Non-turbo M20J at high-elevation airports

[Jsavage3]

Any info out there about flying a normally aspirated M20J into, say, Telluride, CO and then getting back out safely?

In cruise flight at 9,000 feet, I usually see 21" MP at 2500 RPM...

Any shared experiences, techniques, etc would be greatly appreciated. Thanks.

[Smiles201]

Used to fly a 1980 J out of KLAM (elevation 7171), and have visited higher altitude airports in Colorado, If you have no mountain experience, take a mountain flying course with an experienced instructor; all NA planes feel different at altitude. High altitude must be planned for (temperture, winds, load), but presents no special problems for a well running Mooney. Primary issues are: know your POH, usually operate well under gross, especially in summer, depart early in AM to take advantage of lower tempertures, plan for downdrafts/updrafts (terrain, wind and heat related), and become familiar with changes to Vx and Vy at altitude. If I recall correctly, Telluride has steep slope to West and drop offs North, East and South. So, if you know the winds, you will know effects on your climb performance.

[garytex]

Good advise

[aerobat95]

I ran the T/O distance and with 2750lbs at 9000PA at 10 degrees C your T/O distance is around 3300 ft and that is with 0 ft obstacle hight. Goes up to around 5500 ft with 50 ft obstacle hight. Landing at the same 2750lbs would be 2000 ft with no obstacle and 3500 ft with a 50ft obstacle. At high PA's I have found in the KC-135 and T-6 your flare feels different more mushy and less control authority. Also the brakes and engine take significantly longer to cool. When I flew the T-6 out of KAPA I saw a PA of around 7500 ft and the performance was significantly reduced. Takeoff roll seemed like forever. Don't force the aircraft into the air. Based on the POH that I looked at liftoff speed is inbetween 58-59 KIAS. Also realize that at 9000 PA and an approach speed of ~76 kts your TAS will be 89 kts vs the closer to 80 KTAS at say 2000ft. So your gound speed will be higher depending on the winds. From flying a NA engine I would imagine you would not want to go mixture full rich when taking off. The book talks about leaning for smooth operation. It does however say mixture full rich in the landing section. Just run your TOLD before you go and fly the numbers. Also run the TOLD for the worst case conditions expected. Good luck

[mooniac58]

I routinely fly my normally aspirated J out of high airports being based in Santa Fe (6300 MSL) - it gets near 100 here in the summer and density altitude will be around 9,500-10,000. As has been mentioned here, takeoff distance is important to look at but you really need to consider your climb out - and consider that any turn you make will sacrifice your climb as you will sacrifice lift for the turn. If I am max gross weight on a 10,000ft density altitude I will climb out at 150fpm near Vx. That can be pretty damned scary if you have terrain to get away from - and a standard rate turn will easily stop your climb.

My non-professional advice would be 1) take a mountain flying course 2) Don't take more fuel than you need, it is amazing how much 100-200lbs less weight can improve takeoff performance 3) wade into these things, don't just go by book numbers, load up to max gross and attempt to blast in and out of Leadville on a summer day ;-)

I did the first 3 years of flying with my J in Hawaii with no airports over 2,700 feet I had a big shocker coming to be moving into the high desert mountains...after a few hundred hours out here I do finally feel like I am comfortable within the limitations of the aircraft as well as my own very padded safety margins.

[Lood]

Agree, on my F, which has the same engine, is lighter than the normal J model but not aerodynamically as effecient, take off at high altitudes has never scared me as did the very poor climb performance. A climb of 100 - 200 ft/min max, really gets your attention.

[231Pilot]

You guys have just highlighted the reasons I sold my J, and bought a K when I moved from the southeast (elevation 252, no hills) to the Salt Lake City area (elevation 4227, high mountains east, south and west). Climb performance and speed brakes to get down in a hurry once I reach the valley are a huge advantage over the J. It could have been flown it here, but not with the peace of mind of the K. The 150-200 fpm climb at altitude was a bit too disquieting to me.

[stevesm20b]

Good information here.

[jdrake]

Excellent advice above, particularly re weight and performance characteristics. I'm a flatlander from NJ and flew my J to Telluride back in March (trip report linked below). In addition to the high altitude, the winds and the slope of KTEX add complexity. Whatever field you choose, I'd do some research on local peculiarities/customs by talking to an instructor or someone else familiar with the field.

http://www.mooneyspace.com/index.php?/topic/4891-dream-trip-report-long/

[AndyFromCB]

I would also add one more thing: be really aware of winds at altitude of surrounding ridges. What I mean by surrounding can be anything up to 10 or so miles away. If it's howling over 25knots at those altitudes, I would strongly recommend not taking off. I flew my 200hp Arrow for 2 years into the mountains and on a hot day 200fpm to 300fpm being 300lb under gross was par for the course. There is no worst feeling than seeing that 200fpm turn to -500fpm because of even light mountain wave activity. Second of all, forget any sort of IFR operation. A mountain wave or rotor activity will kill even my Bravo's climb rate to zero,

I would always treat my Arrow like a 2 seater with a 30gallon tank when taking off from mountain airports. You can always land once you're back to flat land and top off. Even with my Bravo now, I don't intend to load up more than 50 gallons when taking off from KJAC and don't do IFR in the mountains. Last fellow who tried IFR there in a Mooney became part of the landscape with his 3 boys.

