BillS

Landing speeds

In an effort to understand the P-38 flight characteristics some really stupid questions have been asked. The answers however have been excellent. Thanks.

Has anyone put the radar gun on P-38 landing speed? Better yet have you put the radar gun on a KPM P-38?

Twinman brilliantly suggested adding weight to get the wing loading up. I facetiously replied that two and a half bricks might over stress the airframe. After two days of thought the suggestion seems remarkably good for simulated testing. Must be a lot of stress associated with always being right.

We have a radar gun and will attempt to gradually load the trainer airframes until the appropriate landing speed can be simulated. Stopping short of breaking the airframe will be important.

Thanks.

Bill

William Robison

My Feedback: (3)

BillS:

In your initial test flights of the P-38 get some good altitude, and see how slowly you can fly the plane in level flight without pulling any amount of up elevator. You will have to use some, but keep the plane looking like normal flight as much as you can. Don't judge speed by sight, but rather by throttle stick position. That will be completely independent of any wind, the ground speed might be 30 mph different between one direction and the other, but the throttle stick position will be the same.

When you find that minimum power setting for level flight, you will also have found the power setting for flying your final approach. Don't cut the throttles until you flare for landing.

As you increase the weight (and wing loading) you will find this minimum power setting gets higher to match the weight.

This is a better method than a speed gun, as the speed gun is seldom handy. You do get bragging rights from a radar unit though.

Bill.

BillS

Bill,

The cautious engineer does not always think in predicable terms.

However in this case we will be trying to simulate the landing speed of a yet un-flown P-38. The landing speed will be simulated by incrimentally adding weight to a Four Star until the landing speed approaches the suspected P-38 landing speed or until we become afraid the airframe will break. Rough calculations indicate that 7 pounds of lead will be necessary to achieve P-38 wing loading. The owner is away and the plan will require aproval. The initial conversations should be most interesting.

Bill
Retirement age just in case anyone questions.

evan-RCU

Bill, What are you trying to do here? Are you trying to get a trainer to fly like a KMP P-38? Do you have a KMP P-38 and are trying to get a feel of how it flys before flying it? I have one with a few hours on it now and you don't live too far away.......

BillS

We need to talk.

We are trying to keep a beautiful airplane from self destruction. We have a KPM P-38 and we are trying to gain experience by getting a trainer to fly like a P-38 for preflight experience.

Carl and I have a good friend (good builder and ace engine man) who is building a KPM P-38. Our friend has NO warbird experience, NO retract experience and worse NO twin experience. We have been trying to keep the owner from a 30 second bad experience by developing the expertise to perform initial test flights. I have previous twin experience with light wing loading and a bashed Senior Kadet triple and Carl has a bashed Four Star twin and both are being used for training simulations.

We are in desperate need of an experienced driver. It’s not far to Charlotte and we don’t mind coming your way.

I am sending a PM.

Thanks.

Bill

twinman

My Feedback: (2)

I think, or I hope, that I suggested to increase the structure for an increase in loading for your experiment or consider wing struts.
DO LISTEN TO William Robison warning about throttle management. DO NOT CUT THE THROTTLE and expect t to glide like other planes. You WILL be repairing the landing gear or worse. It will fall. Fly it to the ground. Been there done that.
My soap box again. Remember that Reliability on the engines is your best defense against damaged or destroyed airframes.
The KMP is also slightly more dangerous as the engines are farther apart than the VQ and on the VQ, they are slightly farther apart than scale.
Keep us posed.
Twinman

kram

My Feedback: (7)

Man, I wish I had a radar gun!!

But if I did, I wouldn't use it to land a 38.

Just one more thing to complicate and sabotage the mission.

You're gettin' good advice. In three years of flying several 38's, I have never once said to myself after landing: "That was too hot. I should have cut the power earlier." Landing a P-38 is not that complicated. They have a certain "feel" to final approach unlike any other plane. They're very straight and stable and heavy and they each have a certain optimum power setting for final approach that 38 novices will find surprisingly high (about 1/4-1/2 throttle). At that setting, a 38 will "find its nose" and sink gently to the runway without any elevator input. Only after "reaching the threshhold" (beginning of the runway, <10 ft off the ground) do I cut the throttle and use the elevator to slow descent. If on final approach, the plane starts acting funny or unstable or sinking too fast, the solution is always MORE POWER. The elevator won't help you. And if you've got too much speed or altitude when you get to the runway, go-arounds never hurt nearly as bad as low-altitude stalls!

My buddy RV Man has mastered landing the KMP at much slower speeds than I would ever dare with any of my 38's. I credit that to the gentle design of the airframe (since otherwise I would have to consider him a better pilot). Yes, the engines are wider spaced on the KMP, but if you lose an engine on any 38 that close to the ground, you can kiss it goodbye, so just don't lose an engine. Spend enough time on this forum and you'll grow weary of all us veterans saying that over and over again.


mt

evan-RCU

I am surprised at how slow the KMP will land, even without flaps it slows down stabley(is that a word?) you know what I mean... The only issue I have with mine is the retacts and the struts, even on slow landings the struts bend back and I'm on a paved runway, I would never try to fly it off grass. I have made a few one engine landings and have never had a hint of trouble. Dead sticks have been very smooth too, I think the wing loading on the KMP is low, or at least it feels low...

evan-RCU

You guys feel like flying a P-38 tommorow(sunday)?

BillS

Evan,

I called but got a voice message. Will try again later but before 10 PM.

