Why would the safety factors be any different for an twin than for an SEP?
I’ve yet to see any of the above mentioned SEPs take off from an airfield with less than 400m.
The Aztec in particular is noted for its STOL and its load carrying abilities.
I know a farmer who operates his old Partenavia P68 from his farm strip in the UK. Its grass and not particularly long but I couldn’t give you its dimensions.
I suggest that unless you own your own farm strip it would not be a regular thing to operate out of a short strip in an SEP or a twin.
Or of course unless you fly a STOL aircraft to do just that.🙂
Why would the safety factors be any different for an twin than for an SEP?
I think higher MTOW and VS > 60kts, tend to force for +1200m balanced fields than 400m one way takeoff with outgoing only, there are 2T SEP with 60kts VS, they won’t get out of 400m neither…
Anyway, I never seen an Aztec in 500m airfield, I don’t it ever happened? I have seen Archers, Arrows even Lances…
I flew Aztecs for many years. Vmc is 70 KIAS, Vs1 (clean) 66 KIAS and Toss of 80 KIAS. At 5200lbs it is a lot heavier than a Cherokee Six, and acceleration on grass strip to 80 KIAS will take longer. This comes down to whether you adhere to legal class rating operating techniques, or whether you are happy to take off with partial flap and haul the fat Super Cub wing off the runway below Take off safety speed. FWIW the Aztec does have a history of Vmc LOC EFATO. The type I flew had AoC performance tables, including NTOFP calculation graphs for Performance B. The WAT graph was quite limiting, and NTOFP performance at MAUM was timid at best.
With very few fATPL going onto Performance B types (possibly none), all this apparatus of NTOFP calculations seems to have gone the way of the buggy whip.
The most recent MPL programs today don’t have any MEP, replacing it with several months on a Performance A CAT Twin Turboprop simulator (eg Dash 8/Q400) in the intermediate phase of training. They then go on to jet MCC, type rating and LOFT.
Now 400 meters of grass are a challenge for any type other than STOL planes.
I know that I need a bit less than 400 on MTOW. But I wouldn’t go there (yet). I did 580 meters but kept fuel as low as possible. Landing was more challenging than takeoff.
400m is the quoted performznce figuure for a fully laden Aztec to 50ft.
The figures quoted for the 3 SEPs were the quoted figures to 50ft
It seems strange to me that people are happy to accept the SEP POH quoted figures yet want to argue the POH figures for the twins.
It seems to me that some will try to find all sorts of excuses to prove their point of why they don’t fly twin engined.aircraft.
Whether I personally would take off on grass in an Aztec in anything.less than 600m (which I have done) I doubt. But then that is because of my own SOPs.
I probably would not take off fully laden on grass in less than 600m.in any of the SEPs quoted earlier, either.
In the Super Guepard I’d be happy with 200m🙂
400m is the quoted performznce figuure for a fully laden Aztec to 50ft.
I don’t think it’s possible in real life with 400m and 50ft trees in front? that POH number is meaningless
We can talk about POH as one wish, I doubt one single Aztec has ever landed and took-off even in Belle-Ile (LFEA) near MTOW with +650m? there was an Aztec that overrun the runway at Scillies 600m, weather was challenging but physics is the same: it’s fast & heavy !
Talking about 400m pavement in Aztecs is just nuts: likely no one has ever done it in real setup…in the other hand, I have seen Archers, Dakotas and sometimes even Arrows & vintage Mooneys on 500m grass but yes I don’t see many Cirrus, Rockwells, Diamonds in these places
One can’t refute actual observations
gallois wrote:
400m is the quoted performznce figuure for a fully laden Aztec to 50ft.
Does that require rotation below Vmc? (I’m not arguing single vs. twin, just asking.)
Ibra wrote:
I think the runway limitation is a valid one, C182, C206 or C210 are the closest ones that fall under short runway and heavy load, they are bit higher than my budget…
Don’t forget the PA28-235 or even the original PA28-180. Both are real good load carriers and short field performers. The -180 lacks speed though while a good Dakota is a 130 kt airplane.
I don’t think the Aztec crash at EGHE was related to the runway length, although it has to be said that unless you are skilled enough to land on the ~5% upslope part you have only about 500m left.
Quite a few people successfully ferry families in piston twins, but they tend to be people who have always had twins, right back to the days when twins were the post-PPL fashion. Not many people are getting into twins today, for various reasons, starting with them being a money pit. The Aztec crash guy posted that his annual maintenance was £20k which is absolutely outrageous.
