[mlenoch]

Now all we need is a camera plane (T-6?) and a P-51 pilot (with P-51) who will be at Oshkosh... any volunteers??

OK, I'm in.
VL

[Holedigger]

I was reading about the USN trials of the navalized P-51D and it stated a landing speed of 85mph. Makes me scratch my head. Is that Airspeed, groundspeed?!?!? If the Shangri-La was doing 25 knots into the wind and the Ground speed was 85 indicated, I can wrap my head around that. They also test landed and launched PBJ's aboard her that day!

[Dudley Henriques]

I was reading about the USN trials of the navalized P-51D and it stated a landing speed of 85mph. Makes me scratch my head. Is that Airspeed, groundspeed?!?!? If the Shangri-La was doing 25 knots into the wind and the Ground speed was 85 indicated, I can wrap my head around that. They also test landed and launched PBJ's aboard her that day!

Actual landing speed at touchdown will depend on the GW of the aircraft as it transitions through the flare. Normally I liked 120 over the fence. Naturally the touchdown airspeed was lower. With an extremely light GW you might get the stall speed down to say 87 indicated but I wouldn't recommend messing around with a 51 trying to get it that low on a landing. With higher GW the airplane will pay off at a higher indicated airspeed and the 51 can pay off on you pretty quickly if you're playing around trying to get every inch of airspeed down before touchdown.

[drgondog]

I have very little business getting into the discussion with dudley, vlad and bill - but when my father taught me to fly the 51 the one thing he added to the above discussion is never fly under 120 over the fence and goooooo eeeeeeeasy on the throttle on a missed approach. Bill implied it but flaps and a hard push on throttle at low speed is deadly.

He also liked to land relatively hot and high.

He had a lot of combat time in the 51 and I'm pretty sure heavier gross weights had some influence with his thinking..

[Bill Greenwood]

I am sure Vlado has done more Mustang landings than I have seen. I was giving the figures that are in the pilot manual as well as my best gusss. If I was to actaully fly a P-51 now, there are two ways to find the right approach speed. In some ways the best is to go up and do a couple of stalls, one clean and one gear and flaps down. Then the norm is to use stall speed times 1.3 for final and for real short landing maybe 1.2. Let's say a civilan 51 stalls at 80 mph VSo. This might be a litttle high, but in the ball park. So, 1.3 tmes 80 gives 104 mph, 1.2 would be 96 mph for a real minimum. Actaully doing the stall, gives the curent info for that plane on that day at that weight.

Note these approach speeds would be in close, about at the runway. If the final is long or turning base to final you might not yet have full flaps down and would be a little faster,maybe with some power on.

The other method is to use the information from an experienced owner or pilot, of that plane. The only problem with this is pilots don't always do exaclty what they say. If it is Pilot Notes, it may not give the same gross weight etc. The 51 notes do say to use 120 on final, but no details are given as to weight or type of pattern.

I flew 2 single seat Spitfires, in both cases I did a stall to find the speed to use to land. In one case I had an experinced pilot, Charlie Brown to give me advice on a clipped wing one. His speeds worked out just fine. In the 2nd case the speed was lower due to a short runway,and I had no one to give advice and what I worked out was close. What you DON'T want to do is to try to land a Merln Spitfire at 120 mph, because that is what you use in a Mustang, or worse to try to use 80 mph MAX in a Mustang because that is what that Spit calls for.

By the way I once saw one of the California guys land a P-51 at Santa Paula. The runway is listed as 2713 feet by 60, and right over trees. There is 225 feet of dispalced threshood so only 2900 max. I can promise he did not have any 120 mph on short final and it was not a power on wheel landing. It can be done just fine, I saw it, but there is not a lot of room for error. I would not try it in a 51. Give me a nice little Spit Mk V or a Bearcat and no sweat in a T-6.

Last edited by Bill Greenwood on Tue Jan 19, 2010 4:49 pm, edited 3 times in total.