Head-2-Head Feature IX: Dash Versus ATR

By Ron Blehm (May 30, 2012)

Today we are revisiting a couple of our most popular features from Head-2-Head:

• In July 2011 we presented the Commuter Turboprop Challenge which was a short sprint in the Caribbean.
• In September 2011 we took some of the same aircraft, loaded them with 10,000 pounds and sent them to Nepal to dual it out.
• Today we take stretched versions of the Dash 8 and ATR, load them with 20,000 pounds and send them up against each other and the winds of the Canary Islands.

According to various sources, the ATR 72 entered service back in 1989 and just under 600 have been built (image above, left). Compare this to the newer Dash 8 Q400 which entered service in 2000 and just under 400 have been built (image above, right). Both aircraft haul roughly 70 passengers just over 1000 miles and while the Q400 boasts more speed the ATR boasts greater payload. We'll see which one comes out on top for this round. (The ATR 42 won the last two rounds against the Q200 by the way).

For today's event we load 20,000 pounds of payload and the rest with fuel up to max weight. We load the sim with severe northerly winds and set in a flight plan of 370 miles from Gran Canary to Lanzarote to Reina Sofia to Los Rodeos; cruise at 5000 feet. Departure time is 12:30 PM. In past challenges we have simply flown and landed or done touch-and-goes but today we'll land at the two mid-points and taxi (as slowly and realistically as possible) back to the active end for immediate departure.

First up is the Q400 (Dreamwings for FS2004):

• 20,000 pound payload
• 5120 pounds of gas
• To Lanzarote: (above, left) Smooth flight. Not sure what I expected, I've flown this aircraft quite a bit and it's stable but I certainly felt the wind on approach. I missed the first turn-off and had a pretty long taxi. We'll have to do better next time (above, right).
• To Reina Sofia: This is a longer leg and at the fastest I was showing a ground speed of 335 knots. Seems to me that it should be more but ... The wind was pretty noticeable but I think I had it figured out and landed smoothly; again I couldn't get slowed down as quickly as I'd hoped and had to take a longer taxi (below, left).
• To Los Rodeos: This is a short leg and ends with a big-time crosswind but the Q400 handles it well and we land easily (below, center).
• Total time is 86 minutes flat and I had burned 4416.8 pounds of gas. Efficiency score is 233.2 "minutes" (below, right).

Next is the ATR-72 (Franchisco Sanchez):

• 20,000 pound payload
• 5131 pounds of gas (this is 13,000 pounds overweight!)
• I looked up some information on both aircraft and found that the Q400 is supposed to be able to carry cargo, passengers and fuel up to 26,730 pounds so my 25,120 is about right. The ATR-72 lists cargo, passengers and fuel at only 22,157. So why did the salesman tell me the hauling of the ATR was greater? A little quick math shows that seventy, 200-pound passengers is 14,000 pounds. So I cut the ATR payload to 14,000 pounds. "Sorry folks, no bags today!"
• The Q400 had burned 4000 pounds so I load 4000 pounds into the gas tanks and am still 6000 some-odd pounds too heavy but...
• I depart to Lanzarote: The plane leaps into the air as I might have expected (below, left). This thing is fast, 350 knots ground speed! The Dash is supposed to be faster but not according to this model! The thing is stable like a rock and able to fly a slow approach and landing. I make the first turn off, taxi back to the runway and depart. I'm thinking the ATR has this challenge in the bag (below, right).
• To Reina Sofia: After departure from Lanzarote (as we had done in the Q400) we fly northward over the island before turning back to the south for the 180-mile leg to Tenerife. Half way through my left turn the engines die - I'm totally out of gas!

Now, I was already 6,000 pounds too heavy, (I mean, even the -42 hauled this much and this version is supposed to take 70 passengers plus cargo?). Something is certainly screwed up in the CFG files! So, like we had to do for the DC-10 versus L-1011 challenge, I dive into the CFG. Under engine and fuel data I pull 5% of the power back and turn the fuel consumption down from 100% to 50%. I also change the empty weight and max weight a bit. Then I reload the flight as follows:

• 20,000 pounds of payload
• 5131 pounds of fuel
• Still 6000 pounds overweight!

The first leg flies great but I landed long and in order to make my early turn-off I pulled the throttles back hard to reverse the pitch on the blades (image below). With that, I stopped quickly. As I added more forward throttle the aircraft continued to drive backwards! The more throttle I added, the faster I went backwards! I have never had a turboprop do that before! I cut the engines and rolled to a stop just off the end of the runway. Once stopped I restarted the engines (there's five minutes off the clock) and as the engines came to life they began pushing me backwards again. With the parking brakes on I suffered a tailstrike and crash!

I reloaded the flight a third time and landed at Lanzarote without reversing the pitch this time. I took the same longer taxi that the Q400 had done. I figured the thing lands slowly enough that unless I'm landing on a really short runway I shouldn't need the reverse pitch anyway. I departed again and if it's not my imagination, the ATR still seems to fly better and faster than the Q400. I departed north, made the left turn onto course and flew down to Reina Sofia. With the tweaks I had made I was doing 325 knots now, just a bit slower than the Q400. I landed softly, slowed, taxied back and departed for Los Rodeos. I checked the clock enroute and was through 80 minutes so it was going to be close. I turned onto final, battling the wind and ... POOF! Out of gas. Engines died again. I crashed and burned.

Back into the CFG I dive. I have to wonder if it's a fair competition if I keep tweaking the CFG files until someone comes out on top? I can't find any reason why the reverse pitch gets stuck but I changed the fuel burn from 50% down to 25%. I reloaded the flight for the fourth time and tried a bit of reverse pitch. At the first sign of backwards motion I eased the condition levers full forward. My backwards roll stopped. Very slowly I eased the throttles forward again ... and drove backwards right off the runway at Gran Canaria. At this point I had basically given up on the ATR 72; I hit the brakes, tailstruck again, registered the crash and declared the Q400 the winner of this challenge!

Now, I like how the ATR handled and I think I'd like to have it in my hangar but for crying out loud, I'm going to have to spend some time fixing it first!

Ron Blehm
pretendpilot@yahoo.com