Last but not least, mixture. Do not go full rich on landing in case you have to go around. I'd always do a full power run up on take off and get the mixture set to about 1350EGT in my Arrow. On landing, I'd do the same in the air. You're already running WOT anyway, low MP, you're not going to hurt anything.

[jackn]

I flew an E with a mountain flying instructor into KTEX in the winter. Lean to peak RPM prior to takeoff. We had no trouble. There are a lot of techniques you can use to get additional lift. Fly in the lifting air is one. Get a competent flight instructor before doing it. We did touch & goes at Gunnison(7600' alt, and flew around the 14,000 ft peaks. A flight I won't forget! That being said, I decided to get a K.

[KSMooniac]

Lots of good advice here. I've been to Rifle, Aspen, and Leadville in the Rockies, and a few others on the front range in my J. Forget IFR ops, go as LIGHT as possible, even if you have to add a fuel stop on the way out, and watch out for winds at altitude. Your TAS and thus groundspeed will be much higher than you're used to, so pay attention to the ASI and don't get slower. Ground rolls will be much longer...perhaps in the 3000' range, which will feel really abnormal the first time you try it! Learn the Target EGT method for leaning and do it. Take the Colorado Pilot's Association mountain flying course if you're able.

[jetdriven]

We departed Sedona twice with a density altitude of 7,500 feet. Our takeoff weight was 2550 and the ground run was 2,500'. The climb was ~400 FPM. VX was used until passing 2,000 AGL due to mountains.

Biggest thing is lift the nosewheel at the recommended speed but let it fly when it is ready.

[The-sky-captain]

Good advise above. I've flown into the Front Range Colorado and New Mexico airports in hot conditions and have had no issues, just be sure to lean correctly and leave the plane on the ground until it's ready to fly. Just this past weekend I came out of Colorado Springs, gross weight at 7500' DA. The take off roll is noticibly longer but the climb rate is where I really noticed the lack of muscle. I heartily second the the advise of getting some mountain training if you decide to go into Telluride. The terrain, winds, drafts and DA makes it a different world for our little NA planes.

[Joe Zuffoletto]

deleted

[Jsavage3]

All good points, Gentlemen. Seeing as there did not appear to be anything on this topic in the forum and considering I was actually in Telluride at the time, I felt it was worth getting out in the open. I fly professionally into all of the mountain airports -- TEX, JAC, ASE, EGE, etc and they each have their interesting qualities. Watching all the NA GA airplanes coming and going (to incl a 400-hr PP in a Cardinal), I felt that this was worth delving into.

Will I fly my NA 201 into these airports? Yes, but it will be under optimal conditions. I taught mountain flying in Alaska and I'm here to tell you, mountain flying is some of the most rewarding flying to be had, but one cannot afford to be uneducated about it or complacent with it.

[Bennett]

While I now own a M20J, I previously owned a M20K (231 with the 262 Trophy conversion). The J meets my needs today, as the K did then. Turbocharging does make a huge difference at high altitude airports, and there are times I miss 100% power to FL240. But rotors, strong updrafts and downdrafts in mountainous terrain also affect turboed aircraft, and I have always given a wide berth to mountains in high wind conditions. Fortunately, I've flown with great mountain flying instructors, and that keeps me wary. In the J, I really notice the effects of density altitude, and I try and plan accordingly. Last year, on a really hot day, working back through mountain passes in high winds (no, I didn't want to be there, but sometimes plans just don't work out), I found that I could not outclimb even the moderate downdrafts, let alone the sometimes severe downdrafts, and it was many miles before I could find the updrafts needed to get back to my cruising altitude. The mountain flying instruction received over the years made a huge difference, and I suggest that this training is among the most important training you can have as a seasoned pilot.

