3
$\begingroup$

In common aircraft specifications a "rate of climb", or "maximum rate of climb" is specified. For example the wikipedia page for a Spitfire, or C172.

However my intuition is that the rate of climb depends wildly on various things. Aircraft weight, altitude and so on. Furthermore, you could potentially fly at maximum airspeed, and then pitch up 90 degrees, and climb until you begin to stall. Sure you wouldn't be able to last long, but for a short period you'd have a very high rate of climb.

So the question really is, when aircraft specifications detail "rate of climb", is there some implicit context for when that rate of climb is applicable? Is it optimized for climbing in the most time or distance efficient way for X distance or something?

| improve this question | |
$\endgroup$
1
$\begingroup$

The "maximum rate of climb" is the highest sustainable ROC for the following conditions...

  1. sea level conditions (or standard atmosphere for other altitudes)
  2. maximum gross or takeoff weight
  3. cruise configuration
  4. maximum rated continuous thrust/power

There are additional minor requirements given in FAR 23 such as the rated power 8 seconds (SFAR to 23, par 6 and 23.63-23.67) after the throttles are moved to the full thrust position but the above is a good generalization.

| improve this answer | |
$\endgroup$
  • $\begingroup$ It looks like the FARs usually define the minimum ROC, not the maximum (e.g. 23.2120, 25.119, 25.121). And as a minor point, 23.63-67 aren't current any more although obviously many aircraft were originally certified under them. $\endgroup$ – Pondlife Jun 2 '19 at 0:53
  • $\begingroup$ The term is referring to the maximum rate of climb as in the best that the aircraft can achieve, not a regulatory limit on rate of climb. $\endgroup$ – John K Jun 2 '19 at 1:26
  • $\begingroup$ What does sustainable mean exactly? That you can sustain this rate of climb until you reach your max altitude? $\endgroup$ – DavidColson Jun 3 '19 at 16:17
  • $\begingroup$ "sustainable" means consistent attitude & speed over a reasonable period of time. Diving and pulling up would not be "sustainable". $\endgroup$ – jwzumwalt Jun 3 '19 at 16:59
  • $\begingroup$ @jwzumwalt, You write: «Further more, you could potentially fly at maximum airspeed, and then pitch up 90 degrees »: the issue here is not the rate of climb but the rate of pitch, doing this will at least damage the structure of a long aircraft, modern aircrafts Boeing +Airbus, are protected for pitch rate and for pitch, as a consequence for the rate of climb. $\endgroup$ – user40476 Jun 10 '19 at 18:35

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.