Minos

I am trying to look at landing distances for Part 135 operations.
Mokulele flies C208 to Kalaupapa with a runway length of 2700ft

If I multiply this by 0.6, I get 1,600ft. Is the landing distance from 50ft of a C208 really shorter than 1,600ft? My cursory internet research indicate about 1800ft.

Alternatively, with the Tecnam P2012 having a landing distance from 50ft of 1936ft, it seems to indicate that it could not operate to fields with a runway shorter than 3,200ft. That seems to remove quite a few short runways.
If we were to study a hypothetical scenario and electrify the aircraft to make it a P-Volt, the landing weight will be close to the take off weight which itself will be close to MTOW which will likely be bumped to accommodate a battery. In practice, this means that 3,500ft runways will be the shortest runway it can use. Quite restrictive. Am I missing anything?

Any insights?

Minos

Peabody17

Perhaps they are authorized to use DAAP? https://nbaa.org/wp-content/uploads/...1/jbadc049.pdf

It would allow them to use 80% of the runway given certain other restrictions.

EMAW

Without the time to dig in to the OPs question, unless they have 2 pilot crews they won’t be EOD and can’t use DAA.

Pilot4000

Are single engine turboprops required to abide by the 60% rule?

JohnBurke

The "60% rule" established by 14 CFR 135.385 applies to large, turbine-powered transport-category airplanes, as stated in the title of the regulation. However, applicability to other aircraft is established by 135.399, which refers to small, non-transport category airplanes. specifically, 245.399(b) states:

https://www.ecfr.gov/current/title-1...ection-135.399

That subparagraph points to small reciprocating-powered and turbine-powered small airplanes, and states that the takeoff and landing dispatch requirements of 135.385 and 135.387 are also applicable to these aircraft, despite the title of .385 and .385 being specific to large transport category aircraft. The condition is that any such small aircraft are included if they have a seating configuration of passenger 10 seats or more.

The chain of reference is 135.363(e), which states that small, non-transport category airplanes will comply with 135.399.

https://www.ecfr.gov/current/title-1...-135/subpart-I

135.399, in turn, points to 135.169(b) for defining the applicability of the aircraft certification, and among those requirements are that applicable aircraft are configured for 10 seats or more.

Minos

Ouch, my head spins. So if I understand correctly your answer John, Mokulele and the like to not abide to the 60% rule because their C208 is just 9-seat?
As a result, for those 9-seaters, as long as the POH says that you can land within X feet, then an X+1 ft runway is fine (although not necessarily wise). Am I correct?

Minos

JohnBurke

The applicability of the "60% rule" has been spelled out, and as you quoted, that landing rule applies to aircraft with 10 seats or more. The Caravan is limited to 9 passenger seats because of its type certification under 14 CFR Part 23. It is allowed 2 pilot seats with nine passenger seats; if an operator places a passenger in the right front seat, one of the nine passenger seats must remain unoccupied. This applies in the US, based on the type certification of the airplane. Caravans are also certified for up to 14 passengers in certain configurations, but not under Part 135, and a waiver is applicable to the original certification, allowing it to operate with more than 9 passenger seats. This would be more appropriate to a Grand Caravan in a skydiving configuration. Outside the US, countries may apply other limitations, as they are not bound by the US regulation, Part 23, nor the limits it prescribes. (Other countries do look at the certification for the airplane, and generally follow the same standard, but the Caravan manual indicates a waiver to Part 23 chiefly because outside the US it does get operated with more seats.

That said, the same landing and takeoff criteria apply to other single engine small airplanes that are certificated with a seating capacity of less than 10 passenger seats.

Remember that the "60% rule" is a flight planning and dispatch rule, not a performance rule at the time of landing. In other words, for those circumstances in which it does apply (turbine, transport category, large airplane, commuter, 10 passenger or more, etc), the operator must be able to determine prior to dispatching the flight, that the airplane will be at a weight that will allow it to land in 60% of a dry runway (or 1.15x that distance if wet, or 70 or 80% for eligible on-demand operators). That's planning. When the airplane arrives, it doesn't have to be stopped in 60% of the runway...the "60% rule" is a planning and dispatch requirement, not an operational requirement. It may end up taking the whole runway on landing; it's no longer bound by a requirement to actually land in 60% of the runway. The operator need only show that the published performance data shows that it is capable, at the planned arrival weight and conditions.

Part 23 single engine airplanes do not have the same performance data as other categories of airplane; Part 23 certification standards aren't as stringent on what must be provided for performance or planning. FAA Order 8900.1 provides an enlightening note about the difference in performance data and standards:

https://drs.faa.gov/browse/excelExte...230153703.0001
Note that the "60% rule" is actually a weight limitation; a weight that allows the airplane to get stopped, for planning purposes, in 60% of the available landing distance. For a single engine small airplane certificated under Part 23, the weight must also be limited to be a value that allows landing in the available runway.

It's worth noting that while a multi engine airplane has a host of other requirements, such as segmented takeoff and climb performance, accelerate-stop and accelerate-go, and the capability of meeting climb gradient criteria with an engine shut down, obviously this isn't all applicable to light single engine airplanes. Imagine having to calculate the climb gradient with an engine shut down, in a Cessna Caravan or Cessna 207. Obviously that's going to be negative numbers. Further, the performance limits for Part 23 certified aircraft are not as stringent as those applicable to Part 25 airplanes, nor is the performance data as detailed, or in many cases, even available.