EMB-120 Runway Performance

[Ercos]

Hi all,

I'm wondering - can an EMB-120 operate reliably into and out of a 4500 foot strip using FAA required runway distances (factored length for landing) for FAR 121? The airfield is at 400 feet elevation, typically has a 10+ knot headwind component, can be wet for long periods, and has been known to reach temperatures of about 30 degrees Centigrade. Fuel loads would be most likely for a 45-60 minute flight.

[kbrockman]

The E120 is frequently used on hotter and higher airports in Brasil,
eg Congonhas so I don't see why it cannot be used on a 400ft AGL, 4500ft
long runway @ 30°C on short 1 hour flights.

BTW, are we talking Molokai here?

[Ercos]

It's possible, a resort is looking at possibly setting up a property on Molokai and wants to link it to their property on Maui. They are exploring the option of scheduled daily service between their two properties with connections off of the inbound/outbound flights in Maui.

We're looking at options for equipment and have narrowed it down to the EMB-120 and Saab 340. The DHC-8 is a great aircraft for the mission but the market is far too slim and prices on the aircraft have been driven to insane levels. The ATR-42 is also acceptable but the investors are hesitant since most/all US carriers stop operating that aircraft (and they believe there must be a good reason for that).

[OverRun]

Molokai - Maui looks close: perhaps 46NM unless I've missed something. That should take a lot less than 45-60 minutes.

As an indicative look: EMB-120, off a 4500' runway in 30 degC temperature (ISA+15degC), elevation 400', nil wind, dry runway, PW118A engines: should be able to takeoff at 10800kg. That will take 22 pax and 3 crew on that leg, which is a bit less than full capacity.

However, I keep bumping up against questions that can only be answered by an aircraft performance engineer (which I am not). The wet runway performance will be less than dry, which means fewer pax. The landing distance graphs show that on a wet runway, it will severely limit the weight and pax load (and may be worse than takeoff). There has been no consideration yet of climb gradients. And not all EMB120s have the more powerful 118A engines.

All in all - the operation is a possibility but is marginal and only a close look by an aircraft performance engineer can give you the correct answer. Time to pay someone to do some work for you.