Hello,

This was a topic that always interested me. Never knew why the md80 climbed so well and the other planes not so much. I was assuming the plane may be light or the small, tube like airframe was efficient for climbing. I would like a explanation for this though, as I think many people would be interested in this. Thanks for all comments and replies!

-3star

Although obviously aerodynamic factors such as wing design play a role, the major factor determining an aircraft’s rate of climb is the thrust-to-weight ratio - the greater the engine power (thrust) the faster an aircraft will climb at any given weight.

MDGLongBeach wrote:

Hello,

This was a topic that always interested me. Never knew why the md80 climbed so well and the other planes not so much. I was assuming the plane may be light or the small, tube like airframe was efficient for climbing. I would like a explanation for this though, as I think many people would be interested in this. Thanks for all comments and replies!

-3star

You'll get a more reliable answer to your question by posting it the correct forum "Technical/Operations".

But actually Stratocruiser has hit the nail on the head.

Do you mean a MD80 at MTOW has better climbing performance then let's say a 737 at MTOW?
Did you use any real data in your observation or did you eyeball it?

MD83 maximum rate of climb is 2500 ft/min.

https://doc8643.com/aircraft/MD83

A contemporary, the B737-400, has a max. rate of climb of 3000 ft/min,

https://doc8643.com/aircraft/B734

The Airbus A320 is even better, 3500 ft/min.

https://doc8643.com/aircraft/A320

Do not confuse deck angle at takeoff with rate of climb!

Note these are maximum rates. Actual rate will depend on weight and other factors, such as reduced-thrust takeoffs.

Beech

Watch movie " the flight ". Climbing at maximum rate may produce bad results ( hopefully only in movies ).

Don't forget the take off performance of the Boeing 720B. The MD-80 must be close second in a sweat! Speaking of myself I have flown a DC-9-50 and I could feel it was climbing fast. But it could not compare to the power of the 720B and its rate of climb. It was something different.

If you hang out at say ATL, M80 are scheduled on short flights well below MTOW currently. This means they are probably less performance limited. Again the reason is that Delta and AA schedule them on short flights, not some systematic performance advantage. Actually it is a fuel burn disadvantage that leads to shorter flights, which could lead to an appearance of fast climbing.

gzm wrote:

But it could not compare to the power of the 720B and its rate of climb. It was something different.

The 720B was over-winged for its weight, plus additional leading-edge flaps. It had a lot of lift.

But although the fan 720B had a good thrust-to-weight for a quad ( 68,000 / 234,000lb = 0.291 ) even that is less than a standard early A320-200 ( 50,000 / 162,040lb = 0.309 ) and just ahead of the the 'sport' MD-87 ( 40,000 / 140,000 = 0.286 ). Nothing out of the ordinary.

As mentioned up-thread, baseline rate of climb depends on lift and T/W. Practical RoC depends on engine schedules, atmosphere, payload, noise-abatement regs...

I thought the 757 had the best thrust to weight ratio for airliners.

The CRJ-700 has a pretty good thrust to weight ratio of 0.333. (25,000 lbs thrust / 75,000 lbs MTOW) when it was flying empty (52,000lb) you could be at 10000ft within 2 mins from Vr.

It doesn’t.

While the 80’s have an impressive deck angle below 1000 feet, their climb rate from flap retraction to cruise is on par with any other jetliner. It’s no slouch, but it’s really just average. Look to G5’s for impressive climb rates (5-6000FPM all the way up.)

So the md80 appears to climb faster than it does?

Woodreau wrote:

I thought the 757 had the best thrust to weight ratio for airliners.

The CRJ-700 has a pretty good thrust to weight ratio of 0.333. (25,000 lbs thrust / 75,000 lbs MTOW) when it was flying empty (52,000lb) you could be at 10000ft within 2 mins from Vr.

757-200, 717 and 737-700 all have similar thrust to weight ratios.

Anybody has the climb rate figures for the TU154? That sure felt like a rocket.

I’ve read somewhere that the A319 is more powerful than the Concorde, weight to power compared.

senatorflyer wrote:

I’ve read somewhere that the A319 is more powerful than the Concorde, weight to power compared.

You can easily verify (or debunk) such a claim with 60 seconds of googling.

Concorde thrust with reheat= 76100lbf total
Concorde MTOW= 185000kg

A319 thrust (max option)= 54000lbf total
A319 MTOW= 75500kg

Concorde thrust to weight= 0.41
A319 thrust to weight= 0.71

MDGLongBeach wrote:

So the md80 appears to climb faster than it does?

