MX7-180B rear seat headroom and actual cruise performance?

Trigear? Taildragger? Fixed pitch prop? Which Engine? ...anything related with model selection considerations and questions about buying a Maule
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LowFlyingDuck
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MX7-180B rear seat headroom and actual cruise performance?

Post by LowFlyingDuck »

Hi all

I’m considering purchasing a Maule and the model that appeals most is probably the MX7-180B, since I live at sea level and it’ll mainly be for myself and one other (and the dog on the back seat) but occasionally it would be handy to take a passenger in the back. So my first question is, how tall a passenger can sit on the back seat without bumping their head?

Also, trying to get an idea of actual cruise performance, since I’m told the book is a bit on the optimistic side. Can anyone give some examples of cruise performance at various power settings and with various tire sizes?

Many thanks

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Chris in Milwaukee
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Post by Chris in Milwaukee »

Not a complete apples-to-apples comparison, but I have a ‘93 180A (fixed pitch, universal wing) with 8.50x6 tires. Cruising around on a normal day at 2200 RPM, I see about 110 MPH indicated. If I really get on it with all knobs pushed in, I’ve seen 130 MPH hovering at 2700 RPM. I may be 1-2 MPH slower than some since my lower lift strut farings are off because of my ski fittings and slightly larger tires. But it’s a fair representation of the type, I think.

Casey M has a 180C which is a lot like the 180B except with the spring gear. He’ll be able to tell you if there is a speed difference in that configuration.

Not sure which model year you are considering, but the MX-7-180s have been the same since late 1993 as far as I know, only variation being the A/B/C.
Christopher Owens
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Maule988ms
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Post by Maule988ms »

Little over 120 mph 23sqaure. Extented gear with 850s

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andy
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Post by andy »

I have a 1986 MX-7-180 but it's similar to the MX-7-180B. A 6-footer can sit in the back without bumping his/her head but it depends on the length of their torso vs. their legs. I've had lots of passengers under 6 feet sit in the back without a problem.

Actual cruise performance depends on the size of the tires, whether or not your main gear legs have fairings and how much fuel you want to burn per hour. With 8.00x6 tires, faired gear legs and 10 GPH fuel burn you should be cruising around 120 mph. The most drag comes from parts of the airframe with the largest surface areas that hit the air up front. The -7 degree flap setting reduces induced drag slightly. The increase in speed that the -7 flap setting provides depends on how fast you are cruising. It's not as much at lower airspeeds as it is at higher airspeeds. I've found that it gives me about 2 mph increase in airspeed at 100 mph.

I have 31" ABW tundra tires, unfaired ABW standard HD gear legs and I get about 100 mph at 10 GPH.

Since drag increases as the square of airspeed, increasing the throttle gives me a small increase in airspeed and a large increase in fuel burn. I don't think it's worth it to arrive a few minutes earlier at the expense of a lot more fuel.

Others who own a similar model on the forum can chime in with their experience. You might also be able to search the forum for past threads on this subject. The search engine on the forum isn't as good as using Google to search. The format for a Google search of the forum is search terms first followed by site:maulepilots.org.

Take a look at this thread: http://maulepilots.org/forums/viewtopic ... 2d74aaccd6
Andy
1986 MX7-180
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maules.com
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Post by maules.com »

MX7-180 1985-1993 c/s prop, 30'10" wingspan thus slightly faster in cruise than MX7-180B oleo, or Cwide aluminum,1993 on, c/s prop 32'11" wingspan
MX7-180A F/p oleo, or AC F/p wide, 1993 on, 32'11" wingspan.
Wide gear is 22" wider than oleo and weighs 55b more.
Oleo or Wide, same cruise speed except earlier shorter winged model is a couple mph faster.
All on 7.00 tyres and same drag factors; 59F, 29.92 SL pressure
MX7-180 1985-1993 TAS 146mph max
MX7-180B and C 1993 on TAS 144mph max MXT is 5+mph slower
MX7-180A and AC 1993 on TAS 139mph max MXT is 5+mph slower

These are numbers I have measured from sealevel to 5000msl with throttle and prop and mixture all full forward.
Jeremy
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Maule AK Worldwide

LowFlyingDuck
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Post by LowFlyingDuck »

Thanks for he responses all, much appreciated.

So by the sounds of things, a medium-sized adult (6ft or less) would fit in the back seat of the MX7-180B without bumping their head? With 1000lbs of useful load, that makes it a proper 4-seater at sea level.

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gregorydshanks
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Post by gregorydshanks »

Man and woman up front and a normal man in the rear with nearly full fuel may make you aft CG. Putting the man up front and the woman in the back solves the problem. And yes, I see the humor in the previous comment.

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Chris in Milwaukee
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Post by Chris in Milwaukee »

LowFlyingDuck wrote:Thanks for he responses all, much appreciated.

So by the sounds of things, a medium-sized adult (6ft or less) would fit in the back seat of the MX7-180B without bumping their head? With 1000lbs of useful load, that makes it a proper 4-seater at sea level.
6-footer in the back seat may brush his or her head on the liner depending on torso height. The back seat is also closer to the floor than the front ones, or at least arranged a bit differently. So when I sat back there (I’m 6’1â€￾), my knees were sticking up quite a bit when the front seats were all the way back. Kids and smaller adults would likely be comfortable.
Christopher Owens
1993 MX-7-180A
Members: AOPA EAA VAA

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