Talk:STOL

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[edit] Photo of STOL

Does anyone have a photo of the STOL that they can contribute? WikiDon 16:46, 30 July 2005 (UTC) Contact FIRST AIR out of Ottawa, Ontario, Canada. Ph 613-521-9311 or 800-661-3591 They operate DHC2, DHC6, DHC7 and may have something you can use. We may also have something on the Found Aircraft model FBA-2C1 in about 2 or 3 weeks that could be used. J.W. McPhee, Found Aircraft Canada Inc.

[edit] List of planes

I've removed some planes, like the Airbus A318, that should not be there. Lets limit this list to either planes that meet the official NATO definition, or planes that have significant design trade-offs needed for reduced runway requirements.

The first part gets you things like the Zenith CH-601, and the second part gets you the C-17 (which could have been much faster or carry more had they not needed the runway minimums.

There is no need to have a list of every plane, just a list of significant examples. —Preceding unsigned comment added by Kitplane01 (talk • contribs)

Concur. I about died when I realized the EF Typhoon was on the list! I should probably check the VTOL page so make sure it's not there either. And the spacecraft list too, just in case. And list of kitchen sinks ;) - BillCJ 06:44, 10 August 2007 (UTC)
I can't say that I agree with You on that, since the Airbus A318 is a very exceptional plane when it comes to STOL capability, unlike the bigger A319,A320,A321 etc. The A318 is STOL capable for instance to land and take off from London City Airport (Docklands) and this has has been used in the marketing of this plane. I suggest You should find more information and dig into the subject so to say. - Individual5
Are you kidding?? London City has a 5,000 ft runmay! THat is NOT the accepted definition of STOL, which is landing within 1,500 ft. Please cite verifiable sources before re-adding the A318 again. - BillCJ 22:43, 29 August 2007 (UTC)
Even though it does not formally fulfill the STOL requirements, what about mentioning the Saab 37 Viggen? The STOL-part has been discussed a fair bit on the talk page. T96 grh 00:02, 9 October 2007 (UTC)

[edit] Autogyro

Autogyros are STOL. Unless they have collective pitch control to give VTOL capability they need a short run to gain enough rotor speed and lift to takeoff. My understanding of STOL is that it applies to any aerodyne capable of short field takeoff, not just to fixed wing aeroplanes. Note that the NASA/DoD definition given refers to aircraft, not specifically to aeroplanes. --Cheesy Mike 14:07, 13 November 2007 (UTC)

I guess it depends on the definition of STOL that is being used. If you include all aircraft that can operate out of a 1500 foot runway with a 50 obstacle then you would have to include helicopters, balloons, airships, all ultralights, rockets, powered lifts (tilt wing or rotors), almost all motor gliders and even most towed gliders, plus probably a few other aircraft categories as well. It would really make the designation of STOL rather meaningless. Let me see what I can find in the way of definitions to move this issue forward. - Ahunt 18:48, 13 November 2007 (UTC)
If you take away aerostats such as balloons and airships, just focus on aeordynes and take away true VTOL, then STOL isn't such a wide category of aircraft. The title of this article is STOL not STOL airplanes. Maybe it should be renamed to the latter then another STOL article can be started to cover all STOL aircraft. --Cheesy Mike 18:58, 13 November 2007 (UTC)
Isn't STOL generally considered a category of fixed-wing aircraft? Autoyros are rotary-wing, last time I checked. - BillCJ 19:16, 13 November 2007 (UTC)
Yes, autogyros are rotary wing, but because they don't have a collective pitch they can't do VTOL like a helicopter. An autogyro is not a helicopter, and its principles of flight are completely different. Autogyros need a short(ish) ground run to bring the disc up to speed and generate enough lift to takeoff - hence STOL. Landing on the other hand can be very much like a helicopter - a skilled pilot can land with a zero ground roll - but typically most pilots need a short landing roll as well. --Cheesy Mike 21:14, 13 November 2007 (UTC)

Okay I dug up in the most authoritative references I have on this subject and I have to start off by admitting that you are right, an autogyro should be considered a STOL aircraft.

Here is what I found:

STOL (Short Take Off and Landing) STOL performance of an aircraft is the ability of the aircraft to take off and clear a 50-foot obstruction in a distance of 1,500 feet from the beginning the takeoff run.(sic) It must also be able to stop within 1,500 feet after crossing over a 50-foot obstacle on landing. (Crane, Dale, Dictionary of Aeronautical Terms page 492, Third Edition, Aviation Supplies and Academics, Newcastle Washington, 1997 ISBN 1-56027-287-2)

By this definition then clearly gyros are STOL aircraft. The same book also says:

STOVL (Short TakeOff and Vertical Landing). STOVL performance of an aircraft is the ability of the aircraft to take off and clear a 50-foot obstruction in a distance of 1,500 feet from the beginning of the takeoff run. The aircraft can land vertically, with no forward speed.(Crane, Dale, Dictionary of Aeronautical Terms page 493, Third Edition, Aviation Supplies and Academics, Newcastle Washington, 1997 ISBN 1-56027-287-2)

By this definition Gyros are also STOVL aircraft, STOVL clearly being a sub-set of STOL aircraft, since every STOVL aircraft will meet the STOL definition as well.