“Appears” from where, exactly? From the parking garage, yes. From the jumpseat or on a radar scope, no. It appears to climb like a normal 150,000 pound jet.

“how does the MD-80 climb better than pretty much every other aircraft”


Like others have said it doesn’t. It must just be your perception for whatever reason maybe because the airplane is long and skinny and looks like it is. I’m not saying the aircraft can’t climb good, because in a pinch or when needed sure it can expedite well, but overall it climbs about average or slightly less than your modern aircraft. This is all from an air traffic controllers point of view.

You want to see an aircraft climb well, talk to Southwest and their 700 series airplanes. Those guys are the best.

Starlionblue wrote:

senatorflyer wrote:

I’ve read somewhere that the A319 is more powerful than the Concorde, weight to power compared.

You can easily verify (or debunk) such a claim with 60 seconds of googling.

Concorde thrust with reheat= 76100lbf total
Concorde MTOW= 185000kg

A319 thrust (max option)= 54000lbf total
A319 MTOW= 75500kg

Concorde thrust to weight= 0.41
A319 thrust to weight= 0.71

I know how google works. Just quoted what I’ve read.

Quoting MDGLongBeach (thread starter), "Never knew why the md80 climbed so well and the other planes not so much."

MDGLongBeach, upon what data are you basing this question, and under what conditions?

e38

ELBOB wrote:

rate of climb depends on lift and T/W.

That's the problem-- none of us knows the aircraft's thrust in the climb.

Based on static sea-level thrust, a 767-300 would climb just as well as a B-1. But the B-1 set a climb record at 150 metric tons: 3 min 50 sec I think it was, brake release to 9000 meters. A 150-ton 767 won't do that.

Main factors are:

Thrust-to-weight ratio in the actual flight configuration
Wing loading
Aspect ratio
Efficiency of wing high-lift devices

In terms of the above, easily the most high-performance takeoffs you’ll get are from the Yak-40. Decent thrust-to-weight ratio of 0.26 but a straight, thick wing and above all else, a wing loading of 52 lbs per square foot at MTOW...nothing beats that...


Faro

Woodreau wrote:

I thought the 757 had the best thrust to weight ratio for airliners.

The CRJ-700 has a pretty good thrust to weight ratio of 0.333. (25,000 lbs thrust / 75,000 lbs MTOW) when it was flying empty (52,000lb) you could be at 10000ft within 2 mins from Vr.

The two airliners (ie, not regional jets) with the highest thrust-to-weight ratios are the 717-200 and Tu-204-220. Both have about 0.35 TR ratio at maximum take-off weight and maximum thrust. The 757-200 is at 0.34 at the same conditions.


Faro

Faro wrote:

Woodreau wrote:

I thought the 757 had the best thrust to weight ratio for airliners.

The CRJ-700 has a pretty good thrust to weight ratio of 0.333. (25,000 lbs thrust / 75,000 lbs MTOW) when it was flying empty (52,000lb) you could be at 10000ft within 2 mins from Vr.

The two airliners (ie, not regional jets) with the highest thrust-to-weight ratios are the 717-200 and Tu-204-220. Both have about 0.35 TR ratio at maximum take-off weight and maximum thrust. The 757-200 is at 0.34 at the same conditions.


Faro

Which is interesting because in real life the 717 is a dog. Atleast from an ATC standpoint. Doesn’t climb great, and is relatively slow...or atleast that’s how the airlines fly it. Like I said earlier, is it capable of performing well if needed? Sure, but on a normal everyday basis it’s definitely below average I feel like.

I flew the -80 for four years

Initial climb performance was good, a high attitude was necessary to maintain V2 +10


It did get up and go at lower altitudes, however that small wing did not do well at higher levels, climb rate dropped off dramatically in fact


FL 370 was its maximum, you had to be very light to get up there, it took a while and if you could make it you felt like you were balancing on the ‘head of a pin’

senatorflyer wrote:

Starlionblue wrote:

senatorflyer wrote:

I’ve read somewhere that the A319 is more powerful than the Concorde, weight to power compared.

You can easily verify (or debunk) such a claim with 60 seconds of googling.

Concorde thrust with reheat= 76100lbf total
Concorde MTOW= 185000kg

A319 thrust (max option)= 54000lbf total
A319 MTOW= 75500kg

Concorde thrust to weight= 0.41
A319 thrust to weight= 0.71

I know how google works. Just quoted what I’ve read.

