If a hummingbird got sucked into a commercial jet engine at takeoff would the pilot notice? This is a serious question.


All turbine engines must pass a series of tests, including water ingestion (flying through clouds) and bird strikes. For bird strikes, the following article does a good job explaining the requirements to pass bird strike testing: Aircraft Certification for Bird Strike Risk

It cites 14 CFR Part 33-77 'Foreign object ingestion - ice' (although 14 CFR Part 33-76 'Bird ingestion' seems more appropriate) and EASA Airworthiness Code CS-E 800 'Bird Strike and Ingestion' as sources.

14 CFR Part 33-76:

(4) A small bird ingestion test is not required if the prescribed number of medium birds pass into the engine rotor blades during the medium bird test.

(5) Small bird ingestion tests shall be conducted so as to simulate a flock encounter using one 85 gram (0.187 lb.) bird for each 0.032 square-meter (49.6 square-inches) of inlet area, or fraction thereof, up to a maximum of 16 birds. The birds will be aimed so as to account for any critical exposed locations on the first stage rotor blades, with any remaining birds evenly distributed over the engine face area.

(6) Ingestion of small and medium birds tested under the conditions prescribed in this paragraph may not cause any of the following:

  1. More than a sustained 25-percent power or thrust loss;
    1. The engine to be shut down during the required run-on demonstration prescribed in paragraphs (c)(7) or (c)(8) of this section;
    2. The conditions defined in paragraph (b)(3) of this section.
    3. Unacceptable deterioration of engine handling characteristics

EASA Airworthiness Code CS-E 800

(d) Medium and small birds ingestion tests. Engine ingestion tests and analysis with medium and small sized birds must be carried out as specified below. Alternative evidence may be acceptable as provided under CS-E 800 (f)(1). The small birds test will not be required if the prescribed number of medium birds pass into the Engine rotor blades during the medium bird test.

(B) Small birds. One 85 g bird for each 0·032 m2 of the inlet throat area or fraction thereof with a maximum of 16 birds, distributed to take account of any critical exposed

For more information, refer to 14 CFR Part 33-76, and EASA Airworthiness code CS-E 800.

One more thing to add - the documents do not include any tests for single small birds, only flocking small birds, and use birds that weigh 85 grams. Humming birds do not flock, and 85g is more than most humming birds weigh. That being said, the tests do include much larger birds, and all commercial jet engines found on commercial airlines certify large bird strikes, so it's likely that tests with small bird strikes are not conducted. Bouncing off of physics - if a turbine can withstand a large bird strike, it won't even feel a humming bird strike, therefore it is not a required test if the engine already certified with large bird strikes.

  • $\begingroup$ Including some salient points from the linked article would help, just in case the link goes dead. It's a bit of a tradition 'round these parts. $\endgroup$ – FreeMan Sep 19 '18 at 13:57
  • $\begingroup$ Done. There's quite a bit of information in the CFR and EASA, including lots of tables and numbers. For more information, it's best to just read those documents. $\endgroup$ – MishaP Sep 19 '18 at 14:13
  • $\begingroup$ It seems I was editing while you did that, so your edit was overwritten by mine. I'll add the quotes $\endgroup$ – MishaP Sep 19 '18 at 14:34
  • $\begingroup$ Fair enough! No worries. $\endgroup$ – FreeMan Sep 19 '18 at 14:51

Issues with ingestion most likely start at the point where damage occurs to the turbine blades, which spin at high rpm. Any weight imbalance created by damage can be rapidly catastrophic. There are some fairly interesting videos of frozen turkeys being heaved into jet engines on test stands to check for robustness of the blades, which also can fail from manufacturing defects. We all know what a flock of geese can do.

Fortunately, the Hudson landing beat odds not once, but twice.

  • $\begingroup$ The blade damage in question is NOT to the turbine blades, but to the fan blades (and potentially fwd compressor blades). Also, if you have any links to said videos of "frozen turkeys being heaved into jet engines", please post the link. Although there are certainly bird ingestion test videos on youtube, as far as I know, none of them are turkeys and none of them are frozen. You are more likely to find a seagull (unfrozen) or maybe a Canada goose. AFAIK, the frozen turkey thing is an urban legend. $\endgroup$ – Daniel Kiracofe Sep 19 '18 at 0:16
  • $\begingroup$ Any certainly strengthen the fan blades would help, please do not wait until another flock comes along. $\endgroup$ – Robert DiGiovanni Sep 19 '18 at 10:16
  • 2
    $\begingroup$ No this is not an open discussion forum. This is a question and answer site. Sentences of the form "I wonder if..." are essentially asking a new question, not answering the OP's question, and thus do not belong in an answer section. If you wish to start a new question post about whether returning to trijets would be a good solution to bird ingestion, you are more than welcome to do so. Also, I can assure you that all major engine OEMs spend an enormous amount of time ensuring that engines are safe from birds, and this is highly regulated by the FAA. No one is "waiting for another flock" $\endgroup$ – Daniel Kiracofe Sep 19 '18 at 11:11
  • $\begingroup$ I sincerely say thanks for your comment. It may have been far more appropriate to do so rather than to edit my question without my consent. I now ask for for permission to delete my inappropriate comment. $\endgroup$ – Robert DiGiovanni Sep 19 '18 at 13:20
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    $\begingroup$ @RobertDiGiovanni welcome to Aviation. As was mentioned, this isn't your typical forum - taking the tour and reading the help center will go a long way towards helping you get the feel of the place. Also, if you'd like to delete your comment, hover your cursor over your comment, you'll see a little 'x' in a circle appear. Click that and you can delete it yourself. $\endgroup$ – FreeMan Sep 19 '18 at 13:55

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