There was a story in the news recently that an Air Canada 787-8, enroute from Tel Aviv (TLV) to Toronto (YYZ), diverted to Frankfurt (FRA) when the pilots discovered a problem with the cargo heat. There was a live dog in the cargo hold, and the diversion potentially saved it from freezing to death.

The narrative has been that the pilots diverted specifically in order to save the dog. But I am wondering whether a cargo heat malfunction might require a diversion, as a matter of standard operating procedure, regardless of whether live animals are on board. After all, even if there are no live animals, there might be other valuable temperature-sensitive cargo.

In general, according to airline policies or procedures, under what circumstances would cargo heat failure warrant a diversion?

Any major airline would be of interest; if you want a specific one, let's say Air Canada.

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    $\begingroup$ I would assume unless there is declared valuable cargo that requires a stable temperature above freezing (live animals, produce, etc.) a cargo bay heater failure would not warrant a diversion - it would be unfortunate if your expensive foreign wine froze and shattered in your luggage, but that could just as easily happen when the baggage handlers use the bag as one of the pins a creative airport bowling game... $\endgroup$ – voretaq7 Sep 18 '15 at 4:49
  • $\begingroup$ @mins: Back of the envelope: Service ceiling on the 787-8 is 43,000 feet. Air temperature about -56 C. Assume the cargo hold is half exposed to the outside air, half to the passenger cabin (which is held at 20 C), with equal insulation on both sides. In the long run, we expect the temperature to approach the average of the two, i.e. -18 C. $\endgroup$ – Nate Eldredge Sep 18 '15 at 6:36
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    $\begingroup$ Related: Are cargo holds pressurised these days?. See selected answer (fooot) Even in unheated cargo holds, the temperature should be above freezing. $\endgroup$ – mins Sep 18 '15 at 7:04
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    $\begingroup$ @mins above freezing does not mean won't cause hypothermia. $\endgroup$ – ratchet freak Sep 18 '15 at 12:09
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    $\begingroup$ Related $\endgroup$ – Pondlife Sep 18 '15 at 13:12

Does cargo heat failure require diversion? It depends on the cargo being carried.

For your question about pets, then yes.

Council Regulation (EC) No 1/2005 regulates the protection of animals during transport in the EU, which itself is in accordance to IATA Live Animals Regulations. The guidelines based on that EU regulation say:

Commanders, and loadmasters and aircrew under their authority must ensure that the aircraft and equipment are suitable for carriage of the animals concerned in the manner intended. They must ensure that the animals are loaded, carried and unloaded in a way which will protect their welfare.

In particular they must ensure that the animals are accommodated in accordance with the IATA LAR, and that an appropriate environment of air quality and quantity, temperature and pressure is maintained whilst the animals are on the aircraft.

The ability to ventilate and regulate the temperature of an aircraft belly hold varies considerably. The arrangements vary between individual aircraft depending on the make and type, the compartment, and whether or not ‘standard’ or ‘special’ specifications have been fitted.

It is therefore essential that the aircraft operator, who should know the individual features of each of its aircraft, is satisfied that the belly hold to be used can be sufficiently ventilated and maintained at a satisfactory temperature during all stages of the proposed flight. This assessment should take into account the species, number, weight and size, and volume of the animals to be carried, and the heat and moisture that they will produce. Other cargo being carried at the same time will also need to be taken into account.

Even the Minimum Equipment List of aircraft takes that into consideration. For example, the aircraft can be dispatched with an inoperative cargo heater or ventilation fan, but not if there's an animal in that respective cargo hold.

All that confirms the pilot's action in the story you mention.


Exclusive Cargo airlines are expected to take extreme care of temperature sensitive cargo (pharmaceutical products, food, animals, etc.). Modern cargo aircraft have complex air-conditioning systems not less sophisticated than passenger compartments and special briefing to operating pilots.

Cargo airline company procedures will provide clear guidelines to pilots under what circumstances would cargo heat failure warrant a diversion. This will depend on the ethical nature /and/ cost of damage due to damaged cargo.

(Example: Is the cargo in question, thousands of a day old chicks /or/ a few expensive racing horses)

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    $\begingroup$ Welcome to aviation.SE! please be aware that if possible we like to have references, do you have any for your statements? for example, about these guidelines, do you have any example? $\endgroup$ – Federico Jul 19 '17 at 13:10

Company rules normally dictate diversion/abort rules. For most aircraft there are not temperature requirements for areas of the plane, except for the cockpit and avionics bays. They may require non-polar temperatures to operate correctly, and may require cooling for power equipment like radar transmitters.

Obviously, if one is a carrier like FedEx and transporting live animals, it is different than transporting machined parts. A manifest for cargo will describe handling precautions, including issues with the cargo impacting the operation of the aircraft. (eg. chemicals, radioactive isotopes, strong magnets, etc.)

Also, normally bleed air is used to heat cargo areas. Bleed air takes energy, and is not "free" so normally the areas are not heated to temps like 20C. Generally, if one is flying generic freight, good operating practice avoids having a cargo area which is below 0C. Again, company rules will be where guidance is for a particular flight.

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    $\begingroup$ Is there ant source you can provide a link to which supports your answer? $\endgroup$ – Ralph J Apr 2 '17 at 20:34
  • $\begingroup$ I am familiar with FedEx manifests and some of the issues they have had transporting live animals such as orca and giraffes. Of course, in the case of animals like that, a trainer and sometimes a vet travel with the animal. The manifests have generalized handling instructions. When there is temperature sensitive cargo, they will use an APU cart to supply the airpacks while on the ground. There are similar crew instructions for military crews, along with cargo briefings. I have personally been involved with those when transporting large optics as an example. $\endgroup$ – mongo Apr 26 '17 at 0:23
  • $\begingroup$ Additionally, some pharmaceuticals and medical products have tight environmental parameters, and the manifests reflect that. Things like human and animal organs are packaged to stabilize the temperatures, but that packaging has practical limits. $\endgroup$ – mongo Apr 26 '17 at 0:32
  • $\begingroup$ Is there ant source you can provide a link to which supports your answer? – Ralph J Apr 2 at 20:34 Which part of the answer are you seeking verification about? $\endgroup$ – mongo Apr 26 '17 at 0:37
  • $\begingroup$ @RalphJ, what part of the answer are you looking for a source? Company procedures? The absence of regulations regarding cargo hold temperatures in the US? Or perhaps the energy cost of bleed air? $\endgroup$ – mongo Oct 20 '17 at 10:39

Common sense applies. The regs don't require a diversion for a cargo heat fail. But, if you know there are live animals down there, and you know it's -53 outside, then you're going to divert to save them.

As the other poster said, if it's just some expensive something else down there, then no.

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    $\begingroup$ do you have any source for "The regs don't require a diversion for a cargo heat fail"? $\endgroup$ – Federico Jan 26 '17 at 17:37
  • $\begingroup$ Common sense does not hold in front of procedures. Procedures are designed according several decades of experience to insure good handling of many normal and abnormal situations. Heat failure does not mean the cargo's temperature will immediatly goes down to negative temperatures (insulation, airflow from the rest of presurized area,...). The diverstion decision must take into account many other elements that must be mentionned on procedure and forgotten by common sense. $\endgroup$ – Manu H Feb 26 '17 at 9:04

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