Density Altitude Takeoff Note

[jlunseth]

I have to echo Paul’s comments (gsxrpilot). I rotate when the plane is ready to fly, don’t particularly care what the number is. Especially out west and during the summer. The runways are generally longer out there because of the density altitude issue, so there is room to run. A little back pressure on the elevator might be needed just to keep the aircraft from wheelbarrowing (running on the nose wheel), but just enough pressure so it stays on the mains. Was just at Moriarity during the Mooney PPP a couple of weeks ago, the takeoffs were not an issue. The landings, on the other hand, needed some work, I blamed it on the crosswinds. Well, ok, maybe the rusty pilot had something to do with it, but that was why the rusty pilot was there in the first place.

[Ibra]

19 hours ago, donkaye said:

Also, high DA's also mean flying a wider pattern to account for the higher true airspeed

Indeed, it's a good advice something that did not cross my mind the first time, probably one of the underlying reasons why one may overshoot their turn in valley or runway axis on final (higher TAS on same IAS), maybe it's very relevant to the news of recent mid air collision...  

Edited May 13, 2021 by Ibra

[GeeBee]

10 hours ago, cliffy said:

One is not a safe pilot until one becomes "tempered". And you can't become "tempered" until you do something in an airplane that scares the shit out of you and you know you did it to yourself. Flying takes on an entire different meaning after that experience.

 

That is because when you get your pilot certificate, you get two buckets. One is full of luck and it leaks. The other one is empty and is experience. You try to fill the latter before the first one empties. Remember though, neither bucket ever overflows.

 

 

[cliffy]

10 hours ago, Will.iam said:

Try a tanker with A model engines that were injecting water for added thrust but you only have 90 seconds before the water runs out and you better have sucked up the gear and flaps by then or your not going to make it. Also at 175 knot rotate speed you eat up 1000 feet before the mains liftoff so even if you are not quite at Vr if the 1000ft remaining board is wizzing by you start rotating or the gear is going to take out approach lights! Heard of storied of guys praying they make it over the perimeter fence. On some higher DA fields we were limited to how much fuel we could take to keep from exceeding max tire rotation speed of 195! With no thrust reversers on the R model your V1 speed that allows you to stop is very low (saw 115 a few times) on max weight takeoffs and VR is very high (165+) so you have this loooong time after you are committed to going that even if you blow an engine you are still going with serious seat cushion suction and it seems to take forever for the speed to increase all while the end of the runway when you started was over 2 miles away but now is rapidly coming at you getting bigger by the second. I don’t miss those days at all.  

I've worked on those old water bombers with the straight turbojet engines. Put many thousands of gallons of water on them (CAL Airlines in the old days)

Worked one airline where we had old 737s-200s  (-9 engines) into Midway in the summer. You ask why is fuel so cheap for the airlines at MDW? Look at the runway length. *BTW we flew the highest time 737-200 IN THE WORLD at that airline)

The company wanted to save money so they took as much fuel as they could there. We were always runway limited on T/O due to weight of fuel. Looking at those checker boards at the end of the runway coming up and knowing you had climb above them was interesting at rotation.  We stopped that practice after 1 month at my urging. :-)

Like I said before- high DAs in the Mooney are nothing to fear, just different. Check your numbers before T/O and be ready for a longer roll with less climb rate and acceleration. 

[cliffy]

I have to add this- KOCH Chart   

This subject comes up every year and this chart gets lost in the babble every time

ALWAYS CARRY ONE OF THESE OUT WEST

[Sixstring2k]

Thank you for sharing your story. 

[Gatlin Gun]

On 5/12/2021 at 2:57 PM, CoffeeCan said:

I owe it to y'all to come clean, and take whatever lumps I have coming.   

No lumps should ever be given for a "there I was" story, Coffee Can.  As many have already said, thank you for sharing this.  With summer approaching, the air will be rare and it's a wonderful reminder to us all.  Cause you show me the pilot that "has it all figured out", and I'll show you the most dangerous guy in the sky.  Thank you again for sharing.

[cwaters]

So I must now ask a New owner, low time, all east coast training pilot question. (Just PPL, currently working through ground school for IR)

 

I move to COS in about a year and DA is one thing I've been worried about slightly. Having done all my training on the east coast and not really dealt with high DA I'm unsure about what to do to prepare for the move. I'll be there for 4-6 years then back to the east coast most likely and I love my J so I don't know that exploring a turbo upgrade is worth it for a "short" time out there. I plan to do some training with a CFI once I get out there to familiarize myself with the altitude but is there anything you all would recommend doing before heading out that way? Its hard to practice high DA landing performance on the east. 

 

I can read and calculate the performance numbers but I'd like to hear (read) from those with NA engines out there what some common practices are, is it something where you rarely ever takeoff with full tanks/past a certain time of day in summer and just plan to fuel stop "soon" ? My Main mission out there will just be exploring the area and occasional trips back east to see family. 

