rolling take-off
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XNR
That's an interesting analysis. You believe that if the engine blows that you are better off being in mid-ground-roll than in the hover. I guess that a straightforward engine fail would be fairly gentlemanly in either situation but what if the turbine goes pop and the debris takes out some other vitals? Just maybe you would be better off in the hover.
Of course the strategy of using a rolling take off has a lot to do with minimising power used. Some folk out there believe that this is a smart move if you are fitted with C30s because it puts the engine(s) under less stress therefore you wont suffer any nasty turbine 'events'. The problem with that, especially when you are flying EMS is that you are very likley to find your next armful of collective is required going into a 'primary' site and you will be high and slow and needing every bit of HOGE you can get. This is not the time or place to discover that one of your donkeys has a duff turbine.
IMHO you are better off giving the engines plenty of welly before you leave (all other things being equal - FOD/SNOW/DUST etc). Power check it in the hover, look at the TOTs and the N1s and do that every flight. You should then get a feel for when the trend is beginning to indicate a problem. Not easy when the machine is one of a large fleet (that's when your trend checks and PA checks help) but if you fly just one machine regularly you should be able to pick up anything odd.
This is one case where looking after the machinery doesn't pay. You need to know that you can get all the power you need BEFORE you go anywhere lest the first time you need it you find it aint there.
Your thoughts are welcome - I think this is a serious issue.
G
Of course the strategy of using a rolling take off has a lot to do with minimising power used. Some folk out there believe that this is a smart move if you are fitted with C30s because it puts the engine(s) under less stress therefore you wont suffer any nasty turbine 'events'. The problem with that, especially when you are flying EMS is that you are very likley to find your next armful of collective is required going into a 'primary' site and you will be high and slow and needing every bit of HOGE you can get. This is not the time or place to discover that one of your donkeys has a duff turbine.
IMHO you are better off giving the engines plenty of welly before you leave (all other things being equal - FOD/SNOW/DUST etc). Power check it in the hover, look at the TOTs and the N1s and do that every flight. You should then get a feel for when the trend is beginning to indicate a problem. Not easy when the machine is one of a large fleet (that's when your trend checks and PA checks help) but if you fly just one machine regularly you should be able to pick up anything odd.
This is one case where looking after the machinery doesn't pay. You need to know that you can get all the power you need BEFORE you go anywhere lest the first time you need it you find it aint there.
Your thoughts are welcome - I think this is a serious issue.
G
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FWIW we did rolling take offs in our CH113A Labradors (H46 Sea Knight or BV107 variant). In the summer heat with 6000lbs fuel on board we were over gross and had to run off.
Back door wasn't great, dump fuel and return to the runway but we did this when we knew we had a long SAR trip ahead of us.
I've also done them in Sea Kings, it was more of technique thing to practice getting off the water on one engine. We'd start learning the finesse required by doing running take offs from the runway then we'd do them off the water (simulated by limiting the amount of power used)
If you handle the machine properly and observe the limits you will not harm anything. Brief it first and don't be afraid to knock it off if things don't look right.
Back door wasn't great, dump fuel and return to the runway but we did this when we knew we had a long SAR trip ahead of us.
I've also done them in Sea Kings, it was more of technique thing to practice getting off the water on one engine. We'd start learning the finesse required by doing running take offs from the runway then we'd do them off the water (simulated by limiting the amount of power used)
If you handle the machine properly and observe the limits you will not harm anything. Brief it first and don't be afraid to knock it off if things don't look right.
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Geoff
I hear ya ......as long as the engine pops in the hover......you still need to transition to forward flight....I have seen many pilots transition to forward flight in excess of 5 degrees nose down.....not the place for the engine to go pop IMHO......I am not trying to minimize the strain on the engines by performing rolling take offs and landings....I am trying to put the aircraft in the best position should one fail......its the remaining engine that I am worried about......if you had an engine fail on short final...what type of landing would you perform if you had rwy available.
Of course if the engine comes apart and takes out the other donk and the T/R drive.....its not good to be in the air at all. Pulling hover power doesn't mean that the next time you pull power that the engine is not going to come apart. Actually one of ours went as the crew powered down.
How many guys out there are flying an approach to a rwy and believe that if the engine fails before LDP that they are going to overshoot and go around......not me ....go around to where.....where we are right now.
