Light Aircraft Crash on Isle of Wight
Avoid imitations
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A single engined aircraft isn't in Performance group A.
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there is part of the flight envelope where the take-off could be fairly normal if rather long followed by no spare performance for any additional climb
Not really; once you are out of ground effect and flying OK then the thing should carry on flying. It might climb very slowly (of the order of taking 10 miles to climb a few hundred feet) but it won't crash.
Unless the pilot pulls up a bit too hard (remember that this plane was very likely substantially overloaded) in which case a flight slightly above Vs can turn into a flight below Vs.... or there is a loss of power.
Not really; once you are out of ground effect and flying OK then the thing should carry on flying. It might climb very slowly (of the order of taking 10 miles to climb a few hundred feet) but it won't crash.
Unless the pilot pulls up a bit too hard (remember that this plane was very likely substantially overloaded) in which case a flight slightly above Vs can turn into a flight below Vs.... or there is a loss of power.
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GEMMA, ground effect lasts quite a bit further than you are giving it credit for. We are also looking at the fact that the ground rises as you take off your altitude may be increasing but your height not increasing and you could be on the top of edge of the ground effect.
Ground effect would also allow the aircraft to take off but not climb in an overweight aircraft.
Ground effect would also allow the aircraft to take off but not climb in an overweight aircraft.
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Hi G-EMMA
Ground effect wouldent last very long at all in a 140 - see posts below for my 140 credentials.
As it would appear that several houses had been cleared, also that no high terrain is present between runway and where the aircraft came to rest so it does seem unlikly to me that ground effect has much to do with it.
It appears that this machine was way outside its weight envelope (leave alone balance) but I would be interested in the flap setting.
I use 1st stage of flap for just about every takeoff but sometimes on a 'short' strip the 2nd stage can be useful. To quote the owner of the machine I fly, with 2 stages of flap She tends to levitate rather than rotate.
On the odd occasion when I have been near, but within limits I have to be very careful with RoC - it is only a tiny engine.
But VERY forgiving before stalling - about 30 knots with 2 (big) chaps
Ground effect wouldent last very long at all in a 140 - see posts below for my 140 credentials.
As it would appear that several houses had been cleared, also that no high terrain is present between runway and where the aircraft came to rest so it does seem unlikly to me that ground effect has much to do with it.
It appears that this machine was way outside its weight envelope (leave alone balance) but I would be interested in the flap setting.
I use 1st stage of flap for just about every takeoff but sometimes on a 'short' strip the 2nd stage can be useful. To quote the owner of the machine I fly, with 2 stages of flap She tends to levitate rather than rotate.
On the odd occasion when I have been near, but within limits I have to be very careful with RoC - it is only a tiny engine.
But VERY forgiving before stalling - about 30 knots with 2 (big) chaps
Last edited by Leclairage; 8th Aug 2007 at 17:35. Reason: Forgot a point
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I had a lucky escape not long after I got my licence doing some hour building in California. It was 110degrees on the ground in Maclellan airport, we decided we had enough fuel to get back to California with a 172, thank God we didn't fill it.
Took off with 3 up and bag's. got out of ground effect, next thing was airspeed was reducing from 70kts back to 60kts. We raised the nose and were still simmering down toward the ground. Then the aircraft stopped decending, stayed at the same level for about 20sec's (felt like 20 mins) then slowly, very slowly climed away. We were lucky and I learned from it.
Took off with 3 up and bag's. got out of ground effect, next thing was airspeed was reducing from 70kts back to 60kts. We raised the nose and were still simmering down toward the ground. Then the aircraft stopped decending, stayed at the same level for about 20sec's (felt like 20 mins) then slowly, very slowly climed away. We were lucky and I learned from it.
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SF technique in this aeroplane SHOULD be 2 stages of flap. Otherwise you are just adding drag and not improving climb performance much.
From an eyewitness:
I speculate that flight above Vs could have become flight below Vs.