[Lowbid]

Reading this thread makes me think of how incredibly fortunate I was three years ago. My son was playing Junior hockey and had a playoff series in Wenatchee, WA in March. Well, why not fly there? At the time I had a robust 145 HP, 1966 C-172 with MAYBE 100 hrs total PP time in my logbook. Off I went from WI CAREFULLY planning my route through the mountain passes in Montana and Idaho. On the way west, we were grounded for half a day due to snow squalls and LOW ceilings, but eventually made it to Wenatchee. On the return trip, I kept trying to make it through Look Out Pass east of Couer d Alene and the ceiling would not allow me to get through. I tried twice, easily less than 1,000' AGL. At the time, "mountain wave" was not even In my vocabulary. After landing at Shoshone Co. airport twice, I decided to back out, head west, then south until I could find an appropriate pass to get me back east. Of course, 500 flight hours later and absorbing all the mountain flying information routinely discussed on aviation forums, It was pure luck I didn't end up part of the landscape. Had there been any serious winds, I would have never made it back out of that canyon.

[Seth]

I flew my former 67F model in the summer of 2010 out of Bozeman, MT (4473 MSL) as part of a cross country tour (east coast to west coast and back). It was hot day with Density Altitude in effect and I took off in the mid afternoon. I don't remember the calculation but I wouldn't be suprised if DA was over 7000. I was under gross (full fuel, just me on board), had a lot of runway, and made it just fine - climb was not steller as usual near sea level on the east coast, but was sufficient. Most of that trip during that leg was in the 10,000 to 12,400 range cruise wise.

That was a fun trip. I planned to go to reno this year, but that didn't happen - maybe next year.

-Seth

[HopePilot]

Has anyone tried non-standard or no flap configurations when taking off from high-elevation airports? I haven't done that kind of experimenting (always take off with take-off flaps).

[Jeev]

Has anyone tried non-standard or no flap configurations when taking off from high-elevation airports? I haven't done that kind of experimenting (always take off with take-off flaps).

I once took off out of ABQ with no flaps and a DA of around 7000ft about 100 under gross in my J by accident. I had plenty of runway and room to climb out but I would NEVER try it on purpose in a high DA situation, it was not fun. As many have stated be under gross (I like 200lbs), have a long runway and an out if your FPM isnt what you calculate due to downdrafts / sheer. I often fly to Denver in the summer and depart APA when the DA is 7500-8500, with the long runway and room to climb out every way but west it is really a non event with full tanks and my dog and I (250 under gross). Shoot, being based in Vegas and flying around the SW it is rare for my J to depart with a DA of less than 4500 during the summer! I love flying over to SOCAL, I feel like I have a whole new aircraft on departure from a sea level airport!

[N201MKTurbo]

I just checked my logbook and I made 6 trips to TEX with my 67 M20F 3 for work and three for skiing. The skiing trips = max gross. Once I had a flap pump failure and landed and took off with no flaps (at max gross). Although the climb performance is a bit weak, there was never a problem. The slope of the runway can be a bit distracting, one time I remember lifting off at the bottom of the saddle and then doing a bit of a touch and go on the upslope. As soon as you clear the end of the runway you have instant altitude and the terrain drops off to the west, so it is not as bad as it looks.

As far as the comments from COLOJO I think he is being a bit dramatic; if flying a normally aspirated airplane to the high altitude airports was suicidal then it would be illegal. I do agree with him that the weather in the mountains can be a challenge and if you don't have experience you should start with calm VFR days.

During the 80s I had a job where I flew my Mooney almost every day out of the Aurora (01V RIP) airport to destinations all over the region. I flew 2500 hours in that Mooney in 6 years. Anybody who says that you cannot get around the rockies in a NA Mooney is nuts, although now I have a turbo Mooney.and just fly over the top instead of through the passes and valleys.

[Jeev]

Anybody who says that you cannot get around the rockies in a NA Mooney is nuts, although now I have a turbo Mooney.and just fly over the top instead of through the passes and valleys.

Agreed, though I usually divert over the southern edge of the Rockies so I can stay at 16,000 (3,000 AGL) or below and have an out incase of weather I fly between Denver and Vegas 4-5 times a year in my J. A turbo would make it easier but is NOT a necessity to cross the Rockies.

[Joe Zuffoletto]

N201MKTurbo: You're right, "suicidal" was too strong a word, but I stand by my opinion that tackling the Rockies without a mountain checkout, whether you're NA or turbo, is foolish. It's absolutely true you can fly the Rockies NA without incident as long as you understand your plane's limitations and the sometimes unpredictable winds and weather you might encounter. I did it for years myself before I finally went turbo.

[N201MKTurbo]

Yes, I don't miss those days with the uncontrolled 4000 foot assents and descents in severe turbulence. Went from 13500 to 18000 feet one day in about two minuets, nothing I could do about it, and then went down just about as fast. No oxygen! Trying to figure out what is going to kill me the rocks, hypoxia or the turbulence breaking the plane in half. 26 years old, I owned a Mooney and had a job where I had to get places in the mountains, it's a wonder I'm still alive.

On the flip side, on a calm crisp winter day, flying low altitude through the divide is one of the most beautiful sites you will ever see!