Please explain "stall speed"

[W4RLR]

As a corrolary to that, when you hit the stall speed of a Cessna 172 whilst still ~6-8 feet off of the runway, plan for a change of underwear in your VERY near future (personal experience speaking here...).

Been, done, got t-shirt. Crosswind landings are VERY tricky! The flight instructor was not pleased. I never heard cursing in Farsi (my instructor was an Iranian national) until then.

 

[W4RLR]

I maybe wrong, but as in aircraft and as in automotive, I was under the impression that stall on a vehicle is when the engine can not keep up with the demand and stalls out, like if you could take a car and imobilize it then put it in gear it would increase till the engine could not produce anymore and would just die. like say at 3500 rpm's it just dies, (while not being able to give anywhere,though being imobilized)which i believe is the same as aircraft, the engines can not meet demand and the engines cut off,

As for aircraft in flight Rick, the engines can be screaming full tilt and you can be in a stall condition. Stall in aeronautics refers to the absence of lift. Pitch your wings up to a exaggerated angle (called the angle of attack) without sufficient thrust to sustain forward momentum and the airflow over the wings is no longer sufficient to generate lift. Aircraft then tend to drop, some like rocks unless you learn how to recover. Beginning airmen practice recovery from stalls and spins as part of flight training. It's necessary in case to prevent flyers from disorientation if they bumble into weather they need to get back out of, or they lose sight of the horizon. Night flying is another condition where the horizon is difficult to determine. Properly set instruments don't lie, but trusting the human senses over the instruments will kill you practically every time in instrument flying conditions.

But seeing as I am now permanently grounded as pilot-in-command for medical reasons, I can now only muck around in boats. Some of the same rules, and the sea is just as unforgiving as the air.

 

[WD40]

Daryl, You're da man!

The reason I asked this question is my tranny is being rebuilt and my upgraded TQ has a stall speed of 2200-2500 rpm. I wasn't given an option as to what stall speed I wanted. IYO, is that the optimal range for my truck?

Seams high to me also. If you are driving 55 at say 1650 RPM, what will this do for your fuel mileage? I think you need to ask why such a high stall speed.

 

[DaveBen]

rray, stall speed in aircraft has nothing to do with the engine, only the angle of attack of the air over the wing. There are many factors that contribute to stall, such as wind speed, temperature, just to name a few. The engine has a contributing factor, but you can stall a glider. I am not getting on your case, just pointing out a small error.

Dave

 

[hheynow]

Seams high to me also. If you are driving 55 at say 1650 RPM, what will this do for your fuel mileage? I think you need to ask why such a high stall speed.

Well I've got 2/3 of my answers so far. 1) I called Jody at DP-Tuner who burned my chip and asked him from his experience what is the average stall speed for OBS PSDs. Since he has a questionnaire that has to be filled out prior to him burning chips, he has data on this from many trucks like mine. He said it was average. 2) I asked the tranny rebuilder who just rebuilt my tranny (he is a genius gear head) and he said that the TC I ordered is matched for my truck. On Monday I'll call the manufacturer of the TC and will pick their brains for the final answer.

With my 4.10 rear at 55 mph I tach at +/- 1600 rpms. My fuel mileage is 15-16 mpgs city and almost 19 mpgs on the highway. From info I've gathered at TDS over the past three years (prior to SDD coming on line), my mpgs are in the high normal range, BUT where I live diesel #1 is never offered in the winter.

2200-2500 seams way to high to me for a diesel engine that redlines at 3250.

My stock tach yellow lines between 3450-3800 and red line is over 3800 rpms.

 

[RickGmi]

Thanks for straighting me out on the stall speed answers, I just alway thought engine stall is related to TC stall...interesting....now i have to find another book to read...lol

 

[hheynow]

Well I've got 2/3 of my answers so far. 1) I called Jody at DP-Tuner who burned my chip and asked him from his experience what is the average stall speed for OBS PSDs. Since he has a questionnaire that has to be filled out prior to him burning chips, he has data on this from many trucks like mine. He said it was average. 2) I asked the tranny rebuilder who just rebuilt my tranny (he is a genius gear head) and he said that the TC I ordered is matched for my truck. On Monday I'll call the manufacturer of the TC and will pick their brains for the final answer.

Ford Forgotton & WD-40, Both of you were right on the money. Just spoke to the manufacturer and the stall speed for my aftermarket TC is 1200-1400 and it is matched for my truck.

 

[Ford_Forgotton]

The only reason I said 1200, was I had read somewhere, long long ago, that someone bought a 1200 stall convertor for their truck. What I didnt know is if that was a stock stall speed or what.

What I did know, was that the 2200 stall you originally quoted seemed really high, even for the gassers I have driven.

Glad you got that info!