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YXU, why doing intersection takeoffs?
Posted: Mon Jul 30, 2007 4:02 pm
by KAG
I was in YXU today and saw a number of training AC doing intersection takeoffs off runway 33 leaving 4500' or so behind. Yes the plane can takeoff with 4400' in front of you, but your really going to miss that 4500' behind you. Saving 2 mins of taxi time is not worth planting one in the trees off the end when you could have safely stopped on the remaining runway left.
Posted: Mon Jul 30, 2007 4:52 pm
by TopperHarley
When I did my training there (and even when I flew out of there for work in my 152), it was always an intersection t/o. The only exception was when we did our multi training, we always used full length for that.
I don't really know the reason behind it, but it must be to save fuel and time, especially for a/c departing from Empire taxiing for alpha. Both runways at YXU have more than enough length for any of the training a/c to depart.
Posted: Mon Jul 30, 2007 5:34 pm
by KAG
yes but like I said, fail an engine, and your in trouble. Having had 3 engine failures in single engine trainers (2 on takeoff), I was very glad to have 9000 of runway, and use it all.
Also, telling transport that "well it could get airbourne it 4000', and it's the way we've always done it, might not be the answer they were looking for.
food for thought.
Posted: Mon Jul 30, 2007 6:02 pm
by TopperHarley
I agree with you completely, however, I don't think the flight schools will change the way they do this. I wouldn't be surprised if flight schools and operators use intersection departures at all airports.
Posted: Mon Jul 30, 2007 6:22 pm
by comanchepilot
Empire was at one point considering doing full length, but nothing ever came of it.
I believe it is going to be something that will remain this way until the day someone does the intersection Alpha, and piles it into the ILS LOC array 10 feet off the end of the runway.
Posted: Tue Jul 31, 2007 11:45 am
by 5x5
Well C-HRIS, at CYXD we certainly don't do or teach intersection takeoffs. (and we wouldn't be leaving anywhere near 1/2 the runway behind) Unless there is some specific reason for doing an intersection takeoff we explain to our students that there is no sense in leaving runway behind. As KAG said, it's false economy to save the bit of taxi time should anything go wrong.
Now like so many other aspects of flying, the pilot can always make a decision contrary to what they've been taught based on experience or whatever. However, we want our graduates to realize all the potential ramifications of the decisions they make. If they are taught from the very beginning to simply accept an intersection takeoff, they may not fully understand the safety benefits of using all the runway available.
Posted: Tue Jul 31, 2007 12:11 pm
by cyyz
Doesn't OFC @ CYOW use 04/22 for their flying??
Posted: Tue Jul 31, 2007 1:57 pm
by artw
Yep we do but how is that relevant to this discussion?
Posted: Tue Jul 31, 2007 2:55 pm
by CD
Perhaps cyyz is observing that 04/22 is only 3300 feet long, while 07/25 is 8000 and 14/32 is 10000 feet long...
Perhaps cyyz is wondering why anyone would operate from such a short runway when there are much longer ones available, similar to the observation KAG made in the original post where an intersection departure provides 4400 feet remaining...
Or perhaps it's just an attempt to boost his post count... Oh wait, that's me...

Posted: Wed Aug 01, 2007 5:56 pm
by dangerous
When I worked the ramp I knew a captain that often did intersection take offs half way down a 5000 ft rwy in a Dash 8.
Posted: Wed Aug 01, 2007 9:33 pm
by KAG
That is different. If a twin can make it's ballanced field length, as long as the numbers work, and you can handle a V1 cut, it's not really an issue. In a single the only option is straight ahead. Having runway ahead is nice.
Posted: Thu Aug 02, 2007 4:08 am
by cyyz
KAG wrote: In a single the only option is straight ahead. Having runway ahead is nice.
Perhaps cyyz is observing that 04/22 is only 3300 feet long, while 07/25 is 8000 and 14/32 is 10000 feet long...
Perhaps cyyz is wondering why anyone would operate from such a short runway when there are much longer ones available...
Correct.. =) But I mean we talk about safety all the time, taxiing and waiting for a departure on the longer runway in yow might take
an extra 0.4 hobbs, but what about
safety?
That's KAG's post in a nutshell, why do an intersection take-off? To save 0.X hobbs.
Why do some of us rush through walkarounds, "oh everything was good yesterday(earlier) it's gonna be good today," complacency.
It was safe to do the intersection take-off yesterday, it'll be okay again today.
And it'll continue to be common practice by most, until an accident/incident.
And then the accident victims will sue the airline/club/school for allowing it, and in turn TC will ban them(the take-offs)...
And that's how airline industry works... A couple of deaths to change the minds of a couple pilots, a few more deaths to change the majority and a few more deaths to get TC to say something.
Posted: Sat Aug 04, 2007 10:00 am
by GilletteNorth
A training aircraft (C172? Katana?) that has 4000 ft of runway has more than enough length necessary for safe departure. Saying they should backtrack and use full length (8000 ft) for added safety is like saying they should stay within 1 mile of the airport while practising cross-country flight That way they will always have a runway available in case of emergency. There's an acceptable safe margin and then there's going overboard.
