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Thread: JetPOD crashes on maiden flight, creater lost...

  1. #1
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    Default JetPOD crashes on maiden flight, creater lost...

    I'm posting this in here because, though not a racer, it shows the dangers of creating entirely new and unique designs of small aircraft without the financial backing and testing capable of a large aircraft manufacturing corporation. I'm hoping SOMETHING here may prove helpful or informative enough in making a difference, and maybe saving someone's life somewhere in the future.

    The cause of the crash is unknown, and, judging by the flight path of the airplane, may have been from an elevator problem and not the layout of the airframe. I only say this because the description of the short flight sounds almost identical to those that occur due to a locked or sticking elevator. You decide.

    The witnesses statements are noteworthy, especially his description of earlier attempts of flight. What he describes may have only been high-speed taxi tests, or actual unsuccessful flight attempts. Again, we'll find that out later. I will not speculate on that for obvious reasons.

    I'll add official findings of the cause later as they become available, May the pilot forever rest in peace, and my condolences to family and loved ones.




    An experimental STOL jet aircraft with possible military use has crashed during a test flight in Malaysia, killing its British pilot and inventor.

    Malaysian civil aviation authorities are investigating the accident of the twin-engine raised-wing Jetpod built by London-based Avcen in which company director Michael Robert Dacre, 53, died.

    The accident happened Sunday shortly after takeoff from Tekah airstrip near the city of Taiping, around 190 miles north of the Malaysian capital Kuala Lumpur.

    The incident was witnessed by many residents, according to a report in the English-language newspaper The Star.

    One witness was only 150 feet from the crash. "Earlier I saw it going down the runway three times but it could not take off. However, on the fourth run, the jet took off into the air but at about 200 meters high, it shot vertically to the sky before veering to its left and then falling to the ground," he said.


    The aircraft had been transported in parts in a container to the airstrip about a week ago before being assembled for the test flight, the report said.

    The single-pilot Jetpod was designed by Dacre, who set up Avcen in the United Kingdom in 1998 to produce the aircraft.

    Few design details are available. The two over-wing turbofan engines were said to have a thrust of 2 X 13.3kn, and the plane had an operating payload of around 1,540 pounds. Its range was to be just more than 900 miles.

    The Jetpod was initially marketed as a flying taxi because it needed only 410 feet to take off and land and had a maximum speed of 350 miles per hour.
    Last edited by AirDOGGe; 08-19-2009 at 07:14 PM.

  2. #2

    Exclamation Re: JetPOD crashes on maiden flight, creater lost...

    Quote Originally Posted by AirDOGGe View Post
    I'm posting this in here because, though not a racer, it shows the dangers of creating entirely new and unique designs of small aircraft without the financial backing and testing capable of a large aircraft manufacturing corporation. I'm hoping SOMETHING here may prove helpful or informative enough in making a difference, and maybe saving someone's life somewhere in the future.

    The cause of the crash is unknown, and, judging by the flight path of the airplane, may have been from an elevator problem and not the layout of the airframe. I only say this because the description of the short flight sounds almost identical to those that occur due to a locked or sticking elevator. You decide.

    The witnesses statements are noteworthy, especially his description of earlier attempts of flight. What he describes may have only been high-speed taxi tests, or actual unsuccessful flight attempts. Again, we'll find that out later. I will not speculate on that for obvious reasons.

    I'll add official findings of the cause later as they become available, May the pilot forever rest in peace, and my condolences to family and loved ones.


    I can tell by looking at this desighn that the elevator would be
    in the wind shadow of the main wing on high angles of attack thus
    making it useless. The elevator needs to be much farther back and
    lager too. By the way Tsunami was a home built and it won races too.

  3. #3

    Default Re: JetPOD crashes on maiden flight, creater lost...

    Sounds like the main landing gear was too aft.

  4. #4
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    Default Re: JetPOD crashes on maiden flight, creater lost...

    A too-far-aft landing gear, would make lift-off difficult, but wouldn't make the plane suddenly shoot nose-high from 600 feet alt.

    I'm still gonna wait for OFFICIAL reports myself. There's just too many possible things that could cause the tragedy.

  5. #5

    Default Re: JetPOD crashes on maiden flight, creater lost...

    I think the Short Skyvan is a good plane in that category.

    http://en.wikipedia.org/wiki/Short_SC.7_Skyvan

    That must be a difficult task to make that work..first you have to able to load it..keep the CG right..get thrust etc.