Actually it looks like both of you are having trouble with Google. 76,100 lbf is TWO Concorde Olympus engines in reheat. Double that and you get a .81 Thrust to weight ratio in re-heat by your calculations.

But, you are mixing units (Lbs to Kgs). Assuming your Concorde and A319 MTOWs are correct in kgs (I only found the Concorde Max Taxi weight, 2,000 kg higher than your TO weight). Thrust to weight ratios calculate as below:

......................Thrust (lbs)......Max TO Weight (lbs).......Ratio
Concorde......152,200RH......407,855............................0.37
......................128,000 Dry..............................................0.31
A319..............54,000............166,449.............................0.32

Concorde’s Thrust to weight ratio is higher in reheat, but the A319 is higher than the Concorde at dry thrust.

FrmrKSEngr wrote:

senatorflyer wrote:

Starlionblue wrote:

You can easily verify (or debunk) such a claim with 60 seconds of googling.

Concorde thrust with reheat= 76100lbf total
Concorde MTOW= 185000kg

A319 thrust (max option)= 54000lbf total
A319 MTOW= 75500kg

Concorde thrust to weight= 0.41
A319 thrust to weight= 0.71

I know how google works. Just quoted what I’ve read.

Actually it looks like both of you are having trouble with Google. 76,100 lbf is TWO Concorde Olympus engines in reheat. Double that and you get a .81 Thrust to weight ratio in re-heat by your calculations.

But, you are mixing units (Lbs to Kgs). Assuming your Concorde and A319 MTOWs are correct in kgs (I only found the Concorde Max Taxi weight, 2,000 kg higher than your TO weight). Thrust to weight ratios calculate as below:

Thrust (lbs) Max TO Weight (lbs) Ratio
Concorde 152,200 RH 407,855 0.37
128,000 Dry 0.31
A319 54,000 166,449 0.32

Concorde’s Thrust to weight ratio is higher in reheat, but the A319 is higher than the Concorde at dry thrust.

That's embarrasing...

Full Concorde specs including MTOW can be found here: http://www.concordesst.com/techspec.html

Starlionblue wrote:

senatorflyer wrote:

I’ve read somewhere that the A319 is more powerful than the Concorde, weight to power compared.

You can easily verify (or debunk) such a claim with 60 seconds of googling.

Concorde thrust with reheat= 76100lbf total
Concorde MTOW= 185000kg

A319 thrust (max option)= 54000lbf total
A319 MTOW= 75500kg

Concorde thrust to weight= 0.41
A319 thrust to weight= 0.71

Outch. more wrong than right and you should not mix units.

concorde engine: 38,050 lbf with reheat. _times four_ :: 152,200 lbf
MTOW 408042 lb -> t/w 0.373

A319 engine 27,000 lbf max no reheat _times two_ :: 52,000 lbf
MTOW 166,000 lb -> t/w 0.313

trnswrld wrote:

Which is interesting because in real life the 717 is a dog. Atleast from an ATC standpoint. Doesn’t climb great, and is relatively slow...or atleast that’s how the airlines fly it. Like I said earlier, is it capable of performing well if needed? Sure, but on a normal everyday basis it’s definitely below average I feel like.

You can pretty much copy and paste what Max Q wrote about the MD-80 and apply it to the 717. It just doesn’t have enough wing to perform well at high altitudes.

It’s like a T-Rex. Powerful legs and tiny arms.

The MD-80 climbs well, but it isn't exactly the best when it come to short runways, especially on hot days.

Alias1024 wrote:

It’s like a T-Rex. Powerful legs and tiny arms.

Haha, that’s a perfect analogy.

From a purely qualitative perspective, seat 3E on a Maddog feels like you're heading for LEO. And it's whisper quiet, too. Nothing flying today comes close, IMHO.

I don't think it's been mentioned yet, but I would be willing to bet the biggest reason for the MD-80's climb performance is that they are relatively low bypass engines and the fan
lapse rate isn't nearly as degrading as in high-bypass designs. I know the CFM 56-2 on the KC-135 lost 25lbs of thrust per knot, but I don't know if the -7B improved on that or not.
I believe this is why the 737 out-climbs the somewhat slow-climbing A320 series for a given weight, the bypass is less, resulting in more effective thrust at speed.
I'd like to hear from our resident experts on this...