Me too in an Archer 3! We left Palomar and bearly got off their 5000' runway, with the stall warner buzzing away. Luckily the ground drops at the end of the runway (my father-in-laws office is at the end, so I wouldn't have been too popular if I'd landed on it!). Our IFR clearance was something like "climb straight ahead to 1500'". By 1500' we were way, way, way out to sea!
Unless the pilot pulls up a bit too hard (remember that this plane was very likely substantially overloaded) in which case a flight slightly above Vs can turn into a flight below Vs.... or there is a loss of power.
"He tried to pull the aircraft up to clear the trees which he did do and in order to get lift he pushed the nose of the aircraft down and it immediately crashed and there was an extremely large black bloom of smoke."
I had a lucky escape not long after I got my licence doing some hour building in California. It was 110degrees on the ground in Maclellan airport, we decided we had enough fuel to get back to California with a 172, thank God we didn't fill it.
Took off with 3 up and bag's. got out of ground effect, next thing was airspeed was reducing from 70kts back to 60kts. We raised the nose and were still simmering down toward the ground. Then the aircraft stopped decending, stayed at the same level for about 20sec's (felt like 20 mins) then slowly, very slowly climed away. We were lucky and I learned from it.
Took off with 3 up and bag's. got out of ground effect, next thing was airspeed was reducing from 70kts back to 60kts. We raised the nose and were still simmering down toward the ground. Then the aircraft stopped decending, stayed at the same level for about 20sec's (felt like 20 mins) then slowly, very slowly climed away. We were lucky and I learned from it.
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Pa28 W & B
We have an elderly but much loved PA28 160. We have writtenan automatic weight an balance calculator and keep copies of the performance tables on our web site.
Even with 160hp engine there is no way we would take 3 passsengers. We also have the W & B calculator on a PDA which can be useful.
There are some real odities in the Cherokee which John Davis our local tame instructor pointed out at my biennial, like full fuel and 2 front seat pilots the C of G is in front of the limit so we can (and do) run out of elevator in the flare. Take a look at www.g-atis.co.uk
Sandown is in a bowl. Runway 23 is significantly uphill and even when lighly loaded the acceleration is slow. The temptation is to try and drag the aeroplane off and having dragged it off the slab wing Cherokee soon gets behind the lift drag curve.
For years I have explained to friends and relatives under extreme peer pressure, why I can only take 2 passengers, thankfully I havnt given in yet, there but for the grace of God go I.
Even with 160hp engine there is no way we would take 3 passsengers. We also have the W & B calculator on a PDA which can be useful.
There are some real odities in the Cherokee which John Davis our local tame instructor pointed out at my biennial, like full fuel and 2 front seat pilots the C of G is in front of the limit so we can (and do) run out of elevator in the flare. Take a look at www.g-atis.co.uk
Sandown is in a bowl. Runway 23 is significantly uphill and even when lighly loaded the acceleration is slow. The temptation is to try and drag the aeroplane off and having dragged it off the slab wing Cherokee soon gets behind the lift drag curve.
For years I have explained to friends and relatives under extreme peer pressure, why I can only take 2 passengers, thankfully I havnt given in yet, there but for the grace of God go I.
Be careful about the eyewitness report.
Having done that takeoff several times I can tell you that the trees immediately behind the garden centre - which the plane cleared - are on a slight rise and are the highest point on that heading. If the plane was continuing to climb or even just maintaining altitude it should have cleared the next row of trees.
But there are hills only a mile or so ahead and the pilot would either have to gain another 600 feet on that heading or 100 feet after a turn east to clear Shanklin and get out over the sea. So he would have been desperate to gain height.
Having done that takeoff several times I can tell you that the trees immediately behind the garden centre - which the plane cleared - are on a slight rise and are the highest point on that heading. If the plane was continuing to climb or even just maintaining altitude it should have cleared the next row of trees.
But there are hills only a mile or so ahead and the pilot would either have to gain another 600 feet on that heading or 100 feet after a turn east to clear Shanklin and get out over the sea. So he would have been desperate to gain height.
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G-EMMA, in reply to your questions about Ground Effect, there is a rather "techie" treatise to be found here.