Bill

evan-RCU

Bill, I got your msg, sorry my phone was off and you didn't leave me a number to call you..... it's on now..... 704-779-1767

We fly at a county park in Huntersville, take 85 south to 150 west and about a half mile before it hits I77 you'll take a left on 115. This takes you to "downtown" Huntersville which will be the next red light you come to, you'll see the police station on your left. Keep going south on 115 for one more mile and take a left at Hollbrookes rd, there's a sign for the main park, Waymer Park. The main park is about a half mile down on the right but the flying field is a mile further at the end of the road, can't miss it, I'll be there well before noon unless there's a castastrophe. Give me a phone number to call in case of trouble.... I won't necessarily fly the P-38 that early, I'll have a plane or two or three...


Evan

BillS

Evan,

I will be looking forward to talking with you tomorrow. After flying three days this week my wife was promised some time on Sunday. In order to preserve tranquility in the family she gets to go to the flight field in Huntersville. There is no known reason why she didn’t leave me thirty years ago. Some other time we will bring airplanes.

Thanks.

Bill

spindoctor

BillS,
I'm building a VQ P-38, and would love to come out and see the KMP (or ANY other ) Lightning in the air. I usually fly out of Burlington, east of Greensboro, but will make the drive out early one morning to your field (and beyond) if there's a Lighting or two involved.

I've been using the GP RealFlight P-38 for spin practice, I only hope it's close to reality. Even then, there are plenty of times when an engine out results in a roll, stall and semi-powered entry into terrain. Even when I cause the engine failure myself. I find it hard to judge when the P-38 is nearing stall speed, on the simulator.

I would propose that the $200 investment in RealFlight (or another, if it allows you to simulate engine failure) is much better than the false sense of competancey (sp) that might result from a flight time on a more-forgiving airframe. I don't know if Reflex for Aerofly has a decent P-38.

I built and flew the GP Profile 38, which I blame for getting me into twins. While it flew nicely on one engine, once it got into a spin, it spun hard and fast. I was not able to recover before the earth reached up and smote it.

If possible, I think a SPAD P-38 might me a more ideal learing tool, as they tend to bounce when exposed to Carolina clay at velocity, and a heavy wing loading is easier to attain.

Thanks,

kram-RCU

spin:

There is only one true answer: Do whatever you must to keep both engines running. In several years of P-38 flying I've had two engine-out situations. One I landed and one I totalled. They are hard to fly with one engine, and the amount of time between knowing the engine's out and augering into the earth can be VERY brief.

I, too, use Real Flight to practice, and I think it may be useful to learn the basics of engine-out flight. After some practice, I can land their standard 38 engine-out about 99%, but I'm afraid the simulator won't give you a very good feel for the violence and quickness of an engine-out in a real (model) P-38. I think there are many determinants to the difficulty level of an engine-out situation: Altitude, Attitude, Windspeed and Direction, Airspeed, Airspeed/Thrust Ratio, Drag (Gear, Flaps, Dead Prop), Distance from the Pilot (and Runway), and of course Pilot Skill. Simulators don't duplicate all these, and I think these factors greatly influence whether an engine-out can seem like a cake walk..."All I did was hold a little opposite rudder!" ..... or a disaster......"I thought my trim was a little off and three seconds later I was in pieces on the ground!"


Bottom Line is KEEP THOSE ENGINES RUNNING! I think you'll find twin flyers in general a lot more obsessive about engine reliability. My flying friends say they love to watch my 38's fly, but hate watching me stand on my head fine-tuning the powerplants for two hours before-hand.

twinman

My Feedback: (2)

Kram.
UH,,,,,,,anyone got a LA 40 trainer.....single engine for sale cheap?
Truer words have not been spoken. The multi's fly similar to singles.....as long as you hear the harmonics.
Serious single engine sounds are NOT always good.
I only own six twins and no singles.
Twinman
Proud Twinsanity member

BillS

spindoctor,

We fly at K’ville RC, which is off highway 68 and three miles this side of Stokesdale on Haw River Rd. The P-38 owner is Bill G. of High Point and the airplane is close but not finished. Unfortunately Bill is not a computer person (hates them) and is adamantly opposed to profiles.

I saw Evan fly his P-38 this weekend and he is experienced, careful and very quick to react to engine conditions. The flight was a pleasure to watch.

Another friend and I have been trying to acquire the knowledge and experience to assist in avoiding the potential catastrophic event. We have a bashed triple and a twin currently used to gain experience.

Weather permitting we will be flying shortly after 1 PM tomorrow and I will have the triple. We discovered by mistake that throttling up should be done slowly and the twin is currently under repair.

Bill would enjoy discussing the building process and problems encountered. Somehow you should get together with Bill to exchange ideas.

Bill

spindoctor

Thanks for the information re: your field. I'll drop you an e-mail one Friday and let you know
if I'm coming out to watch the lightnings fly.

I'm breaking in my engines this weekend, and hopefully will maiden before Easter. I'd like to observe a VQ P-38 in the air, and landing, before I attempt it myself.

I'm down to balence and finish, and with two Saito .82's (stock muffler) I'm looking at 1.5 lbs of lead in the nose. Yikes. Bringing the weight up to 14.5+ lbs. At that wing loading, I'd love to find a real runway to test fly from!

BillS

You are most welcome at the field. Bill G. is not finished with his P-38. Carl broke his bashed four star and is now working on a four star 60 triple. I am having blast with my bashed triple but it is not very sophisticated. Both Bill and Carl belong to the High Point Club and some Sundays they fly there. I am also working on a four star 60 triple.

The only P-38 that I have observed flying belongs to Evan. I drove to Huntersville to watch Evan fly earlier in the year. He is good with twins and he is careful.

Drop me a PM and I will get you in touch with Bill G. You and Bill should talk.

Bill S.