Speed limits/G Limits while carrying ordinance and drop tanks

[Krusty]

We do not model structural limits by G's we model them by max forces on the wings. Hence all planes already will break at different G limits with different load outs.

HiTech

How does that work with regards to speed limits on underwing stores? Does it add the "force" from drag to that "failure limit" (for lack of knowing what to call it)? Or am I thinking of it differently than I should?

I've more than once seen (and done it myself) P-47s and P-51s diving at breakneck speed to suicide pork a field before 5 chasing cons can catch them. Going 550+ mph and suffering no ill effects while the manuals limit P-47s (for example) to around 350mph. The Gs might be even in such a dive as described above, but the forward force in real life might rip a chunk out of the wing (bomb and pylon going with it) and cause catastrophic failure.

I'm sure that rockets rails could only sustain so much pressure as well, before ripping the rockets off of them.

[MK-84]

This can very easily be demonstrated with a fully loaded vs light A20.

[RTHolmes]

^ indeed.


although I'd guess that discarding the A20's internal 2k load will prevent the wings coming off when pulling out of a dive better than discarding the wing mounted 2k load, if you had to chose ...

[Krusty]

This can very easily be demonstrated with a fully loaded vs light A20.

That's definitely tied in with the weight on the wings... but what about drag? What about level 1G flight and the max speed allowed in that configuration?

[Ack-Ack]

There is no way we should be able to pull 6 Gs or dive to max speed with drop tanks or ordinance hanging off the plane. There should be much lower limits until ordinance/tanks have been dropped.

As you approach the limits you should get warnings in the form of audio cues that something is wrong.

If you exceed the limits by too far/too long then you should start taking damage. This could randomly be hung ordinance or stuff being ripped off the plane.

There were posted limits, yes. For example, P-47s with tanks or bombs under the wing shackles were limited in top speed and how many Gs they could go. That would make dive bombing tricky, no? Not exceeding the max AS you drop?

Looking at the copy of the P-51D/K manual I have, the only stated limits when carrying bombs is with the 1,000 pounder and the manual states that when carrying a 1,000 pound bomb, only straight and level flight should be done.  There was no stated restrictions on maneuvering or speed with the other lesser bomb load outs.  With fuel tanks, it was stated the limits was for the 110 gallon tank as the weight of these drop tanks imposed a near weight limit on the wings and bomb racks and the same restrictions were in place as the ones for the 1,000 pound bomb.

An interesting note in the Mustang manual that states that it was prohibited to perform aerobatics in the Mustang D/K if the fuselage tank is more than 40% full.

Looking at the P-38 (late model J and L flight manual), there were limits on drop tanks, depending on which ones were carried.  The only limitation for all P-38s was that when carrying the 300 gallon drop tank, it was recommended not to exceed 250mph IAS.  Depending on the model of P-38, there were restrictions on what speeds you can drop empty drop tanks.  On all P-38s, full drop tanks could be safely dropped at speeds up to 400mph IAS.  Only early P-38s, empty 150 gallon drop tanks could only be dropped at speeds below 160mph IAS and late model P-38s the drop tanks were equipped with displacement struts that doubled the speed at which the empty drop tanks could be pickled to 350mph IAS.  Strangly, the manual didn't have any stated limitations for ordnance.

Placing "performance limits" like above when carrying ordnance and drop tanks has been a long time wish of mine that I've wished for on these forums in the past a quite a few times and is tied in with my wish for ordnance be tied with historical usage (when we ever get a perked ordnance system).

ack-ack

 

[SmokinLoon]

This is a very valid wish, imo.  I'm sure it would be a tedious task going from plane to plane coding in a max g-force on X amount of wing loading weight.

This is along the same lines as having max speed for level bombers.  B25's, B26's, B17's, and B24's routinely (via SOP) dropped at 220-230 TAS, at least in the PTO.  Just how often to we see than in AH???  I'd like to believe that HTC could code in a max speed of 250 TAS attached to the "drop bombs" button easy enough on certain level bombers.  Without looking researching, I'm sure bombers like the Ar234, Mossie B Mk XVI, B29, etc etc all dropped at higher speeds.