From this article, it would seem that about 70% of the span-dominated ground effect is lost at a height equivalent to 20% of the aircraft wingspan and it becomes negligible at a height of 100% of the wingspan.
The wingspan of a PA28-140 is 30 feet, so 20% represents 6 feet. As the wing is already 3 feet agl when the wheels are on the ground, this means 70% of any benefit would be lost when the wheels are 3 feet above the ground and there is virtually no beneficial effect at 27 feet agl.
The chord-dominated effect seem much more complicated, so I'll leave you to read the rest ...
Hope this helps.
JD
From this article, it would seem that about 70% of the span-dominated ground effect is lost at a height equivalent to 20% of the aircraft wingspan and it becomes negligible at a height of 100% of the wingspan.
The wingspan of a PA28-140 is 30 feet, so 20% represents 6 feet. As the wing is already 3 feet agl when the wheels are on the ground, this means 70% of any benefit would be lost when the wheels are 3 feet above the ground and there is virtually no beneficial effect at 27 feet agl.
The chord-dominated effect seem much more complicated, so I'll leave you to read the rest ...
Hope this helps.
JD
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SF technique in this aeroplane SHOULD be 2 stages of flap. Otherwise you are just adding drag and not improving climb performance much.
The later, and more powerful versions, of the PA28 do indeed specify 2-stages of flap for a short-field takeoff. However, I have never seen a Cherokee 140 flight manual specify this. The only performance figures I have seen for the Cherokee 140 are 0 degrees of flap for take-off. I would be interested if someone has a Cherokee 140 with performance figures in its flight manual for take-off with flap selected.
SF technique in this aeroplane SHOULD be 2 stages of flap. Otherwise you are just adding drag and not improving climb performance much.
Take off with 0 degree of flap does not add drag, but it may reduce lift at a given airspeed.
The later, and more powerful versions, of the PA28 do indeed specify 2-stages of flap for a short-field takeoff. However, I have never seen a Cherokee 140 flight manual specify this. The only performance figures I have seen for the Cherokee 140 are 0 degrees of flap for take-off. I would be interested if someone has a Cherokee 140 with performance figures in its flight manual for take-off with flap selected.
SF technique in this aeroplane SHOULD be 2 stages of flap. Otherwise you are just adding drag and not improving climb performance much.
Take off with 0 degree of flap does not add drag, but it may reduce lift at a given airspeed.
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Take off with 0 degree of flap does not add drag, but it may reduce lift at a given airspeed
Because 10° (1 stage) is so often used, it is easy to think that all aeroplanes use 1 stage. I had an arguement with an instructor on a checkout once - he wanted me to use 10° of flap in the Warrior, and I was sure that it was 2 stages. Anyway, him being the instructor I did it his way, and we survived.
If my memory serves me correct the CAA scheduled performance in the AFM for the PA28-140 for take off is flaps up. However the FAA manual also shows figures for take off with Flaps 25.
That said take off with flaps 10 degrees in the PA28 is quite a nice compromise where runway performance considerations are not a factor.
Dare I say it but of course aircraft can fly overweight and indeed on ferry flights across the pond in light a/c there is often dispensation given to fly 10% overweight subject to certain conditions. One would only contemplate this off a very long metalled runway (ie not grass) etc.
Sorry to hear our fellow aviators came to grief at Sandown. Remember the swiss cheese model - you get the accident when all the holes line up.
That said take off with flaps 10 degrees in the PA28 is quite a nice compromise where runway performance considerations are not a factor.
Dare I say it but of course aircraft can fly overweight and indeed on ferry flights across the pond in light a/c there is often dispensation given to fly 10% overweight subject to certain conditions. One would only contemplate this off a very long metalled runway (ie not grass) etc.
Sorry to hear our fellow aviators came to grief at Sandown. Remember the swiss cheese model - you get the accident when all the holes line up.
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There but for the grace of god
I was at Sandown at the time, having flown in on Saturday, and was enjoying the sun at the beach with friends. I was alerted something was amiss by fire engines and ambulances screaming through Sandown, then a bit later by my extremely worried mother who has just heard that 4 people had been killed in a light aircraft crash at Sandown.