Posted: Sat Aug 04, 2007 11:56 pm
by 200hr Wonder
I work out of an 1876' strip... safely... with 4000' I can go from rotate to stopped no problem, I would not feel unsafe doing it.
Posted: Sun Aug 05, 2007 3:03 am
by tofo
you think flight schools who charge fight time and expense air time would be all for the extra taxi time.
who knows students taxiing at 1500 rpm ridding the brakes might get expensive for them?

Posted: Sun Aug 05, 2007 8:54 am
by Doc
It's just better "airmanship" to use the full length. And there's no time better to start learning it than as a student pilot......it (airmanship!) just MIGHT save your bacon on some dark night, departing some black hole, northern toilet, later in your career?
Posted: Mon Aug 06, 2007 7:40 am
by niwre
I dont have the luxury of a second engine or know whats it like to loose an engine. But what I do know is I make decisions based on the information that I have. If I want to make an intersection take-off so be it. It should not get me tagged as someone lacking poor airmanship.
Posted: Mon Aug 06, 2007 9:33 am
by 5x5
niwire,
one of the ways to get what you need to know is to read forums like this and sort the wheat from the chaff. Doc was passing on a useful tidbit that shouldn't be dismissed. You may not have had an engine failure yet, but you can imagine what it would be like to have taken off at the intersection, climbed say 75 - 100 feet and have it all go quiet. Sure you took off well before the 4,000 feet of remaining runway was gone. If the engine had pooched prior to or just after take-off you could have stopped safely. However, now you have to descend and flare and then stop - wouldn't the 4,000 feet you left behind look really good in front of you right about now?
As for operating out of 1,876 feet, sure you can because that's all you have. But there are more risks than with a longer field. And you're hopefully prepared mentally before each and every takeoff what you'll do should you have a failure shortly after takeoff when you can't get back down to the field. But I think (hope) no one with a sense of airmanship would choose to operate out of 1,876 feet if it was a 3,500 foot field.
Posted: Mon Aug 06, 2007 10:27 am
by niwre
Again its my choice to do an intersection take-off. Im not dismissing this info all I am saying is that I take the info that I have and use it accordingly. If and extreme like 3500 with only using 1800 of it then what about 10,000 and using 5000 for it? Where do we draw the line?
Posted: Mon Aug 06, 2007 3:23 pm
by Doc
You go right ahead and do all the intersection take offs you want. It's your call. Airmanship goes a lot deeper than just intersection take offs. I don't always do a full backtrack. It's more of a mind set. It's weighing the risks. It's the use of good manners, common sense, and risk management all rolled into one. I learned to fly out of an 1800 foot strip. Many did. 5000 feet would have left a greater margin for error, but we only had 1800!
But, airmanship includes NOT taking the 5-10 knot tailwind. Not taxing in front of the open hangar door. Not blowing prop wash on planing or deplaning passengers. Nobody's accusing anybody of poor airmanship by taking intersection take offs....but it is not using good airmanship. With me?
Posted: Mon Aug 06, 2007 4:22 pm
by Lurch
Ok Kag at what point do you stop? There are runways over 12,000' are you going to taxi all the way or take a 6,000' intersection?
You can be over 1000' in the air by the time you have reached the end of the runway so there is no way you could make it down even if you wanted to.
The balance is how fast you climb verses decend.
Lurch
Posted: Mon Aug 06, 2007 4:29 pm
by Doc
With the airplanes KAG flies, when you call V1, you going flying. End of story. SOP. No time to play the "can I get it back on the runway?" game. After you're in the air, and all the check lists are complete, then you decide what to do next...but...you are launching after V1....that's the beauty of the thing...no guess work.
Of course, a little common sense also enters into the equation here. IF there is 12000 feet of runway remaining, and the problem after V1 is catastrophic, and the pilot has not rotated, the pilot could elect to just roll to a stop. But V1 is predicated on accelerate/stop distance and the usually (almost always) adhered to practice is to continue the take off.
Posted: Mon Aug 06, 2007 4:31 pm
by niwre
Doc wrote:Nobody's accusing anybody of poor airmanship by taking intersection take offs....but it is not using good airmanship. With me?
If its not good airmanship that what kind is it?
I know you have more experience in your pinky finger than I have in my whole body but when someone says that I am not showing good airmanship when I am conducting intersection take offs or teaching them I perk my ears up.
Posted: Mon Aug 06, 2007 4:37 pm
by Doc
Would it make you happier if I referred to it as "better" airmanship to use the whole length?
Posted: Mon Aug 06, 2007 4:45 pm
by niwre
Doc wrote:Would it make you happier if I referred to it as "better" airmanship to use the whole length?
Im just wondering where do we draw the line? Lets just say I want a full backtrack at airports that handle a number of large aircraft im going to piss off every heavy driver wanting to land cause little me Mr. Hotshot 172 wants to backtrack 4000' on a 8000'+ runway.