I was light out of BOM one day in a MD-11 and had the V/S ind. pegged

WIederling wrote:

Starlionblue wrote:

senatorflyer wrote:

I’ve read somewhere that the A319 is more powerful than the Concorde, weight to power compared.

You can easily verify (or debunk) such a claim with 60 seconds of googling.

Concorde thrust with reheat= 76100lbf total
Concorde MTOW= 185000kg

A319 thrust (max option)= 54000lbf total
A319 MTOW= 75500kg

Concorde thrust to weight= 0.41
A319 thrust to weight= 0.71

Outch. more wrong than right and you should not mix units.

concorde engine: 38,050 lbf with reheat. _times four_ :: 152,200 lbf
MTOW 408042 lb -> t/w 0.373

A319 engine 27,000 lbf max no reheat _times two_ :: 52,000 lbf
MTOW 166,000 lb -> t/w 0.313

Was that the absolute maximum power of Concorde or just the normal maximum power? It had a CTY setting for use in emergencies which did provde more power. It could certainly climb quickly once it got up and going.

DFW17L wrote:

From a purely qualitative perspective, seat 3E on a Maddog feels like you're heading for LEO. And it's whisper quiet, too. Nothing flying today comes close, IMHO.

What does ‘heading for LEO’ mean ?

Max Q wrote:

DFW17L wrote:

From a purely qualitative perspective, seat 3E on a Maddog feels like you're heading for LEO. And it's whisper quiet, too. Nothing flying today comes close, IMHO.

What does ‘heading for LEO’ mean ?

Low Earth Orbit

And yes MD-80's can have an impressive deck angle initially but I think a 757 will beat it pretty easily in overall climb performance.

dennypayne wrote:

Max Q wrote:

DFW17L wrote:

From a purely qualitative perspective, seat 3E on a Maddog feels like you're heading for LEO. And it's whisper quiet, too. Nothing flying today comes close, IMHO.

What does ‘heading for LEO’ mean ?

Low Earth Orbit

And yes MD-80's can have an impressive deck angle initially but I think a 757 will beat it pretty easily in overall climb performance.

Low earth orbit, ok, LEO is usually used as an abbreviation for law enforcement officer !


Yes the 757 will outclimb an MD80, but a 762 with the big engines that we operated will leave the 75 in the dust

I got to fly jump seat in an empty 752 being ferried and the pilots requested a high performance takeoff and unrestricted climb.....let me just tell you.....it was insane. He sat on the breaks for spool up and off we went. I wasnt able to read the digital climb rate, but I saw the analog gauge pegged at whatever it was like 6000fpm all the way till we leveled at 14,000. I won’t forget that ride anytime soon.

trnswrld wrote:

I got to fly jump seat in an empty 752 being ferried and the pilots requested a high performance takeoff and unrestricted climb.....let me just tell you.....it was insane. He sat on the breaks for spool up and off we went. I wasnt able to read the digital climb rate, but I saw the analog gauge pegged at whatever it was like 6000fpm all the way till we leveled at 14,000. I won’t forget that ride anytime soon.

(Sigh) I miss the AA 752 departures out of SNA. It was always so much fun.

Starlionblue wrote:

That's embarrasing...

Full Concorde specs including MTOW can be found here: http://www.concordesst.com/techspec.html

We all make mistakes. Thanks for the link. I have multiple references on the book shelves, but was too lazy to get out of the recliner and open one.

WIederling wrote:

Starlionblue wrote:

senatorflyer wrote:

I’ve read somewhere that the A319 is more powerful than the Concorde, weight to power compared.

You can easily verify (or debunk) such a claim with 60 seconds of googling.

Concorde thrust with reheat= 76100lbf total
Concorde MTOW= 185000kg

A319 thrust (max option)= 54000lbf total
A319 MTOW= 75500kg

Concorde thrust to weight= 0.41
A319 thrust to weight= 0.71

Outch. more wrong than right and you should not mix units.

concorde engine: 38,050 lbf with reheat. _times four_ :: 152,200 lbf
MTOW 408042 lb -> t/w 0.373

A319 engine 27,000 lbf max no reheat _times two_ :: 52,000 lbf
MTOW 166,000 lb -> t/w 0.313

Long live the metric system! Haha.
On topic, I bet any modern jet on a short ferry flight will easily make 5-6000ft a minute initially. I've been in a empty A320 on a ferry flight, with max thrust take-off and unrestricted climb and that thing flew up like a home sick angel. Great fun!

