A tug driver at La Guardia got an expensive lesson in physics on Thursday but lived to tell the tale. The unidentified driver ended up trapped under the American Airlines Boeing 737 he was towing. The tug was crushed and there is damage to the belly of the aircraft, but the driver was freed unharmed. Video shows the tug pulling the 90,000-pound airplane at a good clip on a taxiway when the driver makes a sudden sharp right turn toward the gate area. That’s when things got interesting.
The sudden turn caused tail to swing around, the momentum breaking the connection on the tow arm. The driver of the tug appears to hit the brakes and all the rest was up to the natural order of things. Freed of its heavy doorstop at the front, the big fuselage swings right over the tug before running out of all the energy it stored on the brisk trip down the taxiway. There was no one on the plane and American brought in a replacement to take its future passengers to Charlotte.
WTF? When I was an A&P with USAir, (now American) we never, NEVER, towed an aircraft without someone on board riding brakes just for this reason. If the tow bar broke, and they occasionally did due to having a couple strategically placed aluminum bolts as shear pins to prevent damage to the nose gear, the tug driver was to get out of the way and away from the aircraft and the brake rider was to, well, apply the brakes. This guy was lucky!
Hey Jeff W: aren’t there limits on how much angle the nose can take while being towed, like some GA aircraft? Are you aware?
I agree with you 100% about towing without someone riding the brakes. Am a retired A&P and it’s hard to understand why no one was watching or supervising this tug driver. It wasn’t his day to die.
in order to operate the aircraft brakes, did you have to have the APU running to pressurize the hydraulic system?
Hi Jeff. Igot the impression from the article that the author was indicating no passengers, not a completely vacant aircraft. I am currently APU / Brake Rider certified with AA on B737 & A320 family aircraft, and there is no procedure for towing any aircraft without a brake rider. We can tow an aircraft without power, but there still has to be a brake rider in the seat. FWIW, that brake rider must have been totally distracted (complacency) because when that towbar broke away, it would have sounded like a cannon went off underneath the flight deck. No earthly idea why brake weren’t applied.
John
John S.
On further thought, I think you’re probably right. There was a brake rider, but they were distracted or possibly the brake/hyd accumulators were not charged, assuming the APU wasn’t running. Years ago, I had a tow bar break while riding brakes on a USAir DC-9 and it took a moment to realize the tug was driving away from us.
Rob S.
You don’t have to have the APU running if the brakes/hyd accumulators are charged. But it’s best to have the APU running if it’s practical.
‘You can come by Monday to pick up your last paycheck. Go home now’
‘Delta our competition is hiring you can try to get on with them’
Minus reimbursement for damage to the aircraft and reimbursement for the wrecked tug.
Man often defies most everything
including GOD
But it is extremely unwise to
defy the laws of Physics!!
The video is proof positive that LGA is not a sanctuary airport for the laws of Physics.:)
Absolutely! Just about all the aircraft I have worked on, and that’s quite a few, either have tow limits with markings on the nose gear doors, or some method of disengaging/deactivating the nose wheel steering. On some it’s an easy method of decoupling the scissor links, others might have a bypass valve for the steering hydraulics, etc. Different aircraft, different methods. But no matter what method, there will still be at least SOME limits usually due to some wiring going to the scissor links for Weight ON Wheels (WOW) sensing.
To add to your excellent reply Jeff, when they were tearing onto the gate (towing much too fast), it appears that the towbar had already exceeded the steering limit line before it separated from the aircraft.
John
John S.
As you probably know, there’s a fair amount of “extra” travel past the markings but you can definitely see the tow bar break from the nose gear when it hits the solid limits. I’m not that familiar with the B737 nose steering, so I don’t remember what causes the actual limits. It’s been awhile since I worked them and I was an avionics/cockpit/cabin lead, so not so much experience on the gear side of it.
This was supposed to post up top with R Ns question.
Hard to find good help now-days.
Happened to a friend of mine: – Towing a Tornado at the recommended speed, the tug driver braked gently but the tow-bar, which was faulty due to lack of maintenance, snapped. The pitot probe and half the radome entered the cab of the tug narrowly missing my friend and the supervisor. The brake man had no time to react as the aircraft had already speared the tug by the time he knew anything was wrong. So beware, even following the rules, when towing, might get you into a sticky situation. (At an airfield in the sand, not a million miles away from Bahrain)
Yay! Try hard enough and you can ground loop a trike too!
Tug driver seemed not aware of basic physics; an object in motion tends to remain in motion. Large airplanes towed above recommended speeds then turned sharply proved advanced physics of vector forces, suddenly waking up this driver.
Maybe not quite Darwin Award-worthy, but definitely a contender for the coveted Wile E. Coyote Cup.
With banana clusters!
in order to operate the aircraft brakes, did you have to have the APU running to pressurize the hydraulic system?
Forgot he had an airplane behind him?
(In the middle of one night a fem truck driver planted her trailer in the middle of the fountain in downtown Langford BC. Rear wheels of trailer went over a rock wall about 2.5 feet high.
Said to be from ‘misjudging’, but from geometry and length of trailer it looked to me as though she forgot she had a trailer behind her semi truck tractor. The trailer was solidly in the fountain, almost on centreline.)
Well, in this case more likely the tug driver did not understand frailties and physics in maneuvering. With that much weight behind he should have been nervous.
(Even if the weight was less, 90K is a lot though perhaps a long model with much fuel….)
I omitted that the fountain was in the middle of a small traffic circle/roundabout, so she would have driven the tractor around that, in my rough estimation reaching the other side just as the trailer’s rear wheels approached the rock wall, so the tractor pulled the trailer straight into the fountain.
He will be in the lavatory truck forever.The good news is American has too many planes and not enough pilots to fly them.
Anyone want to bet that this is (was) his “normal speed? He probably rags about slow tow drivers who don’t go over the listed limits.
This time, the tow is on the other foot.
luckily the tug was there to stop it from running into other things.
Yes, damage to nose is hard to repair.
Pacific Western Airlines had a B737 hit a heavy hanger door that fell on it. Had to remove overhead panel and wiring to get at roof structure to repair.
(Aircraft was being taxiid to hanger, probably caught by problem with antiskid releasing at low speed after sagging of wiring enabled interference with early model of system.)
Hitting lower front of fuselage could be costly, nose bulkhead, wheel well with gear support structure, avionics racks, ….
New British Airtours hangar at LGW, long gash in metal wall, as an interested 737 Captain at the time, I asked what.how.when this was inflicted on a shiny brand new wall. Told, the towing instructor was training a new tug driver, and the result was evident. At LHR there is a road tunnel under the south runway. BA tug at holding point to cross 27L, long delay as landing traffic. Eventually Heathrow tower tells patient tug to use the freight tunnel Driver answers, difficult, I have 747 on the back.