Navajo overshoot
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1374m is not exactly what I'd call a "seriously short strip" but it would certainly start to feel like it with that kind of tailwind! Can anyone confirm whether a circuit was flown or did he do a straight-in approach?
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Trying to follow the sequence of events here, so the same aircraft overran the runway at Pt Cook as pictured above, got fixed and flew to Carrum and overran the runway again there?
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Trying to follow the sequence of events here, so the same aircraft overran the runway at Pt Cook as pictured above, got fixed and flew to Carrum and overran the runway again there?
I saw it looking pretty sorry on sunday morning. Looked like he went off the end at a fair clip, gave it a boot full to swing it around, slid sideways through a shallow ditch which folded up the gear and stopped short of the fence. Can confirm the left engine was feathered.
Last edited by Wanderin_dave; 3rd Apr 2012 at 04:34.
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The strip at Carrum is a seriously short strip, at about 600m, (fence to fence) for a nevergo. However Driving past it only looks 400m because its hard to see the cut out in the fence-line.
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600 metres is damn short for a Navajo at the best of times given varying conditions. Maybe near empty or half full would be ok. Not surprised it ran off. I've also seen a Caravan on the Carrum strip and not the Barwon Heads kind.
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The incident in carrum, happened during takeoff and it was really wet. He had his park brake still on and full power and sliding down the runway. Somehow managed to overrun
If you open the Navajo manual you will find 600m is no where near the ASDA for a light Navajo.
Dr
Actually, ASDA for 17/35 at YMPC is 1374m.
You don't calculate it, it comes from ERSA RDS.
(Smartarse mode off)
You don't calculate it, it comes from ERSA RDS.
(Smartarse mode off)
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Food for thought
Borrowed this from an old mate - Thanks old mate. 
I hoped it may help with the thought process, it's for a 'Chieftain' but you'll get the idea.
E&EO accepted - I did cherry pick the entire thing for the nuggets. Anyway - it's worth a thought or two.
I hoped it may help with the thought process, it's for a 'Chieftain' but you'll get the idea.
Aerodromes with less than a 1000 meter sealed strip should be considered critical. It is not that the aircraft cannot take off from a shorter distance, however, if the aircraft cannot SAFELY GO, logically, it must be able to SAFELY STOP. The take off is considered critical.
PIC should not attempt a take off from a strip or runway which has a TODA less than the TORR equivalent to ASD under the ambient (WAT) conditions. A 60 meter clearway may be used in the calculation SOP reduce the HWC by 50%, down wind take off is forbidden.
PA 31 – 350 can, at MTOW operate from a little as 870 meters. The accelerate stop distance (ASD) required for the same weight is approximately 1300 meters. The accelerate go distance is longer again, approximately 1800 meters although the manufacturer does not provide this information.
PA 31 350.- Example. For a Max gross Take off (25°C/ 0 wind) The minimum length chart requires 822 metres. The ASD chart calls for 1158 metres. CAO 20.7.4. factors for the minimum length (850 meters) by 1.226. The minimum length requirement becomes 1008 metres which allows a MTOW of 2744 kg, this weight will allow a further refining to define the actual factor for the weight.
PA 31 350. - Example. The Vmca for the type is placed at 76 KIAS, Vsse is placed at 92 KIAS. The OEI rate of climb speed is placed at 106 KIAS at MTOW. There is a 21 knot speed deficit to recover from a Vr of 85 knots and 14 knots from Vr of 92 knots to achieve VYSE. TOSS 95 knots only provides a margin over the stall, and does not imply climb performance. The need to achieve some form of climb performance is obvious.
PIC should not attempt a take off from a strip or runway which has a TODA less than the TORR equivalent to ASD under the ambient (WAT) conditions. A 60 meter clearway may be used in the calculation SOP reduce the HWC by 50%, down wind take off is forbidden.
PA 31 – 350 can, at MTOW operate from a little as 870 meters. The accelerate stop distance (ASD) required for the same weight is approximately 1300 meters. The accelerate go distance is longer again, approximately 1800 meters although the manufacturer does not provide this information.
PA 31 350.- Example. For a Max gross Take off (25°C/ 0 wind) The minimum length chart requires 822 metres. The ASD chart calls for 1158 metres. CAO 20.7.4. factors for the minimum length (850 meters) by 1.226. The minimum length requirement becomes 1008 metres which allows a MTOW of 2744 kg, this weight will allow a further refining to define the actual factor for the weight.
