As long as I’m flying a Cub, no problem. If it’s into wind, anyway.
Generally, how to you consider such requests? Obviously, on a large airport, you can more then easily take-off from the various runway holding points, even beyond half-way. It is however, while you’re already taxiing, ultimately guesswork, because you’re not going to perform a proper take-off distance calculation before responding.
If the distance is not signed — I thought it was at Cologne, but I can’t recall for sure, even though I last used it yesterday evening — then the tower/ground controller should be able to give you the TODA from the intersection. If not, it’s specified on the DFS Aerodrome chart.
Since I’m more than happy to take the 1863 m 32L it would seem churlish to refuse the 1840 m on 32R from A3. They normally give me A2.
Steve6443 wrote:
Nobody has yet raised the best reason for taking the full length available – what happens if you have an engine failure directly after take off?
I did too here.
Steve6443 wrote:
If you’ve taken off from an intersection, chances are you’re landing off field.
Not necessarily true. It depends on how much runway is available and when the failure occurs.
For example if runway available is TODR+LDR and the engine failure occurs at 50’ or less, you should (theoretically) be OK. If it occurs above 50’, but below the altitude at which you can (safely) do a 180° turn and land on the opposite runway, you will end up in a field or at least somewhere else than on the runway 
So if you want to remain 100% safe and avoid ending up in a field, you need enough runway to take off, climb to let’s say 700’ AAL and still be able to land straight ahead. That’s an awful lot of runway.
Patrick wrote:
I did – in the original post.
Josh wrote:
It may also depend on the obstacles around the airfield – an intersection takeoff at an airport with fields around might be fine, but somewhere surrounded by buildings you might prefer a full length departure to gain maximum height over the upwind threshold
As did I, in the second post!
Ultimately, it’s an airmanship decision as to what margins of safety you are prepared to accept. Blindly saying “I always take the full length” is just as poor airmanship in my view as always taking the performance limiting intersection no matter what. If you are operating a piston single or twin out of a busy airport whose main business is heavy jet traffic it behoves you to make an effort to accommodate ATC requests. If you want every meter of a 2000m runway in all cases while regularly operating out of a 1300m runway (all other things being equal,) perhaps you ought to look at the validity of your personal risk assessments.
One should not be complacent about EFATO. In the past 12 months I have had two incidents where after take-off from a short runway I would have landed back on given the option. One was fuel starvation and the other was smoke in the cockpit. Comparisons between commercial jets and single engine GA are irrelevant due to the known performance of commercial jets on one engine.
Even before these events I always took the view that runway before you is much better than runway behind you and these two events have done nothing to make me reconsider. I will ALWAYS take the maximum length available in my aeroplane.
Nobody has yet raised the best reason for taking the full length available – what happens if you have an engine failure directly after take off?
I did – in the original post.
That’s because it is not a particularly good reason. Would you have made the flight if the full runway length was equal to (or only slightly longer than) the required runway length? If yes, you would have deemed the chance of EFATO an acceptable risk – it would be no greater if you did a intersection takeoff from a longer runway.
That’s not a particularly good argument. Having a longer runway available that allows for an emergency landing within one of the most critical phases of flight is clearly an added safety margin (to what magnitude depends on the risk of an EFATO that early, which some argue is rather likely and others feel is rather unlikely). Accepting the risk of an EFATO on a short runway doesn’t mean I can’t consider that added safety margin if it is available.
Similarly, just because I find flying over mountain or water an acceptable risk, as you put it, doesn’t mean that in a situation where the opportunity presents itself to minimize the risk of a crash/ditching after an engine failure, I shouldn’t at least evaluate that opportunity and, if the conditions are right, use it (e.g. by flying a little further over land to minimize time over water). That’s comparable to accepting longer taxiways for a longer, saver runway.
Steve6443 wrote:
Nobody has yet raised the best reason for taking the full length available – what happens if you have an engine failure directly after take off? If you’ve taken off from an intersection, chances are you’re landing off field.
That’s because it is not a particularly good reason. Would you have made the flight if the full runway length was equal to (or only slightly longer than) the required runway length? If yes, you would have deemed the chance of EFATO an acceptable risk – it would be no greater if you did a intersection takeoff from a longer runway.
172driver wrote:
Does that qualify for the 90-day currency rule ?? Couldn’t resist….
JasonC wrote:
Actually it would.
If it was a tail wheel aircraft I believe you’d have to have come to a full stop on the runway before the second and third take offs
172driver wrote:
Does that qualify for the 90-day currency rule
Actually it would.
Silvaire wrote:
so I ended up performing three takeoffs.
Does that qualify for the 90-day currency rule ?? Couldn’t resist….