Furthermore:

Gyrocopters - The gyrocopter has never taken off as a viable commercial enterprise, although this has been tried many times. Where are you now, Umbaugh, Cierva, Avian? Gyroplanes offer STOL performance without helicopter costs and complexity. Gyrocopters can't hover, fly backwards or sideways, or take off and land vertically. But they can come very close to this. (Foster, Timothy RV, The Aviator's Catalog, A Source Book of Aeronautica page 94, Litton Educational Publishing, 1981, ISBN 0-442-22465-6)

I think this source pretty clearly shows that gyroplanes and helicopters too are STOL aircraft.

Of course this does all raise a problem. In checking the Cessna 172N POH I find that the gross weight/sea level/standard day field lengths required over a 50 foot obstacle are 1440 feet for take-off and 1250 feet for landing. This qualifies the unmodified (no STOL kit) 172N as a STOL aircraft. It also means that probably 70% of all the aircraft ever produced are STOL aircraft, yes including all the balloons, motor gliders, airships, ultralights, powered parachutes, paragliders, hang gliders, powered lifts and in fact every category of aircraft, since they meet these definitions and also the NASA one quoted in the article itself (virtually the same definition as here). Only airliners, some bigger twins and conventional military fighters, among a few other types would be excluded.

So by these definitions it is true that autogyros are considered STOL aircraft. It also means that the category of STOL aircraft is so broad and completely inclusive as to not be very useful. - Ahunt 02:07, 14 November 2007 (UTC)

  • Comment. Might want to check this out in regards to setting a definition for STOL. --Born2flie 13:05, 14 November 2007 (UTC)

Thanks for bringing this webpage up. I actually did find that page in my background search. It was written in 1968, which was before the NASA definition was written. The author, Lieutenant Colonel Walter P. Maiersperger, USAF (Ret), essentially says that there is no accepted definition of STOL (at least there wasn't 40 years ago) and proposes his own:

The STOL mode of flight is one during which an airplane taking off or landing is operated at climb-out and approach speeds lower than the conventionally accepted margins of airspeed above the power-off stalling speed of the airplane.

The problems with this definition are two-fold. First it really isn't a functional definition for deciding which aircraft fit the STOL category or not, as any aircraft could be operated at airspeeds below the "conventionally accepted margins". A C-172 flown on approach at 1.2 Vso instead of the "conventionally accepted margin" of 1.3 Vso would qualify. Secondly it has been superseded by definitions like the NASA one and the similar one quoted above from the Dictionary of Aeronautical Terms.

It is probably a good thing that Maiersperger's definition isn't generally used or this talk page would get very long debating which aircraft were "in" or "out". It may do anyway. - Ahunt 15:39, 14 November 2007 (UTC)

Which is the point. He mentions almost exactly the definition you are talking about from NASA, and the problem that you are all discussing here. STOL is a poorly defined category, but I didn't suggest it for his definition. STOL is unlike VTOL, which describes a very easy to recognize capability. I would say that a STOL aircraft is one designed to be able to take off and land in less distance than a comparable aircraft of design, weight, and function; even an unmodified version of the same aircraft. Whether they do that in the safety margin or not is up to the manufacturer.
Compared to airplanes (stuck-wing aerodynes), sure, an autogyro looks like a STOL aircraft, but compared to another autogyro, it doesn't have a capability that another autogyro wouldn't have. Once the aircraft is off the ground, it must function comparable to the other aircraft that define it as being STOL. In other words, calling an autogyro STOL because it takes off and lands in shorter distance than an airplane is erroneous because the autogyro (most modern autogyros) can't compete with the airplane in weight capacity, speed, altitude, etc. It's an apples and oranges thing.
I took off today, and I know I did it in less distance than the C-17 that left after me did. That doesn't qualify my aircraft as STOL. --Born2flie 16:18, 14 November 2007 (UTC)

You do make a good point - that aircraft should only be considered to be STOL if they have shorter take-off and landing performance than a comparable aircraft. That is exactly the point of installing a "STOL kit"! Unfortunately we seem to be stuck with the NASA definition or the similar Dictionary of Aeronautical Terms one, both of which makes the category itself rather moot. I think you are suggesting that this article needs a better definition that would be more "exclusive"? - Ahunt 16:26, 14 November 2007 (UTC)

You're stuck as long as those are the two sources you use. Even Jane's points out that the definitions in industry are a bit unqualified, although I hadn't found where they offer a better one. But, if you're stuck using the 1964 NASA one (Maiersperger's paper was 1968), then any aircraft that can take off in less than 1500 feet and clear a 50 foot obstacle/screen is STOL. And...you'll be back to square one in this discussion. --Born2flie 18:31, 14 November 2007 (UTC)
To muddy the water even further, I checked the Defense Dictionary linked in the artilce (A 700-odd page PDF). THe STO definition states "aircraft", but the STOVL definition states "airplane". So an autogyro would qualify as STOL by that definition, but even if it can VL, it's not a STOVL! - BillCJ 18:55, 14 November 2007 (UTC)

Well I guess we could collect up a list of definitions of STOL that all contradict each other and then the article would cite them all and say that there is no agreement on what STOL means. But that would be the whole article, as you couldn't make any pronouncements as to which aircraft (or airplanes) are included or not. It does all start to form a picture here that this isn't a very useful article. I really don't see a solution here, except to "unwatch" the article! - Ahunt 23:10, 14 November 2007 (UTC)