The Federal Aviation Administration in December published a Boeing request for an exemption from key safety standards on the 737 MAX 7.

Models of the MAX currently flying passengers in the U.S. have had to limit use of the jet’s engine anti-ice system after Boeing discovered a defect in the system with potentially catastrophic consequences.

The pilot procedure the FAA approved as an interim solution — urging pilots to make sure to turn off the system when icing conditions dissipate to avoid overheating that within five minutes could seriously damage the structure of the nacelle — is inadequate given the serious potential danger.