TOGA10 wrote:

On topic, I bet any modern jet on a short ferry flight will easily make 5-6000ft a minute initially. I've been in a empty A320 on a ferry flight, with max thrust take-off and unrestricted climb and that thing flew up like a home sick angel. Great fun!

Yeah you are correct, any jet will do the same, but still it’s not every day you get to perform a takeoff like that in a commercial airliner.

trnswrld wrote:

TOGA10 wrote:

On topic, I bet any modern jet on a short ferry flight will easily make 5-6000ft a minute initially. I've been in a empty A320 on a ferry flight, with max thrust take-off and unrestricted climb and that thing flew up like a home sick angel. Great fun!

Yeah you are correct, any jet will do the same, but still it’s not every day you get to perform a takeoff like that in a commercial airliner.

Unfortunately not .

The most entertaining takeoffs I’ve ever experienced were on Maddogs and 717s...the deck angle on rotation definitely makes you feel like you’re in a rocket ship, even if the climb rate drops when you get higher (and it’s less noticeable as a passenger).

dr1980 wrote:

The most entertaining takeoffs I’ve ever experienced were on Maddogs and 717s...the deck angle on rotation definitely makes you feel like you’re in a rocket ship, even if the climb rate drops when you get higher (and it’s less noticeable as a passenger).

I can tell you, nothing beats a light 757 for deck angle on takeoff. Many, many years ago, as a FO, I operated from YYZ-DTW on a very clear, cold and dry winter day. We did full power takeoff and by the end of the runway were going through 5000'. We had a very light pax load and IIRC, we were at min fuel for dispatch. Even after flying high performance military aircraft, I was amazed at the climb ability of the 757. IIRC our deck angel was in the vicinity of 25 degrees.

mmo wrote:

I can tell you, nothing beats a light 757 for deck angle on takeoff. Many, many years ago, as a FO, I operated from YYZ-DTW on a very clear, cold and dry winter day. We did full power takeoff and by the end of the runway were going through 5000'. We had a very light pax load and IIRC, we were at min fuel for dispatch. Even after flying high performance military aircraft, I was amazed at the climb ability of the 757. IIRC our deck angel was in the vicinity of 25 degrees.

Sounds like I need to get myself onto a lightly loaded 757!

This topic isn't as easily explained as it might seem. Which airliners (and airlines) use derate climbs. My company for example uses max derated (D2) climb thrust on all A340-600, A330-200/300 departure. We don't on th 340-300. This has to do with the Power by the Hour deal from RR. This will effect the perceived climbs performance. The variables are too great for a simple answer. The thrust to weight examples are probably the best measures, but not perfect.

MDGLongBeach wrote:

Hello,

This was a topic that always interested me. Never knew why the md80 climbed so well and the other planes not so much. I was assuming the plane may be light or the small, tube like airframe was efficient for climbing. I would like a explanation for this though, as I think many people would be interested in this. Thanks for all comments and replies!

-3star

In the summer months during delay operations, EWR MD-80 crews talked about a company 757 taking off before them, but then arriving at MCO before the 757 would, beating them in cruise. The MD-80 out of MCO on a hot day seemed to be a dog getting up to altitude, especially if thunderstorms were around and you had the anti-ice on. I had a jumpseat ride where the MD-80 was struggling to make it to 31k with anti-ice on out of MCO. And it was hot till we climbed over 10k.
One summer out of Omaha, after some very strong thunderstorms blew through, sitting in the jumpseat as the MD-80 rocketed out of Omaha for Denver Stapleton. It was a impressive climb.
Same coming out of Salt Lake City after recovering a broken MD-80, we jumped on back to Stapleton. There were only 5 passengers on board, and all were moved up to 1st. That was impressive out of Salt Lake City. Hit some severe clear air turbulence over the front range that shook that MD-80 real good.
One of the most impressive for me was a 727 out of Omaha to Kansas City. Just about 10 passengers, all up front, that thing seemed to be heading for LEO.
Light 737-300s on the DEN-ABQ runs were very impressive.
And a empty 767-200 is quite a sight.
I don't remember the MD-80 climbing better than other aircraft in the fleet on normal full flights.

Wadrs Ctech the MD80 normal cruise Mach was .76


In the 757 we cruised at .8 or a little higher


No MD80 is going to pass a 75 unless the Boeing crew has deliberately slowed down


I enjoyed your post and can relate though


I had to ferry an empty MD80 from JFK to EWR one night ‘non stop’


That was fun, the 757 and 767-2 with the big engines had incredible climb performance light or heavy