[201Mooniac]

I've been flying my M20J all around the west for more than 25 years now and with proper planning, a NA aircraft does just fine.  The important thing is not to have to fly on any given day.  When DA is an issue, I plan to fly early, fly light, and use the longest runways available.  The only way to get comfortable with it is time with a good CFI who understands both mountain flying (it is not only DA to consider) and high DA situations.  If you can take the MAPASF PPP in the CO area, they usually include a trip to Leadville and show that with proper planning it can be done safely in a NA airplane.  Again though, if you need to fly at a particular time, get a turbo (and weather protection), or maybe a twin (though I'll leave that for another debate).

[Ragsf15e]

As @201Mooniacsaid, early and light in the summer.  You’ll be fine.  I plan all my summer flying to finish by noon anyway due to buildups and bumps.  You can still go a long way between 6am and noon in a J!

[carusoam]

cw,

Plan to get some Mountain Flying Training...

Similar to transition training specific to the environment you are going to encounter...

The thin air has a couple of funky challenges that are best to learn about before flying in it...

Nothing beats having a perfect tool for the environment...

A turbo adds some extra capabilities when there are rocks at your usual east coast cruising altitudes...

The M20J is a great tool... 

NA PP thoughts only, not a TC’d pilot...

Best regards,

-a-

[cliffy]

A turbo doesn't negate the visual or physical fact of a higher ground speed for takeoff and landing. I just shortens the time to get to the higher ground speed required. 

You may be seeing your usual indicated speed but VISUALLY (and in reality) you are traveling  lot faster over the ground. It takes getting used to. 

My mantra, taught to me from day one-  Airspeed, airspeed, airspeed, NOTHING trumps airspeed- EVER!

It has always been the "prime directive" for you Trekkie fans

"Lose not thine airspeed lest the earth come up to smite thee!" (to put it in Biblical terms!)

"A man has to know his limitations" as Dirty Harry used to pontificate.

How many accidents can we come up with where this mantra was forgotten? Every stall/spin accident, every go-around crash, and many other scenarios.

Now one item NO ONE ever brings up is a go around at high DA.

HAVE ANY OF YOU EVER TRIED TO DO A GO AROUND AT ALTITUDES APPROACHING 8,000 FEET AND HIGHER 

WITH THE GEAR DOWN?  WITH AND WITHOUT FLAPS EXTENDED?

Try it sometime. Go to 8,000' put the rollers and flaps out and try to climb. Slow to 75 mph and see how the airplane reacts for yourself. 

Remember now you are working with 75% or less of your total certified horsepower.  200HP= 150 HP now

180HP= 135 HP

Try it sometime- It'll wake you up!

 

 

 

[cliffy]

From 1966   the lower airport is Lone Pine CA  Been there many times

[A64Pilot]

If you don’t have mountain experience, stay out of box canyons, and be darn sure your in the correct canyon if your flying through one, next canyon over is a box right around a corner and you don’t want to be there. 

 A good big GPS with terrain maps is really a necessity and a God’s send

‘If possible fly above all of the hard stuff, and become familiar with mountain waves, and if you get into one ignore altitude if it’s carrying you up, ride it up higher, because right after the up elevator ride is the down one and you may not have enough power to keep from descending.

Do some reading learn to avoid things like that cloud at the peak of the mountain that seems to be just sitting there, and be real wary of the lee side of a mountain,lots of things you can learn about by reading

[dogbocks]

1 hour ago, cliffy said:

From 1966   the lower airport is Lone Pine CA  Been there many times

I love how back in the day, you could not wear a headset in a Bonanza and have a normal conversation during cruise. I guess airplanes have all gotten much louder since then? 

[A64Pilot]

Head sets didn’t even become a thing until the 80’s and even then you had to have a portable intercom. I had one that used 9V batteries and mine was deluxe in that there was a separate box for the two in the back seat with a telephone wire that connected the two boxes.

I don’t know when intercoms began being built into comm panels, I didn’t get my first one until I guess 03?

‘I had this big leather “flight bag”  to carry all that stuff.

The whole time growing up though no one had a head set and us kids learned real fast to shut up anytime the radio came on, and to tap Daddy’s shoulder if we heard our tail number.

‘I spent a lot of my early years in the back seat of a 182 and 210 and have never suffered any hearing loss

Edited June 3, 2021 by A64Pilot

[cliffy]

Headsets?  Headsets? We don't need no stinkin' headsets!   

Just like I spent my entire youth riding bicycles everywhere and never wore a helmet!

Now they don't even ride bicycles to school anymore!

I drank water out of any yard garden hose and didn't die

BTW What ever happened to water fountains!!

Now back to our regularly scheduled program-

[David Lloyd]

N5878J, a 1965 S Bonanza is still flying!  Guess they got that density altitude thing figured out.

[Hank]

7 hours ago, David Lloyd said:

N5878J, a 1965 S Bonanza is still flying!  Guess they got that density altitude thing figured out.

Sure did! But thankfully the world forgot about that crazy hat he's wearing! 

[Will.iam]

16 hours ago, Hank said:

Sure did! But thankfully the world forgot about that crazy hat he's wearing! 

Delta didn’t oh how they love their hats.