PA 31 350. - Example. The Vmca for the type is placed at 76 KIAS, Vsse is placed at 92 KIAS. The OEI rate of climb speed is placed at 106 KIAS at MTOW. There is a 21 knot speed deficit to recover from a Vr of 85 knots and 14 knots from Vr of 92 knots to achieve VYSE. TOSS 95 knots only provides a margin over the stall, and does not imply climb performance. The need to achieve some form of climb performance is obvious.
It is not that the aircraft cannot take off from a shorter distance, however, if the aircraft cannot SAFELY GO, logically, it must be able to SAFELY STOP.
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Yup logically, it is a very corageous pilot that puts himself/herself and pax at risk but commiting to an aircraft carrier type operation out of a short strip in a Far 23 twin.
You just need to look at their (any aircraft) performance figures and a wise head simply wouldn't do it.
Stayin Alive I believe is the words to the song, a wise pilots hymn.
You just need to look at their (any aircraft) performance figures and a wise head simply wouldn't do it.
Stayin Alive I believe is the words to the song, a wise pilots hymn.
Yup logically, it is a very corageous pilot that puts himself/herself and pax at risk but commiting to an aircraft carrier type operation out of a short strip in a Far 23 twin.
You just need to look at their (any aircraft) performance figures and a wise head simply wouldn't do it.
You just need to look at their (any aircraft) performance figures and a wise head simply wouldn't do it.
Dr
PS: Man have I lived a dangerous life!
If you attempt to apply FAR25 type performance to a FAR23 aircraft in a commercial operation you will go broke.
If you are nervous flying a single or piston twin and want to apply ridiculous performance penalties to them you are perhaps in the wrong job.
If you are nervous flying a single or piston twin and want to apply ridiculous performance penalties to them you are perhaps in the wrong job.
So how many PA-31 drivers out there in GA land are gonna rock up to their boss tomorrow and say, "I'm not going unless there's 1500m there!"
Bear in mind if you are using manufacturer's data, ie. Piper manual as the POH, the CASA safety factors do NOT have to be applied.
But we are talking about busted-arse 40 year old clunkers now....
Bear in mind if you are using manufacturer's data, ie. Piper manual as the POH, the CASA safety factors do NOT have to be applied.
6.1 Subject to paragraph 6.3, the take-off distance required is the distance to accelerate from a standing start with all engines operating and to achieve take- off safety speed at a height of 50 feet above the take-off surface, multiplied by the following factors:
(a) 1.15 for aeroplanes with maximum take-off weights of 2 000 kg or less;
(b) 1.25 for aeroplanes with maximum take-off weights of 3 500 kg or
greater; or
(c) for aeroplanes with maximum take-off weights between 2 000 kg and
3 500 kg, a factor derived by linear interpolation between 1.15 and 1.25 according to the maximum take-off weight of the aeroplane.
6.2 For aeroplanes operated on land, take-off distances are to be determined for a level short dry grass surface. For aeroplanes operated on water, take-off distances are to be determined taking into account the maximum crosswind component and the most adverse water conditions for the aeroplane type.
6.3 Where there is an approved foreign flight manual or a manufacturer’s data manual for an aeroplane that sets out the take-off distance required for that aeroplane, then that aeroplane must be operated so as to comply with either the requirements set out in paragraphs 6.1 and 6.2 or the requirements relating to take-off distance set out in either of those manuals.
Note: The data contained in some manufacturers’ data manuals is unfactored and makes no allowance for degraded aircraft performance. Where there is a considerable difference between the data in a manufacturer’s data manual and the data in the flight manual for the aeroplane then the manufacturer’s data should be treated with caution.
(a) 1.15 for aeroplanes with maximum take-off weights of 2 000 kg or less;
(b) 1.25 for aeroplanes with maximum take-off weights of 3 500 kg or
greater; or
(c) for aeroplanes with maximum take-off weights between 2 000 kg and
3 500 kg, a factor derived by linear interpolation between 1.15 and 1.25 according to the maximum take-off weight of the aeroplane.
6.2 For aeroplanes operated on land, take-off distances are to be determined for a level short dry grass surface. For aeroplanes operated on water, take-off distances are to be determined taking into account the maximum crosswind component and the most adverse water conditions for the aeroplane type.
6.3 Where there is an approved foreign flight manual or a manufacturer’s data manual for an aeroplane that sets out the take-off distance required for that aeroplane, then that aeroplane must be operated so as to comply with either the requirements set out in paragraphs 6.1 and 6.2 or the requirements relating to take-off distance set out in either of those manuals.
Note: The data contained in some manufacturers’ data manuals is unfactored and makes no allowance for degraded aircraft performance. Where there is a considerable difference between the data in a manufacturer’s data manual and the data in the flight manual for the aeroplane then the manufacturer’s data should be treated with caution.
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Yes - but
As I said, it's only offered as food for thought.
