For you TBM guys: How much runway did you need to operate at maximum gross weight on a 100 degree day at seal level? How much runway do really need to feel comfortable (not book, but real world operation with big margins)?

Finally, can you operate a TBM from grass or gravel strips?

I am not in the market (right now), but the ability to operate from a caliche strip is a must for me.

TBM700 AFM:

http://www.tbm850.com/IMG/pdf/PIM700C.pdf

Page 300.

Seems to be about 1600 ft ground run, 2420 ft to 50 ft obstacle.


No operating experience, but I'd guess 2500 ft with clear approaches would be enough for general use, 3000 ft to be sure.


The AFM talks about grass. Did not see gravel mentioned.

Mike C.

Thanks for the link. I didn't see a limitation prohibiting grass or gravel. There amplified procedures for grass.

A family here runs both a Pilatus and a TBM on grass all the time. Big C182's.

I would not take my TBM off road onto grass. Tires too narrow. Some have/do but I believe the strip is very firm. I've helped a neighbor and myself, stuck with a wheel off the taxiway. Not again.

Runway Distances quoted are reasonable and doable. Pilatus is very good on grass. Pilatus flies like a 172, TBM more like a 182 that likes hard surfaces..

No limitation on gravel or grass.
I never had the need to land on grass or gravel but if I needed to and I knew the runway well I would do it. Some folks in Australia do it all the time on dirt strips.

As for runway performance the TBM does very good, my personal minimum is 2500 ft paved, altough I have never been in shorter than 2900 ft.

Whats fun is takeoff by myself with minimal fuel, your off in under a 1000 ft and climbing at 3000 fpm. Nice rocket.

Tire pressures are too high for anything but really HARD grass runways. Needs to not have rained for some time.

Nose is 94 PSI, mains 120 PSI.

If you want to do grass in a turbine, get an MU2. Nose is 57 PSI, mains 65 PSI, so the MU2 is roughly half the contact pressure of the TBM.

Is this what you called "caliche"?

https://www.youtube.com/watch?v=Sc1Dl_FG-ZU
https://www.youtube.com/watch?v=tGRBzbmwJxQ

Second video is liftoff well under 1000 ft.

Mike C.

You got that right! I was solo the other day and had a head of steam when given an intermediate climb, and did 5500 FPM for a brief period. One of the few, if only airplanes I fly that feels like it has "enough" power.

Personally, I don't like the sound of putting it on grass, but won't judge others for it.

Caliche is calcium carbonate. It is widely used for roads and drilling pads in Texas. Our caliche runway is essentially all weather, but you do get some prop tip erosion if you are not careful. My procedure, whether in the Caravan or B36, is to skip the run up and add power very slowly on take off. No beta or reverse on landing. I always use the inertial separator. We have had B200's and B350's operate loperate safely out of our strip, but I didn't know if TBM's were limited to pavement.

Incidentally, caliche is the best surface in the world for taildraggers. It is even more forgiving than grass.

I guess that would roughly equate to MSL.

Nice double entendre.

The TBM does not have great prop clearance, about 8 inches, so that is something else to be aware of.

Real "bush" work requires getting the engines and props up high (DHC-6 for example).


It has less friction than grass? I find that surprising.

Tires on grass are about half the friction of asphalt. Wet grass can get close to ice.

Mike C.

I know this is thread creep. Caliche is a hard surface that has a little give. Caliche dust can be very fine. So you are landing on smooth surface that feels like it has been dusted with talcum powder. Grass is a great surface, but can be rough. Caliche has all the forgiveness of grass in a smooth surface-assuming you have a well built strip!

As further creep: we are lucky in Fort Worth because Spinks Airport has a first class grass runway. I can sneak down there in the Cub and make several touch and goes per each circuit. I fly back up to Meacham Field with a much better attitude. Cub flying is better than any other therapy.

Back to the original point. It sound like a TBM can operate on an appropriate unpaved strip. The prices for the early TBM's are coming down and getting more attractive. A friend of mine has S/N 001 and loves it. We flew it direct from Fort Worth to the Bahamas. Coming home took a fuel stop. Awesome airplanes.

I'm a rookie. Last weekend 90 degrees, max weight out of 3400 feet easy. Landing was a piece of cake. I've only been flying the TBM for a year and I think 3000 feet would be plenty of room.

This was my 5th landing in a TBM 700B at 67T near Corpus Christi, TX. The runway at the time was only 2700 feet long and 30 feet wide. I wouldn't say it was easy for me, but certainly would not be terribly challenging for a seasoned TBM driver. Fortunately for me, my friend who owned the plane and the airport had a watchful eye on my yoke and throttle commands. He now operates a CE-510 Mustang from the same runway which he has now lengthened to just 3000 feet. Lucky for him the Mustang has amazing brakes.

https://www.youtube.com/watch?v=RFMKgyvbIHg

Or a Commander...