Cheers
I hear ya ......as long as the engine pops in the hover......you still need to transition to forward flight....I have seen many pilots transition to forward flight in excess of 5 degrees nose down.....not the place for the engine to go pop IMHO......I am not trying to minimize the strain on the engines by performing rolling take offs and landings....I am trying to put the aircraft in the best position should one fail......its the remaining engine that I am worried about......if you had an engine fail on short final...what type of landing would you perform if you had rwy available.
Of course if the engine comes apart and takes out the other donk and the T/R drive.....its not good to be in the air at all. Pulling hover power doesn't mean that the next time you pull power that the engine is not going to come apart. Actually one of ours went as the crew powered down.
How many guys out there are flying an approach to a rwy and believe that if the engine fails before LDP that they are going to overshoot and go around......not me ....go around to where.....where we are right now.
Cheers
Last edited by Xnr; 14th Dec 2005 at 01:38.
Join Date: Aug 2001
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Corax
I've come across this mindset before - I'm doing SAR so I can break the rules. Taking off over gross weight is BREAKING THE RULES.
The maintenance schedule is based on the aircraft operating within it's certification (release) requirements. Do it another way and you prejudice the integrity of your machine. Parts are 'lifed' based on the stresses and strains predicted when you do it by the book.
If you can't do your mission with the fuel weight available then turn the mission down! That may get someone's attention and maybe they will decide that you need something bigger and better. Keep on doing the job and as sure as eggs are eggs your protests will fall on deaf ears.
Just remember that when you get back in one piece having used and abused your trusty steed that some other poor sod has to take it on an equally demanding mission.
G
The maintenance schedule is based on the aircraft operating within it's certification (release) requirements. Do it another way and you prejudice the integrity of your machine. Parts are 'lifed' based on the stresses and strains predicted when you do it by the book.
If you can't do your mission with the fuel weight available then turn the mission down! That may get someone's attention and maybe they will decide that you need something bigger and better. Keep on doing the job and as sure as eggs are eggs your protests will fall on deaf ears.
Just remember that when you get back in one piece having used and abused your trusty steed that some other poor sod has to take it on an equally demanding mission.
G
Xnr,
That is rather a statement of the obvious - or is it?
There is an assumption made in your post; you refer to LDP but it is only defined in a Category A procedure and is the last point at which a balked landing can be initiated. AC 29.75A actually states
Hence when operating to a runway, your comment is a reflection of the status quo.
However, what has not been clarified in the rule is that, for offshore approaches where drop down is available (and return to beach fuel is specified), the LDP could be defined by the achievement of the 15ft radial clearance of the deck, the available drop down - taking into account obstacle clearance - and a safe landing. If it had been specified in this way, the LDP could be positioned at the point where the balked landing could still be achieved and the committal to the landing would minimise the single-engine transit.
Jim
How many guys out there are flying an approach to a rwy and believe that if the engine fails before LDP that they are going to overshoot and go around......not me ....go around to where.....where we are right now.
There is an assumption made in your post; you refer to LDP but it is only defined in a Category A procedure and is the last point at which a balked landing can be initiated. AC 29.75A actually states
…At the LDP the aircraft becomes committed to landing. A safe landing should be possible in case of an engine failure at any point before or after LDP…
However, what has not been clarified in the rule is that, for offshore approaches where drop down is available (and return to beach fuel is specified), the LDP could be defined by the achievement of the 15ft radial clearance of the deck, the available drop down - taking into account obstacle clearance - and a safe landing. If it had been specified in this way, the LDP could be positioned at the point where the balked landing could still be achieved and the committal to the landing would minimise the single-engine transit.
Jim
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My line of thinking is...
Rwy/taxiway landing environment OEI situation anywhere on approach
Best option....land aircraft using a rolling landing technique
Second best....go around if you have to .....but I can't think of many reasons why you might have to go around.
Offshore/rooftop helipad.
Best option ......go around
second best ......land on helipad... but only when go around is not possible.
Seems simple but sometimes I wonder if we are training pilots to go around prior to LDP even if they are line up for a rwy or taxiway. Likewise I hear pilots calling committed to a rooftop while they are still able to go around.
Cheers
Rwy/taxiway landing environment OEI situation anywhere on approach
Best option....land aircraft using a rolling landing technique
Second best....go around if you have to .....but I can't think of many reasons why you might have to go around.
Offshore/rooftop helipad.
Best option ......go around
second best ......land on helipad... but only when go around is not possible.
Seems simple but sometimes I wonder if we are training pilots to go around prior to LDP even if they are line up for a rwy or taxiway. Likewise I hear pilots calling committed to a rooftop while they are still able to go around.
Cheers