We departed at 6pm local, and could clearly see the still smouldering wreckage in a corn-field just beyond the ridge at the end of r/w 23. The crash site showed no signed of any marks leading up to it, and two straight black, wing-sized marks coming from a central crater, leading me to think it had most likely stalled and gone in vertically. I am sure the AAIB will do their usual thorough and professional investigation and we will all find out the cause of this terrible tragedy.
I used to fly PA28/140's and hated their poor performance, even in cold weather with a long runway. I feel very fortunate now to have an over-powered wood and fabric 4 seater taildragger which leaps into the air fully loaded, even hot and high.
I hope we can learn something that will help avoid accidents like this in the future when the full causes are known.
God rest the souls of those involved.
We departed at 6pm local, and could clearly see the still smouldering wreckage in a corn-field just beyond the ridge at the end of r/w 23. The crash site showed no signed of any marks leading up to it, and two straight black, wing-sized marks coming from a central crater, leading me to think it had most likely stalled and gone in vertically. I am sure the AAIB will do their usual thorough and professional investigation and we will all find out the cause of this terrible tragedy.
I used to fly PA28/140's and hated their poor performance, even in cold weather with a long runway. I feel very fortunate now to have an over-powered wood and fabric 4 seater taildragger which leaps into the air fully loaded, even hot and high.
I hope we can learn something that will help avoid accidents like this in the future when the full causes are known.
God rest the souls of those involved.
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A couple of weeks ago I flew a Cherokee 140 in Italy fully loaded, in fact 15 kgs above MTOW. Outside temperature was 32 C and field elevation 900 feet.
We indeed had a very long tarmac runway and gave it an extra 10 MPH on takeoff roll and seemed to behave quite nicely. I guess the long runway/clearway makes a huge difference though.
I don't have a lot of experience on 140's and I wonder if the unusual instrument layout (compared to the modern T shaped), the MPH airspeed and the absence of an aural stall warner could have played a part ?
We indeed had a very long tarmac runway and gave it an extra 10 MPH on takeoff roll and seemed to behave quite nicely. I guess the long runway/clearway makes a huge difference though.
I don't have a lot of experience on 140's and I wonder if the unusual instrument layout (compared to the modern T shaped), the MPH airspeed and the absence of an aural stall warner could have played a part ?
We used to fly a Cherokee 140 and a Warrior in our club and the MPH speedo, lack of aural stall warner, shortage of footbrakes and roof mounted trim wheel on the 140 didn't seem to cause anybody constantly swapping between the two any problems (that I know of).
As I understand the pilot in this case to be the owner and thus presumeably using the same aeroplane most of the time, I doubt it even more ..... however high workload/stress situations certainly reduce the ability to respond to the normal number of external stimulii.
As I understand the pilot in this case to be the owner and thus presumeably using the same aeroplane most of the time, I doubt it even more ..... however high workload/stress situations certainly reduce the ability to respond to the normal number of external stimulii.
Last edited by Dave Gittins; 9th Aug 2007 at 14:02. Reason: carp spelling
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Around 1972, our new Cherokee 140s, as they were known to me, came with a T instrument panel layout, a quadrant throttle, and the elevator trim on the floor between the seats. I see that I first flew one of these in September 1972. All this Warrior and Dakota stuff came a year or so after!
(I see that according to Wikipedia, the 'new style' Cherokee - also incorporating the extra cabin window - was introduced as early as 1968.)
(I see that according to Wikipedia, the 'new style' Cherokee - also incorporating the extra cabin window - was introduced as early as 1968.)
Last edited by Georgeablelovehowindia; 9th Aug 2007 at 15:49. Reason: Reference to Wikipedia
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I heard from someone today that they didn't actually refuel at Sandown! Maybe it was just a lunch stop. Afer all, if they'd refuelled at Tatenhill, it ought to have been enough to get to Cherbourg...maybe. Who knows?