An air-breathing jet engine can only operate at relatively low altitude, where the atmosphere is dense enough. However, some jet-powered aircraft can operate at an altitude higher than 20 Km (e.g., the SR-71). For really high altitude, aircraft are equipped with rocket engines (e.g., the X-15)

What is the highest operational altitude for any air-breathing jet-powered aircraft?

  • $\begingroup$ I think somewhere on Wikipedia has a page which lists the highest aircrafts by category: rocket engines / air breathing engines / blimps etc. $\endgroup$
    – kevin
    Commented Oct 18, 2017 at 13:28
  • $\begingroup$ From what I found: MiG-25 37,650 metres (123,520 ft) $\endgroup$
    – bummi
    Commented Oct 18, 2017 at 13:31
  • $\begingroup$ @kevin I did find a page about altitude records but none about operational ceiling $\endgroup$
    – Manu H
    Commented Oct 18, 2017 at 15:02

2 Answers 2


Below[1] shows the hypersonic breathing corridor. Without LOX or rocket assistance, the limit is around 140,000 feet (40 km) at around Mach 15.

In 2004 NASA's X-43 achieved a record Mach 9.6 at 109,000 feet (nasa.gov), which if you compare below, is a good match for the aforementioned corridor.

enter image description here

1: Smart, Michael. "Scramjets." The Aeronautical Journal 111.1124 (2007): 605-619. (PDF)


A Scramjet engine, which is still technically an Air breathing engine, will provide the highest possible service ceiling.

Theoretically, they can operate at up to 250,000 ft (75 km). For comparison, "space" begins at around 330,000 ft (100 km).

More technical info about Scramjet engines can be found here.

  • 2
    $\begingroup$ You should had more references for further readings and to sustain your claim of theoretical ceiling for scramjet. E.g. a research paper from the nasa is quite more authoritative than a wikipedia link and provide more insight $\endgroup$
    – Manu H
    Commented Oct 19, 2017 at 20:17
  • $\begingroup$ @ManuH Maybe this will give you some more info: upcommons.upc.edu/bitstream/handle/2099.1/20295/… $\endgroup$
    – Jimy
    Commented Oct 19, 2017 at 22:20
  • 1
    $\begingroup$ @JimPP you really should edit the question. such a link is better fitted in the answer than in its comments. $\endgroup$
    – Manu H
    Commented Oct 20, 2017 at 7:06
  • $\begingroup$ @ManuH I will, thanks! $\endgroup$
    – Jimy
    Commented Oct 20, 2017 at 8:26
  • $\begingroup$ @Jimy: A bit too late, but I can't find the numbers in your linked document. $\endgroup$
    – user14897
    Commented Mar 18, 2021 at 1:06

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