    The end of the fuse is very non-aeroplane like in form.

    What are the holes underneath the wing...nozzles of some sort ?
    Last edited by First time Juke; 08-24-2009 at 04:30 AM.

  6. #6
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    Default Re: JetPOD crashes on maiden flight, creater lost...

    The latest report says, "According to Taiping deputy police chief Supt Syed A. Wahab Syed A. Majid, the company had NOT obtained permission from the Royal Malaysian Air Force to conduct the flight tests... "


    Quote Originally Posted by Juke View Post
    ...What are the holes underneath the wing...nozzles of some sort ?
    Something like that, I assume. I didn't notice those before.

    Investigating....

    Hmm. The description of the aircraft on one website says "The Jetpod is a Very Quiet Short Take-Off and Landing (VQSTOL) light twin-jet aircraft, can cruise at 300 knots (350 mph, 550 kmh) and requires just 125 metres to take-off or land using a combination of horizontal and vertical thrust.

    And another site says "Using thrust management technology, the VQSTOL (Very Quiet Short Take-off and Landing) jetpod also reduces the noise of a regular jet engine by 50 percent..."


    Still looking for info on the aircraft concept...(searching...)


    OK, here's the description, according to: http://www.prweb.com/releases/2005/01/prweb200545.htm


    "1. The Jetpod operating principle of using a through-wing vertical thrust component, along with its unique wing-shape, have been confirmed by City University in London. City have confirmed that the aircraft can take-off or land in a distance of less than 125 metres (410 feet). Also, that the unique wing shape is well suited to low-high speed flight."


    So it would appear that some of the jet engine's thrust is routed through the wing vertically to increase lift. At least that's what it was SUPPOSE to do. That would explain the unique top-of-the-wing location of the engines.

    Sounds like all this is going to make the investigation more complicated. They have to figure out if this new vertical thrust layout was responsible, there was a control rigging error (the plane was assembled after shipping just days before the flight), there was a flaw in aerodynamics, a defect like a sticking elevator or cockpit control, or (you fill in the blank).

    As I said, the possibilities are endless.
    Last edited by AirDOGGe; 08-24-2009 at 04:10 PM.

  7. #7

    Default Re: JetPOD crashes on maiden flight, creater lost...

    Right Airdogge and that plane looked more like an aeroplane afterall...

    http://www.dailymail.co.uk/news/worl...ne-flight.html

  8. #8
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    Default Re: JetPOD crashes on maiden flight, creater lost...

    I think Juke is correct.

    The gear being too far aft would cause the elevator input required to shove the rear down enough to lift the nose to get the angle of attack high enough to lift off was probably excessive.

    It's possible that the speed at which the elevator could generate enough downforce to pivot the plane on the "too far aft" main gear was high enough such that airplane pitched up rapidly once the wing was able to take weight off the gear and that the difference between the "main gear pivot" and center of lift caused that extreme elevator input to rapidly pitch up the plane once the "pivot point" transferred from main gear to center of lift.

    It probably pitched up high enough such that the wings blanked out the airflow over the elevator making it impossible to get enough elevator effectiveness to get the nose back down.

    If that is the case, then they overestimated the amount of vertical lift generated forward of the main gear at zero angle of attack by the engine placement and ducting since it's obvious from the pictures that it would never have gotten off the ground with so much weight in front of the main gear in a conventional engine configuration.

  9. #9
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    Default Re: JetPOD crashes on maiden flight, creater lost...

    Quote Originally Posted by IcePaq View Post
    I think Juke is correct.

    The gear being too far aft would cause the elevator input required to shove the rear down enough to lift the nose to get the angle of attack high enough to lift off was probably excessive.


    All true, EXCEPT....

    The plane wasn't on the runway when it pitched up...It had already left the ground successfully, and witnesses say it was at 600 feet (200 meters) when that happened. But I've already stated that.

    Article text:

    "...on the fourth run, the jet took off into the air but at about 200 meters high, it shot vertically to the sky "

    So, no, I doubt the sudden pitch-up had anything to do with the gear location.
    Last edited by AirDOGGe; 08-25-2009 at 09:50 AM.

  10. #10

    Exclamation Re: JetPOD crashes on maiden flight, creater lost...

    edited

    I tried to figure out if the but word is there a typo..

    However, on the fourth run, the jet took off but at about 200m high, it shot vertically to the sky before veering to the left and falling to the ground.”
    Last edited by First time Juke; 08-26-2009 at 12:32 AM.

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