Small plane crashed near Boy Scout camp in Plymouth

[farri]

Small plane crashed near Boy Scout camp in Plymouth

[old man emu]

'Twas a Flying Flea.

 

 

[paddo2002]

Just an update on this particular one. I have followed the build on this particular aircraft. It was an HM14-360. It was fitted with a BMW motor and this was about its second flight. The pilot was critical but stable and is recovering well. That is some good news.

 

 

[derekliston]

Last thing I knew Henri Mignet's designs were banned in the UK because of some strange flying characteristics. When did that change?

 

 

[facthunter]

That's going back a long way. There are later versions with extra pitch authority. This seems to be a power failure, rather than anything connected to the history of the Pou de Ciel and it's original design characteristics that some criticise. nev

 

 

[paddo2002]

Quite Correct Nev. Having personally flown flown one, This pilot knew what he was doing as far as design went, but as you put it, the engine seemed to be the problem. Can happen to any type. I am not sure what the current status is in the UK, but here in Oz, I have one flying and I know of a few others.

 

 

[facthunter]

Correct spelling should be Pou du Ciel. I always get that wrong. The first popular simple homebuilt that you could build from material from the hardware store. About 1933, Henri Mignet designed a plane that would not spin as he considered himself a poor pilot in the skills sense. I had a friend bombard me with everything he had on them for many years, and believe me it was a very comprehensive and substantial pile of information. A quick look confirms there is still plenty of info on the net. Go for it.. Nev

 

 

[kasper]

Not banned in the UK - all bans on the HM14 were removed following the investigation in the wind tunnel of the full size airframe that identified three core issues and correction of 2 of those three removed the issue of uncontrolable flight - and that was before WWII so can this urban myth be put to rest please ... the UK does not and has not had a ban on any HM designs or any airframe derived of the the HM control setup and has not had one fore more than 70 years.

 

For clarity on the three isues

 

1. aerofoil used - the sharp leading edge on the original HM14 gave very poor lift and a very sharp and abrupt stall - not in itself fatal but it made the following problems much worse

 

2. pitch control on front wing was by pull cable only with the return being by aeropressure from the centre of lift being behind the pivot point

 

3. combined CofG and placement of the two wings in relation to each other

 

The factual problem was that when the Cof G was too far aft the rear wing was required to do too much lifting and it could stall before the front wing resulting in a pitch up of the fuselage ... correction of this cause was move CofG forward but if it happened in the air the correct response to this horrible situation was to lower the nose and that required stick forward ... but your front wing that lowers the nose is no pull cables so IF there is not sufficient lift from the front wing the cables go slack and you CANT lower the front wing AND YOU WILL CRASH. And the double whammy on wings was IF you had a very low vertical separation and possible overlap of the two wings the rear wing - even when stalled - provided slot effect suction to the trailing edge of the front wing actually PULLING the rear of the front wing down and both worsening and locking in the fatal conditions.

 

So the corrections were to replace front wing pivot control by pull cable with solid steel push/pull control rods, put a better aerofoil on it so that stalls occurred more softly and progressively and keep the CofG such that the front win g stalls first resulting in a pitch situation at stall that is auto recovery not auto death.

 

And having flown HM14 with origianl sharp leading edge wings I can attest that with push rods and corrected CofG its perfectly safe to fly - not a great performer with really low lift for the wing area and a really sudden stall behavior BUT it flew nice enough. Change the HM14 wings out for the HM360 wings (which is what an HM14/360 is) and you get a nicer experience

 

I have flown a couple many Hm and HM derived airframes here in Oz, in the UK and in France and they are all perfectly safe in terms of ability of the aircraft to behave in a controllable and exepected manner.

 

My list is

 

HM14 with 14 wings

 

HM14 with 293 wings

 

HM14 with 360 wings

 

HM290FB

 

HM290

 

HM293

 

all of these were tailwheel plus I have flown 1 HM293 with tri gear and of course the HM1000 which is a pussy cat to fly

 

Plus a Pouchel a BiPou and a couple of Crosses Pous

 

Never flew the HM1100 as I do not fit under the canopy and there was a very in my opinion unsafe flight control disconnect on the front wing if the canopy opened ie if the canopy became open in flight your control links to the pitch control are automatically disconnected ... not for me.

 

 

[paddo2002]

Thanks Kasper,

 

I thought you would drop in soon. This was the plane not long before the first flight. He did a spectacular job on it.

 

 

 

[kasper]

Thanks for the pic Paddo, and given the pic its not even a proper 14/360 as the wing section looks like that of the 360 but the plan-form of the wing has stayed steadfastly 14. But thats the way of home building, little changes here and there and actually you end of with a unique airframe.

 

Hope you are still enjoying the HM290FB ... would love to come a visit it again ... really if it were not for the house building I would get on and finish my HM293KS and come visit by air.

 

 

[farri]