Should have explained properly, the text is part of a briefing related to exactly what Chimbu was talking about, the art of 'nutting it out' before blasting off. That is; OK, it's short, it's hot and old girl is heavy, so if one quits just as I get to the trees, how do I get home for tea with Mum??.
I think the point being made is that without a good knowledge of what you have to work with, the laws of physics and dumb luck will only get you so far. Murphy rules. The boys discussing the SE turn back are saying the same thing - know your aircraft, know the limits and think about it. That can't be bad.
Should have explained properly, the text is part of a briefing related to exactly what Chimbu was talking about, the art of 'nutting it out' before blasting off. That is; OK, it's short, it's hot and old girl is heavy, so if one quits just as I get to the trees, how do I get home for tea with Mum??.
Using rotate speeds of 90 knots and the gear retracting, the aircraft is certainly in a position to rapidly accelerate to 95 knots. On a minimum length strip, the chances of stopping from 85 knots without damage are limited. The chances of accelerating from 90 to 106 are definitely limited without planning and forethought.
There are no available details for OEI 'second segment' acceleration. The difference in acceleration capability between that available on two engines, compared to one engine provides an element of uncertainty. The manufacturers provide detail of the expected single engine climb performance. The CAO require a 1% gradient at all heights up to 5000 ft in ISA conditions. If the aircraft cannot climb below Vyse, then, the aircraft must have room to safely stop after a failure or a "suitable" OEI landing area accessible.
It is most hazardous to attempt, at tree top height, an acceleration segment from below Vsse to a SEBAC (Vxse) speed. On a hot, turbulent day, attempting to feather and secure an engine, whilst achieving a correct asymmetric balance and attempting to find performance for acceleration is difficult from a strip which only allowed acceleration to 80 knots before the DER.
The manufacturers indicate that in high ambient temperatures, to achieve adequate engine cooling in the critical case, the rate of climb may require a reduction of 50 fpm, (an increase in speed).
PA 31 example. At 3175 kg the expected rate of climb is 200 fpm at 25°c. At a Ground speed of 106 knots (still air) and a 50 fpm deficit, the achieved gradient is 1.4 % climb. To achieve a circuit height of 1000 ft AGL there needs to be ::11 miles of obstacle free gradient, straight ahead! (1000 x 100 / 1.4%). OC gradients are based on a take off surface splay (safe area) distance limit of 3000 metres or 7500 metres.
There are no available details for OEI 'second segment' acceleration. The difference in acceleration capability between that available on two engines, compared to one engine provides an element of uncertainty. The manufacturers provide detail of the expected single engine climb performance. The CAO require a 1% gradient at all heights up to 5000 ft in ISA conditions. If the aircraft cannot climb below Vyse, then, the aircraft must have room to safely stop after a failure or a "suitable" OEI landing area accessible.
It is most hazardous to attempt, at tree top height, an acceleration segment from below Vsse to a SEBAC (Vxse) speed. On a hot, turbulent day, attempting to feather and secure an engine, whilst achieving a correct asymmetric balance and attempting to find performance for acceleration is difficult from a strip which only allowed acceleration to 80 knots before the DER.
The manufacturers indicate that in high ambient temperatures, to achieve adequate engine cooling in the critical case, the rate of climb may require a reduction of 50 fpm, (an increase in speed).
PA 31 example. At 3175 kg the expected rate of climb is 200 fpm at 25°c. At a Ground speed of 106 knots (still air) and a 50 fpm deficit, the achieved gradient is 1.4 % climb. To achieve a circuit height of 1000 ft AGL there needs to be ::11 miles of obstacle free gradient, straight ahead! (1000 x 100 / 1.4%). OC gradients are based on a take off surface splay (safe area) distance limit of 3000 metres or 7500 metres.
In the seventies Australian Air Charterers from Moorabbin operated the contract to service Gabo Island using Navajo's and Aztecs. Graham Cambell was the Light House Keeper with his lovely wife Dot. We generally only had light loads of mail and fresh food etc. The strip was around 700m. We all knew an engine failure on take-off was a free swiming lesson. The Navajo was prefered to the Aztec because of its better brakes for the landing. You couldn't apply Airline thinking of ASDA, you'd never go. It was all approved by 'The Department of Changing Names' and each pilot had to be 'strip endorsed'. Our only real concern, was wet grass but Graham kept the strip short and raked up the dead mulch to keep braking action.
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It is all about choices and how you value your and your pax lives.
You are not serious are you? You're just jerk'in our chain!
You roll the dice, you take the consequence when it goes bad.
You are not serious are you? You're just jerk'in our chain!
You roll the dice, you take the consequence when it goes bad.